Adhesive fixed partial dentures (bridges) as posttreatment retention in missing tooth cases

CASE REPORT

Adhesive fixed partial dehtures (bridges) as posttreatment retention in missing tooth cases Toshio

Deguchi,

Shiojiri,

Nagano,

D.D.S., D.D.Sc.,

M.S.D.,’

and Mitsuharu

Amari,

D.D.S., D.D.Sc.**

Japan

F

or clinical use in dentistry, adhesive fixed partial dentures (AFPDs) may be recommended for the replacement of missing teeth.? periodontal splinting,” and postorthodontic fixed retention.’ Recently, retentive mechanisms for enamel-to-resin bonding and resin-to-metal bonding’.“’ have been improved. An adhesive fixed partial denture may be considered as a medium- to long-term restoration, serving only until traditional fixed restorations may be placed. As Zachrisson” has pointed out, Class I space deficiency and Class II cases can or should be treated by orthodontic space closure. On the other hand, Class 1 and Class III cases with no space deficiency are more suitable for prosthetic replacement procedures. Generally, a Hawley-type retainer may be used to prevent a space from reopening after active treatment. However, it is frequently difficult to get good patient cooperation with the use of a removable retainer. Too often patients do not wear their removable retainers and partial relapse occurs, prejudicing the placement of permanent restoration at a later date. There are few case reports in orthodontic literature of young adult patients with missing teeth that have been replaced by AFPDs as a temporary fixed crownbridge and a fixed retainer following active orthodontic treatment. The purpose of this report is to present six cases with Class I malocclusions and two cases with Class III malocclusions showing no space inadequacy and demonstrating the use of adhesive fixed partial dentures as replacements for the missing teeth. CLINICAL PARTIAL

PROCEDURES DENTURES

FOR ADHESIVE

FIXED

The metals used in the adhesive fixed partial dentures described in the following cases are Degvdent-

*Professor and Chairman. Department of Orthodontics, Matsumoto Dental College: Board eligible to American Board cf Orthodontics. **Professor and Chairman. Second Department of Prosthndontics. Matsumoto Dental College.

(Sandblast

Rmsmg

Treatment

wtth

Alumma

Powder)

I I In Water

with

SupersonIc

4

Wave

4 Drymg

(I Placement

Fig.

1. Metal

of Prosthesis surface

treatment

)

1

(Restorative)

procedures.

Universal* as the precious metal and Shofu Uni Metalias the nonprecious metal. For bonding materials, PANAVIA EX$ composite resin and 4-META adhesive resins were used. Treatment of the metal to improve the resin-to-metal bond is described in Fig. 1. Bonding procedures for *Mitsubishi Metal Co.. Tokyo. Japan. +Shofu Inc.. Kyoto, Japan. *Kuraty Co.. LTD. Osaka. Japan. Nuper-Bond. Sun Medical Co.. LTD. Kyoto.

Japan

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Fig. 2. Case 1. A, Occlusion before orthodontic treatment. Upper central incisors were impacted and extracted prior to treatment. 6, Occlusion after orthodontic treatment. C, Occlusion after the AFPD was placed. D, Occlusal view of the AFPD.

enamel to resin are the same as for the bonding of orthodontic brackets. The general procedures for enamel preparation of the abutment teeth, the etched alloy surface, and the bonding placement of the bridge in the cases reported here are similar to those of the Maryland bridge, advanced by Simonsen, Thompson, and Barrack,” which is commonly used in the United States. The differences between the Maryland bridge and the adhesive fixed partial dentures used in the present cases are as follows: (1) 4-META adhesive resin, developed to increase the resin-to-metal bond, results in greater strength than that of the Maryland bridge type of bonding with a nonadhesive composite resin to metal; and (2) unlike the Maryland bridge, which is usually made of nonprecious metal, the etched alloy surface of precious metal needs electrodeposition treatment (Kura Ace$), as shown in Fig. 1. Disadvantages of the application of 4-META ad-

hesive resin are (1) difficulty in placing the bridge in the desired position during hardening of the resin, and (2) as Hamada, Shigeto, and Yanagihara5 have described, difficulty in removing the excess adhesive resin from the tooth surface. The AFPDs in the present study were constructed and bonded in combination with two different bonding agents and metals. Care must be taken to obtain an accurate impression for the bridge. When appliances are not being wow, 0.016 or 0.018-inch round wire (stainless steel) is bonded on the labial surface of the teeth as a fixed retainer, as shown in Figs. 6, B, and 8, D, until the preparation of the teeth and the bonding placement of the bridge are completed. On the other hand, when the patient is still wearing appliances, the wire is removed to take the impression. Before taking the impression, the whole undercut area should be blocked out.

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Fig. 3. Case 2. A, Occlusion before orthodontic treatment. B, Maxillary arch with second premolar missing. C, Mandibular arch with the right first and second premolars, and left second premolar missing. D, Occlusion after four sets of AFPDs were placed. E, Maxillary arch showing occlusal view of the AFPD. F, Mandibular arch showing occlusal view of the AFPD.

