- Email: [email protected]
Split pedicle roll envelope technique around implants and pontics: a prospective case series study
YIJOM-3152; No of Pages 7
Int. J. Oral Maxillofac. Surg. 2015; xxx: xxx–xxx http://dx.doi.org/10.1016/j.ijom.2015.04.012, available online at http://www.sciencedirect.com
Clinical Paper Dental Implants
Split pedicle roll envelope technique around implants and pontics: a prospective case series study
Y. Man1,2, Q. Wu1,2, T. Wang1,2, P. Gong1,2, T. Gong1,2, Y. Qu1,3 1 State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, PR China; 2Department of Oral Implantology, West China Hospital of Stomatology, Sichuan University, Chengdu, PR China; 3Department of Prosthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
Y. Man, Q. Wu, T. Wang, P. Gong, T. Gong, Y. Qu: Split pedicle roll envelope technique around implants and pontics: a prospective case series study. Int. J. Oral Maxillofac. Surg. 2015; xxx: xxx–xxx. # 2015 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
Abstract. Recreating a harmonious gingival contour for contiguous missing teeth in the anterior maxilla is challenging. The aim of this study was to evaluate a split pedicle roll envelope technique designed for pontics. Twelve patients presented a labial flat or concave profile at the implant and pontic sites before second-stage surgery. The contour deficiency was compensated with a palatal split pedicle flap with the implant part rolled into the labial envelope and the pontic part covering the denuded ridge. Interim restorations were screwed in to guide tissue remodelling. The labial convex profile (CPF) and facial mucosal level (FML) at the implant and pontic sites, the Jemt papilla index (PIS) in the different restorative environments, and peri-implant bone levels were recorded at baseline and at 1 week, 3 months, and 6 months postoperative. Results showed that the CPF had increased by 1.4 mm at the implant site and 1.5 mm at the pontic site at 6 months after surgery. PIS had increased by 2 at the implant–tooth/pontic–tooth sites and by 2.6 at the implant– pontic site. FML was coordinated with that of the contralateral teeth. All indices were favourable at 3 months and then remained stable. Within the limitations identified, this combined therapy can be considered as an alternative to achieve aesthetic success when contiguous maxillary anterior teeth are missing.
The treatment concept of implant dentistry has shifted from implant survival to aesthetic rehabilitation. When aesthetics is added to the criteria for success, the success rate of implant-supported prostheses drops significantly.1 For contiguous missing maxillary anterior teeth, aesthetics is even less predictable than with a single 0901-5027/000001+07
missing tooth, particularly regarding the maintenance of inter-implant tissue.2 When the bone morphology permits implant installation, the ‘one tooth, one implant’ treatment protocol can be adopted where space allows.3 However, anatomical limitations, patient-centred issues, and aesthetic considerations may
Keywords: implant-supported dental prosthesis; pontic; dental aesthetics; pedicled flap; dental papilla. Accepted for publication 23 April 2015
justify implant-supported bridges or cantilevers. Although Tarnow et al.4 recommend an inter-implant horizontal distance of at least 3 mm to reduce crestal bone loss, it is usually hard to meet this requirement in the anterior maxilla. In addition, the predicted inter-implant papilla height is lower than that adjacent to a natural
# 2015 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
Please cite this article in press as: Man Y, et al. Split pedicle roll envelope technique around implants and pontics: a prospective case series study, Int J Oral Maxillofac Surg (2015), http://dx.doi.org/10.1016/j.ijom.2015.04.012
YIJOM-3152; No of Pages 7
2
Man et al.
tooth or pontic.5,6 Thus it appears advisable to circumvent this risky inter-implant dilemma by using pontics. Among the various pontic designs, the ovate pontic is recommended as an effective replication of the natural emergence profile,7 and long-term mucosal health can be maintained.8,9 Adequate alveolar bone and soft tissue volume are the prerequisites for aesthetic reconstructions of either a pontic or an implant site. Many ridge augmentation techniques have been applied to condition the ridge topography.10 However, the grafted tissues often undergo unpredictable resorption. Therefore, re-grafting is often necessary at the second-stage surgery. It is documented that a deficiency of <3 mm in dimension can be resolved by soft tissue augmentation alone.11 Thus soft tissue grafting and various flap designs have been devised for contour compensation. The acquirement of soft tissue from the palate aggravates patient morbidity, and compared to pedicled grafts, free connective tissue grafts (CTG) have a higher risk of shrinkage.12 To circumvent these problems, Man et al.13 developed a palatal roll envelope technique for soft tissue reconstruction around single implants that
is minimally invasive and has the potential to reduce graft shrinkage and scar formation. However, it cannot be applied to the pontic area because it might expose the alveolar bone there directly to the oral cavity. The purpose of this study was to: (1) present a therapy consisting of a split pedicle roll envelope technique and restorative designs with ovate pontics, and (2) objectively evaluate its efficacy and predictability.
and five ITI bone level implants (Institut Straumann AG, Basel, Switzerland) between August 2012 and March 2013. Of the 12 patients, five had single-implantsupported cantilevers with the pontic situated in the position of lateral incisor and seven had three-unit implant-supported bridges. Informed consent was obtained. After healing for 3 months, the split pedicle roll envelope technique was performed at second-stage surgery. This study was designed as an observational prospective study.
Materials and methods Patients and study design
Surgical procedure
Twelve consecutive patients (six women and six men, mean age 34 5.8 years) were included in this study. To be enrolled, the patient had to fulfil the following criteria: (1) age 18 years with good oral hygiene and compliance; (2) presenting at least one location with multiple adjacent maxillary anterior teeth missing; (3) presenting a flat or concave profile before the second-stage surgery, with a sufficient bone base; (4) no tobacco abuse. A total of 19 implants were installed, including 14 Osstem GS II implants (Osstem Implant Co., Ltd, Busan, Korea)
Under local anaesthesia, an initial partialthickness crestal incision was made 1– 2 mm towards the palatal side, to gain a maximum amount of keratinized tissue in the labial flap, and 1–2 mm away from the adjacent teeth, to preserve the papilla. Two partial-thickness vertical incisions, 5–10 mm in length, were made on the palatal side (see the superficial incision in Fig. 1a). The superficial part was elevated by sharp dissection (see the dissected superficial flap and underlying connective tissue in Fig. 1b). Then, another incision, parallel to the union of the two
Fig. 1. Split pedicle roll envelope technique performed at implant (Nos. 8 and 10) and pontic (No. 9) sites. (a) Incision design. Partial-thickness crestal and palatal incisions were made. The blue line indicates the deeper connective tissue incision. The dotted green line shows the labial profile feature in occlusal view. (b) Sharp dissection of the palatal superficial flap. (c) Divided split pedicle flap. The dotted green lines indicate the incision design. (d) Occlusal view immediately after surgery. The increase in labial convexity is evident. The connective tissue between the dotted blue lines is exposed directly to the oral cavity.
Please cite this article in press as: Man Y, et al. Split pedicle roll envelope technique around implants and pontics: a prospective case series study, Int J Oral Maxillofac Surg (2015), http://dx.doi.org/10.1016/j.ijom.2015.04.012
YIJOM-3152; No of Pages 7
Split pedicle roll envelope around pontics split palatal flaps, involving only the deeper one, further disconnected the two flaps (see the deep incision in Fig. 1a, indicated by the blue lines). The deeper half was elevated and transformed into a wide mobile pedicled flap, which was divided into two narrow peri-implant parts and one wide pontic part with two small vertical incisions (see the divided flap in Fig. 1c). In the case of single-implant-supported cantilevers, only one vertical incision was needed. A labial envelope was prepared. After the insertion of healing abutments, the peri-implant parts were rolled and positioned in the labial envelope to imitate the emergence profile at the implant site. The tissue rolled into the envelope further pushed the mucosa covering the pontic ridge labially, eliminating the labial concavity of the pontic site. The pontic part was then left in situ loosely to cover the denuded ridge, leaving a strip of de-epithelialized connective tissue exposed. Then on the palatal side, the dissected superficial flap was extended labially with a blood clot underneath, to provide tension-free closure over the pontic ridge. Interrupted or mattress sutures (6–0) were anchored into the exposed connective tissue and the palatal superficial flap to stabilize both of the flaps and close the wound (see the augmented labial contour and exposed connective tissue band in Fig. 1d).
