The impact of different surface treatments on the shear bond strength of orthodontic metal brackets applied to different CAD/CAM composites

To investigate the shear bond strength (SBS) of orthodontic metal brackets applied to different CAD/CAM composites treated with different surface treatments. Specimens of two CAD/CAM composites were obtained of Lava Ultimate (LU; n=60) and Brilliant Cri

Shear Bond Strength of Orthodontic Brackets Fixed with Remineralizing Adhesive Systems after Simulating One Year of Orthodontic Treatment

The objective of this study is to assess, in vitro, the shear bond strength of orthodontic brackets fixed with remineralizing adhesive systems submitted to thermomechanical cycling, simulating one year of orthodontic treatment. Sixty-four bovine incisor teeth were randomly divided into 4 experimental groups (n=16): XT: Transbond XT, QC: Quick Cure, OL: Ortholite Color, and SEP: Transbond Plus Self-Etching Primer. The samples were submitted to thermomechanical cycling simulating one year of orthodontic treatment. Shear bond strength tests were carried out using a universal testing machine with a load cell of 50 KgF at 0.5 mm/minute. The samples were examined with a stereomicroscope and a scanning electron microscope (SEM) in order to analyze enamel surface and Adhesive Remnant Index (ARI). Kruskal-Wallis and Mann-Whitney (with Bonferroni correction) tests showed a significant difference between the studied groups (p<0.05). Groups XT, QC, and SEP presented the highest values of adhesive resistance and no statistical differences were found between them. The highest frequency of failures between enamel and adhesive was observed in groups XT, QC, and OL. Quick Cure (QC) remineralizing adhesive system presented average adhesive resistance values similar to conventional (XT) and self-etching (SEP) adhesives, while remineralizing system (OL) provided the lowest values of adhesive resistance

Effects of Brown and Green Propolis on Bond Strength of Fiberglass Posts to Root Canal Dentin

Introduction: The purpose of this study was to evaluate the effect of brown and green propolis on bond strength of the fiberglass posts to root canal dentin, and to compare it with conventional endodontic irrigants. Methods and Materials: Sixty bovine teeth were selected, decoronated and randomly distributed into six groups (n=10), according to the irrigation solution: 0.9% saline solution (Control); 2% chlorhexidine (CHX); 5% malic acid (MA); 0.5% ethanolic extract of brown propolis (BP); 0.25% ethanolic extract of green propolis (GP); 2.5% sodium hypochlorite (NaOCl). After root canal treatment, fiber posts were cemented into prepared root canals with a self-adhesive resin cement. The roots were cross-sectioned to obtain two discs from each third and submitted to the micro push-out test. Failure patterns were evaluated under optical microscopy. The influence of irrigants agents was analyzed using one-way ANOVA followed by Games-Howell’s test (α=0.05). Failure modes were analyzed using Fischer’s exact test (α=0.05). Results: There were statistically significant differences among the groups (P&lt;0.05). The control, NaOCl and BP groups showed the highest bond strength with no statistically significant difference between them (P&gt;0.05). Adhesive failure type was the predominant in all groups. Conclusion: Based on this in vitro study, the use of 0.5% brown propolis did not influence the bond strength of fiberglass posts to root canal dentin, while the use of 0.25% green propolis did affect it negatively

Repair of Iatrogenic Furcal Perforation with Mineral Trioxide Aggregate: A Seven-Year Follow-up

Teeth with furcal perforation present difficult resolution and dubious prognosis. Several materials have been proposed and calcium silicate-based cements such as mineral trioxide aggregate (MTA) are the most recommended. However, its long-term clinical behavior still remains poorly understood. The present study reports a clinical case of furcal perforation repair using Angelus MTA, with a 7-year follow-up. Patient sought treatment 2 months after iatrogenic accident. First lower right molar presented clinical signs such as fistula and bone loss between mesial and distal roots. Firstly, all root canals were treated and then furcal perforation was sealed with MTA Angelus and the dental crown was restored with composite resin. Radiographic evaluation was immediately performed to analyze the furcal perforation filling. After 7 years, a new clinical and imaging evaluation using periapical radiography and cone-beam computed tomography (CBCT) showed absence of clinical signs and symptoms, and alveolar bone reconstitution with periodontal space reduction. Angelus MTA presented good clinical behavior in the iatrogenic furcal perforation resolution based on long-term clinical evidence.Keywords: Endodontics; Furcation Perforation; Mineral Trioxide Aggregate; Root Canal Treatment; Root Perforation; Tooth Perforation

Bond strength and internal adaptation of customized glass fiber posts using different bulk-fill flow resins

This study aimed to evaluate the bond strength and internal adaptation of customized glass fiber posts using Bulk Fill flowable composite resins (BF) and conventional composite resin. Fifty bovine teeth were randomly divided (n=10) according to the fol

