Evaluation of the effect of bracket and archwire composition on frictional forces in the buccal segments.

Aim of the study: The aim of this study was to consider friction in buccal segment attachments during overjet reduction by means of sliding mechanics. Friction was compared in Stainless Steel, Titanium and Cobalt Chromium brackets, using Stainless Steel and Beta Titanium wires. Materials and Methods: This in-vitro study comprised 18 samples (6 x 3 brackets of different materials-stainless steel, titanium and cobalt chromium). Each jig comprised of a buccal segment model of two premolar brackets and a molar tube simulating the upper posterior buccal segment. Each jig was coupled with the wire of 0.019 x 0.025 inch dimension and was tested with a Universal Testing Machine. Ligation was achieved using low friction elastomeric modules (Slide TM , Leone, Italy), a non-conventional elastomeric module. Results: All three bracket systems showed significantly higher frictional forces for the beta titanium wire than for the stainless steel wire. When coupled with the stainless steel wire, the titanium bracket showed the least friction, followed by stainless steel and cobalt chromium brackets. When coupled with the beta titanium wire, the titanium brackets again showed the least friction; while the difference in frictional levels between the stainless steel and cobalt chromium brackets was not statistically significant. The titanium brackets showed the least friction among all the groups tested for both wires. Conclusion: Titanium bracket with Beta Titanium wires could and probably should be the alternative metal bracket used in the nickel sensitive patient.

Efficacy of CPP-ACP and CPP-ACPF on enamel remineralization - An in vitro study using scanning electron microscope and DIAGNOdent®.

Introduction: Remineralization as a treatment procedure has received a lot of attention both from clinicians as well researchers. The objective of this in vitro study was to find out the efficacy of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) and casein phosphopeptide-amorphous calcium phosphate fluoride (CPP-ACPF) in remineralizing enamel surface on which artificial caries lesion had been created. The changes were analyzed using DIAGNOdent® (KaVo) and scanning electron microscope (SEM). Materials and Methods: Ninety maxillary premolars were selected and divided into three groups of 30 teeth each: A (artificial saliva), B (CPP-ACP), and C (CPP-ACPF). All the samples were assessed using DIAGNOdent® at the baseline and after demineralization and remineralization. Three samples were randomly selected from each group after remineralization for surface evaluation using SEM. Results: Statistical analysis showed that group B {CPP-ACP (4.1±1.8)} and group C {CPP-ACPF (4.8±1.2)} had a significantly higher amount of remineralization than group A (1.7±0.7). Conclusion: All the three groups showed a statistically significant amount of remineralization. However, because of the added benefit of fluoride (NaF 0.2%), CPP-ACPF (Tooth Mousse-Plus®) showed marginally more amount of remineralization than CPP-ACP (Tooth Mousse®).