Clinical accuracy outcomes of splinted and nonsplinted implant impression methods in dental residency settings

Objective: The splint technique of implant-supported restorations is a popular impression method; however, in-vivo studies showing the advantage of this method are scarce. The objective was to compare radiographic fit of the metal frameworks fabricated according to splinted or nonsplinted impression techniques. The null hypothesis was that splinting techniques would result in more accurate impressions. Method and Materials: A retrospective analysis was performed on 71 patients who had undergone multi-implant-supported rehabilitation in the years of 2012 to 2013. The treatment was carried out by three senior dentists or by residents in the department of Oral Rehabilitation at the Hebrew University Hadassah Medical Center. Each senior and the residents under his guidance treated patients consistently by only one different impression method: (1) no splint; (2) splinted transfers with pattern resin over dental floss scaffold; (3) splinting of transfers to impression tray with pattern resin. Orthoradial radiographs were used to determine if the metal framework fit the implant abutments. Results: In total, 81 impressions and 285 implants were included in the study; 56 impressions were done by seniors and 25 by residents. There was no difference in success between the three methods when done by seniors (P = .76). The fixation to tray method was found to be significantly unsuccessful in the hands of residents (P = .01). Conclusion: Because the splint methods were not found to be more accurate, splinting the transfers might be an unnecessary step. Splinting of transfers to the impression tray is not recommended for inexperienced dentists. Keywords: advanced general dentistry program, multi-unit implant impressions, ragiodraphic fit accuracy, selective laser melting, splint