Survey of United States dental schools on cementation protocols for implant crown restorations.
Commentary by Howard E. Strassler, DMD
STATEMENT OF PROBLEM: With conflicting results in the literature and various manufacturer recommendations, it is not known what cementation protocols are currently being used for implant restorations in US dental schools.
PURPOSE: The purpose of this survey was to determine what dental cementation protocols are taught and recommended by 62 US dental schools and postgraduate programs.
MATERIAL AND METHODS: From February 2008 to September 2008, 96 questionnaires, consisting of 8 questions, were sent to the chairperson or director of restorative departments, advanced prosthodontics programs, and implant programs. The questionnaire asked recipients which implant manufacturers provided the products used at their dental schools. Recipients were also queried regarding their institution's choice of material and techniques for abutment and restoration preparations prior to definitive cementation. Data were analyzed with descriptive statistics.
RESULTS: A total of 68 surveys (71%) were returned, and 52, or 84%, of the 62 predoctoral and postgraduate programs were represented. After deleting duplicate responses, 31 surveys were returned from restorative department chairpersons, 29 from advanced prosthodontic program directors, and 2 from implant program directors. Frequency of responses to each question was tabulated, and results were presented in 3 sections. Nobel Biocare was reported to be the most widely used implant system across all 3 types of programs, followed by Biomet 3i, Straumann, Astra Tech, and Zimmer Dental systems. The most commonly used technique prior to definitive cementation was to airborne-particle abrade the intaglio surface of the restoration. Resin-modified glass ionomer was cited as the most frequently used luting agent for cementing implant restorations. The 5 most commonly used materials to fill screw access openings were cotton pellets, composite resin, rubber-based material, gutta-percha, and light-polymerized provisional composite resin. Most predoctoral and postgraduate programs reported teaching students to fill the screw access opening completely to the occlusal surface.
CONCLUSIONS: A wide range of implant cementation protocols and materials are used. However, some common trends were identified among predoctoral and postgraduate programs.
Implants restored with cement- and screw-retained crowns have continued to evolve. It has been generally accepted that implants are highly successful. Screw-retained prostheses have an advantage over cement-retained restorations, in that they are retrievable. Over the past decade, manufacturers have changed recommendations for the protocols used for implant restoration cementation.
This article presents the data from a well-designed survey of dental schools on cementation protocols used to cement implants when compared to conventional fixed restorations. Most schools teach multiple protocols. Resin- modified glass-ionomer cements were the most commonly used for both. More than 40% of respondents indicated they still use zinc-oxide and eugenol provisional cements for implants, but none reported using it for conventional fixed restorations. There was also significant variation in the materials used for filling screw access openings.