3
Fig. 2. (a) Occlusal view of the soft tissue contour at T2. The peri-implant tissue is mature. (b) Buccal view of the soft tissue contour before definitive restoration. (c) Occlusal view of the definitive restoration. (d) Peri-apical radiograph of No. 8 tooth after final restoration (T3). (e) Peri-apical radiograph of No. 10 tooth after final restoration (T3). The black arrows indicate the marginal bone level, while the white arrows indicate the proximal bone level.
Prosthetic restoration
Immediately after suture removal, an impression was made for interim prosthesis fabrication. On the plaster cast, a composite resin crown, modelled according to the shape of the contralateral teeth, was formed onto one or two temporary abutments. The ovate pontic site was carefully prepared in such a way that the tissue surface of the acrylic pontic was a little over-contoured, which gave rise to the illusion of a natural emergence profile. Sufficient room was reserved for interproximal tissue regeneration and access for oral hygiene. After the tissue surface had been highly glazed, it was manually screwed in and adjusted until no excursive contact existed. Patients were instructed to properly use dental floss and brush their teeth. Postoperative healing was monitored and the interim restoration was adjusted 1–3 times in the next 3 months to optimize aesthetics. Although a mature status of the soft tissue was achieved by the third month, the use of the interim restorations was continued for a further 3 months to avoid tissue deformation. The peri-implant and pontic circumferential
indices were then accurately transferred to assist the dental laboratories, and the definitive restoration was seated 6 months after surgery (Fig. 2a–c). Clinical evaluation
Evaluations were done at the preoperative examination (T0) as the baseline and then at follow-up visits 1 week (T1), 3 months (T2), and 6 months (T3) after surgery. The following variables were recorded at the designated time points: (1) Convex profile on the facial aspect (CPF14): CPF overcontour = 3, CPF present = 2, CPF partially present = 1, CPF absent = 0; this was measured at T0, T1, T2, and T3. (2) Facial mucosal level (FML), recorded as a positive value when located in a coronal position when compared to the contralateral tooth or restoration; this was measured at T0, T1, T2, and T3. (3) Jemt papilla index score (PIS15): no papilla = 0, less than one half the height of the papilla = 1, more than half of the height of the interproximal space = 2, papilla fills the entire proximal space = 3, hyperplastic papilla = 4; this
was measured at T0, T1, T2, and T3. (4) The marginal bone level (MBL), measured at T1 and T3. (5) The proximal bone level (PBL), measured at T1 and T3. (6) The modified plaque index (mPLI): no plaque = 0, plaque recognized only by running a probe across the marginal surface of the implant restoration = 1, plaque seen with the naked eye = 2, abundance of soft matter = 3; this was measured at T0, T2, and T3. Digital photographs were taken to record CPF, PIS, and FML. The preoperative examinations were carried out by graphically adding the imaginary contour of an optimal restoration to the preoperative photograph. The same operator performed all the measurements. The MBL and PBL were measured using sequential peri-apical radiographs with a paralleling technique (Fig. 2d and e). The distance from the prosthetic platform to the first bone contact was calculated at the mesial and distal sites for each implant separately, and then given as a mean value averaged to the nearest 0.1 mm. Angular differences between T1 and T3 were standardized by implant
Please cite this article in press as: Man Y, et al. Split pedicle roll envelope technique around implants and pontics: a prospective case series study, Int J Oral Maxillofac Surg (2015), http://dx.doi.org/10.1016/j.ijom.2015.04.012
YIJOM-3152; No of Pages 7
4
Man et al.
length. A value of zero was given to T1. A negative value was given when the MBL and PBL was apical to T1. Statistical analysis
The Friedman test was applied to evaluate CPF, PIS, and FML changes. A difference was considered significant if the P-value was <0.05. If an overall significant difference existed, separate Wilcoxon signed-
rank tests were added. The statistical analysis was performed using IBM SPSS Statistics for Windows, version 19.0 (IBM Corp., Armonk, NY, USA). The MBL/ PBL and mPLI changes were explained descriptively. Results
During the 6-month follow-up, no patient was lost and no implant showed loss of
osseointegration. Postsurgical inconveniences were minimal and all patients showed good oral hygiene at T2 and T3, indicated by low plaque indices (Table 1). The pedicled flap blended in well with the surrounding tissue. The screw of one cantilever had come loose at the 1-month recall and this was tightened manually. A minor crown fracture occurred in three interim restorations; these were mended with composite resin.
Table 1. Convex profile on the facial aspect (CPF, in millimetres), facial mucosal level (FML, in millimetres), and Jemt papilla index score (PIS) results at the different time points. Index CPF Peri-implant
Values
Friedman test
Wilcoxon signed-rank test
T0 = 0.53 0.51 T1 = 2.63 0.50 T2 = 1.95 0.23 T3 = 1.89 0.32
x2 = 52.21; df = 3 P < 0.001
T1–T0: T2–T0: T3–T0: T2–T1: T3–T1: T3–T2:
Z = 4.185; P < 0.001 Z = 3.946; P < 0.001 Z = 3.963; P < 0.001 Z = 3.606; P < 0.001 Z = 3.742; P < 0.001 Z = 1.000; P = 0.317
T0 = 0.33 0.49 T1 = 2.83 0.39 T2 = 1.92 0.29 T3 = 1.83 0.39
x2 = 34.76; df = 3 P < 0.001
T1–T0: T2–T0: T3–T0: T2–T1: T3–T1: T3–T2:
Z = 3.145; P = 0.002 Z = 3.153; P = 0.002 Z = 3.145; P = 0.002 Z = 3.317; P = 0.001 Z = 3.207; P = 0.001 Z = 1.000; P = 0.317
T0 = 0.79 0.63 T1 = 1.21 0.63 T2 = 2.53 0.51 T3 = 2.79 0.42
x2 = 52.85; df = 3 P < 0.001
T1–T0: T2–T0: T3–T0: T2–T1: T3–T1: T3–T2:
Z = 2.828; Z = 3.912; Z = 3.886; Z = 4.017; Z = 3.919; Z = 1.667;
P = 0.005 P < 0.001 P < 0.001 P < 0.001 P < 0.001 P = 0.096
Implant–pontic
T0 = 0.26 0.45 T1 = 1.21 0.42 T2 = 2.63 0.50 T3 = 2.89 0.32
x2 = 54.86; df = 3 P < 0.001
T1–T0: T2–T0: T3–T0: T2–T1: T3–T1: T3–T2:
Z = 4.243; Z = 3.923; Z = 3.963; Z = 3.946; Z = 3.987; Z = 1.890;
P < 0.001 P < 0.001 P < 0.001 P < 0.001 P < 0.001 P = 0.059
Pontic–tooth
T0 = 0.80 0.45 T1 = 1.40 0.55 T2 = 2.60 0.55 T3 = 2.80 0.45
x2 = 17.11; df = 3 P = 0.001
T1–T0: T2–T0: T3–T0: T2–T1: T3–T1: T3–T2:
Z = 1.890; Z = 2.264; Z = 2.449; Z = 2.264; Z = 2.232; Z = 1.342;
P = 0.059 P = 0.024 P = 0.014 P = 0.024 P = 0.026 P = 0.180
T0 = 0.16 0.22 T1 = 1.22 0.41 T2 = 0.05 0.15 T3 = 0.01 0.15
x2 = 41.92; df = 3 P < 0.001
T1–T0: T2–T0: T3–T0: T2–T1: T3–T1: T3–T2:
Z = 3.828; P < 0.001 Z = 3.294; P = 0.001 Z = 2.614; P = 0.009 Z = 3.828; P < 0.001 Z = 3.831; P < 0.001 Z = 1.309; P = 0.190
Pontic
T0 = 0.55 0.38 T1 = 1.16 0.30 T2 = 0.03 0.14 T3 = 0.03 0.13
x2 = 30.26; df = 3 P < 0.001
T1–T0: T2–T0: T3–T0: T2–T1: T3–T1: T3–T2:
Z = 3.063; P = 0.002 Z = 2.950; P = 0.003 Z = 2.810; P = 0.005 Z = 3.068; P = 0.002 Z = 3.069; P = 0.002 Z = 1.273; P = 0.203
mPLI
T0 = 0.42 0.67 T2 = 0.33 0.49 T3 = 0.25 0.45
–
–
Pontic
PIS Implant–tooth
FML Peri-implant
SD, standard deviation; mPLI, modified plaque index. Results are presented as the mean standard deviation.
