Resistência de união e microinfiltração em restaurações de resina

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Accuracy of radiographic examination in determining the depth of approximal carious lesions in primary molars

The purpose of this study was to evaluate the accuracy of the depth of carious lesions on bitewing radiographs. Methods Recently extracted primary molars had their proximal surfaces evaluated visually (EC) and classified as healthy surface (0), signs that suggest the presence of carious lesions in enamel (1), signs of a superficial lesion in dentin (2) and carious lesions in deep dentin (3). Results The results were obtained by consensus between the investigators. The gold standard was determined by histological analysis. The values of sensitivity, specificity, accuracy and area under the ROC (Receiver Operating Characteristic) curve were evaluated. There was equilibrium between sensitivity (76.92% EC and 88.46% ER) and specificity (95.83% EC and 95.83% ER). Accuracy was 86.01% (EC) and 88.46% (ER). The Spearman correlation test was used to prove the correlation between clinical and radiographic examinations (0.886), for clinical and histological (0.736) and for radiographic and histological analysis (0.843).

Desgaste e rugosidade superficial de um cimento de ionômero de vidro nanoparticulado

To compare the abrasion wear resistance and superficial roughness of different glass ionomer cements used as restorative materials, focusing on a new nanoparticulate material. Material and Method: Three glass ionomer cements were evaluated: Ketac Molar, Ketac N100 and Vitremer (3M ESPE, St. Paul, MN, USA), as well as the Filtek Z350 (3M ESPE, St. Paul, MN, USA). For each material were fabricated circular specimens (n=12), respecting the handling mode specified by the manufacturer, which were polished with sandpaper disks of decreasing grit. The wear was determined by the amount of mass (M) lost after brushing (10,000 cycles) and the roughness (Ra) using a surface roughness tester. The difference between the Minitial and Mfinal (ΔM) as well as beroughness of aesthetic restorative materials: an in vitro comparison. SADJ. 2001; 56(7): 316-20. 11. Yip HK, Peng D, Smales RJ. Effects of APF gel on the physical structure of compomers and glass ionomer cements. Oper. Dent. 2001; 26(3): 231-8. 12. Ma T, Johnson GH, Gordon GE. Effects of chemical disinfectants on the surface characteristics and color of denture resins. J Prosthet Dent 1997; 77(2): 197-204. 13. International organization for standardization. Technical specification 14569-1. Dental Materials – guidance on testing of wear resistance – PART I: wear by tooth brushing. Switzerland: ISO; 1999. 14. Bollen CML, Lambrechts P, Quirynen M. Comparison of surface roughness of oral hard materials to the threshold surface roughness for bacterial plaque retention: a review of the literature. Dent Mater.1997; 13(4): 258-9. 15. Kielbassa AM, Gillmann C, Zantner H, Meyer-Lueckel H, Hellwig E, Schulte-Mönting J. Profilometric and microradiographic studies on the effects of toothpaste and acidic gel abrasivity on sound and demineralized bovine dental enamel. Caries Res. 2005; 39(5): 380-6. 16. Tanoue N, Matsumara H, Atsuta M. Wear and surface roughness of current prosthetic composites after toothbrush/dentifrice abrasion. J Prosthet Dent. 2000; 84(1): 93-7. 17. Heath JR, Wilson HJ. Abrasion of restorative materials by toothpaste. J Oral Rehabil. 1976; 3(2): 121-38. 18. Frazier KB, Rueggeberg FA, Mettenburg DJ. Comparasion of wearresistance of class V restorative materials. J Esthet Dent. 1998; 10(6): 309-14. 19. Momoi Y, Hirosakil K, Kohmol A, McCabe JF. In vitro toothebrushdentifrrice abrasion of resin-modified glass ionomers. Dent Mater. 1997; 13(2): 82-8. 20. Turssi CP, Magalhães CS, Serra MC, Rodrigues Jr.AL. Surface roughness assessment of resin-based materials during brushing preceded by pHcycling simulations. Oper Dent. 2001; 26(6): 576-84. 21. Wang L, Cefaly DF, Dos Santos JL, Dos Santos JR, Lauris JR, Mondelli RF, et al. In vitro interactions between lactic acid solution and art glassionomer cements. J Appl Oral Sci. 2009; 17(4): 274-9. 22. Carvalho FG, Fucio SB, Paula AB, Correr GM, Sinhoreti MA, PuppinRontani RM. Child toothbrush abrasion effect on ionomeric materials. J Dent Child (Chic). 2008; 75(2): 112-6. 23. Coutinho E, Cardoso MV, De Munck J, Neves AA, Van Landuyt KL, Poitevin A, et al. Bonding effectiveness and interfacial characterization of a nano-filled resin-modified glass-ionomer. Dent Mater. 2009; 25(11): 1347-57. tween Rainitial and Rafinal (ΔRa) were also used for statistical analysis (α=0.05). Results: Except for the composite, significant loss of mass was observed for all glass ionomer cements and the ΔM was comparable for all of them. Significant increase in roughness was observed only for Vitremer and Ketac N100. At the end of the brushing cycle, just Vitremer presented surface roughness greater than the composite resin. Conclusion: All glass ionomer cements showed significant weight loss after 10,000 cycles of brushing. However, only Vitremer showed an increase of roughness greater than the Z350 resin, while the nanoparticulate cement Ketac N100 showed a smooth surface comparable to the composite.

