Evaluation of the accuracy of different transfer impression techniques for multiple implants

Abstract

The aim of this study was to evaluate the accuracy of three implant transfer impression techniques. Four groups (n = 5) were defined, according to the technique: TC -tapered copings without splint; SCsquare copings without splint; SCS -square copings splinted with dental floss and acrylic resin, and CG (control group) -master model with four external hexagonal implants and a superstructure. Individual trays and polyether were used for the impression. All casts were checked for their fit into the master superstructure; for this, all four screws were placed in the implants. Digital photos were taken and images were analyzed using UTHSCSA ImageTool software. Statistical analyses were performed using one-way analysis of variance and Student's t test (p < 0.05). The means and standard deviation were (µm): CG = 2.03 ± 0.00, TC = 14.74 ± 3.41, SC = 12.08 ± 2.56, and SCS = 6.51 ± 0.09. The control group was found to be statistically different from the TC and SC groups. Within the limitations of this study, all groups presented clinically acceptable standard gap values, and the SCS group showed no statistical difference in relation to the CG (control group), demonstrating more accuracy and fidelity to transfer implants.

Accuracy Comparison of Implant Impression Techniques: A Systematic Review

“…Ten studies evaluate different coping types . From these, seven studies advocate the open technique with square copings as the most accurate, and three studies report similar results between copings .…”

“…5,17,[22][23][24]36 It was verified that a predominant use of square copings was associated to the open technique. Table 2 compares the accuracy between splinted and non-splinted impression techniques, 4,[14][15][16]18,19,[27][28][29]31,37,[39][40][41] resuming the analysis of 14 articles, where all advocate the splinted technique. It was also verified that there was a predominant use of square copings in 10 of the 14 studies.…”

Different materials and techniques for accurate molding for adaptation in angled implants

“…The open tray technique with the square transfer impressions joined with acrylic resin have been widely used since they were advocated by Branemark 11 . Several authors have studied their effectiveness 8,[11][12] , though the results have not been conclusive in terms of their superiority over other transfer techniques. However, Hsu et al 13 pointed out that "there was no difference in accuracy between moldings carried out using square transfer impressions, whether bonded or not", results which are seen to be in agreement with the findings of Spector et al 11 , Pinto 14 , Goiato et al 15 , Herbest et al 16 and Faria et al 8 , who also found no difference between the two techniques, nor was there any difference when compared with the conical transfer impression technique.…”

“…Several authors have studied their effectiveness 8,[11][12] , though the results have not been conclusive in terms of their superiority over other transfer techniques. However, Hsu et al 13 pointed out that "there was no difference in accuracy between moldings carried out using square transfer impressions, whether bonded or not", results which are seen to be in agreement with the findings of Spector et al 11 , Pinto 14 , Goiato et al 15 , Herbest et al 16 and Faria et al 8 , who also found no difference between the two techniques, nor was there any difference when compared with the conical transfer impression technique. Burawi et al 5 stated that "the technique that uses transfer impressions that are not bonded is more accurate when compared to the technique that uses bonded transfer impressions, using addition silicone for the molding material".…”

Análise da precisão de uma nova moldeira para implantes dentários

“…Já as medidas do grupo teste foram, em média, maiores que 150 µm (tabela 5.10). Caso houvesse sido realizada a união dos transferentes, muito provavelmente melhores resultados teriam sido obtidos, conforme relatado por diversos autores (Assif et al, 1992;Chee;Jivraj, 2006;Cabral;Guedes, 2007;Conrad et al, 2007;Del'Acqua et al, 2008;Filho et al, 2009;Del'Acqua et al, 2010;Yamamoto et al, 2010;Faria et al, 2011 …”