Combination restoration in full mouth rehabilitation.

Successful restoration of the dentition requires plenty of contemporary and conventional treatment techniques and planning and attachment retained partial dentures are one such kind of treatment modality in prosthodontics. Satisfactory restoration in a patient with a partially edentulous situation can be challenging especially when unilateral or bilateral posterior segment of teeth is missing. One such treatment modality is attachment-retained cast partial dentures. The purpose of this article is to provide an overview of a case with maxillary complete denture and opposing cast partial denture with precision attachment.

Esthetically and functionally successful prosthetic rehabilitation requires careful attention and meticulous treatment planning. Rehabilitation of partially edentulous arch can be challenging when it is a distal extension situation classified under Kennedy's class I and class II situations.[1] In such a condition, a fixed partial denture cannot be fabricated because of missing distal abutment. Implant-supported prosthesis can be planned, but it is sometimes not feasible due to an insufficient amount of bone and economic reason. So, in such situation an acrylic partial denture or a cast partial denture is largely preferred. Cast partial dentures are made retentive by the use of retainers and precision attachment components.[2] Precision attachments could be extracoronal and intracoronal. Attachment-retained cast partial dentures facilitate both esthetic and functional replacement of missing teeth. Studies have shown a survival rate of 83.35% for 5 years, of 67.3% up to 15 years, and of 50% when extrapolated to 20 years.[34] This paper describes a case report of a patient with mandibular bilateral distal extension Kennedy's class I condition, which is prosthetically restored by a cast partial denture retained using a extracoronal precision attachment.

Case Report

A 49-year-old female reported with multiple missing maxillary and mandibular teeth bilaterally. She gave a history of unsatisfactory acrylic partial denture. Examination revealed that some of the teeth required periodontic and endodontic management. She was diagnosed for full-mouth rehabilitation. According to the Kennedy's classification system and Applegate's rules, the maxillary partially edentulous arch was classified as class II modification 4 and the mandibular arch as class I modification 1 [Figures 1 and 2].

Figure 1

Maxillary occlusal view

Figure 2

Mandibular occlusal view

After complete clinical and radiographic examination, a treatment plan was formulated. She was referred for a complete oral prophylaxis following, which she was advised an intentional root canal procedure for all the mandibular teeth. Her maxillary teeth revealed grade III mobility and was referred to the department of surgery for extraction of all the maxillary teeth. She was advised to report back to for full-mouth rehabilitation after complete healing of the extraction site.

Prosthetic phase

Primary impressions were made for the maxillary and mandibular arches

Special tray was fabricated for the maxilla following, which a secondary impression was made

Master casts were fabricated, and bite rims were made. Using the maxillary bite rims and camper's plane as guide an occlusal plane was established and bite was taken using the lower teeth

The bite was mounted on a three-point articulator and teeth setting were done

Following this wax up for the lower cast was done, and index was made for temporization

Tooth preparation was done for 33, 34, 35, 43, 44, 45 and temporization was done

Metal copings were fabricated with extracoronal precision attachment [Figure 3]

Figure 3

Metal try in with attachments

Waxing-up of abutments was performed, and milling of lingual area of the metal ceramic setup was done. Articulation spaces and bulkiness were evaluated in order to proceed with optimal positioning of attachments using proper parallelometer mandrel

Metal ceramic crowns waxed up with attachment structure were casted, and porcelain firing was done. Joint crowns were fabricated with the attachments in the laboratory, and the trial of the same was done to check the exact fit of the crowns

Cast partial denture with attachment was fabricated in the laboratory, and the metal framework trial was done in the patient's mouth for the accuracy of fit. Cast structure framework was checked up for stability and precision, and jaw relation was recorded

Waxing-up of teeth was performed and teeth setting trial was done [Figures 4–6]. The trial dentures were sent for acrylization

Figure 4

Maxillary wax trial

Figure 6

Wax trial in occlusion

Mandibular wax trial with anterior FPD

Trial seating of the finished prosthesis was performed, and cementation of crowns was done using glass ionomer cement. Attachments are protected with a thin layer of petroleum jelly (Vaseline), Uniliver, Mumbai, India in order to easily remove cast partial denture after joint porcelain fused to metal crowns with attachment have been seated. Complete seating of finished mandibular combined prosthesis with extracoronal castable distal extension precision attachment was evaluated clinically and maxillary complete denture was seated in the patient's mouth and the patient was recalled after 24 h for review [Figure 7].

Figure 7

Final finished prosthesis

Discussion

To meet the patient expectations of masticatory efficiency the procedure described in the rehabilitation of this patient is an innovative way of restoration of partially edentulous arches. In the conventional removable partial denture fabrication forces or loads will be destructive and directed toward the abutments to supportive bone and tissue. But in the current technique force management, maximal retention and stability for the removal prosthesis is achieved. The impact strength, compressive strength of the alloys stands superior in comparison with the denture base materials and mainly this will enable the patient to fulfill his needs. An extra coronal attachment requires only a routine full coverage abutment preparation and provides easy patient insertion and removal. The only servicing requirement is occasional, fast and easy female replacement.

Precision attachment is a connector consisting of two or more parts. One part is connected to a root, tooth, or implant and the other part to the prosthesis providing a mechanical connection between the two. These attachments allowed prosthesis to combine the advantage of fixed and removable restorations.[5] It was Dr. Herman Chayes who first reported the invention of attachment in the early 20th century.[6] Precision attachment gives a removable prosthesis the exceptional feature of improved esthetics, less postoperative adjustments, and improved comfort. It is mostly indicated for long-span edentulous arches, distal extension bases, and nonparallel abutments.[7] There is a wide range of attachments available for use in all manners of restorative procedures, from partial dentures to implant-supported prosthesis. By analyzing study models and X-rays, the clinician can make several important points of determination, each of which will influence final attachment selection. Apart from improving esthetics and retention of removable partial dentures, the availability of the precision attachment has made designing of removable partial dentures more flexible. Various cases with esthetic and retention challenges can be solved with correct selection of attachment. Thus, unnecessary surgery and cutting of sound tooth for abutment preparation can be avoided in restoring missing teeth. However, precision attachments are not without disadvantages. Most of the attachments are very small and come with many parts to assemble. Construction of such attachment requires skill from dental technicians that cannot be acquired easily and needs training. The parts of the attachment are usually exposed to wear and tear and needed to be replaced over time.[8]

The RHEIN 83 OT CAP-New Rochelle, New York. attachments system used in the case discussed in this paper is extracoronal castable attachment positioned on the distal of the crowns as an extension allowing a lot of vertical space for optimal esthetics. The castable OT CAP male can be easily shaped together with the crowns during waxing-up stage avoiding complicated adaptation procedures like welding a metal attachment after crown casting. The male component design is sphere with a flat head, and female component is retentive nylon caps which are color-coded according to different retentive properties.

Conclusion

Removable partial dentures still have a good place as a treatment option for partially edentulous Kennedy's class I and class II conditions. With proper case selection and treatment plan, precision attachment such as RHEIN 83 OT CAP attachments system can be used to improve retention, esthetics, and function of removable partial denture. The above-mentioned procedure using allows fabrication of very functional and comfortable prosthetic solution for the edentulous bilateral distal extension patient cases. Attachments retention can be monitored and upgraded during time just replacing retentive caps into the framework of dentures for patients comfort and satisfaction.