Impact of a Tutored Theoretical-Practical Training to Develop Undergraduate Students' Skills for the Detection of Caries Lesions: Study Protocol for a Multicenter Controlled Randomized Study.

BACKGROUND: Tutored laboratorial activities could be a manner of improving the competency development of students. However, its impact over conventional theoretical classes has not yet been tested. Additionally, different university contexts could influence this issue and should be explored. OBJECTIVE: To assess the impact of a tutored theoretical-practical training for teaching undergraduate students to detect caries lesions as compared with theoretical teaching activities. The impact of these teaching/learning activities will be assessed in terms of efficacy, cost/benefit, retention of knowledge/acquired competences, and student acceptability. METHODS: Sixteen centers (7 centers from Brazil and 9 centers from other countries throughout the world) are involved in the inclusion of subjects for this protocol. A randomized controlled study with parallel groups will be conducted. One group (control) will be exposed to a 60- to 90-minute conventional theoretical class and the other group (test) will be exposed to the same theoretical class and also a 90-minute laboratory class, including exercises and discussions based on the evaluation of a pool of images and extracted teeth. The mentioned outcomes will be evaluated immediately after the teaching activities and also in medium- and long-term analyses. To compare the long-term outcomes, students who enrolled in the university before the participating students will be interviewed for data collection and these data will be used as a control and compared with the trained group. This stage will be a nonrandomized phase of this study, nested in the main study. Appropriate statistical analysis will be performed according to the aims of this study. Variables related to the centers will also be analyzed and used to model adjustment as possible sources of variability among results. RESULTS: This ongoing study is funded by a Brazilian national funding agency (CNPq- 400736/2014-4). We expect that the tutored theoretical-practical training will improve the undergraduate students' performance in the detection of caries lesions and subsequent treatment decisions, mainly in terms of long-term retention of knowledge. Our hypothesis is that tutored theoretical-practical training is a more cost-effective option for teaching undergraduate students to detect caries lesions. CONCLUSIONS: If our hypothesis is confirmed, the use of laboratory training in conjunction with theoretical classes could be used as an educational strategy in Cariology to improve the development of undergraduate students' skills in the detection of caries lesions and clinical decision-making.

Desempenho de métodos baseados em indução de fluorescência na avaliação da remoção de dentina cariada / Performance of fluorescence-based methods in evaluating dentin caries removal

Introdução: Critérios clínicos vêm sendo utilizados para determinação da presença de tecido cariado remanescente, mas geram dúvidas, tornando-se relevante a utilização de métodos que auxiliem na determinação da presença de cárie dentária remanescente. Objetivo: Avaliar in vitro a eficácia de métodos de indução de fluorescência no diagnóstico da remoção de tecido cariado artificial dentinário. Material e método: O esmalte oclusal de 94 terceiros molares humanos hígidos foi removido, expondo a dentina subjacente, para indução microbiológica de lesão de cárie artificial. Após a remoção do tecido cariado induzido, o remanescente dentinário foi avaliado por dois examinadores com DIAGNOdent, DIAGNOdent pen e Quantitative Light-Induced Fluorescence (QLF). Após todas as avaliações, secções dos dentes foram observadas e fotografadas em lupa estereoscópica com 30× de aumento por um examinador independente. As imagens foram analisadas no software Image J, permitindo a quantificação de tecido remanescente em milímetros quadrados. Foi calculada a reprodutibilidade interexaminador através de coeficiente intraclasse, sensibilidade, especificidade e área sob a curva ROC, e o teste de McNemar (p< 0,05) foi aplicado para comparação dos diferentes métodos. Resultado: Dos 94 dentes, 51 (54,2%) apresentaram remanescente de tecido cariado. Os valores de sensibilidade, especificidade e área sobre a curva ROC foram semelhantes para os três grupos (p> 0,05). Os valores de reprodutibilidade variaram entre 0,952 e 0,978. Conclusão: Dentre os métodos utilizados, o DIAGNOdent e o DIAGNOdent pen apresentaram melhor desempenho na avaliação da presença de cárie artificial remanescente quando comparados ao QLF.

