Effect of different placement techniques on color stability and surface roughness of resin composites / Efeito das técnicas de inserção e alisamento na estabilidade de cor e rugosidade superficial de resinas compostas

Abstract Introduction Longevity and clinical success of dental restorations can be influenced by many factors during the restorative procedures. Objective This study aimed to evaluate the influence of different placement techniques on color stability and surface roughness of two resin composites. Material and method The groups of specimens (n=10) were divided according to resin composite (FiltekTM Z250 XT and FiltekTM Z350 XT) and placement technique: Mylar strip, spatula, dry brush, modeling liquid, and surface sealant. Color stability and surface roughness were accessed using a spectrophotometer (CIELab color space) and a rugosimeter (standard cutoff of 0.8 mm), respectively, after water storage. Subsequently, the specimens were immersed in coffee for 48 h and final color was measured. The data were analyzed using ANOVA and the Tukey's post hoc test (α=5%) and the correlation between surface roughness (Ra) and color change (∆Eab) was assessed using the Pearson's correlation coefficient. Result The different placement techniques influenced Ra and ∆Eab on both resin composites. The groups treated with surface sealant showed greater difference in ∆Eab for both resin composites. The FiltekTM Z250 XT resin showed greater color stability compared with the FiltekTM Z350 XT resin regardless of the placement technique used. Ra of each placement technique was similar among the resin composites except for the FiltekTM Z350 XT modeling liquid group, which presented lower Ra values compared with those of FiltekTM Z250 XT. A correlation between Ra and staining was identified (p=0.268). Conclusion Color stability and Ra are influenced by different placement techniques.

Resumo Introdução A longevidade e o sucesso clínico das restaurações dentárias podem ser influenciados por muitos fatores durante os procedimentos restauradores. Objetivo Avaliar a influência da técnica de alisamento na estabilidade de cor e rugosidade superficial de duas resinas compostas. Material e método Os grupos de amostras (n=10) foram divididos conforme a resina composta (FiltekTM Z250 XT e FiltekTM Z350 XT) e as técnicas empregadas: tira de poliéster, espátula, pincel seco, selante de superfície. A cor e a rugosidade da superfície foram avaliadas por espectrofotômetro (espaço de cor CIELab) e rugosímetro (corte padrão de 0,8 mm), respectivamente, após o armazenamento em água. Posteriormente, as amostras foram imersas em café por 48h e a cor final foi aferida. Os dados foram analisados usando teste ANOVA e Tukey post hoc (α = 5%) e a correlação entre rugosidade da superfície (Ra) e variação de cor (∆Eab) através do coeficiente de correlação de Pearson. Resultado As técnicas de alisamento influenciaram a Ra e a ∆Eab em ambas as resinas compostas. Os grupos tratados com selante de superfície apresentaram maior diferença na ∆Eab. A resina FiltekTM Z250 XT apresentou maior estabilidade de cor comparada à FiltekTM Z350 XT, independentemente da técnica utilizada. A Ra das técnicas de alisamento foi semelhante entre os compósitos, exceto para o grupo do líquido modelador da FiltekTM Z350 XT, que apresentou os menores valores. Uma correlação entre Ra e manchamento (p = 0,268) foi identificada. Conclusão A estabilidade da cor e a Ra são influenciadas pelas técnicas de alisamento utilizadas.

Marginal staining of ultra-thin ceramic veneers

The pigmentation of the resin cement at the tooth/ceramic interface compromises the esthetic and longevity of ultra-thin ceramic veneers. Aim: The aim of this study was to evaluate marginal staining of ultra-thin ceramic veneers cemented to intact enamel (non-prepared) and prepared enamel. Methods:Thirty-two (32) permanent central incisors were selected and randomly divided into two groups: intact enamel (IE) and prepared enamel (PE). The ceramic veneers of PE group were bonded to the prepared enamel and the ceramic veneers of IE group were cemented directly onto the intact enamel, with no preparation. Both preparation and cementation were standardized and performed by a single operator. Each group was subdivided into two subgroups (n = 8) with different immersion media - coffee and water. After an immersion period of 10 days, stereomicroscope images were made at 20X magnification of the mesial, distal, cervical and incisal surface of each specimen. Three blinded, trained and calibrated examiners evaluated the images of the resin cement interface of each surface. The data were subjected to KruskalWallis and MannWhitney statistical analysis. Immersion media and enamel preparation influenced the marginal staining of the tooth/ceramic interface. Results: When immersed in coffee, prepared interfaces presented greater marginal staining than unprepared interfaces. When immersed in water, there was no statistically significant difference between the groups. Conclusion: The cementation of ultra-thin ceramic veneers onto intact enamel is associated with less marginal staining and, consequently, improved esthetics

In-office Treatments for Dentin Hypersensitivity: A Randomized Split-mouth Clinical Trial.

