A comparison of two solder registration materials: a three-dimensional analysis

Area of Science:

• Dental Materials Science
• Biomaterials Engineering
• Prosthodontics

Background:

• Segmental indexing and soldering are used for complete arch implant framework assembly to achieve passive fit.
• Previous studies lacked mathematical 3-dimensional (3-D) distortion analysis comparing segmental assembly to 1-piece frameworks requiring sectioning and soldering.

Purpose of the Study:

• To compare the efficacy of autopolymerizing acrylic resin versus light-polymerized composite resin for solder registration in complete-arch implant frameworks.
• To evaluate 3 framework/indexing material combinations: gold/light-polymerized composite resin, silver palladium/autopolymerizing acrylic resin, and silver palladium/light-polymerized composite resin.

Main Methods:

• Fabricated 15 frameworks (5 per alloy/index combination) and fitted them to 5 implant abutments each.
• Utilized a coordinate measurement machine (CMM) to measure 3-D spatial orientation changes (linear and angular distortions) after indexing and soldering.
• Employed 1-way ANOVA and Student-Newman-Keuls tests for statistical analysis of distortions.

Main Results:

• Mean total linear change (dR) ranged from 31.56 ± 24.37 µm to 34.87 ± 27.99 µm across groups.
• Mean total angular change (dθ(R)) ranged from 0.46 ± 0.17° to 0.52 ± 0.15° across groups.
• No significant differences in linear or overall angular distortion were found between the alloy/index combinations.

Conclusions:

• Both autopolymerizing acrylic resin and light-polymerized composite resin are suitable for indexing complete arch implant frameworks.
• No significant differences in framework distortion were observed between the tested alloy/indexing material combinations, except for angular change about the Y axis (dθ(y)).
• The choice of indexing material does not significantly impact the passive fit of complete arch implant frameworks.