CASEREPORTS Case 1 The patient was a girl 12 years 1 month of age with a Class III malocclusion. skeletal Class III (ANB, - 2.5”), and small Frankfort mandibular angle (FMA). The right and left

upper central incisors were badly impacted. Both central incisors were extracted in treatment and an orthopedic chin retractor was used to achieve a downward and backward rotation of the mandible. The AFPD was placed in November 1983 (Fig. 2. A through D).

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Fig. 4. Case 3. A, Occlusion before orthodontic treatment. The upper lateral incisors, upper right premolars, and lower second premolar are missing. B, Occlusal view of the maxillary AFPD. C, Occlusion after the AFPD was placed. 0, Occlusal view of the mandibular AFPD.

Fig. 5. Case 4. A, Occlusion lower left lateral incisor was before orthodontic treatment. dibular AFPD.

before orthodontic extracted because C, Occlusion after

treatment. of severe the AFPD

Lower central incisors are missing. The periodontal damage. B, Mandibular arch was placed. D, Occlusal view of the man-

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Fig. 6. Case 5. A, Occlusion before orthodontic treatment. B, Occlusion after active orthodontic treatment, ready for the AFPD. C, Frontal view of the AFPD. D, Occlusal view.

Case 2 The patient was a girl 13 years 5 months of age with a skeletal Class I malocclusion (ANB. 5.0”). Five premolars had been lost. After active treatment, the sites of the missing teeth were restored with an AFPD for retention. The AFPD was placed in September 1984. An AFPD for two lost premolars in the lower right segment was refabricated in September 1985 because of loosening of the canine abutment (Fig. 3, A through F). Case 3 The patient was a girl 18 years of age with a skeletal Class I malocclusion (ANB, 1.5”) and small FMA. Two upper lateral teeth. two upper premolars, and two lower premolars had been lost, and the two upper central incisors showed a diastema. As postactive treatment, the AFPD was positioned to close the spaces between the missing teeth. All units of the AFPD were placed in April 1985 (Fig. 4. A through D). Case 4 The patient was a boy 15 years II months of age with a Class I dental malocclusion and skeletal Class I (ANB, I .5”). The upper and lower incisors were flared and spaced. The lower central incisors had been lost and a lower left lateral incisor showed severe periodontal damage. Prior to treatment. the lower left lateral incisor was extracted and the AFPD was

fixed in the extracted and missing spaces. The AFPD was placed in October 1985 (Fig. 5. A through D). Case 5 The patient was a girl 8 years 3 months of age with a Class I dental malocclusion and skeletal Class I (ANB, 3.5”). The upper right central incisor was missing and a mesiodens was present. The me&dens was removed to regain space for the missing central incisor and to achieve an upper midline correction. The AFPD was then placed in December 1985 (Fig. 6, A through D). Case 6 The patient was a girl 8 years 6 months of age with a skeletal Class I malocclusion (ANB, I .5”). The upper and lower incisors were flared, the upper right central incisor was impacted, and the upper right lateral incisor had been lost. The impacted central incisor was orthodontically treated to regain space for the missing lateral incisor and the AFPD was placed in December 1985 (Fig. 7, A through D). Case 7 The patient was a boy 10 years of age with a Class III dental malocclusion and a functional and skeletal Class III (ANB, - 3.0” in centric relation). The upper canine teeth had been lost. A chin retracting extraoral appliance was used as

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Fig. 7. Case 6. A, Occlusion impacted left central incisor

Am. J. Orrhod.

before orthodontic treatment. A left central incisor is erupting. C, Frontal view of the AFPD. D, Occlusal

Fig. 8. Case 7. A, Occlusion before orthodontic treatment. B, Occlusal dontic appliances are removed. C, Occlusion after orthodontic treatment.

is impacted. view.

B, The

view immediately before orthoD, Occlusal view of the AFPD.

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Fig. 9. Case 8. A, Occlusion before orthodontic treatment. The lateral has been gained for the lateral incisors, correcting the diastema with view of the AFPD. D, Occlusal view of the completed restoration.

an orthopedic force to produce a downward and backward rotation of the mandible because of the small FMA. As a secondtreatment phase, edgewise applianceswere combined with Class III elastics and the chin retractor for the sagittal correction. The bilateral AFPDs were placed in May 1986 (Fig. 8, A through D). Case

8

This adult female patient was 25 years 8 months of age. initially exhibiting a Class I dental malocclusion and skeletal Class I relatjonship. The upper lateral incisorshad been lost and a diastema was apparent. For treatment. a lingual appliance and prosthetic procedureswere used to create spacefor the missing lateral incisors, followed by placement of the AFPD in April 1986 (Fig. 9. A through D). DISCUSSION

Various reports on adhesive fixed partial dentures have been published since 1973.’ In orthodontic literature, Reinhardt, Denehy, and Ghan’ have reported a method using acid-etched, bonded castings as a fixed retainer in postactive orthodontic treatment. However, metal-resin interface failure has been noted as one of the major drawbacks of acid-etched metal retainers. To solve that problem, Masaharu” and Yamashita’4.‘c recently developed 4-META adhesive

incisors are missing. a lingual appliance.