Please cite this article in press as: Man Y, et al. Split pedicle roll envelope technique around implants and pontics: a prospective case series study, Int J Oral Maxillofac Surg (2015), http://dx.doi.org/10.1016/j.ijom.2015.04.012
YIJOM-3152; No of Pages 7
Split pedicle roll envelope around pontics
5
The CPF, FML, and PIS results and the related statistical analyses are given in Table 1 and Figs. 3–5. The mean MBL ranged from 0.28 mm at T1 to 1.19 mm at T3, the mean change being 0.85 0.44 mm. The mean PBL ranged from 0.32 mm at T1 to 0.12 mm at T3, the mean change being 0.11 0.25 mm. Discussion
In the present study, all patients underwent guided bone regeneration or ridge splitting at the time of implant placement. All implants were submerged to prevent infection, which facilitated subsequent soft tissue augmentation by taking advantage of the mucosa over the implant and adjacent palatal gingiva when a lack of facial convexity occurred at the second-stage surgery. Using the combined therapy of the split pedicle roll envelope technique and ovate pontic design, a harmonious soft tissue contour was gained at the implant and pontic sites, which were favourably rehabilitated and remained stable during 6 months of follow-up. Traditional exposure surgery techniques make little or no use of the soft tissue covering the implant, and little attention is given to the solution of pontic area concavity. A minimally invasive modified flap design, such as the split finger technique, can endow the wasted tissue with the potential to over-contour interproximal tissue.16 However, when the facial marginal level is apically positioned or facial concavity occurs, which is prevalent in the extended edentulous ridge, the overlying tissue is inadequate and connective tissue grafts derived from the palate are frequently referred to. Although the grafting procedure has been refined, as shown by the envelope and tunnel techniques,17,18 morbidity remains. Commercially available substitutes are superior in reducing morbidity, but this adds to the costs and there is still a lack of long-term predictability.19 The technique presented herein, aimed at reconstructing facial curvature and scalloping the gingival outline, has the following benefits which underline its appropriateness for use: (1) it provides sufficient tissue volume for the implant and pontic sites, (2) early tissue healing can be expected because of the increased blood supply, (3) the graft is readily stabilized, and (4) the donor site is still protected. The elastic split graft adapts better to the ovate pontic, and its guided epithelialization facilitates papilla regeneration. In the present study, the convex profile and papillary height were improved significantly
Fig. 3. Pre- and postoperative evaluations of the convex profile on the facial aspect (CPF, in millimetres). The maximum CPF was apparent immediately after surgery. The mean CPF declined in the following 3 months and then became stable. There was no statistically significant difference between T2 and T3 (peri-implant P = 0.317, pontic P = 0.317). The variation in CPF at the implant and pontic sites was similar. T2 = 3 months after the soft tissue operation; T3 = 6 months after the soft tissue operation. *P < 0.05, a significant difference.
Fig. 4. Pre- and postoperative evaluations of the Jemt papilla index score (PIS). Mean PIS increased over time and reached a maximum at T3. It became relatively stable after T2. There was no statistically significant difference between T2 and T3 (implant–tooth P = 0.096, implant–pontic P = 0.059, pontic–tooth P = 0.180). The variation in PIS in the different restorative environments was similar. T2 = 3 months after the soft tissue operation; T3 = 6 months after the soft tissue operation. *P < 0.05, a significant difference.
Please cite this article in press as: Man Y, et al. Split pedicle roll envelope technique around implants and pontics: a prospective case series study, Int J Oral Maxillofac Surg (2015), http://dx.doi.org/10.1016/j.ijom.2015.04.012
YIJOM-3152; No of Pages 7
6
Man et al.
Fig. 5. Pre- and postoperative evaluations of the facial mucosal level (FML, in millimetres). Mean FML reached a maximum in the coronal direction immediately after surgery. It then dropped to the level of the baseline at T2 and then remained relatively stable. There was no statistically significant difference between T2 and T3 (peri-implant P = 0.190, pontic P = 0.203). The variation in FML at the implant and pontic sites was similar. T2 = 3 months after the soft tissue operation; T3 = 6 months after the soft tissue operation. *P < 0.05, a significant difference.
and were appreciable clinically at 100% of the sites evaluated. Thirty-six papillae (of 43 in total) actually achieved 100% filling. The grafts blended in well and displayed healthy keratinized mucosa after 3 months of healing. No significant reduction was subsequently detected, in agreement with the results of a previous study.20 Papillary dimensions have been shown to be affected by the restorative environment.5 Three categories of papilla, namely tooth–implant, implant–pontic, and pontic–tooth, were included in this study, and the procedure worked well for all of these combinations. However, the efficacy in PIS improvement varied. The top ranking position of the implant–pontic papilla can be attributed to the following: (1) the underlying osseous architecture was well preserved by having the implants far apart, (2) the initial value was the lowest, and (3) the ovate pontic favoured new papilla formation. In contrast, with the nutrition of the adjacent teeth, tooth–implant and pontic–tooth papillae were better preserved before surgery and not involved in the flap design, making the pre- and post-surgery discrepancy minor. Consequently, it is impossible to decide whether the modified approach works better for one papilla type over another. The FML revealed obvious apical displacement during the healing phase. This
could be attributed in part to the physiological remodelling of soft tissue. To compensate for the predicated recession, part of the keratinized mucosa was pushed labially, resulting in a more coronal location of the marginal level at T1. This coronal discrepancy, if it existed, was adjusted by interim crown reshaping. All these physiological and artificial reasons accentuate the contrast between T1 and T2 (T3). Nevertheless, the final aesthetic results were clinically appreciable and the FML was located at almost the same level as the contralateral facial margin or optimal FML outlined by the imaginary preoperative prosthesis. In this study, the mean marginal bone loss from T0 to T3 was higher than that found in other research.21,22 This discrepancy may be the result of implant, clinical, and patient-related factors that are reported to cause marginal bone loss.23 Two implants can adequately support a three-unit fixed partial prosthesis, which might create a bone stress comparable to that calculated for connected crowns supported by three implants.24 Thus it appears inappropriate to attribute the excess bone loss to the fixed bridge design. However, implants supporting distal extension prostheses have been shown to lose significantly more bone in the first year of loading.22 More bone loss may be
expected if passive adaptation is not achieved due to an inaccurate impression or interim prosthesis deformation. Detachment of the periosteum can add further to bone loss. In this study, a loose screw and fracture of the crown were found in some patients, which might imply misuse of the interim crown. Each of these factors warranted further investigation. Although marginal bone loss was a little higher, it did not compromise aesthetics, and stability of the soft tissue was attained. The technique presented here is also applicable for the traditional fixed bridge. It can be applied alone or in combination with a CTG and guided bone regeneration to enhance aesthetics when necessary. Fine manipulation of the flap is of great importance because the de-epithelialized flap covering the bone may become too taut or loose when the flap is improperly approximated and sutured, which may lead to stagnant haemostasis, unnecessary bone destruction, and patient discomfort.25 Careful fabrication of the interim crown and an optimal plaque control regimen are also essential for success. This study has limitations. The results are difficult to interpret due to the lack of a control group. The gingival index was not assessed and subjective patient evaluations were not done, making the aesthetic evaluation incomplete. A long-term control study is needed to further verify the combined therapy. Within the limitations of this study, this combined therapy appears to be highly effective and minimally invasive. It may provide an opportunity to achieve aesthetic and functional rehabilitation of adjacent missing teeth in the anterior maxilla. Funding
This study was funded by the Sichuan Provincial Science and Technology Pillar Program (No. 2014SZ0019) and a Small Grant from ITI (No. 2009660) for the State Key Clinical Specialty of China for Oral Implantology. The funders had no involvement in the study design, or in the collection, analysis, and interpretation of the data. Competing interests
All authors report no conflicts of interest related to this study. Ethical approval
Ethical approval was given by the Human Ethics Committee of the West China School of Stomatology (Protocol 2009034).
Please cite this article in press as: Man Y, et al. Split pedicle roll envelope technique around implants and pontics: a prospective case series study, Int J Oral Maxillofac Surg (2015), http://dx.doi.org/10.1016/j.ijom.2015.04.012
YIJOM-3152; No of Pages 7
Split pedicle roll envelope around pontics Patient consent
Written patient consent was obtained to publish the clinical photographs. Appendix A. Supplementary data
Supplementary data associated with this article can be found, in the online version, at http://dx.doi.org/10.1016/j. ijom.2015.04.012. References 1. Papaspyridakos P, Chen CJ, Singh M, Weber HP, Gallucci GO. Success criteria in implant dentistry: a systematic review. J Dent Res 2012;91:242–8. http://dx.doi.org/10.1177/ 0022034511431252. 2. Belser U, Buser D, Higginbottom F. Consensus statements and recommended clinical procedures regarding esthetics in implant dentistry. Int J Oral Maxillofac Implants 2004;19(Suppl):73–4. http://dx.doi.org/ 10.11607/jomi.2013.g3. 3. Davidoff SR. Restorative-based treatment planning: determining adequate support for implant-retained fixed restorations. Implant Dent 1996;5:179–84. http://dx.doi.org/ 10.1097/00008505-199600530-00005. 4. Tarnow DP, Cho SC, Wallace SS. The effect of inter-implant distance on the height of inter-implant bone crest. J Periodontol 2000;71:546–9. http://dx.doi.org/10.1902/ jop.2000.71.4.546. 5. Salama H, Salama MA, Garber D, Adar P. The inter-proximal height of bone: a guidepost to esthetic strategies and soft tissue contours in anterior tooth replacement. Pract Periodontics Aesthet Dent 2003;5:64–73. 6. Tarnow D, Elian N, Fletcher P, Froum S, Magner A, Cho SC, et al. Vertical distance from the crest of bone to the height of the interproximal papilla between adjacent implants. J Periodontol 2003;74:1785–8. http://dx.doi.org/10.1902/jop.2003.74.12. 1785. 7. Johnson GK, Leary JM. Pontic design and localized ridge augmentation in fixed partial denture design. Dent Clin North Am 1992;36:591–605. 8. Zitzmann NU, Marinello CP, Berglundh T. The ovate pontic design: a histologic observation in humans. J Prosthet Dent 2002;88:375–80. http://dx.doi.org/10.1067/ mpr.2002.128758.
9. Tripodakis AP, Constandtinides A. Tissue response under hyperpressure from convex pontics. Int J Periodontics Restorative Dent 1990;10:408–14. 10. Milinkovic I, Cordaro L. Are there specific indications for the different alveolar bone augmentation procedures for implant placement? A systematic review. Int J Oral Maxillofac Surg 2014;43:606–25. http:// dx.doi.org/10.1016/j.ijom.2013.12.004. 11. Seibert J. Soft tissue grafts in periodontics. In: Robinson PJ, Guernsey LH, editors. Clinical transplantation in dental specialties. St Louis: Mosby; 1980. p. 107–45. 12. Schneider D, Grunder U, Ender A, Hammerle CH, Jung RE. Volume gain and stability of peri-implant tissue following bone and soft tissue augmentation: 1-year results from a prospective cohort study. Clin Oral Implants 2011;22:28–37. http://dx.doi.org/ Res 10.1111/j.1600-0501.2010.01987.x. 13. Man Y, Wang Y, Qu Y, Wang P, Gong P. A palatal roll envelope technique for peri-implant mucosa reconstruction: a prospective case series study. Int J Oral Maxillofac Surg 2013;42:660–5. http://dx.doi.org/10.1016/ j.ijom.2013.01.008. 14. Belser UC, Grutter L, Vailati F, Bornstein MM, Weber HP, Buser D. Outcome evaluation of early placed maxillary anterior single-tooth implants using objective esthetic criteria: a cross-sectional, retrospective study in 45 patients with a 2- to 4-year follow-up using pink and white esthetic scores. J Periodontol 2009;80:140–51. http://dx.doi.org/10.1902/jop.2009.080435. 15. Jemt T. Regeneration of gingival papillae after single-implant treatment. Int J Periodontics Restorative Dent 1997;17:326–33. 16. Shahidi P, Jacobson Z, Dibart S, Pourati J, Nunn ME, Barouch K, et al. Efficacy of a new papilla generation technique in implant dentistry: a preliminary study. Int J Oral Maxillofac Implants 2008;23:926–34. 17. Ribeiro FS, Zandim DL, Pontes AE, Mantovani RV, Sampaio JE, Marcantonio E. Tunnel technique with a surgical maneuver to increase the graft extension: case report with a 3-year follow-up. J Periodontol 2008;79:753–8. http://dx.doi.org/10.1902/ jop.2008.070274. 18. Raetzke PB. Covering localized areas of root exposure employing the ‘envelope’ technique. J Periodontol 1985;56:397– 402. http://dx.doi.org/10.1902/jop.1985. 56.7.397.
7
19. Batista Jr EL, Batista FC, Novaes Jr AB. Management of soft tissue ridge deformities with acellular dermal matrix. Clinical approach and outcome after 6 months of treatment. J Periodontol 2001;72:265–73. http:// dx.doi.org/10.1902/jop.2001.72.2.265. 20. Cardaropoli G, Lekholm U, Wennstrom JL. Tissue alterations at implant-supported single-tooth replacements: a 1-year prospective clinical study. Clin Oral Implants Res 2006;17:165–71. http://dx.doi.org/10.1111/ j.1600-0501.2005.01210.x. 21. Boven GC, Meijer HJ, Vissink A, Raghoebar GM. Reconstruction of the extremely atrophied mandible with iliac crest onlay grafts followed by two endosteal implants: a retrospective study with long-term follow-up. Int J Oral Maxillofac Surg 2014;43:626–32. http://dx.doi.org/10.1016/j.ijom.2013.11. 003. 22. Nikzad S, Azari A. Custom-made radiographic template, computed tomography, and computer-assisted flapless surgery for treatment planning in partial edentulous patients: a prospective 12-month study. J Oral Maxillofac Surg 2010;68:1353–9. http://dx.doi.org/10.1016/j.joms.2009.04. 108. 23. Clementini M, Rossetti PH, Penarrocha D, Micarelli C, Bonachela WC, Canullo L. Systemic risk factors for peri-implant bone loss: a systematic review and meta-analysis. Int J Oral Maxillofac Surg 2014;43:323–34. http://dx.doi.org/10.1016/j.ijom.2013.11. 012. 24. Stegaroiu R, Sato T, Kusakari H, Miyakawa O. Influence of restoration type on stress distribution in bone around implants: a three-dimensional finite element analysis. Int J Oral Maxillofac Implants 1998;13:82–90. 25. Hashemi HM, Parhiz A, Ghafari S. Vestibuloplasty: allograft versus mucosal graft. Int J Oral Maxillofac Surg 2012;41:527–30. http:// dx.doi.org/10.1016/j.ijom.2011.09.014.
