ABSTRACT
The aim of this study was to evaluate the effects of bleaching and delayed bonding on the shear bond strengths of metal and ceramic brackets bonded with light and chemically cure composite resin to human enamel. One hundred and twenty extracted human premolar teeth were randomly divided into three groups of 40 each. The first two groups were bleached with 20 per cent carbamide peroxide (CP) at-home bleaching agent. No bleaching procedures were applied to the third group and served as control. The first two and control groups were divided into equal subgroups according to different adhesive-bracket combinations. Specimens in group 1 (n = 40) were bonded 24 hours after bleaching process was completed while the specimens in group 2 (n = 40) were bonded 14 days after. The specimens in all groups were debonded with a Universal testing machine while the modified adhesive remnant index was used to evaluate fracture properties. No statistically significant differences were found between the shear bond strengths of metal and ceramic brackets bonded to bleached enamel after 24 hours, 14 days, and unbleached enamel with light or chemical cure adhesives (P > 0.05). The mode of failure was mostly at the bracket/adhesive interface and cohesive failures within the resin were also observed. Our findings indicated that at-home bleaching agents that contain 20 per cent CP did not significantly affect the shear bond strength of metal and ceramic orthodontic brackets to enamel when bonding is performed 24 hours or 14 days after bleaching.
Subject(s)
Ceramics/chemistry , Dental Alloys/chemistry , Dental Bonding , Dental Enamel/ultrastructure , Orthodontic Brackets , Tooth Bleaching Agents/chemistry , Tooth Bleaching/methods , Acid Etching, Dental/methods , Adhesiveness , Aluminum Oxide/chemistry , Bisphenol A-Glycidyl Methacrylate/chemistry , Carbamide Peroxide , Dental Enamel/drug effects , Dental Stress Analysis/instrumentation , Humans , Light-Curing of Dental Adhesives , Materials Testing , Peroxides/chemistry , Peroxides/pharmacology , Resin Cements/chemistry , Self-Curing of Dental Resins , Shear Strength , Silicon Dioxide/chemistry , Stainless Steel/chemistry , Stress, Mechanical , Surface Properties , Temperature , Time Factors , Tooth Bleaching Agents/pharmacology , Urea/analogs & derivatives , Urea/chemistry , Urea/pharmacologyABSTRACT
The purpose of this study was to make a detailed evaluation of hard and soft tissue changes after Delaire orthopedic mask therapy (France-Orthodontie). The treatment group, which comprised 16 girls (mean age: 8.65 years, SD: 1.4 years) with skeletal Class III relationships caused by maxillary retrognathism, was compared with an untreated control group of 10 girls (mean age: 9.29 years, SD: 1.4 years). The following results were obtained: (1) After maxillary protraction, the maxilla was displaced anteriorly, whereas the mandible rotated posteriorly; (2) the maxillary incisors moved in the anterior direction, whereas the mandibular incisors moved posteriorly; (3) the mandibular plane angle and anterior lower and total face heights increased; (4) these changes were reflected in the profile, whereby the skeletal profile convexity increased and soft tissue facial angle and facial convexity decreased; and (5) the Class III concave profile became more balanced, with the upper lip area becoming more marked.
Subject(s)
Extraoral Traction Appliances , Face/anatomy & histology , Malocclusion, Angle Class III/therapy , Orthodontics, Corrective/methods , Case-Control Studies , Cephalometry , Child , Female , Humans , Treatment Outcome , Vertical DimensionABSTRACT
The purpose of this study was to investigate whether orthodontic toothbrushes were superior to classical toothbrushes in the elimination of microbial dental plaque on teeth and brackets and in the maintenance of periodontal tissue health in patients, ages 12 to 22 years, with fixed appliances. Twenty patients undergoing orthodontic treatment with fixed appliances and brushing with the Bass technique were included in the study. Ten patients used the Oral B Ortho type toothbrushes (Oral B Laboratories Ltd.), whereas the remaining 10 patients used the Oral B Plus 35 type toothbrushes. Quigley-Hein plaque index, bonded bracket index, sulcus bleeding index, and periodontal pocket depth measurements were made at the beginning of the study and a month later. No statistically significant difference was found for plaque, sulcus bleeding, and periodontal pocket depth between Oral B Ortho and Plus 35 groups when the preinvestigatory and postinvestigatory measurements for the vestibular and proximal surfaces of upper and lower teeth were compared. This short-term study concluded that the Ortho-type toothbrush is not superior to the Plus 35-type toothbrush.
