Shimizu et al.

Int Chin J Dent 2006; 6: 45-47.

Continuous posterior resin-bonded fixed partial denture
incorporated with existing adjacent resin-bonded fixed partial
denture: A clinical report
Hiroshi Shimizu, DDS, PhD, and Yutaka Takahashi, DDS, PhD
Division of Removable Prosthodontics, Department of Oral Rehabilitation, Fukuoka Dental College,Fukuoka, Japan
This clinical report describes the procedure to make a continuous anterior-posterior resin-bonded fixed partial
denture (RBFPD) incorporated with an existing adjacent posterior RBFPD. A new design was used to make aposterior three-unit silver-palladium-copper-gold alloy RBFPD for a 49-year-old man. Six years after theRBFPD was seated, the tooth next to the RBFPD was extracted. A second three-unit RBFPD made of the samealloy was incorporated with the existing adjacent RBFPD. Consequently, a continuous five-unit RBFPD wascreated and has been functioning without any problem for more than three years after the seating of the second
RBFPD. (Int Chin J Dent 2006; 6: 45-47.)
Key Words: adhesive, metal conditioner, resin-bonded fixed partial denture, silver-palladium-copper-gold alloy.

Introduction
When the tooth next to an existing fixed partial denture is lost, clinicians must remove the denture and thenfabricate a new larger denture. Although this conventional method is reliable, it requires a lot of appointments, along treatment period, a great amount of materials, and the cost is high. The retainers of resin-bonded fixed
partial dentures (RBFPDs) cover a narrower area of the abutment teeth compared to conventional full-coverage
restorations. In a new type of posterior RBFPDs, the retainers are designed to cover the distolinguobuccal areain the mesial abutment and the mesiolinguobuccal area in the distal abutment.1 Therefore, the application of thisnew RBFPD, in which the remaining enamel surface of the abutment tooth is not covered with the retainer, isrecommended to eliminate the above problems of the conventional treatment. This clinical report describes thefinal procedure to complete a continuous RBFPD incorporated with an existing adjacent RBFPD.

Clinical Report
Seating of the first RBFPD
A 49-year-old man was seen with the chief complaint of masticatory disturbance resulting from a missing left
mandibular first molar. An innovative RBFPD1 made of a silver-palladium-copper-gold alloy (Castwell M.C. 12,GC Corp., Tokyo, Japan) was seated using a thiouracil metal conditioner for noble metal alloys (Metaltite,Tokuyama Dental Corp., Tokyo, Japan)2 and an adhesive resin cement (Super-Bond C&B Ivory, Sun MedicalCo., Ltd., Moriyama, Japan).
Seating of the second RBFPD incorporated with the first RBFPD
Six years after seating, the patient complained of occlusal pain of the left mandibular first premolar. The firstpremolar had severe tooth mobility, and an X-ray photograph indicated that there was considerable loss of bone
support. Conservative treatment appeared to be impossible. Therefore, the tooth was extracted with his consent.
He did not want a single-tooth implant, which would involve surgical treatment along with a single-tooth
removable partial denture, and preferred the fixed prosthetic treatment. The left mandibular canine was intact
and the left mandibular second premolar was still vital with no caries, although the latter was one of theabutment teeth of the existing posterior RBFPD (Fig. 1). Therefore, the addition of a continuous RBFPD to the45

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Int Chin J Dent 2006; 6: 45-47.

existing RBFPD with minimal vital tooth reduction was proposed, and he chose this treatment option.

Fig. 1.

Fig. 2.

Fig. 3.

Fig. 4.

Fig. 1.
Fig. 2.
Fig. 3.
Fig. 4.
Fig. 5.
Fig. 5.

Missing left mandibular first premolar.
Master cast showing the preparations.
Intaglio of the second RBFPD.
Completed RBFPD incorporated with theexisting RBFPD blends well.
Whole continuous RBFPD has functionedfor more than three years.