Address: Yili Qu State Key Laboratory of Oral Diseases West China Hospital of Stomatology Sichuan University No. 14 3rd Section Renmin Nan Road Chengdu Sichuan 610041 China. Fax: +86 28 85483678 E-mail: [email protected]
Please cite this article in press as: Man Y, et al. Split pedicle roll envelope technique around implants and pontics: a prospective case series study, Int J Oral Maxillofac Surg (2015), http://dx.doi.org/10.1016/j.ijom.2015.04.012
Int. J. Oral Maxillofac. Surg. 2015; xxx: xxx–xxx http://dx.doi.org/10.1016/j.ijom.2015.04.012, available online at http://www.sciencedirect.com
Clinical Paper Dental Implants
Split pedicle roll envelope technique around implants and pontics: a prospective case series study
Y. Man1,2, Q. Wu1,2, T. Wang1,2, P. Gong1,2, T. Gong1,2, Y. Qu1,3 1 State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, PR China; 2Department of Oral Implantology, West China Hospital of Stomatology, Sichuan University, Chengdu, PR China; 3Department of Prosthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
Y. Man, Q. Wu, T. Wang, P. Gong, T. Gong, Y. Qu: Split pedicle roll envelope technique around implants and pontics: a prospective case series study. Int. J. Oral Maxillofac. Surg. 2015; xxx: xxx–xxx. # 2015 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
Abstract. Recreating a harmonious gingival contour for contiguous missing teeth in the anterior maxilla is challenging. The aim of this study was to evaluate a split pedicle roll envelope technique designed for pontics. Twelve patients presented a labial flat or concave profile at the implant and pontic sites before second-stage surgery. The contour deficiency was compensated with a palatal split pedicle flap with the implant part rolled into the labial envelope and the pontic part covering the denuded ridge. Interim restorations were screwed in to guide tissue remodelling. The labial convex profile (CPF) and facial mucosal level (FML) at the implant and pontic sites, the Jemt papilla index (PIS) in the different restorative environments, and peri-implant bone levels were recorded at baseline and at 1 week, 3 months, and 6 months postoperative. Results showed that the CPF had increased by 1.4 mm at the implant site and 1.5 mm at the pontic site at 6 months after surgery. PIS had increased by 2 at the implant–tooth/pontic–tooth sites and by 2.6 at the implant– pontic site. FML was coordinated with that of the contralateral teeth. All indices were favourable at 3 months and then remained stable. Within the limitations identified, this combined therapy can be considered as an alternative to achieve aesthetic success when contiguous maxillary anterior teeth are missing.
The treatment concept of implant dentistry has shifted from implant survival to aesthetic rehabilitation. When aesthetics is added to the criteria for success, the success rate of implant-supported prostheses drops significantly.1 For contiguous missing maxillary anterior teeth, aesthetics is even less predictable than with a single 0901-5027/000001+07
missing tooth, particularly regarding the maintenance of inter-implant tissue.2 When the bone morphology permits implant installation, the ‘one tooth, one implant’ treatment protocol can be adopted where space allows.3 However, anatomical limitations, patient-centred issues, and aesthetic considerations may
Keywords: implant-supported dental prosthesis; pontic; dental aesthetics; pedicled flap; dental papilla. Accepted for publication 23 April 2015
justify implant-supported bridges or cantilevers. Although Tarnow et al.4 recommend an inter-implant horizontal distance of at least 3 mm to reduce crestal bone loss, it is usually hard to meet this requirement in the anterior maxilla. In addition, the predicted inter-implant papilla height is lower than that adjacent to a natural
# 2015 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
Please cite this article in press as: Man Y, et al. Split pedicle roll envelope technique around implants and pontics: a prospective case series study, Int J Oral Maxillofac Surg (2015), http://dx.doi.org/10.1016/j.ijom.2015.04.012
YIJOM-3152; No of Pages 7
2
Man et al.
tooth or pontic.5,6 Thus it appears advisable to circumvent this risky inter-implant dilemma by using pontics. Among the various pontic designs, the ovate pontic is recommended as an effective replication of the natural emergence profile,7 and long-term mucosal health can be maintained.8,9 Adequate alveolar bone and soft tissue volume are the prerequisites for aesthetic reconstructions of either a pontic or an implant site. Many ridge augmentation techniques have been applied to condition the ridge topography.10 However, the grafted tissues often undergo unpredictable resorption. Therefore, re-grafting is often necessary at the second-stage surgery. It is documented that a deficiency of <3 mm in dimension can be resolved by soft tissue augmentation alone.11 Thus soft tissue grafting and various flap designs have been devised for contour compensation. The acquirement of soft tissue from the palate aggravates patient morbidity, and compared to pedicled grafts, free connective tissue grafts (CTG) have a higher risk of shrinkage.12 To circumvent these problems, Man et al.13 developed a palatal roll envelope technique for soft tissue reconstruction around single implants that
is minimally invasive and has the potential to reduce graft shrinkage and scar formation. However, it cannot be applied to the pontic area because it might expose the alveolar bone there directly to the oral cavity. The purpose of this study was to: (1) present a therapy consisting of a split pedicle roll envelope technique and restorative designs with ovate pontics, and (2) objectively evaluate its efficacy and predictability.
and five ITI bone level implants (Institut Straumann AG, Basel, Switzerland) between August 2012 and March 2013. Of the 12 patients, five had single-implantsupported cantilevers with the pontic situated in the position of lateral incisor and seven had three-unit implant-supported bridges. Informed consent was obtained. After healing for 3 months, the split pedicle roll envelope technique was performed at second-stage surgery. This study was designed as an observational prospective study.
Materials and methods Patients and study design
Surgical procedure
Twelve consecutive patients (six women and six men, mean age 34 5.8 years) were included in this study. To be enrolled, the patient had to fulfil the following criteria: (1) age 18 years with good oral hygiene and compliance; (2) presenting at least one location with multiple adjacent maxillary anterior teeth missing; (3) presenting a flat or concave profile before the second-stage surgery, with a sufficient bone base; (4) no tobacco abuse. A total of 19 implants were installed, including 14 Osstem GS II implants (Osstem Implant Co., Ltd, Busan, Korea)
Under local anaesthesia, an initial partialthickness crestal incision was made 1– 2 mm towards the palatal side, to gain a maximum amount of keratinized tissue in the labial flap, and 1–2 mm away from the adjacent teeth, to preserve the papilla. Two partial-thickness vertical incisions, 5–10 mm in length, were made on the palatal side (see the superficial incision in Fig. 1a). The superficial part was elevated by sharp dissection (see the dissected superficial flap and underlying connective tissue in Fig. 1b). Then, another incision, parallel to the union of the two
Fig. 1. Split pedicle roll envelope technique performed at implant (Nos. 8 and 10) and pontic (No. 9) sites. (a) Incision design. Partial-thickness crestal and palatal incisions were made. The blue line indicates the deeper connective tissue incision. The dotted green line shows the labial profile feature in occlusal view. (b) Sharp dissection of the palatal superficial flap. (c) Divided split pedicle flap. The dotted green lines indicate the incision design. (d) Occlusal view immediately after surgery. The increase in labial convexity is evident. The connective tissue between the dotted blue lines is exposed directly to the oral cavity.
Please cite this article in press as: Man Y, et al. Split pedicle roll envelope technique around implants and pontics: a prospective case series study, Int J Oral Maxillofac Surg (2015), http://dx.doi.org/10.1016/j.ijom.2015.04.012
YIJOM-3152; No of Pages 7
Split pedicle roll envelope around pontics split palatal flaps, involving only the deeper one, further disconnected the two flaps (see the deep incision in Fig. 1a, indicated by the blue lines). The deeper half was elevated and transformed into a wide mobile pedicled flap, which was divided into two narrow peri-implant parts and one wide pontic part with two small vertical incisions (see the divided flap in Fig. 1c). In the case of single-implant-supported cantilevers, only one vertical incision was needed. A labial envelope was prepared. After the insertion of healing abutments, the peri-implant parts were rolled and positioned in the labial envelope to imitate the emergence profile at the implant site. The tissue rolled into the envelope further pushed the mucosa covering the pontic ridge labially, eliminating the labial concavity of the pontic site. The pontic part was then left in situ loosely to cover the denuded ridge, leaving a strip of de-epithelialized connective tissue exposed. Then on the palatal side, the dissected superficial flap was extended labially with a blood clot underneath, to provide tension-free closure over the pontic ridge. Interrupted or mattress sutures (6–0) were anchored into the exposed connective tissue and the palatal superficial flap to stabilize both of the flaps and close the wound (see the augmented labial contour and exposed connective tissue band in Fig. 1d).
3
Fig. 2. (a) Occlusal view of the soft tissue contour at T2. The peri-implant tissue is mature. (b) Buccal view of the soft tissue contour before definitive restoration. (c) Occlusal view of the definitive restoration. (d) Peri-apical radiograph of No. 8 tooth after final restoration (T3). (e) Peri-apical radiograph of No. 10 tooth after final restoration (T3). The black arrows indicate the marginal bone level, while the white arrows indicate the proximal bone level.
Prosthetic restoration
Immediately after suture removal, an impression was made for interim prosthesis fabrication. On the plaster cast, a composite resin crown, modelled according to the shape of the contralateral teeth, was formed onto one or two temporary abutments. The ovate pontic site was carefully prepared in such a way that the tissue surface of the acrylic pontic was a little over-contoured, which gave rise to the illusion of a natural emergence profile. Sufficient room was reserved for interproximal tissue regeneration and access for oral hygiene. After the tissue surface had been highly glazed, it was manually screwed in and adjusted until no excursive contact existed. Patients were instructed to properly use dental floss and brush their teeth. Postoperative healing was monitored and the interim restoration was adjusted 1–3 times in the next 3 months to optimize aesthetics. Although a mature status of the soft tissue was achieved by the third month, the use of the interim restorations was continued for a further 3 months to avoid tissue deformation. The peri-implant and pontic circumferential
indices were then accurately transferred to assist the dental laboratories, and the definitive restoration was seated 6 months after surgery (Fig. 2a–c). Clinical evaluation
Evaluations were done at the preoperative examination (T0) as the baseline and then at follow-up visits 1 week (T1), 3 months (T2), and 6 months (T3) after surgery. The following variables were recorded at the designated time points: (1) Convex profile on the facial aspect (CPF14): CPF overcontour = 3, CPF present = 2, CPF partially present = 1, CPF absent = 0; this was measured at T0, T1, T2, and T3. (2) Facial mucosal level (FML), recorded as a positive value when located in a coronal position when compared to the contralateral tooth or restoration; this was measured at T0, T1, T2, and T3. (3) Jemt papilla index score (PIS15): no papilla = 0, less than one half the height of the papilla = 1, more than half of the height of the interproximal space = 2, papilla fills the entire proximal space = 3, hyperplastic papilla = 4; this
was measured at T0, T1, T2, and T3. (4) The marginal bone level (MBL), measured at T1 and T3. (5) The proximal bone level (PBL), measured at T1 and T3. (6) The modified plaque index (mPLI): no plaque = 0, plaque recognized only by running a probe across the marginal surface of the implant restoration = 1, plaque seen with the naked eye = 2, abundance of soft matter = 3; this was measured at T0, T2, and T3. Digital photographs were taken to record CPF, PIS, and FML. The preoperative examinations were carried out by graphically adding the imaginary contour of an optimal restoration to the preoperative photograph. The same operator performed all the measurements. The MBL and PBL were measured using sequential peri-apical radiographs with a paralleling technique (Fig. 2d and e). The distance from the prosthetic platform to the first bone contact was calculated at the mesial and distal sites for each implant separately, and then given as a mean value averaged to the nearest 0.1 mm. Angular differences between T1 and T3 were standardized by implant
Please cite this article in press as: Man Y, et al. Split pedicle roll envelope technique around implants and pontics: a prospective case series study, Int J Oral Maxillofac Surg (2015), http://dx.doi.org/10.1016/j.ijom.2015.04.012
YIJOM-3152; No of Pages 7
4
Man et al.
length. A value of zero was given to T1. A negative value was given when the MBL and PBL was apical to T1. Statistical analysis
The Friedman test was applied to evaluate CPF, PIS, and FML changes. A difference was considered significant if the P-value was <0.05. If an overall significant difference existed, separate Wilcoxon signed-
rank tests were added. The statistical analysis was performed using IBM SPSS Statistics for Windows, version 19.0 (IBM Corp., Armonk, NY, USA). The MBL/ PBL and mPLI changes were explained descriptively. Results
During the 6-month follow-up, no patient was lost and no implant showed loss of
osseointegration. Postsurgical inconveniences were minimal and all patients showed good oral hygiene at T2 and T3, indicated by low plaque indices (Table 1). The pedicled flap blended in well with the surrounding tissue. The screw of one cantilever had come loose at the 1-month recall and this was tightened manually. A minor crown fracture occurred in three interim restorations; these were mended with composite resin.
Table 1. Convex profile on the facial aspect (CPF, in millimetres), facial mucosal level (FML, in millimetres), and Jemt papilla index score (PIS) results at the different time points. Index CPF Peri-implant
Values
Friedman test
Wilcoxon signed-rank test
T0 = 0.53 0.51 T1 = 2.63 0.50 T2 = 1.95 0.23 T3 = 1.89 0.32
x2 = 52.21; df = 3 P < 0.001
T1–T0: T2–T0: T3–T0: T2–T1: T3–T1: T3–T2:
Z = 4.185; P < 0.001 Z = 3.946; P < 0.001 Z = 3.963; P < 0.001 Z = 3.606; P < 0.001 Z = 3.742; P < 0.001 Z = 1.000; P = 0.317
T0 = 0.33 0.49 T1 = 2.83 0.39 T2 = 1.92 0.29 T3 = 1.83 0.39
x2 = 34.76; df = 3 P < 0.001
T1–T0: T2–T0: T3–T0: T2–T1: T3–T1: T3–T2:
Z = 3.145; P = 0.002 Z = 3.153; P = 0.002 Z = 3.145; P = 0.002 Z = 3.317; P = 0.001 Z = 3.207; P = 0.001 Z = 1.000; P = 0.317
T0 = 0.79 0.63 T1 = 1.21 0.63 T2 = 2.53 0.51 T3 = 2.79 0.42
x2 = 52.85; df = 3 P < 0.001
T1–T0: T2–T0: T3–T0: T2–T1: T3–T1: T3–T2:
Z = 2.828; Z = 3.912; Z = 3.886; Z = 4.017; Z = 3.919; Z = 1.667;
P = 0.005 P < 0.001 P < 0.001 P < 0.001 P < 0.001 P = 0.096
Implant–pontic
T0 = 0.26 0.45 T1 = 1.21 0.42 T2 = 2.63 0.50 T3 = 2.89 0.32
x2 = 54.86; df = 3 P < 0.001
T1–T0: T2–T0: T3–T0: T2–T1: T3–T1: T3–T2:
Z = 4.243; Z = 3.923; Z = 3.963; Z = 3.946; Z = 3.987; Z = 1.890;
P < 0.001 P < 0.001 P < 0.001 P < 0.001 P < 0.001 P = 0.059
Pontic–tooth
T0 = 0.80 0.45 T1 = 1.40 0.55 T2 = 2.60 0.55 T3 = 2.80 0.45
x2 = 17.11; df = 3 P = 0.001
T1–T0: T2–T0: T3–T0: T2–T1: T3–T1: T3–T2:
Z = 1.890; Z = 2.264; Z = 2.449; Z = 2.264; Z = 2.232; Z = 1.342;
P = 0.059 P = 0.024 P = 0.014 P = 0.024 P = 0.026 P = 0.180
T0 = 0.16 0.22 T1 = 1.22 0.41 T2 = 0.05 0.15 T3 = 0.01 0.15
x2 = 41.92; df = 3 P < 0.001
T1–T0: T2–T0: T3–T0: T2–T1: T3–T1: T3–T2:
Z = 3.828; P < 0.001 Z = 3.294; P = 0.001 Z = 2.614; P = 0.009 Z = 3.828; P < 0.001 Z = 3.831; P < 0.001 Z = 1.309; P = 0.190
Pontic
T0 = 0.55 0.38 T1 = 1.16 0.30 T2 = 0.03 0.14 T3 = 0.03 0.13
x2 = 30.26; df = 3 P < 0.001
T1–T0: T2–T0: T3–T0: T2–T1: T3–T1: T3–T2:
Z = 3.063; P = 0.002 Z = 2.950; P = 0.003 Z = 2.810; P = 0.005 Z = 3.068; P = 0.002 Z = 3.069; P = 0.002 Z = 1.273; P = 0.203
mPLI
T0 = 0.42 0.67 T2 = 0.33 0.49 T3 = 0.25 0.45
–
–
Pontic
PIS Implant–tooth
FML Peri-implant
SD, standard deviation; mPLI, modified plaque index. Results are presented as the mean standard deviation.