Introduction: Clinical criteria have been used for the determination of the presence of residual caries, however in a subjective manner. Then the use of auxiliary methods that assist in determination of the remaining presence of caries can be considered for this purpose. Objective: Evaluate the in in vitro efficacy fluorescence induction methods in the diagnosis of removing artificial dentinal caries. Material and method: Ninety-four thirds sound human molars without occlusal enamel were used for microbiological artificial caries lesion induction. The decayed tissue was removed and the remaining dentin evaluated by two examiners with DIAGNOdent, DIAGNOdent pen and Quantitative Light-Induced Fluorescence - QLF. After all assessments, sections of the specimens were observed and photographed in stereoscopic lens with 30× increase by an independent examiner. These images were analyzed with Image J software, allowing quantitation of remaining caries tissue in mm2. The inter-examiner reliability, sensitivity, specificity, and area under the ROC curve was calculated and the McNemar test (p< 0.05) was used to compare the different among methods. Result: Of the 94 teeth, 51 (54.2%) had residual caries. The sensitivity, specificity, and area under the ROC curve were similar for the three methods (p> 0.05). The inter-examiner agreement ranged between 0.952 and 0.978. Conclusion: Among the methods used, the DIAGNOdent, DIAGNOdent pen showed better performance in residual caries detection after dentin caries removal when compared to QLF.

Assessment of Enamel Bond Strength of Hypoplastic Primary Teeth.

PURPOSE: The purpose of this study was to compare the enamel bond strength of hypoplastic and healthy primary teeth. METHODS: Twenty-five hypoplastic teeth (experimental group) and 25 healthy primary teeth (control group) were selected and conditioned with 35 percent orthophosphoric acid before a two-layer adhesive system (Single Bond) was applied. Composite resin (Filtek Z350) was inserted in a single application, two-mm high and one-mm in diameter, and then light-cured for 20 seconds. After being stored in distilled water for 24 hours, the specimens were submitted to a shear bond strength test. Fractures were analyzed under a stereomicroscope. RESULTS: No significant differences in bond strength were observed between the experimental group (70.27±20.40 MPa) and control group (67.84±23.37 MPa; P>0.05). However, adhesive fractures were more frequently observed in healthy teeth (72 percent) while hypoplastic teeth presented mixed fractures (60 percent) and enamel cohesive fractures (36 percent). CONCLUSIONS: The shear bond strength of the enamel of hypoplastic primary teeth was similar to that of healthy teeth. However, distinct characteristics were observed in the dental samples following fracture.

Oral Manifestations and Dental Management of Epidermolysis Bullosa Simplex.

Epidermolysis bullosa (EB) is a group of hereditary chronic disorders, characterized by fragility of the skin and mucous membranes in response to minor mechanical trauma. The objective of this study was to report the case of a young girl diagnosed with epidermolysis bullosa simplex (EBS), transmitted by an autosomal dominant gene. Cutaneous findings included blisters and dystrophy following minimal friction. Recurrent blisters and vesicle formation on the hard palate were the main oral findings. In conclusion, publications concerning the oral and clinical manifestations of EBS are important for providing knowledge and an early multidisciplinary approach that prevents blister formation and improves these patients' quality of life, with the dentist playing an important role in oral health management. How to cite this article: Scheidt L, Sanabe ME, Diniz MB. Oral Manifestations and Dental Management of Epidermolysis Bullosa Simplex. Int J Clin Pediatr Dent 2015;8(3):239-241.

Oral, physical, and behavioral aspects of patient with chromosome 47, XYY syndrome.

Chromosome 47, XYY syndrome is usually diagnosed late. Some of the clinical characteristics of XYY syndrome may be perceptible in dental care. The slow development of cognitive and motor activities and tall stature is common in XYY patients. The aim of this article was to relate the oral, physical, and behavioral aspects of a 6-year-old patient with the chromosome 47, XYY syndrome, diagnosed by means of karyotyping. The patient presented motor difficulty, which led to a fall and traumatism in the anterior region. In the radiography, agenesia of the permanent maxillary lateral incisors, presence of taurodontism in the primary molars, and macrodontia of the maxillary central incisors and permanent molars could be observed. Once the diagnosis was made, it was possible to understand his difficulty at school, and make available appropriate monitoring by a suitable multidisciplinary team to stimulate, control, and minimize the day-to-day difficulties found by patients with this syndrome.

Different bacterial models for in vitro induction of non-cavitated enamel caries-like lesions: Microhardness and polarized light miscroscopy analyses.

The aim of this study was to compare different bacterial models for in vitro induction of non-cavitated enamel caries-like lesions by microhardness and polarized light microscopy analyses. One hundred blocks of bovine enamel were randomly divided into four groups (n = 25) according to the bacterial model for caries induction: (A) Streptococcus mutans, (B) S. mutans and Lactobacillus acidophilus, (C) S. mutans and L. casei, and (D) S. mutans, L. acidophilus, and L. casei. Within each group, the blocks were randomly divided into five subgroups according to the duration of the period of caries induction (4-20 days). The enamel blocks were immersed in cariogenic solution containing the microorganisms, which was changed every 48 h. Groups C and D presented lower surface hardness values (SMH) and higher area of hardness loss (ΔS) after the cariogenic challenge than groups A and B (P < 0.05). As regards lesion depth, under polarized light microscopy, group A presented significantly lower values, and groups C and D the highest values. Group B showed a higher value than group A (P < 0.05). Groups A and B exhibited subsurface caries lesions after all treatment durations, while groups C and D presented erosion-type lesions with surface softening. The model using S. mutans, whether or not it was associated with L. acidophilus, was less aggressive and may be used for the induction of non-cavitated enamel caries-like lesions. The optimal period for inducing caries-like lesions was 8 days.

Exposed collagen in aged resin-dentin bonds produced on sound and caries-affected dentin in the presence of chlorhexidine.

PURPOSE: To evaluate the effect of chlorhexidine on the presence of collagen in aged resin-dentin bonds produced on sound and caries-affected dentin. MATERIALS AND METHODS: Flat dentin surfaces were obtained from 16 sound molars, from which 8 were microbiologically processed for induction of caries. Single Bond 2 was applied to both sound and caries-affected substrates. In half of the teeth assigned for 6-month storage in water, the phosphoric acid demineralized dentin was impregnated with 2% chlorhexidine before the application of the adhesive. Specimens (2 x 2 x 5 mm) were produced and stored in water for 24 h, or 6 months in either water or mineral oil. The specimens were subjected to histological processing and sections were stained with Goldner's Trichrome. The thickness of the zone of exposed collagen was measured by optical microscopy and the data were subjected to two-way ANOVA and Tukey's test (α = 0.05). RESULTS: There was no statistically significant difference (p > 0.05) between sound and caries-affected dentin regardless of the storage condition. For both substrates, significantly greater collagen exposure was observed after 6 months in water. Chlorhexidine-treated groups resulted in similar collagen exposure to that of the control and 6 months in water groups (p > 0.05), while no increase of the exposed collagen zone was observed after mineral oil storage. CONCLUSION: Aging in water resulted in degradation of the resin-dentin bond, as demonstrated by the increase of the zone of exposed collagen. However, the degradation of the exposed collagen was decelerated in the presence of chlorhexidine.

Sedação consciente: um recurso coadjuvante no atendimento odontológico de crianças não cooperativas / Conscious sedation: a backup resource for providing dental care to uncooperative children

Na prática clínica, existem muitas crianças imaturas e ansiosas ou pacientes com comportamento físico e/ou metal que não cooperam durante o tratamento odontológico. Como alternativa para o manejo desses pacientes utiliza-se a sedação consciente através da pré-medicação ou sedação com o óxido nitroso/ oxigênio. Essas técnicas, quando empregadas de maneira adequada, são válidas e seguras, obtendo-se ótimos resultados principalmente com crianças. Desta forma, o objetivo deste estudo é relatar os tipos de sedação conscientes mais utilizados em odontopediatria, como uma alternativa no tratamento odontológico de crianças com comportamento difícil.(AU)

In clinical practice, there are immature and anxious children or patients with physical and/or mental behavior who do not cooperate when dental care is being provided. Conscious sedation with premedication or sedation with nitrous oxide is used as an alternative for the management of these patients. When these techniques are used correctly they are considered valid and safe, and excellent results are commonly obtained, especially with children. Thus, the objective of this study is to report the types of conscious sedation most often used in pediatric dentistry as alternative sedation methods for providing dental treatment to children with difficult behavior.(AU)

Effect of chlorhexidine on bond strength of two-step etch-and-rinse adhesive systems to dentin of primary and permanent teeth.

PURPOSE: To evaluate the influence of chlorhexidine digluconate (CHX) application on the immediate microtensile bond strength (microTBS) of two-step etch-and-rinse adhesive systems to the dentin of primary and permanent teeth. METHODS: Noncarious human teeth (24 primary molars and 24 premolars) were used. The primary and permanent teeth were randomly assigned to three groups (n = 8) according to the adhesive system: Adper Single Bond, Prime & Bond NT and Excite DSC. Each group was further divided in two subgroups (n = 4) in which the phosphoric acid-etched dentin was treated with 20 microL of either 2% CHX or deionized water for 60 seconds prior to adhesive system application. The adhesive systems were applied according to the manufacturers' instructions and resin composite blocks were built up on the treated surfaces. The teeth were vertically sectioned perpendicular to adhesive interface and beam-shaped specimens with a 0.81 mm2 cross-sectional area were obtained and subjected to microTBS testing at a crosshead speed of 0.05 mm/minute. MicroTBS data were analyzed statistically by ANOVA and Tukey's test (alpha = 0.05). The failure modes were verified with a stereomicroscope. RESULTS: CHX application increased significantly (P < 0.05) the microTBS of Prime & Bond NT and Single Bond to the acid-etched primary and permanent dentin, while no positive or negative effect was observed for Excite DSC. There was a predominance of adhesive failures in all control and CHX-treated groups. No fracture distribution pattern was observed.

Acurácia das medidas de limas endodônticas em radiografias digital e convencional: estudo in vitro em dentes decíduos / Conventional and digital endodontic files measurement accuracy: an in vitro on primary teeth

O presente estudo tem por objetivo avaliar a acurácia das medidas de limas endodônticas obtidas em radiografias digitais e convencionais de dentes decíduos. Para tanto, limas tipo K e Hedstroen calibre 20, com cursor registrando o comprimento aparente do dente, foram introduzidas no interior do canal de 18 incisivos decíduos extraídos, que foram radiografados pela técnica digital direta e convencional. Medidas da distância do cursor à extremidade apical da lima foram realizadas por um profissional treinado e repetidas no intervalo de uma semana, com auxílio de régua eletrônica na radiografia digital e paquímetro digital na radiografia convencional. Os dados obtidos foram analisados pelo teste de correlação de Pearson e teste t (p=0,05). A correlação entre o primeiro e o segundo exames foi r=0,99, independentemente do tipo de lima utilizado, tanto para a radiografia digital quanto para a convencional. Em relação ao tipo de lima, Kerr ou Hedströen, a concordância foi r=0,99 nos dois métodos radiográficos. Comparando-se as medidas obtidas na radiografia digital com as da convencional, a concordancia foi r=0,96 para as limas tipo K e r=0,95 para as limas Kedströen. Os valores de comprimento das limas na radiografia digital foram estatisticamente inferiores aos obtidos na radiografia convencional (p=0,02); no entanto, as medidas obtidas nos dois métodos radiográficos foram estatisticamente semelhantes ao compromisso real do dente tanto para as limas tipo K (p=0,029) quanto para as limas Heddströes (p=0,18). Conclui-se que a radiografia digital se mostrou um método confiável para obtenção do comprimento de limas endodônticas

Bond strength of two-step etch-and-rinse adhesive systems to the dentin of primary and permanent teeth.

OBJECTIVE: The purpose of this study was to compare the immediate microtensile bond strength (microTBS) of two-step etch-and-rinse adhesive systems to the dentin of primary and permanent teeth. STUDY DESIGN: Non-carious human teeth (12 primary molars and 12 premolars) were assigned to 3 groups according to the adhesive system. The adhesive systems were applied to flat superficial coronal dentin surfaces etched with phosphoric acid and composite resin blocks were built up. The teeth were sectioned to produce beam-shaped specimens with 0.81 mm2 cross-sectional area subjected to microTBS testing. MicroTBS data were analyzed statistically by ANOVA and Tukey's test (a = 0.05). RESULTS: The adhesive systems produced statistically similar mean microTBS to each other (p > 0.05) and no significant differences (p > 0.05) were found when the same material was applied to primary or permanent tooth dentin. The mean microTBS values (MPa) obtained were: Prime & Bond NT: 41.7 +/- 14.4 (permanent) and 40.8 +/- 13.4 (primary); Single Bond: 42.9 +/- 8.6 (permanent) and 41.4 +/- 11.9 (primary); Excite DSC: 46.3 +/- 11.3 (permanent teeth) and 43.4 +/- 12.0 (primary). CONCLUSION: There was no difference in the immediate microTBS of two-step etch-and-rinse adhesive systems when applied to the dentin of primary and permanent teeth.

Urgências em traumatismos dentários: classificação, características e procedimentos / Dental traumatism urgencies: classification, signs and procedures

OBJETIVO: Discutir os aspectos das urgências odontológicas relacionadas aos traumatismos dentários, disponibilizando mais informações para médicos pediatras ou plantonistas de serviços de atendimento de urgências e emergências. FONTES DE DADOS: O levantamento dos dados foi realizado na base de dados Pubmed e Bireme, selecionando os artigos dos últimos 13 anos. As palavras-chave utilizadas foram: traumatismo dentário, dente decíduo e dente permanente. Os critérios de inclusão utilizados foram: artigos em inglês e português sobre incidência, prevalência e etiologia, guias de procedimentos e casos clínicos apenas de traumatismo dentário, sendo excluídos artigos de clareamento de dentes traumatizados, traumas faciais ósseos e casos clínicos de acompanhamento reduzido. SÍNTESE DOS DADOS: Os dados foram descritos de forma concisa para se tornar um guia de fácil leitura e rápido acesso em relação à conduta, necessidade de atendimento imediato e correta escolha de soluções para armazenagem dos dentes e fragmentos. CONCLUSÕES: O conhecimento sobre o assunto, a agilidade no tratamento de urgência e o correto encaminhamento do paciente proporcionam melhor prognóstico.

OBJECTIVE: The aim of this literature review is to discuss the clinical aspects of dental urgencies related to dental traumatisms, providing more information for health professionals who work in emergency units, such as pediatricians or physicians on-call and nurses. DATA SOURCE: The studies were searched and selected in the Pubmed and Bireme databases, from the past 13 years. The keywords were: tooth injuries, deciduous tooth and permanent tooth. The inclusion criteria were: articles written in English and Portuguese related to incidence, prevalence, cause, guidelines and case reports of dental traumatism. Studies about dental bleaching in dental trauma, face bone trauma and reduced post-operative case reports were excluded. DATA SYNTHESIS: The data were briefly described so that it can be easily read and quickly accessible regarding procedures, urgency attention and correct choice for dental and fragment storage. CONCLUSIONS: The knowledge on the subject, the agility to deal with urgent situations and the correct patient follow-up improve prognosis.

Artificial methods of dentine caries induction: A hardness and morphological comparative study.

OBJECTIVE: To assess the ability of two chemical and a microbiological methods to produce dentine caries lesions resembling naturally developed dentine caries lesions. DESIGN: Forty sound second primary molars were divided into four experimental groups according to the method to produce artificial caries lesions: (1) sound (negative control); (2) acidified gel; (3) pH-cycling; and (4) microbiological, all for 14 days. Ten second primary molars presenting natural dentine caries lesions comprised the (5) positive control group. After the artificial caries induction, all samples were longitudinally sectioned and polished in order to obtain Knoop microhardness values from 10 to 500microm depth from the bottom of the cavities. Morphological analysis of the surfaces was carried out by SEM. Hardness data were compared among the five experimental groups using One-Way ANOVA and post hoc SNK's test. RESULTS: The hardness values of chemically created caries-like lesions did not differ from that of natural caries lesions on shallower depths. The results indicated that chemical caries induction methods promote a superficial demineralization and that pH-cycling is more effective than acidified gel. The former, produced a thicker layer of demineralization, with similar hardness values than natural lesions. Despite the microbiological method provided an excessive softness of the primary dentine, this method presented morphology more comparable to natural lesions. CONCLUSIONS: pH-cycling is more appropriated to simulate a substrate that resembles affected caries dentine layer, after caries removal. The microbiological method seems more indicated to simulate a dentine caries lesion with an infected layer, previously to caries removal.

Ação cariostátixa de selantes ionomérixos aderidos ao esmalte com sistemas adesivos autocondicionantes simplicados / Cariostatic effect of resin-modified glass-ionomer sealants bonded to unground enamel with one-bottleself-etching adhesives

O objetivo desse estudo foi investigar a perda mineral do esmalte não desgastado ao redor de selantesionoméricos aderidos por sistemas autocondicionantes. Trinta e dois incisivos bovinos foram distribuídosem 3 grupos segundo o tratamento da superfície de esmalte: Prompt (Pr), Xeno III (Xe), Vitremer Primer (VP)e um outro grupo (controle) utilizando resina composta (RC). Após o tratamento do esmalte, um cilindro deionômero de vidro Vitremer foi construído, com exceção do grupo RC, onde foi utilizado o compósito Z250.Os espécimes foram submetidos à desafio cariogênico e seccionados, ao final do mesmo, para realizaçãode testes de dureza. Edentações foram realizadas em 3 regiões para cada uma das faces incisal e cervical,até a profundidade de 300 μm. Apenas para o grupo RC foi observada perda mineral significante na regiãoexterna à margem esmalte-resina. Nessa mesma região, a comparação dos grupos (testes de Mann-Withney)demonstrou que os maiores valores de perda mineral foram obtidos para o grupo RC, enquanto nenhumadiferença foi observada para VP, Pr e Xe. Pôde ser concluido que a utilização de sistemas adesivosautocondicionantes simplificados não afetou de forma adversa o efeito cariostático do cimento de ionômerode vidro modificado por resina aplicado ao esmalte não desgastado.

The purpose of this study was to investigate the mineral loss of the unground enamel around resinmodifiedglass ionomer sealants bonded with one-step self-etching adhesive systems. Thirty-two bovine incisorswere randomly assigned into 4 groups according to the enamel surface treatment: Prompt (Pr), Xeno III(Xe), Vitremer (VP) or resin (RC). Followed the enamel treatment, a cylinder of Vitremer was built-up, exceptfor RC where a composite resin Z250 was used. The teeth were submitted to a cariogenic challenge and cutinto halves by the end of the cycle to enamel hardness determination. Indentations were performed in threeregions for each face, incisal and cervical, up to the depth of 300 μm. As results, only for RC it was detectedsignificant mineral loss in the external area of the enamel-resin margin. For that same area, the comparisonof the groups (Mann-Withtney tests) demonstrated the highest mineral lost for RC, while no difference wasobserved among VP, Pr and Xe. It could be concluded that the use of one-step self-etching adhesive systemsas intermediary layer to improve the retention of a resin-modified glass-ionomer sealant to the ungroundenamel did not adversely influence its cariostatic effect.

Digital versus conventional radiography for determination of primary incisor length

Aim: This in vitro study evaluated the accuracy of primary incisor lengths determined by digital and conventional radiography compared to the actual tooth length. Methods: Twenty extracted primary maxillary incisors were mounted in acrylic blocks. Tooth length was estimated by using a straight-line measurement provided by the distance measurement tool of a digital dental imaging system (Computed Dental Radiography, Schick Technologies Inc.) and conventional E-speed film radiographs by using a digital caliper. Two operators familiar with both radiographic methods performed the estimates. The estimated tooth lengths were compared to the actual tooth lengths measured with the digital caliper. Data were statistically analyzed by Dahlberg’s equation, paired t test, Pearson’s correlation coefficient and ANOVA at 5% significance level. Results: There were no statistically significant differences (p = 0.85) between tooth length estimated on digital and conventional radiographs. Admitting as clinically acceptable a 0.5-mm discrepancy between the actual tooth lengths and the radiographically estimated lengths, 60% of the radiographic measurements were considered as accurate. When the acceptable difference range was 1.0 mm, the accuracy of the radiographic measurements increased to 100%. Conclusions: Digital and conventional radiography provided similar tooth length measurements and were equivalent to the actual tooth lengths.

Effect of acid etching time on the degradation of resin-dentin bonds in primary teeth.

PURPOSE: To investigate the influence of etching time on the degradation of resin-dentin bonds produced in primary teeth. METHODS: 40 primary molars were randomly divided into four groups according to the adhesive system, Single Bond (SB) and Clearfil SE Bond (CSEB), and acid etching time. SB was applied to dentin after phosphoric acid etching for 15 or 7 seconds, whereas CSEB was applied after the application of SE Primer for 20 or 10 seconds. Resin composite crowns were built-up followed by the production of specimens with a cross-sectional area of 0.49 mm2, which were further divided according to the storage condition, 24 hours, 6 and 12 months in water. Data were submitted to ANOVA and Tukey tests (alpha=0.05). RESULTS: After 24 hours there was no significant difference between bond strengths produced by the adhesive systems, irrespective of the acid etching time. Water storage for 6 and 12 months significantly reduced bond strengths of SB, especially when the dentin was acid etched for 15 seconds. For CSEB, no significant alteration in bond strength was seen up to the storage period of 12 months for both etching times.

Efeito da smear layer na degradação da união entre a dentina e um sistema adesivo autocondicionante / Effect of the smear layer on the degradation of dentin bonds produced by a self-etching adhesive system

O objetivo deste estudo foi avaliar o efeito da incorporação da smear layer na degradação da união resina-dentina produzida por um sistema adesivo primer autocondicionante. Superfícies planas em dentina foram obtidas de 24 molares e divididas em três grupos (n = 8) de acordo com o tratamento da smear layer: sem remoção (G1), remoção com ácido fosfórico (G2) ou EDTA (G3). Após o tratamento da smear layer, o sistema Clearfil SE Bond foi aplicado, seguido da construção da coroa em resina. Os dentes foram seccionados para a produção de espécimes comárea de secção transversal de 1 mm2, que foram armazenados por 24 horas ou 24 meses em água previamente ao ensaio mecânico de microtração. Aos dados de resistência de união (RU), foramaplicados teste-t de Student e de ANOVA a um critério fixo, complementado por teste de Tukey (a = 0,05). Os maiores valores de RU para ambos os períodos de envelhecimento foram registrados para G3. Redução significante da RU foi observada para todas as condições de tratamento da smear layer: 21,6, 26,6 e 21,7% para G1, G2 e G3, respectivamente. Em conclusão, embora a remoção da smear layer com EDTA tenha favorecido o aumento da resistência de união imediata do sistema Clearfil SE Bond, a degradação da união resina-dentina não foi negativamente afetada pela incorporação dessa estrutura.

The aim of this study was to evaluate the effect of the incorporation of the smear layer on the degradation of resin-dentin bonds produced by a self-etching adhesive system. Flat dentin surfaces were produced from 24 molars and randomly assigned to three groups (n = 8)according to the treatment of the smear layer, no removal (G1), removal with phosphoric acid (G2) or EDTA (G3). After treating the smear layer, Clearfil SE Bond was applied on the surface followed by the built-up of a resin crown. The teeth were cut to produce specimens with a crosssectional area of 1 mm2, which were stored in water for 24 hours or 24 months before being tested under tension. Bond strength data were analyzed by Student?s t-tests and ANOVA complemented by Tukey at a preset level of significance of 5%. The highest bond strengths, for both periods of aging, were produced in G3. Significant reduction in bond strength was recorded for all groups, 21.6, 26.6 and 21.7% for G1, G2 and G3, respectively. In conclusion, although the removal of the smear layer with EDTA significantly improved the immediate bond strength, the incorporation of the smear layer did not adversely affect the biodegradation of resin-dentin bonds.

Influência da contaminação da dentina por cimentos temporários na resistência da união de sistemas adesivos / Influence of dentin contamination by temporary cements on the bond strength of adhesive systems

Objetivo: Avaliar a resistência da união de sistemas adesivos à dentina contaminada por cimentos temporários com ou sem eugenol. Método: Foram obtidas superfícies planas de dentina de 24 terceiros molares humanos. Com exceção do grupo controle (n=8), as superfícies foram cobertas com Interim Restorative Material (Caulk Dentsplay, Milford, DE, USA) ou Cavit (3M ESPE, St. Paul, MN, EUA) e mantidas em estufa a 37°C por sete dias. Após a remoção dos cimentos, os sistemas adesivos Adper Single Bond (3M ESPE, St. Paul, MN, EUA) ou Clearfil SE Bond (Kuraray Co. Ltd., Osaka, Japão) foram aplicados segundo a recomendação dos fabricantes e, em seguida, realizadas as construções de coroas em resina composta. Os dentes foram secionados em espécimes com área transversal de união de 0,81mm², os quais foram submetidos ao teste de microtração em máquina para ensaios mecânicos com velocidade do atuador de 0,5mm/min. Os dados foram analisados por testes t e Anova, complementada por testes de Tukey (α=0,05). Resultados: Para Adper Single Bond (3M ESPE, St. Paul, MN, EUA), a resistência de união foi estatisticamente não-diferente (p>0,05) para todas as condições experimentais. Para Clearfil SE Bond (Kuraray Co. Ltd., Osaka, Japão), apenas o grupo Interim Restorative Material (Caulk Dentsplay, Milford, DE, USA) apresentou resistência de união significativamente inferior (30,1±13,8 MPa) em relação aos demais grupos; controle (38,9±13,5 MPa) e Cavit (3M ESPE, St. Paul, MN, EUA) (42,1±11,0 MPa), os quais não apresentaram diferença significativa entre si. Conclusão: Concluiu-se que o recobrimento prévio da dentina com cimento temporário, contendo eugenol, exerceu efeito deletério apenas no desempenho adesivo do sistema autocondicionante.

Objective: The aim of this study was to assess the bond strength of adhesive systems to dentin contaminated by temporary cements with or without eugenol. Method: Flat dentin surfaces were obtained from twenty-four human third molars. With exception of the control group (n=8), the surfaces were covered with Interim Restorative Material (Caulk Dentsplay, Milford, DE, USA) or Cavit (3M ESPE, St. Paul, MN, USA) and kept in an oven at 37°C for seven days. After removing the cements, the adhesive systems Adper Single Bond (3M ESPE, St. Paul, MN, USA) or Clearfil SE Bond (Kuraray Co. Ltd., Osaka, Japan) were applied in accordance with the manufacturers' recommendations, and then the crowns were constructed in of resin composite. The teeth were sectioned into specimens with a cross-sectional bond area of 0.81mm², which were submitted to microtensile testing in a mechanical test machine at an actuator speed of 0.5mm/min. The data were analyzed by t- and ANOVA tests, complemented by Tukey tests (α=0.05). Results: For Adper Single Bond (3M ESPE, St. Paul, MN, USA), bond strength did not differ statistically (p>0.05) for all the experimental conditions. For Clearfil SE Bond (Kuraray Co. Ltd., Osaka, Japan), only the Interim Restorative Material (Caulk Dentsplay, Milford, DE, USA) Group showed significantly lower bond strength (30.1±13.8 MPa) in comparison with the other groups; control (38.9±13.5 MPa) and Cavit (3M ESPE, St. Paul, MN, USA) (42.1±11.0 MPa), which showed no significant difference between them. Conclusion: It was concluded that the previous covering of dentin with temporary cement containing eugenol had a deleterious effect on the adhesive performance of the self-etching system only.

Efeito da inibição de metaloproteinases da matriz dentinária na produção e estabilidade mecânica da união resina-dentina afetada por cárie / Effect of a matrix metalloproteinase inhibitor on the production and stability of resin-caries affected dentin bonds

Objetivo: O objetivo geral deste trabalho, dividido em três estudos, foi avaliar in vitro o efeito da aplicação da clorexidina na morfologia, resistência de união imediata e em longo prazo da união resina-dentina hígida e dentina afetada por cárie produzida por sistemas adesivos convencionais e autocondicionantes. Materiais e Métodos: No estudo 1, espécimes obtidos de interfaces produzidas pelo sistema adesivo Adper Single Bond 2 com a dentina hígida e a dentina afetada por cárie foram armazenados por 24 horas em água, 6 meses em água, clorexidina a 0,12% ou óleo mineral e subseqüentemente preparados para a avaliação do colágeno exposto na interface (coloração de Tricrômico de Goldner). Aos dados foram aplicados os testes de ANOVA e Tukey. No estudo 2, sobre a dentina hígida (n=24) ou artificialmente afetada por cárie (n=24), foram aplicados os sistemas adesivos Adper Scotchbond MP, Adper Single Bond 2, Clearfil SE Bond ou Adper Prompt L-Pop, na presença ou ausência de clorexidina. Espécimes para o ensaio mecânico de microtração foram produzidos (0,81 mm2) e os valores de resistência de união foram confrontados pelos testes de ANOVA e Tukey, para cada sistema adesivo. No estudo 3, 48 dentes foram artificialmente cariados e divididos segundo os mesmos sistemas adesivos utilizados no estudo 2 e aplicação ou não da clorexidina. Os espécimes produzidos (0,81 mm2) foram armazenados em água por 24 horas ou 6 meses sendo em seguida submetidos ao ensaio mecânico de microtração. Os dados obtidos foram analisados pelos testes de ANOVA e Tukey. Para todos os estudos, os testes estatísticos foram considerados ao nível pré-estabelecido de significância de 5%. Resultados: Não houve diferença estatística para as medidas de colágeno exposto dos grupos hígidos e cariados; entretanto foi detectada maior exposição do colágeno no grupo armazenado em água...

Objective: The overall purpose of this work, divided into three studies, was to evaluate the in vitro effect of chlorhexidine application on the morphology, immediate and longterm bond strength of resin-noncarious dentin and resin-caries affected dentin bonds produced by etch-and-rinse and self-etching adhesive systems. Materials and Methods: In the first study, specimens obtained from bonds produced by Single Bond 2 applied on noncarious and caries-affected dentin were stored for 24 h in water, 6 m in water, in 0.12 chlorexidine or mineral oil. Subsequently, they were prepared for collagen identification within the bonds (Goldner’s Trichrome stain). Data were submitted to ANOVA and Tukey tests. In the second study, Scotchbond MP, Single Bond 2, Clearfil SE Bond and Prompt were applied on noncarious (n=24) or cariesaffected dentin (n=24) with or without chlorhexidine. Specimens were produced (0.81 mm2) and microtensile tested. The data for each adhesive system were submitted to ANOVA e Tukey tests. For the third study, 48 artificially decayed teeth were divided according to the same adhesive system used in study 2 and the use or not of chlorhexidine. The produced specimens (0.81 mm2) were stored in water for 24 h or 6 m before being stressed to failure. Data were analyzed by ANOVA and Tukey tests. For all the studies, the statistical tests were considered at the preset level of significance of 5%. Results: No statistical significant difference was seen between the width of the exposed collagen zone in bonds produced on noncarious and carious dentin. However, thicker zones were observed after 6 m of water storage for both substrates. Specimens stored in 0.12 chlorhexidine and mineral oil did not differ from those stored in water for 24 h (control). Bond strengths produced on caries-affected dentin were significantly lower than those produced on noncarious dentin when chloherxidine...

Shortening of primary dentin etching time and its implication on bond strength.

OBJECTIVE: The aim of this study was to investigate the influence of shortening the etching time on the bond strength of a conventional and a self-etching primer adhesive system used in primary tooth dentin. METHODS: Flat dentin surfaces were obtained from 24 primary molars, randomly assigned to 4 experimental groups. The adhesive systems Single Bond and Clearfil SE Bond were applied in two groups according to the manufacturers' recommendations. In the other two groups, the adhesives were applied after half-time of acid etching, 7 s for Single Bond and 10 s for Clearfil SE Primer. Resin crowns were built up and after 24 h storage in water at 37 degrees C, the teeth were sectioned to produce beams with cross-sectional area of approximately 0.49 mm2. Specimens were tested in tension at 0.5 mm/min until failure. Fractured specimens were analyzed to determine the failure mode. RESULTS: Tensile bond strengths for Single Bond in primary dentin were higher than for Clearfil SE Bond. Shortening of acid etching time improved bond strength only for Single Bond, while no statistically significant difference was observed for Clearfil SE Bond when both etching times were compared. SIGNIFICANCE: No detrimental effect on bond strength was observed when the time of acid etching was shortened in 50%. Shortening the time for a procedure in a small child without compromising the quality of the work is a very important finding for the practicing pediatric dentist.