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Comparison of non-invasive radiographic measurements of soft tissue in the interdental space: a cadaver study
YBJOM-5111; No. of Pages 6
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ScienceDirect British Journal of Oral and Maxillofacial Surgery xxx (2017) xxx–xxx
Comparison of non-invasive radiographic measurements of soft tissue in the interdental space: a cadaver study Kristian Kniha a , Stephan Christian Möhlhenrich b , Florian Peters a , Tsanko Yovev a , Manuel Räsch a , Andreas Prescher c , Frank Hölzle a , Ali Modabber a,∗ a b c
Department of Oral and Cranio-Maxillofacial Surgery, University Hospital Aachen, Germany Department of Orthodontics, University Hospital Aachen, Germany Institutes of Molecular and Cellular Anatomy, University Hospital Aachen, Germany
Received 21 November 2016; accepted 25 January 2017
Abstract When we use implants the aesthetic appearance of the patient is dependent to a large extent on identification of factors that influence the presence of interdental papillae. The aim of this study was to compare the accuracy of different non-invasive measurements to indicate the top of the interdental papilla on dental radiographs. The sample comprised six fresh, partly edentulous cadavers. The distance from the level of the interproximal bone next to the tip of the papilla was measured (n = 330) on standard radiographic images. Five different mixtures of radiopaque markers that had been used to highlight the top of the papilla in recently published studies were analysed. All measurements were compared with the bone probing length, which was evaluated clinically. The mixture of zinc oxide, eugenol cement, and tungsten powder (mean (SD) 0.14 (0.17) mm) deviated least from the control value. The deviation was significant (p < 0.01) between the zinc oxide, eugenol cement, and tungsten powder mixture and each of the other individual combinations. The most accurate non-invasive radiographic method of measuring the interproximal length of the papilla relative to the alveolar bone crest was therefore the mixture of zinc oxide, eugenol cement, and tungsten powder. © 2017 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
Keywords: Soft tissue; Noninvasive measurement; Interproximal papilla; Radiography
Introduction For a long time it has been commonplace when teeth have been lost to treat both functional and aesthetic aspects with dental implants and it has been professionally challenging, particular at the front. The position of each individual implant in the jaw has an effect on the peri-implant bone crest and margin of soft tissue. Several authors have evaluated important
∗ Corresponding author at: Department of Oral and Cranio-Maxillofacial Surgery, University Aachen, Pauwelsstraße 30, 52074 Aachen, Germany. Tel.: +49 2418088231. E-mail address: [email protected] (A. Modabber).
soft and hard tissue landmarks around the teeth and implants for the development of the papilla and the amount of alveolar bone.1–3 These landmarks include the first contact of crestal bone with the implant, the level of bone at the neighbouring tooth, the bone crest, and the top of the interdental papilla.3,4 The most important landmark, the top of the tip of the papilla in the interdental space, has been investigated by several workers.2,3,5–12 Kan and Kwon6,7 described the relation between the height of the papilla and the interproximal bone next to the adjacent teeth. If the papilla is non-existent, and the gingiva has recessed because the implant is in a unsatisfactory position, results are poor and include longer crowns, or the appearance of the root
http://dx.doi.org/10.1016/j.bjoms.2017.01.015 0266-4356/© 2017 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
Please cite this article in press as: Kniha K, et al. Comparison of non-invasive radiographic measurements of soft tissue in the interdental space: a cadaver study. Br J Oral Maxillofac Surg (2017), http://dx.doi.org/10.1016/j.bjoms.2017.01.015
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of a tooth or the dark grey titanium shoulder of the body of an implant.3,13 At its worst the lack of formation of a papilla may lead to a so-called “black triangle” in the interdental space, which is unpleasant for patients,who develop visible soft tissue linings or even “gummy” smiles.14 Currently there are several invasive and non-invasive techniques that permit the measuring of the distances between these landmarks to describe the individual patient’s soft and hard tissue topography. A recent multicentre study emphasised that there was a need for a technique to permit the unbiased and metric assessment of implant-related dimensions of soft and hard tissues.15 Some of these landmarks can be evaluated only with the aid of radiographs, but others can be measured directly. We made invasive measurements in a clinical investigation in which a “sounding” (a forced probing measurement of the depth of the bone crest or an operative re-entry using a mucoperiostal flap) are exact metric measurements of the height of the papilla.16 Disadvantages of taking a sounding are the need for anaesthesia and traumatic access through the peri-implant gingival, which risks recession of soft tissue at the gingival margin. All non-invasive methods use radiodense markers that show the top of the interdental papilla in the right-angle of the standard radiographic image. Several authors have described four different radiodense mixtures: zinc phosphate cement and barium sulphate; calcium hydroxide polymeric sealant; zinc oxide, eugenol cement, and barium sulphate; and zinc oxide, eugenol cement, and tungsten powder.1,4,10,12 One non-invasive method visualised the top of the papilla radiograpically by pointing a wire at its tip.2 However, we know of no papers that have described which of the different techniques is the most precise and userfriendly for marking the top of the papilla. The aim of this study, therefore, was to compare the accuracy of the four different non-invasive measurements of the top of the papilla in the interdental space.
Material and Methods All cadavers used in this investigation were obtained from the Department of Anatomy of the University Hospital. Cadavers with normal teeth, dental fillings, and crowns were included. The guidelines of the Declaration of Helsinki were followed throughout the investigation. The measurements made radiographically included the length of the papilla and the bone probing length for each interproximal site. The length of the papilla was measured from the point of contact with the bone at the tooth to the tip of the papilla. To analyse this we used four different radiodense mixtures to mark the top of the papilla, and a ligature wire pointed at the top of the papilla (Table 1). The radio-opaque material was put in place with no pressure on the soft tissue (Fig. 1). Using this radiodense marker, a right-angled standard radiograph showed a clear, sharp delin-
Fig. 1. Marking the tip of the papilla with the radiodense mixtures.
eated negative image of the top of the interdental papilla, or (in case of the ligature wire) pointing exactly at the top of the papilla. While the radiograph was being taken, a standard radio® graphic grid (Rinn XCP , Dentsply Corporate, USA), at a defined distance from the objective, combined with an occlusal silicone bite block (Silaplast Futur, Detax GmbH & Co. KG, Germany) was applied to the sensor. The standard radiograph was obtained at a 90◦ angle to the axis of the papilla on a computer screen. The identification of the tip of the papilla allowed measurement of the length of the papilla on standard dental radiographs. The length of the papilla was measured on the radiograph as the distance between the interproximal bone at the teeth to the base of the radio-opaque material using a computer-aided software device. To calibrate the radiographic images, we used a gutta-percha point (ISO 40, Coltene GmbH, Germany) with a defined length of 5 mm. For digital measurements on the images, we used the software MB-Ruler (EOSMetrology, Heidenheim, Germany). This software allowed us to place the endpoints of the measurements of distance in enlarged pictures with the aid of a loupe function that has a magnification x 2–16 (Fig. 2). The clinical bone probing length was used as a control value of the distance from the crest of the bone to the tip of the papilla. A Williams graduated periodontal probe was inserted from the tip of the papilla until the examiner felt strong resistance (Fig. 3). The same examiner made all the measurements, and each one was made three times and the mean value taken. All distance values were rounded off to the nearest 0.5 mm. Statistical analysis Statistical analyses were made with the aid of the software IBM SPSS Statistics for Windows (version 22, IBM Corp, Armonk, USA) and we used the paired Student’s t test. Probabilities of ≤0.05 were accepted as significant. All mea-
Please cite this article in press as: Kniha K, et al. Comparison of non-invasive radiographic measurements of soft tissue in the interdental space: a cadaver study. Br J Oral Maxillofac Surg (2017), http://dx.doi.org/10.1016/j.bjoms.2017.01.015
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Table 1 Composition, atomic number, and density of the different radiographic mixtures. Method
Manufacturer
Atomic number
Density (g/cm3 )
First author
-Temp Bond, Kerr GmbH, Germany
56 (Barium)
3.62
Chen10
1
Mixture of zinc oxide, eugenol cement, and barium sulphate
2
Mixture of zinc phosphate cement and barium sulphate
-Harvard cement, Harvard Dental International GmbH, Germany -Metallpulver24, Sankt Augustin, Germany
56 (Barium)
3.62
Lee12,17
3
Calcium hydroxide polymeric sealant
Sealapex, Kerr GmbH, Germany
83 (Bismuth oxide)
8.93
Kim1
4
Ligature wire (0.5 mm)
Interdent, USA
28 (Nickel)
7.90
Martegani2
5
Mixture of zinc oxide, eugenol cement, and tungsten powder
-Temp Bond, Kerr GmbH, Germany
74 (Tungsten powder)
19.3
Kniha4
-Metallpulver24, Sankt Augustin, Germany
-Metallpulver24, Sankt Augustin, Germany
Fig. 2. Measurements of the length of the papilla from the bone crest to the tip on the dental radiograph.
Please cite this article in press as: Kniha K, et al. Comparison of non-invasive radiographic measurements of soft tissue in the interdental space: a cadaver study. Br J Oral Maxillofac Surg (2017), http://dx.doi.org/10.1016/j.bjoms.2017.01.015
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Table 2 Statistical analysis of the deviation of the radiographic bone probing length from the control length of the papilla for each combination (n = 275). Summary of measurements (mm) and results of t tests
1 = Mixture of zinc oxide, eugenol cement, and barium sulphate
2 = Mixture of zinc phosphate cement and barium sulphate
3 = Calcium hydroxide polymeric sealant
4 = Ligature wire
5 = Mixture of zinc oxide, eugenol cement, and tungsten powder
Mean (SD) Range
0.52 (0.4) 0–1.3
0.67 (0.38) 0–1.2
0.5 (0.38) 0–1.5
0.71 (0.49) 0–1.7
0.14 (0.17) 0–0.7
Results of t tests: 1 compared with 2 1 compared with 3 1 compared with 4 1 compared with 5 2 compared with 3 2 compared with 4 2 compared with 5 3 compared with 4 3 compared with 5 4 compared with 5
<0.01 0.60 <0.01 <0.01 <0.01 <0.01 0.40 <0.01 <0.01 <0.01
between mixture 5 and each individual combination. With respect to SD, mixtures 1 and 3 and mixtures 2 to 4 did not differ significantly from each other. However, mixtures 2 and 4 scored significantly worse than mixtures 1 and 3.
Discussion
Fig. 3. Clinical measurements of the length of the papilla (sounding) from the bone crest to the tip.
surements were made in the frontal region (15 to 25 in the upper jaw and 35 to 45 in the lower jaw).
Results The study included six fresh, partially-toothed cadavers (two male and four female, age range 72–85 years), and a total of 330 measurements were studied. Table 2 shows the deviation of the radiographic bone probing length for each combination from the control length of the papilla. The combination of zinc oxide, eugenol cement, and tungsten powder (mixture 5) gave the lowest SD (0.17 mm) (Fig. 4). A significant difference (p < 0.01) was measured
Both clinicians and patients desire an aesthetic soft tissue margin around natural teeth and implant-supported crowns, and aesthetic evaluation after dental treatment is of value scientifically. Various methods have been described for evaluating the length from the alveolar crest to the tip of the interdental papilla. Although clinical bone probing was described as the most accurate way to measure the distance from the level of the bone to the tip of the papilla, it is invasive, and requires the patient’s cooperation because local anaesthesia is necessary before probing.16–18 Potential volumetric changes in the soft tissue after the local anaesthetic has been given may affect the measurement, and invasive methods may cause problems with soft tissue such as gingival recession. Non-invasive measurements of the soft tissue with a radiographic mixture are also accepted as an exact measuring method.12,19 Fourmousis et al. proposed the use of an underexposed radiograph to show soft tissue changes around dental implants. However, underexposed radiographs do not contain enough information for clinicians.20 Several authors have described non-invasive measurements using radiodense mixtures on the soft tissue.1,10,12 In the present study we assessed the length of the papilla using five different non-invasive radiodense mixtures, and compared their accuracy. The visualisation of the exact position of the tip of the papilla on a radiographic image with a radiographically dense substance is particularly important for accurate metric measurement. Overlapping crowns, dental fillings, and ceramic or metal crowns could be troublesome, as they may hide radiodense mixtures in the interdental
Please cite this article in press as: Kniha K, et al. Comparison of non-invasive radiographic measurements of soft tissue in the interdental space: a cadaver study. Br J Oral Maxillofac Surg (2017), http://dx.doi.org/10.1016/j.bjoms.2017.01.015
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Fig. 4. Box-plots of the different radiodense mixtures. The most accurate, non-invasive mixture for calculating the bone probing length radiographically was zinc oxide, eugenol cement, and tungsten (n = 275).
spaces. The two decisive factors that indicate the radiographic denseness of the combinations were the atomic number and the density of the material. The density was apparent from the masses of the atoms that made up the material, and from the spacing between those atoms. A dental radiograph indicated the contrast from the difference in the absorption of the radiation in different types of tissue. Because it has an atomic number of 74 and a density of 19.3 g/cm3 , tungsten powder showed ideal radio-opacity. The degree of radioopacity, the atomic number, and the density values of the remaining mixtures were lower. We found that the combination of zinc oxide, eugenol cement, and tungsten powder was significantly more accurate than the remaining mixtures. Additionally, standardisation of radiographs using Rinn ® XCP radiographic grids led to a greater degree of accuracy.17 ® The Rinn XCP was therefore used to standardise the radiographs and simplify the positioning of the film in the patient’s mouth. To avoid elongation or shortening of the radiograph, a grid was placed in front of the radiographic film, and measurements were made with computer-aided software to minimise human error.21 It has been commonly assumed that realistic measurements to a length of roughly 0.2 mm were possible using a dental film.16 Zinc oxide and eugenol cement mixtures proved to be advantageous in terms of setting time and removability. The
calcium hydroxide polymeric sealant and mixture of zinc phosphate cement and barium sulphate remained fluid for a long time, in which case they were difficult to remove. Pointing to the papilla tip with a ligature wire was not practical because it was challenging to fix, particularly in the molar region, and most of the wires were displaced in the radiograph. However, this study was conducted in cadavers, and patients’ muscular movements may complicate the final measurements with ligature wires. Considering the accuracy of the measurements and handling characteristics of all five combinations, we suggest the use of the mixture of zinc oxide, eugenol cement, and tungsten powder for further non-invasive assessments of soft tissue. We conclude that the most reliable non-invasive radiographic method of assessing the interproximal length of the papilla relative to the alveolar bone crest was to mark the papilla tip with a mixture of zinc oxide, eugenol cement, and tungsten powder.
Conflict of interest We have no conflict of interest.
Please cite this article in press as: Kniha K, et al. Comparison of non-invasive radiographic measurements of soft tissue in the interdental space: a cadaver study. Br J Oral Maxillofac Surg (2017), http://dx.doi.org/10.1016/j.bjoms.2017.01.015
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Ethics statement/confirmation of patients’ permission Not required.
References 1. Kim SA, Choi SS, Byun SJ, Chang M. Analysis of the embrasure dimensions between maxillary central incisors in relation to the topography of the interdental papilla. J Periodontal Implant Sci 2011;41:273–8. 2. Martegani P, Silvestri M, Mascarello F, et al. Morphometric study of the interproximal unit in the esthetic region to correlate anatomic variables affecting the aspect of soft tissue embrasure space. J Periodontol 2007;78:2260–5. 3. Tarnow D, Magner A, Fletcher P. The effect of the distance from the contact point to the crest of bone on the presence or absence of the interproximal dental papilla. J Periodontol 1992;63:995–6. 4. Kniha K, Gahlert M, Hicklin S, Bragger U, Kniha H, Milz S. Evaluation of hard and soft tissue dimensions around zirconium oxide implant supported crowns: a one-year retrospective study. J Periodontol 2016;87:511–8. 5. Choquet V, Hermans M, Adriaenssens P, Daelmans P, Tarnow DP, Malevez C. Clinical and radiographic evaluation of the papilla level adjacent to single-tooth dental implants. A retrospective study in the maxillary anterior region. J Periodontol 2001;72:1364–71. 6. Kan JY, Rungcharassaeng K, Umezu K, Kois JC. Dimensions of periimplant mucosa: an evaluation of maxillary anterior single implants in humans. J Periodontol 2003;74:557–62. 7. Kwon HJ, Lee DW, Park KH, Kim CK, Moon IS. Influence of the tooth- and implant-side marginal bone level on the interproximal papilla dimension in a single implant with a microthread, conical seal, and platform-switched design. J Periodontol 2009;80:1541–7. 8. Palmer RM, Farkondeh N, Palmer PJ, Wilson RF. Astra Tech singletooth implants: an audit of patient satisfaction and soft tissue form. J Clin Periodontol 2007;34:633–8. 9. Ryser MR, Block MS, Mercante DE. Correlation of papilla to crestal bone levels around single tooth implants in immediate or delayed crown protocols. J Oral Maxillofac Surg 2005;63:1184–95.
10. Chen MC, Liao YF, Chan CP, Ku YC, Pan WL, Tu YK. Factors influencing the presence of interproximal dental papillae between maxillary anterior teeth. J Periodontol 2010;81:318–24. 11. Sun SP, Moon IS, Park KH, Lee DW. Effect of crown to implant ratio and anatomical crown length on clinical conditions in a single implant: A retrospective cohort study. Clin Implant Dent Relat Res 2015;17:724–31. 12. Lee DW, Kim CK, Park KH, Cho KS, Moon IS. Non-invasive method to measure the length of soft tissue from the top of the papilla to the crestal bone. J Periodontol 2005;76:1311–4. 13. Small PN, Tarnow DP. Gingival recession around implants: a 1year longitudinal prospective study. Int J Oral Maxillofac Implants 2000;15:527–32. 14. Singh VP, Uppoor AS, Nayak DG, Shah D. Black triangle dilemma and its management in esthetic dentistry. Dent Res J (Isfahan) 2013;10:296–301. 15. Gahlert M, Kniha H, Weingart D, Schild S, Gellrich NC, Bormann KH. A prospective clinical study to evaluate the performance of zirconium dioxide dental implants in single-tooth gaps. Clin Oral implants Res 2016;27:e176–84. 16. Kolte RA, Kolte AP, Ghodpage PS. Non invasive and surgical measurement of length of soft tissue from the tip of interdental papilla to the alveolar crest. Saudi Dental J 2013;25:153–7. 17. Wahi S, Chhina K, Chhabra V, Bhatnagar R. Invasive versus non-invasive method of assessment of distance between the tip of papilla to the crest of interdental bone. European Journal of General Dentistry (serial online) 2013;2:37–41. 18. Attaelmanan A, Borg E, Grondahl HG. Digitisation and display of intraoral films. Dentomaxillofac Radiol 2000;29:97–102. 19. Zybutz M, Rapoport D, Laurell L, Persson GR. Comparisons of clinical and radiographic measurements of inter-proximal vertical defects before and 1 year after surgical treatments. J Clin Periodontol 2000;27:179–86. 20. Fourmousis I, Bragger U, Burgin W, Tonetti M, Lang NP. Digital image processing. II. In vitro quantitative evaluation of soft and hard periimplant tissue changes. Clin Oral Implants Res 1994;5:105–14. 21. Rosling B, Hollender L, Nyman S, Olsson G. A radiographic method for assessing changes in alveolar bone height following periodontal therapy. J Clin Periodontol 1975;2:211–7.
Please cite this article in press as: Kniha K, et al. Comparison of non-invasive radiographic measurements of soft tissue in the interdental space: a cadaver study. Br J Oral Maxillofac Surg (2017), http://dx.doi.org/10.1016/j.bjoms.2017.01.015
ARTICLE IN PRESS Available online at www.sciencedirect.com
ScienceDirect British Journal of Oral and Maxillofacial Surgery xxx (2017) xxx–xxx
Comparison of non-invasive radiographic measurements of soft tissue in the interdental space: a cadaver study Kristian Kniha a , Stephan Christian Möhlhenrich b , Florian Peters a , Tsanko Yovev a , Manuel Räsch a , Andreas Prescher c , Frank Hölzle a , Ali Modabber a,∗ a b c
Department of Oral and Cranio-Maxillofacial Surgery, University Hospital Aachen, Germany Department of Orthodontics, University Hospital Aachen, Germany Institutes of Molecular and Cellular Anatomy, University Hospital Aachen, Germany
Received 21 November 2016; accepted 25 January 2017
Abstract When we use implants the aesthetic appearance of the patient is dependent to a large extent on identification of factors that influence the presence of interdental papillae. The aim of this study was to compare the accuracy of different non-invasive measurements to indicate the top of the interdental papilla on dental radiographs. The sample comprised six fresh, partly edentulous cadavers. The distance from the level of the interproximal bone next to the tip of the papilla was measured (n = 330) on standard radiographic images. Five different mixtures of radiopaque markers that had been used to highlight the top of the papilla in recently published studies were analysed. All measurements were compared with the bone probing length, which was evaluated clinically. The mixture of zinc oxide, eugenol cement, and tungsten powder (mean (SD) 0.14 (0.17) mm) deviated least from the control value. The deviation was significant (p < 0.01) between the zinc oxide, eugenol cement, and tungsten powder mixture and each of the other individual combinations. The most accurate non-invasive radiographic method of measuring the interproximal length of the papilla relative to the alveolar bone crest was therefore the mixture of zinc oxide, eugenol cement, and tungsten powder. © 2017 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
Keywords: Soft tissue; Noninvasive measurement; Interproximal papilla; Radiography
Introduction For a long time it has been commonplace when teeth have been lost to treat both functional and aesthetic aspects with dental implants and it has been professionally challenging, particular at the front. The position of each individual implant in the jaw has an effect on the peri-implant bone crest and margin of soft tissue. Several authors have evaluated important
∗ Corresponding author at: Department of Oral and Cranio-Maxillofacial Surgery, University Aachen, Pauwelsstraße 30, 52074 Aachen, Germany. Tel.: +49 2418088231. E-mail address: [email protected] (A. Modabber).
soft and hard tissue landmarks around the teeth and implants for the development of the papilla and the amount of alveolar bone.1–3 These landmarks include the first contact of crestal bone with the implant, the level of bone at the neighbouring tooth, the bone crest, and the top of the interdental papilla.3,4 The most important landmark, the top of the tip of the papilla in the interdental space, has been investigated by several workers.2,3,5–12 Kan and Kwon6,7 described the relation between the height of the papilla and the interproximal bone next to the adjacent teeth. If the papilla is non-existent, and the gingiva has recessed because the implant is in a unsatisfactory position, results are poor and include longer crowns, or the appearance of the root
http://dx.doi.org/10.1016/j.bjoms.2017.01.015 0266-4356/© 2017 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
Please cite this article in press as: Kniha K, et al. Comparison of non-invasive radiographic measurements of soft tissue in the interdental space: a cadaver study. Br J Oral Maxillofac Surg (2017), http://dx.doi.org/10.1016/j.bjoms.2017.01.015
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of a tooth or the dark grey titanium shoulder of the body of an implant.3,13 At its worst the lack of formation of a papilla may lead to a so-called “black triangle” in the interdental space, which is unpleasant for patients,who develop visible soft tissue linings or even “gummy” smiles.14 Currently there are several invasive and non-invasive techniques that permit the measuring of the distances between these landmarks to describe the individual patient’s soft and hard tissue topography. A recent multicentre study emphasised that there was a need for a technique to permit the unbiased and metric assessment of implant-related dimensions of soft and hard tissues.15 Some of these landmarks can be evaluated only with the aid of radiographs, but others can be measured directly. We made invasive measurements in a clinical investigation in which a “sounding” (a forced probing measurement of the depth of the bone crest or an operative re-entry using a mucoperiostal flap) are exact metric measurements of the height of the papilla.16 Disadvantages of taking a sounding are the need for anaesthesia and traumatic access through the peri-implant gingival, which risks recession of soft tissue at the gingival margin. All non-invasive methods use radiodense markers that show the top of the interdental papilla in the right-angle of the standard radiographic image. Several authors have described four different radiodense mixtures: zinc phosphate cement and barium sulphate; calcium hydroxide polymeric sealant; zinc oxide, eugenol cement, and barium sulphate; and zinc oxide, eugenol cement, and tungsten powder.1,4,10,12 One non-invasive method visualised the top of the papilla radiograpically by pointing a wire at its tip.2 However, we know of no papers that have described which of the different techniques is the most precise and userfriendly for marking the top of the papilla. The aim of this study, therefore, was to compare the accuracy of the four different non-invasive measurements of the top of the papilla in the interdental space.
Material and Methods All cadavers used in this investigation were obtained from the Department of Anatomy of the University Hospital. Cadavers with normal teeth, dental fillings, and crowns were included. The guidelines of the Declaration of Helsinki were followed throughout the investigation. The measurements made radiographically included the length of the papilla and the bone probing length for each interproximal site. The length of the papilla was measured from the point of contact with the bone at the tooth to the tip of the papilla. To analyse this we used four different radiodense mixtures to mark the top of the papilla, and a ligature wire pointed at the top of the papilla (Table 1). The radio-opaque material was put in place with no pressure on the soft tissue (Fig. 1). Using this radiodense marker, a right-angled standard radiograph showed a clear, sharp delin-
Fig. 1. Marking the tip of the papilla with the radiodense mixtures.
eated negative image of the top of the interdental papilla, or (in case of the ligature wire) pointing exactly at the top of the papilla. While the radiograph was being taken, a standard radio® graphic grid (Rinn XCP , Dentsply Corporate, USA), at a defined distance from the objective, combined with an occlusal silicone bite block (Silaplast Futur, Detax GmbH & Co. KG, Germany) was applied to the sensor. The standard radiograph was obtained at a 90◦ angle to the axis of the papilla on a computer screen. The identification of the tip of the papilla allowed measurement of the length of the papilla on standard dental radiographs. The length of the papilla was measured on the radiograph as the distance between the interproximal bone at the teeth to the base of the radio-opaque material using a computer-aided software device. To calibrate the radiographic images, we used a gutta-percha point (ISO 40, Coltene GmbH, Germany) with a defined length of 5 mm. For digital measurements on the images, we used the software MB-Ruler (EOSMetrology, Heidenheim, Germany). This software allowed us to place the endpoints of the measurements of distance in enlarged pictures with the aid of a loupe function that has a magnification x 2–16 (Fig. 2). The clinical bone probing length was used as a control value of the distance from the crest of the bone to the tip of the papilla. A Williams graduated periodontal probe was inserted from the tip of the papilla until the examiner felt strong resistance (Fig. 3). The same examiner made all the measurements, and each one was made three times and the mean value taken. All distance values were rounded off to the nearest 0.5 mm. Statistical analysis Statistical analyses were made with the aid of the software IBM SPSS Statistics for Windows (version 22, IBM Corp, Armonk, USA) and we used the paired Student’s t test. Probabilities of ≤0.05 were accepted as significant. All mea-
Please cite this article in press as: Kniha K, et al. Comparison of non-invasive radiographic measurements of soft tissue in the interdental space: a cadaver study. Br J Oral Maxillofac Surg (2017), http://dx.doi.org/10.1016/j.bjoms.2017.01.015
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Table 1 Composition, atomic number, and density of the different radiographic mixtures. Method
Manufacturer
Atomic number
Density (g/cm3 )
First author
-Temp Bond, Kerr GmbH, Germany
56 (Barium)
3.62
Chen10
1
Mixture of zinc oxide, eugenol cement, and barium sulphate
2
Mixture of zinc phosphate cement and barium sulphate
-Harvard cement, Harvard Dental International GmbH, Germany -Metallpulver24, Sankt Augustin, Germany
56 (Barium)
3.62
Lee12,17
3
Calcium hydroxide polymeric sealant
Sealapex, Kerr GmbH, Germany
83 (Bismuth oxide)
8.93
Kim1
4
Ligature wire (0.5 mm)
Interdent, USA
28 (Nickel)
7.90
Martegani2
5
Mixture of zinc oxide, eugenol cement, and tungsten powder
-Temp Bond, Kerr GmbH, Germany
74 (Tungsten powder)
19.3
Kniha4
-Metallpulver24, Sankt Augustin, Germany
-Metallpulver24, Sankt Augustin, Germany
Fig. 2. Measurements of the length of the papilla from the bone crest to the tip on the dental radiograph.
Please cite this article in press as: Kniha K, et al. Comparison of non-invasive radiographic measurements of soft tissue in the interdental space: a cadaver study. Br J Oral Maxillofac Surg (2017), http://dx.doi.org/10.1016/j.bjoms.2017.01.015
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Table 2 Statistical analysis of the deviation of the radiographic bone probing length from the control length of the papilla for each combination (n = 275). Summary of measurements (mm) and results of t tests
1 = Mixture of zinc oxide, eugenol cement, and barium sulphate
2 = Mixture of zinc phosphate cement and barium sulphate
3 = Calcium hydroxide polymeric sealant
4 = Ligature wire
5 = Mixture of zinc oxide, eugenol cement, and tungsten powder
Mean (SD) Range
0.52 (0.4) 0–1.3
0.67 (0.38) 0–1.2
0.5 (0.38) 0–1.5
0.71 (0.49) 0–1.7
0.14 (0.17) 0–0.7
Results of t tests: 1 compared with 2 1 compared with 3 1 compared with 4 1 compared with 5 2 compared with 3 2 compared with 4 2 compared with 5 3 compared with 4 3 compared with 5 4 compared with 5
<0.01 0.60 <0.01 <0.01 <0.01 <0.01 0.40 <0.01 <0.01 <0.01
between mixture 5 and each individual combination. With respect to SD, mixtures 1 and 3 and mixtures 2 to 4 did not differ significantly from each other. However, mixtures 2 and 4 scored significantly worse than mixtures 1 and 3.
Discussion
Fig. 3. Clinical measurements of the length of the papilla (sounding) from the bone crest to the tip.
surements were made in the frontal region (15 to 25 in the upper jaw and 35 to 45 in the lower jaw).
Results The study included six fresh, partially-toothed cadavers (two male and four female, age range 72–85 years), and a total of 330 measurements were studied. Table 2 shows the deviation of the radiographic bone probing length for each combination from the control length of the papilla. The combination of zinc oxide, eugenol cement, and tungsten powder (mixture 5) gave the lowest SD (0.17 mm) (Fig. 4). A significant difference (p < 0.01) was measured
Both clinicians and patients desire an aesthetic soft tissue margin around natural teeth and implant-supported crowns, and aesthetic evaluation after dental treatment is of value scientifically. Various methods have been described for evaluating the length from the alveolar crest to the tip of the interdental papilla. Although clinical bone probing was described as the most accurate way to measure the distance from the level of the bone to the tip of the papilla, it is invasive, and requires the patient’s cooperation because local anaesthesia is necessary before probing.16–18 Potential volumetric changes in the soft tissue after the local anaesthetic has been given may affect the measurement, and invasive methods may cause problems with soft tissue such as gingival recession. Non-invasive measurements of the soft tissue with a radiographic mixture are also accepted as an exact measuring method.12,19 Fourmousis et al. proposed the use of an underexposed radiograph to show soft tissue changes around dental implants. However, underexposed radiographs do not contain enough information for clinicians.20 Several authors have described non-invasive measurements using radiodense mixtures on the soft tissue.1,10,12 In the present study we assessed the length of the papilla using five different non-invasive radiodense mixtures, and compared their accuracy. The visualisation of the exact position of the tip of the papilla on a radiographic image with a radiographically dense substance is particularly important for accurate metric measurement. Overlapping crowns, dental fillings, and ceramic or metal crowns could be troublesome, as they may hide radiodense mixtures in the interdental
Please cite this article in press as: Kniha K, et al. Comparison of non-invasive radiographic measurements of soft tissue in the interdental space: a cadaver study. Br J Oral Maxillofac Surg (2017), http://dx.doi.org/10.1016/j.bjoms.2017.01.015
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Fig. 4. Box-plots of the different radiodense mixtures. The most accurate, non-invasive mixture for calculating the bone probing length radiographically was zinc oxide, eugenol cement, and tungsten (n = 275).
spaces. The two decisive factors that indicate the radiographic denseness of the combinations were the atomic number and the density of the material. The density was apparent from the masses of the atoms that made up the material, and from the spacing between those atoms. A dental radiograph indicated the contrast from the difference in the absorption of the radiation in different types of tissue. Because it has an atomic number of 74 and a density of 19.3 g/cm3 , tungsten powder showed ideal radio-opacity. The degree of radioopacity, the atomic number, and the density values of the remaining mixtures were lower. We found that the combination of zinc oxide, eugenol cement, and tungsten powder was significantly more accurate than the remaining mixtures. Additionally, standardisation of radiographs using Rinn ® XCP radiographic grids led to a greater degree of accuracy.17 ® The Rinn XCP was therefore used to standardise the radiographs and simplify the positioning of the film in the patient’s mouth. To avoid elongation or shortening of the radiograph, a grid was placed in front of the radiographic film, and measurements were made with computer-aided software to minimise human error.21 It has been commonly assumed that realistic measurements to a length of roughly 0.2 mm were possible using a dental film.16 Zinc oxide and eugenol cement mixtures proved to be advantageous in terms of setting time and removability. The
calcium hydroxide polymeric sealant and mixture of zinc phosphate cement and barium sulphate remained fluid for a long time, in which case they were difficult to remove. Pointing to the papilla tip with a ligature wire was not practical because it was challenging to fix, particularly in the molar region, and most of the wires were displaced in the radiograph. However, this study was conducted in cadavers, and patients’ muscular movements may complicate the final measurements with ligature wires. Considering the accuracy of the measurements and handling characteristics of all five combinations, we suggest the use of the mixture of zinc oxide, eugenol cement, and tungsten powder for further non-invasive assessments of soft tissue. We conclude that the most reliable non-invasive radiographic method of assessing the interproximal length of the papilla relative to the alveolar bone crest was to mark the papilla tip with a mixture of zinc oxide, eugenol cement, and tungsten powder.
Conflict of interest We have no conflict of interest.
Please cite this article in press as: Kniha K, et al. Comparison of non-invasive radiographic measurements of soft tissue in the interdental space: a cadaver study. Br J Oral Maxillofac Surg (2017), http://dx.doi.org/10.1016/j.bjoms.2017.01.015
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References 1. Kim SA, Choi SS, Byun SJ, Chang M. Analysis of the embrasure dimensions between maxillary central incisors in relation to the topography of the interdental papilla. J Periodontal Implant Sci 2011;41:273–8. 2. Martegani P, Silvestri M, Mascarello F, et al. Morphometric study of the interproximal unit in the esthetic region to correlate anatomic variables affecting the aspect of soft tissue embrasure space. J Periodontol 2007;78:2260–5. 3. Tarnow D, Magner A, Fletcher P. The effect of the distance from the contact point to the crest of bone on the presence or absence of the interproximal dental papilla. J Periodontol 1992;63:995–6. 4. Kniha K, Gahlert M, Hicklin S, Bragger U, Kniha H, Milz S. Evaluation of hard and soft tissue dimensions around zirconium oxide implant supported crowns: a one-year retrospective study. J Periodontol 2016;87:511–8. 5. Choquet V, Hermans M, Adriaenssens P, Daelmans P, Tarnow DP, Malevez C. Clinical and radiographic evaluation of the papilla level adjacent to single-tooth dental implants. A retrospective study in the maxillary anterior region. J Periodontol 2001;72:1364–71. 6. Kan JY, Rungcharassaeng K, Umezu K, Kois JC. Dimensions of periimplant mucosa: an evaluation of maxillary anterior single implants in humans. J Periodontol 2003;74:557–62. 7. Kwon HJ, Lee DW, Park KH, Kim CK, Moon IS. Influence of the tooth- and implant-side marginal bone level on the interproximal papilla dimension in a single implant with a microthread, conical seal, and platform-switched design. J Periodontol 2009;80:1541–7. 8. Palmer RM, Farkondeh N, Palmer PJ, Wilson RF. Astra Tech singletooth implants: an audit of patient satisfaction and soft tissue form. J Clin Periodontol 2007;34:633–8. 9. Ryser MR, Block MS, Mercante DE. Correlation of papilla to crestal bone levels around single tooth implants in immediate or delayed crown protocols. J Oral Maxillofac Surg 2005;63:1184–95.
10. Chen MC, Liao YF, Chan CP, Ku YC, Pan WL, Tu YK. Factors influencing the presence of interproximal dental papillae between maxillary anterior teeth. J Periodontol 2010;81:318–24. 11. Sun SP, Moon IS, Park KH, Lee DW. Effect of crown to implant ratio and anatomical crown length on clinical conditions in a single implant: A retrospective cohort study. Clin Implant Dent Relat Res 2015;17:724–31. 12. Lee DW, Kim CK, Park KH, Cho KS, Moon IS. Non-invasive method to measure the length of soft tissue from the top of the papilla to the crestal bone. J Periodontol 2005;76:1311–4. 13. Small PN, Tarnow DP. Gingival recession around implants: a 1year longitudinal prospective study. Int J Oral Maxillofac Implants 2000;15:527–32. 14. Singh VP, Uppoor AS, Nayak DG, Shah D. Black triangle dilemma and its management in esthetic dentistry. Dent Res J (Isfahan) 2013;10:296–301. 15. Gahlert M, Kniha H, Weingart D, Schild S, Gellrich NC, Bormann KH. A prospective clinical study to evaluate the performance of zirconium dioxide dental implants in single-tooth gaps. Clin Oral implants Res 2016;27:e176–84. 16. Kolte RA, Kolte AP, Ghodpage PS. Non invasive and surgical measurement of length of soft tissue from the tip of interdental papilla to the alveolar crest. Saudi Dental J 2013;25:153–7. 17. Wahi S, Chhina K, Chhabra V, Bhatnagar R. Invasive versus non-invasive method of assessment of distance between the tip of papilla to the crest of interdental bone. European Journal of General Dentistry (serial online) 2013;2:37–41. 18. Attaelmanan A, Borg E, Grondahl HG. Digitisation and display of intraoral films. Dentomaxillofac Radiol 2000;29:97–102. 19. Zybutz M, Rapoport D, Laurell L, Persson GR. Comparisons of clinical and radiographic measurements of inter-proximal vertical defects before and 1 year after surgical treatments. J Clin Periodontol 2000;27:179–86. 20. Fourmousis I, Bragger U, Burgin W, Tonetti M, Lang NP. Digital image processing. II. In vitro quantitative evaluation of soft and hard periimplant tissue changes. Clin Oral Implants Res 1994;5:105–14. 21. Rosling B, Hollender L, Nyman S, Olsson G. A radiographic method for assessing changes in alveolar bone height following periodontal therapy. J Clin Periodontol 1975;2:211–7.
Please cite this article in press as: Kniha K, et al. Comparison of non-invasive radiographic measurements of soft tissue in the interdental space: a cadaver study. Br J Oral Maxillofac Surg (2017), http://dx.doi.org/10.1016/j.bjoms.2017.01.015