• Oliveira, Lrs
• Cardenas, Afm
• Soares, Cj
• Melo, C.
• Cavalcanti, Kgba
• Soares, Pbf

Abstract

<jats:title>SUMMARY</jats:title><jats:sec><jats:title>Objectives</jats:title><jats:p>To measure the proximal contact force in newtons (N) between incremental and bulk fill class II resin composite restorations and implant molar teeth or adjacent premolar teeth with simulated periodontal ligament.</jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p>The model used was created with a typodont first molar tooth with two bilateral occlusal-proximal class II cavities, an adjacent tooth simulating an implanted molar tooth (Titamax CM, Neodent, Curtiba, PR, Brazil) and a premolar with simulated periodontal ligament. Two resin composite restorative techniques were used: Inc-Z350XT, (Filtek Z350, 3M Oral Care, St. Paul, MN, USA) inserted incrementally and Bulk-OPUS, (Opus Bulk Fill APS, FGM, Joinville, SC, Brazil) high viscosity bulk fill resin composite (n=10). As a control, a typodont having intact teeth without restorations was used. After the restorative procedure, each specimen was radiographed using a digital system (Dürr Dental, Bietigheim-Bissingen, Germany). The proximal contact force (N) was measured using dental floss with a microtensile machine (Microtensile ODEME, Luzerna, SC, Brazil). The specimens were then subjected to mechanical fatigue cycling to simulate 5 years of aging. All the parameters were measured after aging. The X-rays were blindly qualitatively analyzed by two operators to identify the loss of proximal contact. One-way ANOVA was used for comparing the initial contact force between restored and intact teeth. Two-way ANOVA followed by Tukey testing was performed for contact area data and for the contact force/contact area ratio. The proximal contact force data were analyzed using one-way repeated measurement ANOVA followed by Tukey testing (α=0.05). The X-ray proximal contact analyses were described by the frequency.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>The initial proximal contact force was similar for intact and restored teeth. The contact force and contact area with the molar were significantly higher than with the premolar; however the contact force/contact area ratio was similar for all tested groups. The bulk fill technique showed a contact force similar to the incremental filling technique. Fatigue resulted in a significant reduction in the proximal contact force (p&amp;lt;0.001), irrespective of the region analyzed or restorative material used. The digital X-rays detected no alteration in the proximal contact after occlusal fatigue.</jats:p></jats:sec><jats:sec><jats:title>Conclusions</jats:title><jats:p>Larger contact area resulted in higher proximal contact force. Proximal contact force decreased with 5 years of simulated occlusal fatigue. The bulk fill technique showed a proximal contact force similar to that of the incremental filling technique.</jats:p></jats:sec>

Topics

• fatigue
• composite
• viscosity
• aging
• resin
• size-exclusion chromatography
• aging
• appearance potential spectroscopy