Endodontic Management of Open Apex Teeth Using Lyophilized Collagen Sponge and MTA Cement: Report of Two Cases

Teeth with open apices, such as in immature teeth or those with apical root resorption are clinical cases with difficult immediate resolution. With the use of mineral trioxide aggregate (MTA) in dentistry, it was possible to optimize the treatment time of these cases by immediate placement of apical plug and the root canal filling. However, some negative effects can occur if MTA is extruded beyond the apex. To avoid this accident, it has been recommended to use of an apical matrix prior to placement of MTA. This study reports two clinical cases of apical plug placement in teeth with pulp necrosis and open apices. One case had an immature apex due to dental trauma and the other case had apical resorption due to the presence of endodontic infection in the root canal. MTA apical plug with approximately 4 mm thickness, was placed in the apical zone of the root and immediately the canal was obturated with gutta-percha and endodontic sealer. Follow-up evaluations showed clinical and radiographic evidence of success.Keywords: Apex; Collagen; Endodontics; Mineral Trioxide Aggregat

Toothpaste Prevents Debonded Brackets on Erosive Enamel

This study evaluated the effect of high fluoride dentifrice on the bond strength of brackets after erosive challenge. Eighty-four enamel specimens were divided into seven groups (n=12): WN (distilled water/no acid challenge), W3C (distilled water/3 cycles of acid challenge), and W6C (distilled water/6 cycles of acid challenge) were not submitted to dentifrice treatment. Groups RF3C (regular fluoride dentifrice/3 cycles of acid challenge) and RF6C (regular fluoride dentifrice/6 cycles of acid challenge) were treated with dentifrices containing 1450 μg F−/g and HF3C (high fluoride dentifrice/3 cycles of acid challenge) and HF6C (high fluoride dentifrice/6 cycles of acid challenge) were with 5000 μg F−/g. Acid challenges were performed for seven days. After bond strength test, there was no significant difference among groups submitted to 3 cycles of acid challenge (P>0.05). Statistically significant difference was found between the regular and high fluoride dentifrices after 6 cycles of acid challenge (<0.05). Similar areas of adhesive remaining were found among control groups and among groups W6C, RF3C, RF6C, HF3C, and HF6C. The high fluoride dentifrice was able to prevent the reduction of bond strength values of brackets submitted to acid challenge. Clinical relevance: the high fluoride toothpaste prevents debonded brackets on erosive enamel

Influência do tratamento de superfície na adaptação externa de cavidade classe V hígida e afetada por cárie submetidas á ciclagem térmica

O presente trabalho propôs avaliar a utilização de clorexidina e laser de Er,Cr:YSGG no processo de adaptação externa em restaurações de cavidades hígidas e afetadas por cárie submetidas a ciclagem térmica. Foram realizados preparos cavitários mistos de classe V vestibular em 36 molares humanos, dos quais metade foram induzidos artificialmente à cárie. Os dentes foram subdivididos em 6 grupos, cavidade hígida: sem tratamento prévio, utilização de clorexidina e utilização de laser de Er,Cr:YSGG e cariados: sem tratamento prévio, utilização de clorexidina e utilização de laser de Er,Cr:YSGG. Foi empregado o sistema adesivo Single Bond 2 (3M ESPE, St. Paul, MN, EUA) e resina composta Filtek Z350 XT (3M ESPE, St. Paul, MN, EUA). Os espécimes foram submetidos a 3000 ciclos térmicos (5-55° C em banihos de 60 segundos). Para avaliação da adaptação externa foram obtidas réplicas de epóxi pela impressão da superfície das restaurações. Foi realizada a análise quantitativa da adaptação externa, tanto em dentina hígida quanto afetada, por meio de réplicas de epóxi, utilizando MEV. Os valores porcentuais de margem contínua mostraram que não houve diferença estatisticamente significante em relação aos diferentes tratamentos de superfície e a ciclagem térmica pode influenciar nos valores de adaptação quando comparado os valores antes e após a ciclagemThe present study proposed to evaluate the use of chlorhexidine and laser Er,Cr:YSGG in the process of external adaptation in mixed healthy and caries affected cavities subjected to thermal cycling. Mixed class V cavity preparations were performed on the buccal surface of 36 human molars, Half of them were artificially caries induced. After this procedure, the teeth received different forms of surface treatment: without previous treatment, use of chlorhexidine and the use of Er,Cr:YSGG. Adhesive system Single Bond 2 and Z350 XT composite resin were used to restoration. The specimens were subjected to 3000 thermal cycles (5-55°C 60 seconds). Epoxy replicas were obtained and then observed under SEM to verify the external adaptation. It was concluded that the application of laser and chlorhexidine did not affect the percentages of marginal adaptation of Class V restorations. Furthermore, thermocycling may influence adaptation valuesCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES