Prosthetic complications with mandibular bar-retained implant overdentures having distal attachments and metal frameworks: A 2- to 12-year retrospective analysis

Accuracy of Selective Laser Melted Bar Retaining Mandibular Implant-Assisted Overdenture: An In Vitro Comparison of Different Impression Materials and Techniques

This study aimed to assess the accuracy of the marginal fit of 2 implant-supported overdenture bars fabricated with selective laser melting technology, using polyvinyl siloxane and vinyl siloxane ether impression materials and different impression techniques. Two implants with multi-unit abutments were inserted in a 3D-printed mandibular model and used as a reference model, then duplicated into a stone cast to fabricate custom trays for obtaining impressions with polyvinyl siloxane and vinyl siloxane ether impression materials, using both open and closed-tray techniques. This resulted in a total of 4 groups, each with 8 specimens. The impressions were poured and scanned, and 32 cobalt-chromium bars were fabricated using selective laser melting technology. Each bar was screwed onto one abutment of the reference model, and a standardized digital periapical radiograph of the opposite unscrewed side was taken; this process was repeated to the other abutment. The vertical misfit was measured at 3 predetermined positions on the unscrewed side, and 6 values per bar were recorded. The mean gap distance was measured, and the data were subjected to statistical analysis; the present study found that the open-tray technique with vinyl polyether siloxane impression material may offer improved accuracy for obtaining impressions for 2 implant-supported bars. The open-tray technique groups also showed better marginal fit than the closed-tray groups. However, further clinical research is required to confirm these findings.

Prosthetic Rehabilitation Options in Post-Ablative Maxillomandibular Microvascular Reconstructions

Objective

Surgery remains the mainstay for managing most neoplasms arising in the head and neck area. Removable or fixed prostheses are commonly used for prosthetic rehabilitation of head and neck defects following surgical resection. Some major challenges in prosthetic rehabilitation after maxillomandibular microvascular reconstruction include excessive prosthetic space, soft tissue bulk, and occlusal disharmony in the remaining dentition. This review focuses on the challenges we have experienced in the real clinical scenario while rehabilitating reconstructed maxillomandibular defects and the effective prosthetic treatment options that could be considered in each situation.

Discussion

Digital revolution has changed all arenas of life, and it has created a significant impact on cancer treatment planning and the delivery of quality treatment to the needy. Creating adequate retention while ensuring stability and support for the prosthesis can be challenging with temporary acrylic and cast partial removable dentures. Endosseous dental implants are considered a stable, reliable, and esthetic option for reconstruction with advantages such as increased chewing efficiency, preservation of the remaining bone height and width, and improved quality of life. The FP3 to RP5 (Misch's classification) are some commonly followed prosthetic rehabilitation options after microvascular reconstruction. The prosthetic design should permit the usage of interdental aids that ensure the longevity of prostheses.

Conclusion

Occlusion-driven/prosthetic-driven implant-assisted prostheses are considered a reliable option that ensures stable and functional oral rehabilitation among patients with free fibula flap reconstruction. Multidisciplinary teamwork is mandatory for an optimal outcome that improves patients' quality of life.

Clinical performance of implant supported mandibular overdentures with cantilever bar and stud attachments: A retrospective study

BACKGROUND

Treatment of edentulous patients with implant-supported over-dentures improves denture's retention and stability. Published data concerning implant-supported overdenture with cantilever bars that claimed that can affect the survival and bone loss of implants are scarce.

PURPOSE

The purpose of this study was to evaluate 5-year clinical performance of mandibular implant-supported over-dentures with different attachment systems.

MATERIALS AND METHODS

In this retrospective study, 103 patients who had received mandibular over-dentures supported by two implants were evaluated in a 5-year follow up. Studied groups were patients with Spherblock ball attachment (58 patients), Dolder bar with cantilever (36 patients), and Locator attachment (9 patients). Marginal bone-loss around implants, prosthetic complications, soft tissue status of the implants (gingival index, plaque index, pocket depth, and bleeding on probing) were used to compare studied groups. Visual Analogue Scale (VAS) criteria was used to assay patient's satisfaction. One-way ANOVA, Scheffe, Kruskal-Wallis, Mann-Whitney, and Fisher's exact tests, were used for the data analysis (α = 0.05).

RESULTS

One hundred and three patients (46 male, 57 female, mean age 64.7 ± 8.6) with 206 implants (Strauman) were studied. The implant survival rate was 100% with mean bone loss of 0.22 mm around implants in 5 years. Prosthetic complications including attachment wear and denture fracture occurred more often with ball attachments. The number of attachment replacement, and post insertion appointments were significantly less in patients with bar attachments (p < 0.05). Pocket depth and gingival index were less in the ball attachment (p < 0.05).

CONCLUSION

Mandibular overdenture supported by two implants can be considered a successful treatment in edentulous patients. The frequency of prosthetic complication is higher in unsplinted than splinted superstructures.