In vitro Analysis of Shear Bond Strength and Adhesive Remnant Index of Stainless Steel Brackets with Different Adhesive Systems to Enamel.

AIM: This study aimed at evaluating and comparing the bond strength of stainless steel brackets bonded with multiple orthodontic adhesives. MATERIALS AND METHODS: About 60 premolars extracted to create space during orthodontic treatment were included in the present study. Premolar stainless steel brackets of size 0.022" slot with the surface area of bracket base of 11.15 mm2 were used. The premolars were divided randomly into three groups of 20 in each. Group I: Conventional Acid Etching (Transbond XT); group II: Seventh-generation adhesive materials (Xeno V); and group III: Flowable composite (Filtek Z350 XT). Calculation of Adhesive Remnant Index (ARI) was done and shear bond strength was assessed. The probability level of 0.05 was considered as clinically significant. RESULTS: The shear bond strength was highest in group II (17.46 ± 1.36), which was followed by group I (15.33 ± 2.78) and the least was shown by group III (13.96 ± 1.44). A statistically significant difference was found between group I vs II, group II vs III, and group III vs II. Utmost prevalence of about 35% was found in Transbond XT with an ARI score of 3 (followed by all adhesive left on the tooth), Filtek Z350 XT with 20%, and the least was found with Xeno V, about 5%. The probability was found to be p = 0.025 among different groups, which is statistically significant according to chi-square test. CONCLUSION: The study concluded that the adhesive materials of the seventh generation showed higher shear bond strength than that of the flowable composite and conventional acid etching. The ARI indicated that a minimum amount of the residual adhesive was found on the surface of the enamel after debonding. CLINICAL SIGNIFICANCE: This study helps orthodontists to select appropriate adhesive and orthodontic brackets for the benefit of the patient and to distinguish the distribution of stress homogeneously within the layer of cement while loading and subsequently minimizing the damage to the enamel during the debonding of orthodontic brackets.

An Innovative Approach to Retention: Thermoplastic Retainer.

AIM: The aim of this study was to design and introduce a retainer that overcomes the common shortcomings seen in other retainers. MATERIALS AND METHODS: Hard thermoplastic sheet of 0.5 mm thickness is vacuum or pressure-molded onto the patient cast. Lingual portion of the retainer is trimmed according to the contours of the anterior teeth. Contact points between the maxillary and mandibular anterior teeth are marked on the retainer and reduced. Punch cut holes are placed on the retainer for the exit of flash and air bubbles while fixation. The retainer is bonded onto the lingual surface of the anterior teeth using composite. RESULTS: A 1-month review of the retainer showed no patient discomfort, occlusal interference, or bond failure. The aim of the article was found to have been achieved. CONCLUSION: Initial evaluation has shown positive findings. Long-term clinical findings will determine the overall success of this new retainer. CLINICAL SIGNIFICANCE: As compared with other retainers, thermoplastic retainer has shown reduced tendency to debond from occlusal forces, decreased patient discomfort, and occlusal interference.