The lingual and proximal surfaces of the canine were prepared with a horizontal cingulum groove and acombination of opposing vertical grooves3,4 placed at line angles for mechanical retention. A mesial occlusal
rest seat and two vertical grooves at each end of the lingual and buccal surfaces of the second premolar wereprepared to avoid reducing the retainer of the existing RBFPD, if possible; however, a small part of the end of
the lingual retainer was reduced. A master impression was made, and the master cast was formed using
high-strength stone (Fig. 2). The second RBFPD was conventionally fabricated using the same alloy as the firstand an indirect composite material (Solidex, Shofu Inc., Kyoto, Japan) (Fig. 3). The second RBFPD was seated(Fig. 4) with the same primer, luting agent, and technique as the existing RBFPD. After seating the RBFPD, thepatient followed a regular check-up program. The complete continuous RBFPD has been functioning without
any problem for more than three years since the second RBFPD was seated, although the surface of the castinghas discolored to some degree (Fig. 5).

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Int Chin J Dent 2006; 6: 45-47.

Discussion
The creation of a five-unit anterior-posterior continuous RBFPD by seating a second three-unit RBFPD next
to an existing adjacent RBFPD has been described. For cases in which the tooth adjacent to the existing fixed
partial dentures is expected to be extracted in the future, the new type of retainer design for posterior RBFPDs
should be applicable1 because the remaining enamel surface of the abutment tooth, which is not covered by theretainer of the existing RBFPD, can be utilized for the retainer of the second RBFPD.
The advantages of this technique are 1) relief of patient’s discomfort from dislodgement of the existingRBFPD, 2) fewer appointments, 3) time savings, 4) simplification of laboratory procedures, and 5) a reduction in
the amount of materials and costs required.

However, a disadvantage is its esthetics because themesiolinguobuccal area in the premolar is covered, although the retainer is hidden from view by the cheek. If thepatient’s consent regarding this esthetic problem is not obtained, the procedure should not be used.
Additional retentive preparation forms3-5 are particularly required when there are pathologically mobile teeth
in the abutments, since a long-term follow-up study indicated that mobility of the abutment teeth was one of thedecisive prognostic factors for successful resin-bonded prostheses.6 Finally, V-Primer (Sun Medical Co., Ltd.),7
one of the thione conditioners for noble metal alloys as well as Metaltite used in the present case, can be usedwith a silver-palladium-copper-gold alloy.
Acknowledgment
Editorial assistance by Mrs. Jeanne Santa Cruz is appreciated.

References
1. Shimizu H, Takahashi Y. Retainer design for posterior resin-bonded fixed partial dentures: A technical report. Quintessence
Int 2004; 35: 653-4.
2. Matsumura H, Kamada K, Tanoue N, Atsuta M. Effect of thione primers on bonding of noble metal alloys with an adhesive
resin. J Dent 2000; 28: 287-93.
3. El Salam Shakal MA, Pfeiffer P, Hilgers RD. Effect of tooth preparation design on bond strengths of resin-bonded prostheses:a pilot study. J Prosthet Dent 1997; 77: 243-9.
4. Saad AA, Claffey N, Byrne D, Hussey D. Effects of groove placement on retention/resistance of maxillary anterior
resin-bonded retainers. J Prosthet Dent 1995; 74: 133-9.
5. Shimizu H, Habu T, Yanagida H. Stabilization by splinting of an endodontically treated premolar and a minimally reduced vital
canine with a resin-bonded cast retainer: A clinical report. Int Chin J Dent 2002; 2: 121-5.
6. Probster B, Henrich GM. 11-year follow-up study of resin-bonded fixed partial dentures. Int J Prosthodont 1997; 10: 259-68.
7. Matsumura H, Taira Y, Atsuta M. Adhesive bonding of noble metal alloys with a triazine dithiol derivative primer and anadhesive resin. J Oral Rehabil 1999; 26: 877-82.

Correspondence to:Dr. Hiroshi Shimizu
Division of Removable Prosthodontics, Department of Oral Rehabilitation, Fukuoka Dental College
2-15-1, Tamura, Sawaraku, Fukuoka 814-0193, Japan
Fax: +81-92-801-0513 E-mail: simizuh1@college.fdcnet.ac.jp
Received January 24, 2006. Accepted February 26, 2006.
Copyright ©2006 by the International Chinese Journal of Dentistry.

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