Objective: To assess microleakage of a tooth-adhesive-bracket complex when metal or ceramic brackets were bonded with a conventional and an antibacterial self-etching adhesive. Materials and Methods: Forty freshly extracted human premolars were randomly assigned to four equal groups and received the following treatments: group 1 = Transbond XT + metal bracket, group 2 = Transbond XT + ceramic bracket, group 3 = Clearfil Protect Bond + ceramic bracket, and group 4 = Clearfil Protect Bond + metal bracket. After photopolymerization, the teeth were kept in distilled water for 1 month and thereafter subjected to thermal cycling (500 cycles). Specimens were further sealed with nail varnish, stained with 0.5% basic fuchsin for 24 hours, sectioned and examined under a stereomicroscope, and scored for marginal microleakage for the adhesive-tooth and bracket-adhesive interfaces from incisal and gingival margins. Statistical analysis was accomplished by Kruskal-Wallis test and Mann-Whitney U-test with Bonferroni correction. Results: All groups demonstrated microleakage between the adhesive-enamel and bracket-adhesive interfaces. A significant difference was observed among all groups (P < .05) for the microleakage between the bracket-adhesive interface. Metal brackets exhibited significantly more microleakage than did ceramic brackets between the bracket-adhesive interface with either of the adhesives. Clearfil Protect Bond exhibited results similar to Transbond XT. Clearfil Protect Bond may be a choice of adhesive in bracket bonding because of its antibacterial activity and similar microleakage results with the orthodontic adhesive. Conclusions: Metal brackets cause more leakage between an adhesive-bracket interface, which may lead to lower clinical shear bond strength and white-spot lesions.

No abstract

Evaluation of curing distance of high intensity led curing units on microleakage of ceramic restorations Background: To assess the microleakage in slot shaped cavities restored with IPS e.max Press inlays luted with a resin cement that cured with two types of high intensity LEDs units at 0 or 9 mm distances.

The aim of this study was to examine the dentofacial changes in Class III patients treated with fixed appliances subsequent to rapid maxillary expansion (RME) and facemask therapy. The material consisted of the cephalograms and hand-wrist films of 14 (9 girls, 5 boys) skeletal Class III and 15 (10 girls, 5 boys) untreated subjects obtained at the beginning of treatment/observation T1, immediately after orthopaedic therapy T2, and at the end of the observation period T3. The mean pre-treatment/control ages were approximately 11.5 years and the observation period was 3 years T2-T1: 1 year, T3-T2: 2 years). The cephalometric films were analysed according to the structural superimposition method of Björk. All tracings were double-digitized and the measurements were calculated by a computer program. Intragroup changes and intergroup differences were statistically analysed. Forward movement of the maxilla (P < 0.01), backward movement and rotation of the mandible, an increase in the ANB angle (P < 0.001), lower face height and overjet (P < 0.001), a decrease of overbite, and an improvement in the sagittal lip relationship (P < 0.01) presented significant intergroup differences between T2 and T1. During the second phase of treatment T3-T2, although not statistically significant, forward movement of the maxilla was less than in the control subjects. Overall changes during the observation period T3-T1 revealed that correction was mainly due to favourable changes in the mandibular and dentoalveolar components of the discrepancy, while these in maxillary position were not different from the control group. The soft tissue profile improved significantly (P < 0.001) in the treatment group. Comparison with the Class I controls at the end of the observation period confirmed that some Class III characteristics still remained in the treated patients.

No abstract