Comparison of the accuracy for three dental impression techniques and index: An in vitro study

详细信息    查看全文

• 作者：Erica Dorigatti de Avila ; Luiz Antonio Borelli Barros ; Marcelo Antonialli Del鈥橝cqua ; Sabrina Maria Castanharo ; Francisco de Assis Mollo Jr.
• 关键词：Dental implant ; Impression technique ; Transfer coping ; Impression material
• 刊名：Journal of Prosthodontic Research
• 出版年：October, 2013
• 年：2013
• 卷：57
• 期：4
• 页码：268-274
• 全文大小：1509 K

文摘

Objectives

This in vitro study compared the dimensional accuracy of stone index (I) and three impression techniques: tapered impression copings (T), squared impression copings (S) and modified squared impression copings (MS) for implant-supported prostheses.

Methods

A master cast, with four parallel implant abutment analogs and a passive framework, were fabricated. Vinyl polysiloxane impression material was used for all impressions with two metal stock trays (open and closed tray). Four groups (I, T, S and MS) were tested (m>nm> = 5). A metallic framework was seated on each of the casts, one abutment screw was tightened, and the gap between the analog of implant and the framework was measured with a stereomicroscope. The groups鈥?measurements (80 gap values) were analyzed using software (LeicaQWin - Leica Imaging Systems Ltd.) that received the images of a video camera coupled to a Leica stereomicroscope at 100脳 magnification. The results were statistically analyzed with Kruskal-Wallis One Way ANOVA on Ranks test followed by Dunn's Method, 0.05.

Results

The mean values of abutment/framework interface gaps were: Master Cast = 32 渭m (SD 2); Group I = 45 渭m (SD 3); Group T = 78 渭m (SD 25); Group S = 134 渭m (SD 30); Group MS = 143 渭m (SD 27). No significant difference was detected among Index and Master Cast (m>Pm> = .05).

Conclusion

Under the limitations of this study, it could be suggested that a more accurate working cast is possible using tapered impression copings techniques and stone index.