In vitro evaluation of effect of implant angulation and splinting impression copings on accuracy of open tray impression technique

The purpose of the current study was to evaluate the effect of implant angulation and splinting impression copings on accuracy of open tray impression technique. Three maxillary definitive casts were fabricated with 6 lab analogs which have different degrees of angulations. Analogs were placed in the molar, premolar and canine regions each side. For first definitive cast, all lab analogs were placed parallel to each other and perpendicular to occlusal plane. For second definitive cast lab analogs were placed on molar region with 0º degree to the perpendicular axis on the occlusal plane , on premolar region position mesially with 15º, on canine region position mesially with 30º to the perpendicular axis on the occlusal plane. For third definitive cast lab analogs were placed on molar region with 0º degree , on premolar region position buccally with 10º, on canine region position buccally with 20º to the perpendicular axis on the occlusal plane. Three definitive casts were divided into the 3 subgroups. For first group nonsplinted impression copings, for second group splinted with auto-polymerized acrylic resin impression copings, for third group splinted with light-polymerized acrylic resin were used. For groups with auto-polymerized acrylic resin, splint material was sectioned after 17 minutes and reconnected before impression. Total 90 casts were obtained. (n=10). Definitive casts and stone casts were scanned by using scan bodies with optical scanner. STL datas were obtained with scanner. 3D deviations of scan bodies between definitive casts and stone cast were calculated and compared Data were statistically evaluated with Shapiro-Wilks test, analysis of variance (One-way ANOVA), Tukey HDS test. Significance was evaluated in p<0.05 level. Expect comparing 14 no analog between S,P and L techniques for B and C models, no significant difference was found. For 14 no analog in B and C model, S technique is significantly higher than P and L techniques. ( B cast - (p1:0.032; p2:0.027; p<0.05), C cast - (p1:0.029; p2:0.037; p<0.05). We think that this difference is not clinically significant.