ABSTRACT
OBJECTIVE: In this randomized study, the caries-protective effect on vestibular enamel of two fluoride-containing sealants (Protecto® and Light Bond®) during multibracket treatment was investigated. MATERIALS AND METHODS: In all, 40 orthodontic patients about to receive a multibracket appliance with the brackets bonded to the vestibular tooth surfaces were randomly included in this study. Each one was randomly assigned to one of four groups. A crossover design was selected in which a sealed quadrant was contralateral to an unsealed quadrant, then choosing the reverse configuration in the opposite jaw. Two sealants were, thus, tested on vestibular enamel on left and right anterior teeth and premolars in both jaws of each patient over 6 months of multibracket treatment. A DIAGNOdent® pen measuring laser fluorescence was used to analyze the relevant enamel surfaces both at baseline and after 6 months. RESULTS: Neither the incidence nor the characteristics of the demineralization we observed during the study differed between the 4 groups. CONCLUSION: Single application of smooth-surface sealants did not protect enamel around brackets from incipient carious lesions during the first 6 months of multibracket treatment.
Subject(s)
Dental Bonding/adverse effects , Dental Enamel/pathology , Methacrylates/therapeutic use , Orthodontic Brackets/adverse effects , Pit and Fissure Sealants/therapeutic use , Silicates/therapeutic use , Tooth Demineralization/etiology , Tooth Demineralization/prevention & control , Adolescent , Cariostatic Agents/therapeutic use , Female , Humans , Male , Tooth Demineralization/pathology , Treatment OutcomeABSTRACT
This study was undertaken to investigate if transversal expansion with removable plates is a predisposing factor in the occurrence for buccal recessions in the molar region. In order to clarify a possible causal relationship, it is important to know to what extent the therapeutic expansion remains stable, 58 former patients, ages ten to 15, were studied following transversal expansion and non-extraction therapy with removable appliances. Intermolar expansion and stability, clinical crown length, and the incidence of buccal recessions on the incisors and six-year molars were evaluated. The study revealed that with relatively good intermolar stability (relapse between 13% and 14%), when compared with an untreated control group and with the data contained in the literature, recessions do not increasingly occur.
Subject(s)
Gingival Recession/etiology , Palatal Expansion Technique/instrumentation , Follow-Up Studies , Gingival Recession/epidemiology , Humans , Incidence , Mandible , Maxilla , Molar , Palatal Expansion Technique/adverse effects , Palatal Expansion Technique/statistics & numerical data , Recurrence , Time FactorsABSTRACT
The third premolars of Beagle dogs were subjected to tipping force of 20N, applied for between 20 minutes and 7 hours. Ten minutes before the end of the experiment the animals were injected intravenously with disulphine blue in order to show the capillary circulation and the tissue perfusion in the PDL under loading. The animals were then killed, and vertical histological sections were made of the loaded and the control teeth. The width of the PDL of the loaded and control teeth was measured at seven levels along the root surface and an analysis of variance was carried out. There was no circulatory disturbance and only slight irreversible changes in the shape of the PDL with loading for up to 3 hours. Only the teeth which had been loaded for at least 3 hours showed clear zones of irreversible compression and expansion. As the amount of irreversible compression increased so the blood supply and the circulation were impaired. Further increased compression of the periodontal ligament caused by long-term force application resulted in localized blood clotting.