PURPOSE: To assess the effectiveness of four in-office therapies used for the treatment of dentin hypersensitiviy (DH) after one single application. MATERIALS AND METHODS: A randomised, controlled, split-mouth clinical trial was designed to evaluate the following treatments: 5% sodium fluoride varnish (positive control); 3% potassium oxalate; two-step self-etching adhesive; high power diode laser. Nineteen patients were selected and one tooth per quadrant was included in the study. After evaporative stimulation, pain was quantified by the Visual Analog Scale (VAS) at baseline, immediately after treatment, and after 15, 30 and 60 days. RESULTS: Compared to the baseline values, fluoride varnish (p = 0.00) and potassium oxalate (p = 0.00) presented an immediate desensitising effect that remained constant at 15, 30 and 60 days. The high-power diode laser presented significant reduction in VAS scores after 15 days (p = 0.00), while in the self-etching adhesive group, a significant reduction in VAS scores was observed only after 60 days (p = 0.03). The change in VAS ([VAS x days] - VAS baseline) differed among the groups immediately after treatment, being higher in the fluoride varnish and lower in the adhesive groups, but no statistically significant difference was found at time intervals of 15, 30 and 60 days. CONCLUSION: When an immediate desensitising effect is desired after one single application, fluoride varnish and potassium oxalate should be used. High-power diode laser and self-etching adhesive may not be clinically considered an appropriate desensitising therapy after one single application.

The effect of immediate and delayed polishing on the color stability of a composite resin.

Polishing techniques are known to enhance the longevity and appearance of composite resin restorations. However, the influence of the timing of polishing on the final results of a restoration is not well documented. The aim of this study was to determine the effect of immediate and delayed polishing on the color stability of a composite resin. Sixty composite resin specimens were fabricated and randomly divided into 2 groups according to immersion solutions: group 1, deionized water (control); and group 2, coffee (as staining solution). The groups were further divided according to polishing time periods (immediate, 1 day, 7 days, 14 days, and 21 days). The polishing was performed by 1 calibrated operator using a sequence of aluminum oxide discs with different granulations. Color measurements were assessed at baseline and after a 48-hour immersion in the assigned medium by a reflection spectrophotometer, according to CIE L*a*b* parameters. The data were submitted to an analysis of variance (ANOVA) and the post hoc Tukey test at a significance level of 0.05. The ANOVA showed that the immersion solutions had a statistically significant difference (α = 0.05) on color stability. The composite resin color stability was not influenced by the timing of polishing, and all subgroups showed clinically unacceptable discoloration after exposure to coffee. Thus, with regard to color stability, the timing of final polishing may be established according to the preferences of the clinician.

Evaluation of the surface roughness of a nanofilled composite resin submitted to different smoothing and finishing techniques / Avaliação da rugosidade superficial de uma resina nanoparticulada submetida a diferentes técnicas de alisamento e finalização

Introduction: Controlling the surface smoothness characteristics of the composite resin when performing a direct restorative technique is one of the factors involved in achieving restorative success. Objective: The purpose of this study was to evaluate the surface roughness of a nanofilled composite resin submitted to different smoothing and finishing techniques. Material and method: Fifty test specimens were made with the Z350 XT composite resin (3M ESPE) and then divided into five study groups according to the smoothing and finishing method applied, as follows: G1 (control), polyester strip; G2, composite spatula; G3, brush cleaned with absolute alcohol and dried; G4, brush cleaned with absolute alcohol, dried and moistened with Single Bond (3M ESPE); and G5, brush cleaned with absolute alcohol, dried and moistened with Natural Glaze surface sealant (DFL). After fabrication, the specimens were stored for 24 h in deionized water. The surface roughness of the specimens was measured using a profilometer. Surface roughness means were compared by analysis of variance followed by Tukey’s test at a level of significance of 5%. Result: The lowest surface roughness was observed in G1 (control group) and the highest, in G3. G5 had lower surface roughness values compared to the other test groups, and presented values similar to those of the control group. Conclusion: The smoothing and finishing techniques influenced the surface roughness of the composite resin. Application of the surface sealant by the copolymerization technique resulted in lower roughness values. The use of a clean, dry brush promoted roughness values beyond the acceptable limit, and is therefore liable to compromise the performance of composite resin restorations.

