Effect of bleaching treatments on the adhesion of orthodontic brackets: a systematic review.

BACKGROUND: Nowadays bleaching procedures have gained popularity in orthodontic patients. Peroxide and Carbamide acids are the common agents which are used in in-office and at home bleaching techniques. Consequently, the Bonding adhesion to the enamel can be influenced by the orthodontic phase and the residual peroxide might interfere with the polymerization and the adhesion of the brackets. Frequent debonding of the brackets from teeth after the bleaching procedure could cause the lengthening of the therapy and promote irregularities on enamel surface derived from an additional bonding phase of the brackets. The aim of this systematic review is to appraise the influence regarding the effect of the bleaching procedure on the bond strength of orthodontic brackets. METHODS: An electronic database search was performed. Search terms included: bleaching, brackets, adhesion; data were extracted and summarized. Risk of bias was assessed using the Chocrane risk of bias tool, adapted for in vitro studies. RESULTS: A total of 8689 articles were screened and 11 studies met the inclusion criteria of this systematic review. 1000 teeth of human and bovine origin were analyzed for the shear bond strength (SBS) of stainless and ceramic brackets after the bleaching treatments. All the authors divided the groups in different subgroups with different bleaching agents and in different concentration. The SBS value allowed to demonstrate the necessity to delay the bonding of the brackets for two weeks after a bleaching treatment and its improvement when tooth mousse or antioxidants agents are used. CONCLUSIONS: The SBS values and the delay of the bonding procedure must be considered in dental practice and clinical strategies are necessary in order to avoid drawbacks which could cause the debonding of the brackets after bleaching due to the alterations of the dental substrate, thus interfering with the orthodontic treatments.

General Health, Systemic Diseases and Oral Status in Adult Patients with Coeliac Disease.

The prevalence of coeliac disease in the general population is 0.5%-1%; however, most patients remain undiagnosed until adult age. In some cases, the onset is represented by sub-clinical signs, some of which can be found in the mouth. The aim of this research was to identify any associations between the clinical characteristics of coeliac disease and oral manifestations. A structured questionnaire was administered to a group of 237 individuals with coeliac disease. 100% of the subjects fully completed the questionnaire. Among them, 182 (76.7%) were female, 64 patients (27%) were aged 15 to 24 years, 159 (67%) were aged 25 to 55 and 14 (6%) were aged 56 and over. Significant associations were observed in caries prevalence and dentin sensitivity; in addition, an inappropriate diet was related to oral manifestations; following a gluten-free diet could be important to control the gingival bleeding levels and to manage oral symptoms associated to coeliac disease. In general, the presence of inflammatory symptoms in the mouth seems to be associated with general symptoms of inflammation related to coeliac disease.

Dentoskeletal Class II Malocclusion: Maxillary Molar Distalization with No-Compliance Fixed Orthodontic Equipment.

Dentoskeletal class II malocclusion due to a protruded upper dental arch is a major reason for an orthodontic treatment. In these cases, the correction of class II can be hindered by molar distalization, obtained with 'no-compliance therapy' that involves the use of appliances which minimize the need for such co-operation and attempt to maximize the predictability of results. The aim of this review was to outline the effectiveness of no-compliance fixed orthodontic devices in the molar distalization. After selection according to the inclusion/exclusion criteria, 16 articles from 2000 to 2019 were qualified for the final analysis. The literature shows various no-compliance fixed devices whose effect is to distalize the maxillary molars. The present revision allows to conclude that there is a need to increase the number of studies, especially with regard to the most recently introduced devices in the literature. The analysed studies allow to hypothesize that these appliances act with a minimal variability of molar distalization and disto-inclination among them, although different effects among the appliances can be observed as regards to the anchorage.

Prevalence of Caries and Associated Risk Factors in a Representative Group of Preschool Children from an Urban Area with High Income in Milan Province, Italy.

The present survey provides a quantitative assessment of caries prevalence, covering a group of 3-5 year-old children from an urban area generally with a high income in the province of Milan, and a comparison of the obtained results with the data presented by the W.H.O. A cross-sectional study was conducted in the period from March to September 2018 to investigate the prevalence of caries in a sample of 160 children (82 females and 78 males). The absence/presence of caries was defined as a dependent variable. Factors concerning lifestyle, diet, oral habits, oral hygiene, the presence and type of malocclusion and mouth breathing attitude were considered as risk factors. Data were analyzed by Chi-square (χ2) and regression tests using SPSS (version 25.0) software. In total, 84.38% of children (135 out of 160) showed no caries. A regression analysis demonstrated that children who had already received an early first dental visit were mostly those already affected by caries. Furthermore, children who had four meals daily or more were less exposed to the risk of developing caries compared to those who had only 1-3 meals daily. The caries prevalence of preschool children from urban areas with a high income in Milan province is relatively close to that considered acceptable by the W.H.O. in its proposed goals for the year 2020. Therefore, it can be concluded from the obtained results that there is a possibility for further improvement in preventing caries growth at its initial stage: it is necessary for the number of meals daily consumed by children to be controlled by parents, and conducting a dental visit early in childhood must not be neglected.

Comparison of apical extrusion of intracanal bacteria by various glide-path establishing systems: an in vitro study.

OBJECTIVES: This study compared the amount of apically extruded bacteria during the glide-path preparation by using multi-file and single-file glide-path establishing nickel-titanium (NiTi) rotary systems. MATERIALS AND METHODS: Sixty mandibular first molar teeth were used to prepare the test apparatus. They were decoronated, blocked into glass vials, sterilized in ethylene oxide gas, infected with a pure culture of Enterococcus faecalis, randomly assigned to 5 experimental groups, and then prepared using manual stainless-steel files (group KF) and glide-path establishing NiTi rotary files (group PF with PathFiles, group GF with G-Files, group PG with ProGlider, and group OG with One G). At the end of canal preparation, 0.01 mL NaCl solution was taken from the experimental vials. The suspension was plated on brain heart infusion agar and colonies of bacteria were counted, and the results were given as number of colony-forming units (CFU). RESULTS: The manual instrumentation technique tested in group KF extruded the highest number of bacteria compared to the other 4 groups (p < 0.05). The 4 groups using rotary glide-path establishing instruments extruded similar amounts of bacteria. CONCLUSIONS: All glide-path establishment instrument systems tested caused a measurable apical extrusion of bacteria. The manual glide-path preparation showed the highest number of bacteria extruded compared to the other NiTi glide-path establishing instruments.