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6, Space C, Frontal

resin (Super-Bond) that adheres to both metal and the teeth. Hamada, Shigeto, and Yanagihara’ have reported 57 clinical cases of adhesive fixed partial dentures that used this method and suggested that long-range studies and scientific improvements may be needed to make the placement of resin-bonded metal prostheses more stable than the standard techniques in fixed prosthodontics. The authors have often had difficulty after active treatment in retaining the spaces for missing teeth until a traditional crown-bridge could be inserted to replace the Hawley-type retainer. For young adult cases, we generally use a temporary adhesive fixed partial denture and fixed retainer. Because the AFPD requires less sacrifice of enamel, it is particularly suited for young adult patients who have a large pulp chamber vulnerable to the preparation of abutment teeth. In addition, orthodontically treated patients have more occlusal clearance than nontreated patients and thus abutment preparation can be done to sacrifice the minimum amount of enamel. Patients seem to prefer the AFPD because it is more attractive and comfortable than a removable retainer despite the inconvenience of occasional refabrication. As a pilot study, the authors started to apply four

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cases of AFPD, including Class II malocclusion cases, in 1983. Many successful case reports of AFPDs have been published in prosthodontic journals in the United States and Japan. Now most prosthodontists concur that the AFPD or the Maryland bridge may be used as a temporary fixed bridge for several years. After the pilot study, we came to the conclusion that the AFPD may be useful as semipermanent restoration for approximately 5 years if grooves are made in the abutment teeth and there is more coverage of the metal framework on the enamel. Yamashita” has presented many such cases in his text. At present, careful instructions for the AFPD are given to the patient and prosthodontists and dental technicians have become accustomed to handling it. However, more experience with casesof AFPDs is necessary to discover which combination of resin and metal is most useful in practice. Credit for English language assistanceis given to Karen L. Kelsky and to the Editor.

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II. 12.

13. 14.

15. REFERENCES I. HoweDF. Denehy GE. Anteriorfixedpartialdenturesutilizing the acid-etch technique and a case metal framework. J Prosthet Dent 1977:37:28-31. 2. Livaditis GJ. Cast metal resin-bonded retainers for posterior teeth. J Am Dent Assoc 1980;101:926-9. 3. Barrack G. Recent advances in etched cast restorations. J Prosthet Dent 1984;52:619-25. 4. Eshleman JB. Moon PC, Barnes RF. Clinical evaluation of cast metal resin-bonded anterior fixed partial dentures. J Prosthet Dent 1984;51:761-4. 5. Hamada T, Shigeto N, Yanagihara T. A decade of progress for

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the adhesive fixed partial denture. J Prosthet Dent 1985;54: 25-9. Rochette A. Attachment of a splint to enamel of lower anterior teeth. J Prosthet Dent 1979;30:418-23. Reinhardt JW, Denehy GE, Chan KC. Acid-etch bonded cast orthodontic retainers. AM J ORTHOD 1979;75:138-42. Tanaka T, Atsuta M, Uchiyama Y, Kawashima I. Pitting corrosion for retaining acrylic resin facings. J Prosthet Dent 1979;42:282-91. Livaditis GJ, Thompson VP. Etched castings: an improved retentive mechanism for resin-bonded retainers. J Prosthet Dent 1982;47:52-8. Thompson JP, Castillo ED, Livaditis GJ. Resin-bonded retainers. Part 1. Resin bond to electrolytically etched nonprecious alloys. I Prosthet Dent 1983;50:771-9. Zachrisson BU. improving orthodontic results in cases with maxillary incisors missing. AM J OR~HOD 1978:73:274-89. Simonsen R, Thompson V, Barrack G. Etched cast restorations: clinical and laboratory techniques. Chicago: Quintessence Publishing Co., 1983. Masuhara E. New 4-META adhesive resin. Dent Outlook 1982;59:661-70. Yamashita A. The clinical application of new adhesive resin (MA-4-META TBB-0) to adhesion bridge (adhesion splint). Dent Outlook 1982;59:671-82. Yamashita A, Kondo Y, Fujita M. Adhesive strength of adhesive resin PANAVIA EX to dental alloys. Part II. Adhesive strength of precious alloys. J Jpn Prosthet 1984;28:43-53. Yamashita A. A dental adhesive and its clinical applications. 2nd vol. Tokyo: Quintessence Publishing Co., 1983.

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to:

Dr. Toshio Deguchi Department of Orthodontics Matsumoto Dental College 1780. Gohbara Hirooka Shiojiri. Nagano. 399-07 Japan