Introdução: O controle da técnica restauradora direta com resina composta no que se refere às características de lisura superficial, é um dos fatores que deve ser considerado para o sucesso restaurador. Objetivo: O propósito deste estudo foi avaliar a rugosidade superficial de uma resina composta nanoparticulada submetida a diferentes técnicas de alisamento e finalização. Material e método: Cinquenta corpos de prova foram confeccionados utilizando a resina composta Z 350 XT (3M ESPE), divididos em cinco grupos sendo: G1 (controle): padrão tira de poliéster; G2: espátula para inserção de resina; G3 pincel limpo com álcool e seco; G4; pincel limpo com álcool, seco e umedecido com adesivo Single Bond (3M ESPE); e, G5: pincel limpo álcool, seco e umedecido com selante de superfície Natural Glaze (DFL). Após a confecção os corpos de prova foram estocados por 24 horas em água deionizada. A rugosidade superficial foi mensurada por meio de um rugosímetro de precisão. As médias foram comparadas por análise de variância, seguida do Teste de Tukey a 5% de significância. Resultado: A menor rugosidade superficial foi observada em G1 e a maior em G3 O grupo G5, apresentou valores de rugosidade superficial inferiores aos demais grupos testados e próximos ao grupo controle. Conclusão: As técnicas de alisamento e finalização influenciaram a rugosidade superficial da resina composta. O uso de selante resinoso, pela técnica de copolimerização, resultou em menor rugosidade e o emprego do pincel limpo e seco promoveu rugosidade, além do limite aceitável o que pode comprometer o desempenho de restaurações.

Micromorphological evaluation of dentin treated with different desensitizing agents.

INTRODUCTION: The purpose of a desensitizing agent is a permanent coating or filling of dentin surface. Morphological analysis in vitro of this treated surface is essential to understand the interaction between desensitizing agent and hypersensitive dentin. The aim was to evaluate the morphology of four dentin surface treated with desensitizing agents. METHODS: This was an in vitro laboratory study, where fifteen specimens from extracted human premolars were obtained. The enamel was removed to expose the dentin surface, polished with silicon carbide abrasive papers and etched with 6% citric acid for 2 min.The specimens were randomly divided into 5 groups: G1 - without treatment (control) (C), G2 - fluoride varnish (FV), G3 - potassium oxalate (PO), G4 - 2-step self-etching adhesive system (AS), G5 - diode laser (DL). The specimens were cleaved in the lingual buccaldirection, prepared for analysis by Scanning Electron Microscope and the surface and interior of the dentinal tubules were observed at 1500× magnification. RESULTS: In the control group, the dentin etching promoted smear layer removal and exposure of dentinal tubules. In the group of fluoride varnish, a film was observed on the surface, with plugs of varnish into tubules. In the group of oxalate, partial obliteration of the tubular entrances was observed. In the group of the adhesive system, the tubules were obstructed through the formation of hybrid layer and a physical barrier on the surface. In the group of the diode laser, dentin melting and solidification with partial occlusion of dentinal tubules were observed. CONCLUSIONS: All desensitizing agents evaluated demonstrated ability to modify the surface of dentin, with partial or total occlusion of dentinal tubules. Thus, it is suggested to do more clinical studies to verify the effectiveness of the findings.

Association between occlusal anomalies and dental caries in 3- to 5 year-old Brazilian children.