Digital radiography for determination of primary tooth length: in vivo and ex vivo studies

Background. Methods for determining the root canal length of the primary tooth should yield accurate and reproducible results. In vitro studies show some limitations, which do not allow their findings to be directly transferred to a clinical situation. Aim. To compare the accuracy of radiographic tooth length obtained from in vivo digital radiograph with that obtained from ex vivo digital radiograph. Method. Direct digital radiographs of 20 upper primary incisors were performed in teeth (2/3 radicular resorption) that were radiographed by an intraoral sensor, according to the long-cone technique. Teeth were extracted, measured, and mounted in a resin block, and then radiographic template was used to standardise the sensor-target distance (30 cm). The apparent tooth length (APTL) was obtained from the computer screen by means of an electronic ruler accompanying the digital radiography software (CDR 2.0), whereas the actual tooth length (ACTL) was obtained by means of a digital calliper following extraction. Data were compared to the ACTL by variance analysis and Pearson’s correlation test. Results. The values for APTL obtained from in vivo radiography were slightly underestimated, whereas those values obtained from ex vivo were slightly overestimated. No significance was observed between APTL and ACTL. Conclusion. The length of primary teeth estimated by in vivo and ex vivo comparisons using digital radiography was found to be similar to the actual tooth length.

Indirect cytocompatibility of a low-concentrated hydrogen peroxide bleaching gel to odontoblast-like cells

Aim To assess the initial cytotoxicity and the late phenotype marker expression of odontoblast-like cells (MDPC-23) subjected to less aggressive in-office bleaching therapies. Methodology A 17.5% hydrogen peroxide (H2O2) gel was applied for 45, 15 or 5 min to enamel/dentine discs adapted to trans-wells positioned over cultured MDPC-23 cells. No treatment was performed on the negative control. Immediately after bleaching, the cell viability, gene expression of inflammatory mediators and quantification of H2O2 diffusion were evaluated. The ALP activity, DSPP and DMP-1 gene expression and mineralized nodule deposition (MND) were assessed at 7, 14 or 21 days post-bleaching and analysed statistically with Mann–Whitney U-tests (α = 5%). Results H2O2 diffusion, proportional to treatment time, was observed in all bleached groups. Reductions of approximately 31%, 21% and 13% in cell viability were observed for the 45-, 15- and 5-min groups, respectively. This reduction was significant (P < 0.05) for the 45- and 15-min groups, which also presented significant (P < 0.05) over-expression of inflammatory mediators. The 45-min group was associated with significant (P < 0.05) reductions in DMP-1/DSPP expression at all periods, relative to control. The ALP activity and MND were reduced only in initial periods. The 15-min group had less intense reduction of all markers, with no difference to control at 21 days. Conclusions The 17.5% H2O2 applied to tooth specimens for 5 min caused no alteration in the odontoblast-like cells. When this gel was applied for 45 or 15 min, a slight cytotoxicity, associated with alterations in phenotypic markers, was observed. However, cells were able to recover their functions up to 21 days post-bleaching.

Responses of dental pulp cells to a less invasive bleaching technique applied to adhesive restored teeth

To assess the cytotoxicity of 35% hydrogen peroxide (HP) bleaching gel applied for 15 min to sound or restored teeth with two-step self-etching adhesive systems and composite resin. Materials and Methods: Sound and restored enamel/dentin disks were stored in water for 24 h or 6 months + thermocycling. The disks were adapted to artificial pulp chambers and placed in compartments containing culture medium. Immediately after bleaching, the culture medium in contact with dentin was applied for 1 h to previously cultured odontoblast-like MDPC-23 cells. Thereafter, cell viability (MTT assay) and morphology (SEM) were assessed. Data were analyzed by two-way ANOVA and Tukey's test (a = 5%). Results: In comparison to the negative control group (no treatment), no significant cell viability reduction occurred in those groups in which sound teeth were bleached. However, a significant decrease in cell viability was observed in the adhesive-restored bleached groups compared to negative control. No significant difference among bleached groups was observed with respect to the presence of restoration and storage time. Conclusion: The application of 35% HP bleaching gel to sound teeth for 15 min does not cause toxic effects in pulp cells. When this bleaching protocol was performed in adhesive-restored teeth, a significant toxic effect occurred.

Variáveis que afetam o procedimento de colagem direta ortodôntica: braquetes e materiais adesivos

Following the introduction of the acid-etching technique in enamel surface, direct attachment of orthodontic appliances on the surface of the tooth and/or restorations became a routine procedure in the assembly of the fixed devices. The attainment of a success result is related to the criterion attention to the details and the steps of the bonding technique, as well as, to the knowledge of the characteristics of the adhesive materials and orthodontic brackets. This paper presents some aspects of various types of brackets and adhesives materials.

The performance of conventional and fluorescence-based methods for occlusal caries detection: an in vivo study with histological validation

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Controlling mechanical undesirable side effects with a tooth indicated for extraction: free anchorage

This manuscript describes the use of a tooth indicated for extraction due
to orthodontic reasons as an anchorage aid to receive undesirable side effects caused by orthodontic uprighting of a contralateral molar tooth. The mandibular right second molar was mesially tipped as a result of loss of the adjacent first molar. Since the treatment plan involved extraction of the mandibular left first premolar, undesirable side effects associated with the molar uprighting movement were transferred to this tooth. Once the second molar was vertical, the premolar was extracted and the treatment continued. The results suggest that treatment time can be reduced if undesirable orthodontic mechanical side effects can be directed to a tooth whose extraction is indicated.

Efeito citotóxico de agentes clareadores a base de peróxido de hidrogênio a 20% e 38% sobre células odontoblastóides

The aim of this in vitro study was to evaluate the trans-enamel and transdentinal cytotoxic effects of two in-office tooth bleaching techniques that employ bleaching gels containing 20% and 38% of H2 O2 on cultured odontoblast-like cell line (MDPC-23). Sixty enamel/dentin discs were obtained from bovine central incisors and placed individually in artificial pulp chambers. Six groups were formed according to the following enamel treatments: G1- 20% H2 O2 (1 application); G2- 20% H2 O2 (2 applications); G3- 38% H2 O2 (1 application); G4- 38% H2 O2 (2 applications); G5- 38% H2 O2 (3 applications); and G6- control (no treatment). In G1 and G2, the bleaching gel was left in contact with the enamel surface for 45 min in each application. However, in G3, G4, and G5 the bleaching gel was applied for only 10 min per application. After the last application, the extracts were collected and applied on previously cultured cells (30.000 cells/cm2 ) for 24 h. Cell metabolism was evaluated by the MTT assay and cell morphology was analysed by scanning electron microscopy. Cell metabolism decreased by 96.29%; 96.11%; 96.42%; 95.62%; and 97.18% in G1, G2, G3, G4, and G5, respectively. All treated groups differed significantly from non-treated control group (G6) (p < 0.05). However, the difference in cell metabolism among treated groups was not significant statistically. In addition, significant morphological cell alterations were observed in all treated groups. Under the tested experimental conditions, the extracts collected after both tooth bleaching techniques evaluated in this study caused severe toxic effects on cultured odontoblast-like cell MDPC-23.

Tratamento do sorriso gengival: como estabelecer proporção e harmonia

The etiology of gingival smile is multifactorial and the correct diagnosis eill determine a successful treatment planning. Altered passive eruption occurs during the final stages of tooth eruption, when apical migration of the periodontal tissues does not occur, resulting in a distance > 2mm between the alveolar crest and the cement-enamel juncrion. This change leads to the shortening of the clinical crown and even further may lead to excessive gingival exposure. For treatment, there is a necessity for the combined removal of gingiva and bone tissue. This article discusses the literature on the issue and reports a case where periodontal plastic surgery was performed for the correcrion of a gingival smile.

Associação da raspagem com antibioticoterapia em um caso de periodontite agressiva generalizada

The treatment of aggressive periodontitis is a challenge to the clinician, therefore the search for effective treatment protocols of this disease is important. The aim of this case report was demonstrate the effectiveness of the combination of systemic antibiotics with non-surgical periodontal therapy in the treatment of generalized aggressive periodontitis. a 27-year-old patient (RCS), smoker for 11 years (10 cigarettes/day on average), with no systemic alteration, attended the periodontal clinic with a complaint abnormal dental position. After the clinical examination, the diagnosis of generalized aggressive periodontitis was defined. The non-surgical periodontal treatment was executed associated with administration of amoxicillin plus metronidazole for ten days. Clinical parameters (Clinical Attachment level, marginal gingival level, periodontal probing depth, bleeding on probing, plaque index and gingival index) and radiographic parameters (distance between the cemento-enamel junction and the bone crest) were evaluated before and after non-surgical periodontal treatment, after antibiotic therapy and three, six and 12 months after the treatment. After one year follow-up, the results showed improvement in clinical and radiographic parameters with stabilized and decreased tooth mobility and absence of tooth loss. It was concluded that the association of non-surgical periodontal therapy with the administration of amoxicillin/metronidazole was effective in the treatment of generalized aggressive periodontitis.

A combined approach for the treatment of resorbed fresh sockets allowing immediate implant restoration: a 2-year follow-up

Introduction: The demand for optimal esthetics has increased with the advance of the implant dentistry and with the desire for easier, safer and faster technique allowing predictable outcomes. Thus, the aim of this case report was to describe a combined approach for the treatment of a periodontally compromised tooth by means of atraumatic tooth extraction, immediate flapless implant placement, autogenous block and particulate bone graft followed by connective tissue graft and immediate provisionalization of the crown in the same operatory time. Case Report: A 27-year-old woman underwent the proposed surgical procedures for the treatment of her compromised maxillary right first premolar. The tooth was removed atraumatically with a periotome without incision. A dental implant was inserted 3 mm apical to the cement-enamel junction of the adjacent teeth enabling the ideal tridimensional implant position. An osteotomy was performed in the maxillary tuber for block bone graft harvesting that allowed the reconstruction of the alveolar buccal plate. Thereafter, an autogenous connective tissue graft was placed to increase both the horizontal and vertical dimensions of the alveolar socket reaching the patient functional and esthetic expectations. Conclusion: This treatment protocol was efficient to create a harmonious gingival architecture with sufficient width and thickness, maintaining the stability of the alveolar bone crest yielding excellent aesthetic results after 2-years of follow-up. We suggest that this approach can be considered a viable alternative for the treatment of periodontally compromised tooth in the maxillary esthetic area enhancing patient comfort and satisfaction.

Efeito de um gel de peróxido de carbamida a 10% sobre a resistência de união de restaurações adesivas à dentina

The present study aimed to analyze the effects of tooth bleaching with 10% carbamide peroxide (CP) gel on the bond strength of resin composite restorations to dentin. Material and Methods: Twenty cavities were prepared on the buccal surface of bovine teeth. After acid etching and application of bonding agent on dentin and enamel, the cavities were restored with composite resin. The specimens were divided into groups according to treatment on the surface of enamel / restoration: G1 - control (no treatment) and G2 (10% PC gel application for 8h/day during 14 days). After this period, the teeth were cut to produce beams with 0.81 mm2 cross-sectional area, which were subjected to microtensile test. The fractures were examined with a stereomicroscope and classified as cohesive in resin or dentin, adhesive, or mixed. Results: The statistical analysis (ANOVA / χ2) revealed that the factor treatment interfered with the bond strength, which was significantly higher for specimens of G2 (p <0.05). Adhesive fractures occurred in most of specimens of both groups with values ranging from 48.3% to 75%. Mixed fractures were the second more frequent in G1 and cohesive resin failure in G2. Conclusion: It was concluded that tooth bleaching with 10% of PC increased the bond strength of adhesive restorations to dentin.