Please cite this article in press as: Man Y, et al. Split pedicle roll envelope technique around implants and pontics: a prospective case series study, Int J Oral Maxillofac Surg (2015), http://dx.doi.org/10.1016/j.ijom.2015.04.012
YIJOM-3152; No of Pages 7
Split pedicle roll envelope around pontics
5
The CPF, FML, and PIS results and the related statistical analyses are given in Table 1 and Figs. 3–5. The mean MBL ranged from 0.28 mm at T1 to 1.19 mm at T3, the mean change being 0.85 0.44 mm. The mean PBL ranged from 0.32 mm at T1 to 0.12 mm at T3, the mean change being 0.11 0.25 mm. Discussion
In the present study, all patients underwent guided bone regeneration or ridge splitting at the time of implant placement. All implants were submerged to prevent infection, which facilitated subsequent soft tissue augmentation by taking advantage of the mucosa over the implant and adjacent palatal gingiva when a lack of facial convexity occurred at the second-stage surgery. Using the combined therapy of the split pedicle roll envelope technique and ovate pontic design, a harmonious soft tissue contour was gained at the implant and pontic sites, which were favourably rehabilitated and remained stable during 6 months of follow-up. Traditional exposure surgery techniques make little or no use of the soft tissue covering the implant, and little attention is given to the solution of pontic area concavity. A minimally invasive modified flap design, such as the split finger technique, can endow the wasted tissue with the potential to over-contour interproximal tissue.16 However, when the facial marginal level is apically positioned or facial concavity occurs, which is prevalent in the extended edentulous ridge, the overlying tissue is inadequate and connective tissue grafts derived from the palate are frequently referred to. Although the grafting procedure has been refined, as shown by the envelope and tunnel techniques,17,18 morbidity remains. Commercially available substitutes are superior in reducing morbidity, but this adds to the costs and there is still a lack of long-term predictability.19 The technique presented herein, aimed at reconstructing facial curvature and scalloping the gingival outline, has the following benefits which underline its appropriateness for use: (1) it provides sufficient tissue volume for the implant and pontic sites, (2) early tissue healing can be expected because of the increased blood supply, (3) the graft is readily stabilized, and (4) the donor site is still protected. The elastic split graft adapts better to the ovate pontic, and its guided epithelialization facilitates papilla regeneration. In the present study, the convex profile and papillary height were improved significantly
Fig. 3. Pre- and postoperative evaluations of the convex profile on the facial aspect (CPF, in millimetres). The maximum CPF was apparent immediately after surgery. The mean CPF declined in the following 3 months and then became stable. There was no statistically significant difference between T2 and T3 (peri-implant P = 0.317, pontic P = 0.317). The variation in CPF at the implant and pontic sites was similar. T2 = 3 months after the soft tissue operation; T3 = 6 months after the soft tissue operation. *P < 0.05, a significant difference.
Fig. 4. Pre- and postoperative evaluations of the Jemt papilla index score (PIS). Mean PIS increased over time and reached a maximum at T3. It became relatively stable after T2. There was no statistically significant difference between T2 and T3 (implant–tooth P = 0.096, implant–pontic P = 0.059, pontic–tooth P = 0.180). The variation in PIS in the different restorative environments was similar. T2 = 3 months after the soft tissue operation; T3 = 6 months after the soft tissue operation. *P < 0.05, a significant difference.
Please cite this article in press as: Man Y, et al. Split pedicle roll envelope technique around implants and pontics: a prospective case series study, Int J Oral Maxillofac Surg (2015), http://dx.doi.org/10.1016/j.ijom.2015.04.012
YIJOM-3152; No of Pages 7
6
Man et al.
Fig. 5. Pre- and postoperative evaluations of the facial mucosal level (FML, in millimetres). Mean FML reached a maximum in the coronal direction immediately after surgery. It then dropped to the level of the baseline at T2 and then remained relatively stable. There was no statistically significant difference between T2 and T3 (peri-implant P = 0.190, pontic P = 0.203). The variation in FML at the implant and pontic sites was similar. T2 = 3 months after the soft tissue operation; T3 = 6 months after the soft tissue operation. *P < 0.05, a significant difference.
and were appreciable clinically at 100% of the sites evaluated. Thirty-six papillae (of 43 in total) actually achieved 100% filling. The grafts blended in well and displayed healthy keratinized mucosa after 3 months of healing. No significant reduction was subsequently detected, in agreement with the results of a previous study.20 Papillary dimensions have been shown to be affected by the restorative environment.5 Three categories of papilla, namely tooth–implant, implant–pontic, and pontic–tooth, were included in this study, and the procedure worked well for all of these combinations. However, the efficacy in PIS improvement varied. The top ranking position of the implant–pontic papilla can be attributed to the following: (1) the underlying osseous architecture was well preserved by having the implants far apart, (2) the initial value was the lowest, and (3) the ovate pontic favoured new papilla formation. In contrast, with the nutrition of the adjacent teeth, tooth–implant and pontic–tooth papillae were better preserved before surgery and not involved in the flap design, making the pre- and post-surgery discrepancy minor. Consequently, it is impossible to decide whether the modified approach works better for one papilla type over another. The FML revealed obvious apical displacement during the healing phase. This
could be attributed in part to the physiological remodelling of soft tissue. To compensate for the predicated recession, part of the keratinized mucosa was pushed labially, resulting in a more coronal location of the marginal level at T1. This coronal discrepancy, if it existed, was adjusted by interim crown reshaping. All these physiological and artificial reasons accentuate the contrast between T1 and T2 (T3). Nevertheless, the final aesthetic results were clinically appreciable and the FML was located at almost the same level as the contralateral facial margin or optimal FML outlined by the imaginary preoperative prosthesis. In this study, the mean marginal bone loss from T0 to T3 was higher than that found in other research.21,22 This discrepancy may be the result of implant, clinical, and patient-related factors that are reported to cause marginal bone loss.23 Two implants can adequately support a three-unit fixed partial prosthesis, which might create a bone stress comparable to that calculated for connected crowns supported by three implants.24 Thus it appears inappropriate to attribute the excess bone loss to the fixed bridge design. However, implants supporting distal extension prostheses have been shown to lose significantly more bone in the first year of loading.22 More bone loss may be
expected if passive adaptation is not achieved due to an inaccurate impression or interim prosthesis deformation. Detachment of the periosteum can add further to bone loss. In this study, a loose screw and fracture of the crown were found in some patients, which might imply misuse of the interim crown. Each of these factors warranted further investigation. Although marginal bone loss was a little higher, it did not compromise aesthetics, and stability of the soft tissue was attained. The technique presented here is also applicable for the traditional fixed bridge. It can be applied alone or in combination with a CTG and guided bone regeneration to enhance aesthetics when necessary. Fine manipulation of the flap is of great importance because the de-epithelialized flap covering the bone may become too taut or loose when the flap is improperly approximated and sutured, which may lead to stagnant haemostasis, unnecessary bone destruction, and patient discomfort.25 Careful fabrication of the interim crown and an optimal plaque control regimen are also essential for success. This study has limitations. The results are difficult to interpret due to the lack of a control group. The gingival index was not assessed and subjective patient evaluations were not done, making the aesthetic evaluation incomplete. A long-term control study is needed to further verify the combined therapy. Within the limitations of this study, this combined therapy appears to be highly effective and minimally invasive. It may provide an opportunity to achieve aesthetic and functional rehabilitation of adjacent missing teeth in the anterior maxilla. Funding
This study was funded by the Sichuan Provincial Science and Technology Pillar Program (No. 2014SZ0019) and a Small Grant from ITI (No. 2009660) for the State Key Clinical Specialty of China for Oral Implantology. The funders had no involvement in the study design, or in the collection, analysis, and interpretation of the data. Competing interests
All authors report no conflicts of interest related to this study. Ethical approval
Ethical approval was given by the Human Ethics Committee of the West China School of Stomatology (Protocol 2009034).
Please cite this article in press as: Man Y, et al. Split pedicle roll envelope technique around implants and pontics: a prospective case series study, Int J Oral Maxillofac Surg (2015), http://dx.doi.org/10.1016/j.ijom.2015.04.012
YIJOM-3152; No of Pages 7
Split pedicle roll envelope around pontics Patient consent
Written patient consent was obtained to publish the clinical photographs. Appendix A. Supplementary data
Supplementary data associated with this article can be found, in the online version, at http://dx.doi.org/10.1016/j. ijom.2015.04.012. References 1. Papaspyridakos P, Chen CJ, Singh M, Weber HP, Gallucci GO. Success criteria in implant dentistry: a systematic review. J Dent Res 2012;91:242–8. http://dx.doi.org/10.1177/ 0022034511431252. 2. Belser U, Buser D, Higginbottom F. Consensus statements and recommended clinical procedures regarding esthetics in implant dentistry. Int J Oral Maxillofac Implants 2004;19(Suppl):73–4. http://dx.doi.org/ 10.11607/jomi.2013.g3. 3. Davidoff SR. Restorative-based treatment planning: determining adequate support for implant-retained fixed restorations. Implant Dent 1996;5:179–84. http://dx.doi.org/ 10.1097/00008505-199600530-00005. 4. Tarnow DP, Cho SC, Wallace SS. The effect of inter-implant distance on the height of inter-implant bone crest. J Periodontol 2000;71:546–9. http://dx.doi.org/10.1902/ jop.2000.71.4.546. 5. Salama H, Salama MA, Garber D, Adar P. The inter-proximal height of bone: a guidepost to esthetic strategies and soft tissue contours in anterior tooth replacement. Pract Periodontics Aesthet Dent 2003;5:64–73. 6. Tarnow D, Elian N, Fletcher P, Froum S, Magner A, Cho SC, et al. Vertical distance from the crest of bone to the height of the interproximal papilla between adjacent implants. J Periodontol 2003;74:1785–8. http://dx.doi.org/10.1902/jop.2003.74.12. 1785. 7. Johnson GK, Leary JM. Pontic design and localized ridge augmentation in fixed partial denture design. Dent Clin North Am 1992;36:591–605. 8. Zitzmann NU, Marinello CP, Berglundh T. The ovate pontic design: a histologic observation in humans. J Prosthet Dent 2002;88:375–80. http://dx.doi.org/10.1067/ mpr.2002.128758.
9. Tripodakis AP, Constandtinides A. Tissue response under hyperpressure from convex pontics. Int J Periodontics Restorative Dent 1990;10:408–14. 10. Milinkovic I, Cordaro L. Are there specific indications for the different alveolar bone augmentation procedures for implant placement? A systematic review. Int J Oral Maxillofac Surg 2014;43:606–25. http:// dx.doi.org/10.1016/j.ijom.2013.12.004. 11. Seibert J. Soft tissue grafts in periodontics. In: Robinson PJ, Guernsey LH, editors. Clinical transplantation in dental specialties. St Louis: Mosby; 1980. p. 107–45. 12. Schneider D, Grunder U, Ender A, Hammerle CH, Jung RE. Volume gain and stability of peri-implant tissue following bone and soft tissue augmentation: 1-year results from a prospective cohort study. Clin Oral Implants 2011;22:28–37. http://dx.doi.org/ Res 10.1111/j.1600-0501.2010.01987.x. 13. Man Y, Wang Y, Qu Y, Wang P, Gong P. A palatal roll envelope technique for peri-implant mucosa reconstruction: a prospective case series study. Int J Oral Maxillofac Surg 2013;42:660–5. http://dx.doi.org/10.1016/ j.ijom.2013.01.008. 14. Belser UC, Grutter L, Vailati F, Bornstein MM, Weber HP, Buser D. Outcome evaluation of early placed maxillary anterior single-tooth implants using objective esthetic criteria: a cross-sectional, retrospective study in 45 patients with a 2- to 4-year follow-up using pink and white esthetic scores. J Periodontol 2009;80:140–51. http://dx.doi.org/10.1902/jop.2009.080435. 15. Jemt T. Regeneration of gingival papillae after single-implant treatment. Int J Periodontics Restorative Dent 1997;17:326–33. 16. Shahidi P, Jacobson Z, Dibart S, Pourati J, Nunn ME, Barouch K, et al. Efficacy of a new papilla generation technique in implant dentistry: a preliminary study. Int J Oral Maxillofac Implants 2008;23:926–34. 17. Ribeiro FS, Zandim DL, Pontes AE, Mantovani RV, Sampaio JE, Marcantonio E. Tunnel technique with a surgical maneuver to increase the graft extension: case report with a 3-year follow-up. J Periodontol 2008;79:753–8. http://dx.doi.org/10.1902/ jop.2008.070274. 18. Raetzke PB. Covering localized areas of root exposure employing the ‘envelope’ technique. J Periodontol 1985;56:397– 402. http://dx.doi.org/10.1902/jop.1985. 56.7.397.
7
19. Batista Jr EL, Batista FC, Novaes Jr AB. Management of soft tissue ridge deformities with acellular dermal matrix. Clinical approach and outcome after 6 months of treatment. J Periodontol 2001;72:265–73. http:// dx.doi.org/10.1902/jop.2001.72.2.265. 20. Cardaropoli G, Lekholm U, Wennstrom JL. Tissue alterations at implant-supported single-tooth replacements: a 1-year prospective clinical study. Clin Oral Implants Res 2006;17:165–71. http://dx.doi.org/10.1111/ j.1600-0501.2005.01210.x. 21. Boven GC, Meijer HJ, Vissink A, Raghoebar GM. Reconstruction of the extremely atrophied mandible with iliac crest onlay grafts followed by two endosteal implants: a retrospective study with long-term follow-up. Int J Oral Maxillofac Surg 2014;43:626–32. http://dx.doi.org/10.1016/j.ijom.2013.11. 003. 22. Nikzad S, Azari A. Custom-made radiographic template, computed tomography, and computer-assisted flapless surgery for treatment planning in partial edentulous patients: a prospective 12-month study. J Oral Maxillofac Surg 2010;68:1353–9. http://dx.doi.org/10.1016/j.joms.2009.04. 108. 23. Clementini M, Rossetti PH, Penarrocha D, Micarelli C, Bonachela WC, Canullo L. Systemic risk factors for peri-implant bone loss: a systematic review and meta-analysis. Int J Oral Maxillofac Surg 2014;43:323–34. http://dx.doi.org/10.1016/j.ijom.2013.11. 012. 24. Stegaroiu R, Sato T, Kusakari H, Miyakawa O. Influence of restoration type on stress distribution in bone around implants: a three-dimensional finite element analysis. Int J Oral Maxillofac Implants 1998;13:82–90. 25. Hashemi HM, Parhiz A, Ghafari S. Vestibuloplasty: allograft versus mucosal graft. Int J Oral Maxillofac Surg 2012;41:527–30. http:// dx.doi.org/10.1016/j.ijom.2011.09.014.
Address: Yili Qu State Key Laboratory of Oral Diseases West China Hospital of Stomatology Sichuan University No. 14 3rd Section Renmin Nan Road Chengdu Sichuan 610041 China. Fax: +86 28 85483678 E-mail: [email protected]
Please cite this article in press as: Man Y, et al. Split pedicle roll envelope technique around implants and pontics: a prospective case series study, Int J Oral Maxillofac Surg (2015), http://dx.doi.org/10.1016/j.ijom.2015.04.012