OBJECTIVE: To investigate the association between certain occlusal anomalies and the occurrence and severity of dental caries in Brazilian preschool children. DESIGN: Cross-sectional study. SETTING: Twenty-eight public nursery schools in Canoas, southern Brazil. SUBJECTS AND METHODS: The study population comprised 890 three- to five-year-old children. Five trained and calibrated observers examined children for determination of decayed, missing and filled tooth (dmft) index (World Health Organization criteria including white spots) and orthodontic variables. OUTCOME MEASURES: Caries severity (dmft) and caries occurrence (dmft ≥ 1). STATISTICAL ANALYSIS: Multivariable analysis was performed using Poisson regression with robust variance in order to determine the occlusal anomalies which represent risk factors for the occurrence of the binary outcome. RESULTS: Caries severity was significantly higher among children without spacing in the maxillary anterior teeth (P = 0·001) and mandibular anterior teeth (P = 0·003) and among children without accentuated overjet (P = 0·023). The multivariable analysis demonstrated that children without spacing in maxillary anterior teeth had an increased risk of dental caries (prevalence ratio = 1·43; 95% CI, 1·05-1·93). Open bite, accentuated overjet and posterior cross-bite were not associated with this outcome in the final model. CONCLUSIONS: Absence of spacing in the maxillary labial segment represents a risk factor for dental caries in preschool children.

Shear bond strengths of orthodontic brackets with a new LED cluster curing light.

OBJECTIVE: To evaluate the shear bond strength of orthodontic brackets bonded to bovine enamel using a new curing appliance composed of an LED cluster. DESIGN: In vitro, laboratory study. MATERIALS AND METHODS: Standard edgewise maxillary central incisor metal brackets (0.022'' slot) were bonded to 60 bovine incisors which were arranged in a parabola, simulating the dental arch. The arches were randomly allocated to one of five groups: three experimental groups in which a half arch was cured using the Whitening Lase Ortho LED Cluster light for 10, 20 and 40 s (EG10s, EG20s, EG40s) and two control groups. Control group 1 (CGH) were cured using a halogen light for 20 s and control group 2 (CGL) were cured using a conventional LED light for 20 s per tooth. A shear debond test was performed using an EMIC machine and the results were analyzed by ANOVA and post hoc Tukey multiple comparisons. The Adhesive Remnant Index (ARI) was determined at 10x magnification. RESULTS: The one-way ANOVA showed a statistically significant difference between the groups (P<0.001). The post hoc Tukey comparison showed that the bond strength for group EG10s was significantly lower than both the control groups CGH (P<0.001) and CGL (P<0.001). There was no significant difference between the bond strengths for groups EG10s and EG20s (P = 0.100). Neither were there any statistically significant differences detected between groups EG20s, EG40s, CGL and CGH (P>0.05).The ARI analysis revealed a higher frequency of score 2 for groups CGL, EG10s, EG20s, a higher frequency of score 0 and 1 for the CGH group and a score of 1 was most frequent for the EG40s group. CONCLUSION: The Whitening Lase Ortho LED Cluster light shows promise when bonding a half dental arch with a curing time of 40 s.

Resistance to degradation of bonded restorations to simulated caries-affected primary dentin.

PURPOSE: To investigate the resistance to degradation of resin modified glass-ionomer cement (RMGIC) and adhesive/composite restorations in sound and simulated caries-affected dentin of primary teeth subjected to carious challenge using a pH-cycling model and load-cycling, by means of a microtensile test. METHODS: Occlusal cavities were prepared in 60 sound exfoliated primary second molars. Half the specimens were submitted to pH-cycling to induce simulated caries lesion. The teeth were randomly restored with one of the two materials: (1) a RMGIC (Vitremer) and (2) a total-etch adhesive system (Adper Single Bond 2) followed by resin composite (Filtek Z100). After storage in distilled water at 37 degrees C for 24 hours, control group specimens were subjected to test procedures while the specimens in the experimental groups were subjected to two different aging methods: load-cycling (50,000 cycles, 90N, 3Hz) or carious challenge (pH-cycling: alternately 8 hours in demineralizing and 16 hours in remineralizing solutions, for 10 days). Teeth were sectioned into 1 mm2 beams and tested to failure under tension. ANOVA and multiple-comparisons tests were used (P<0.05). RESULTS: Vitremer bond strength was not altered by the condition of dentin. Conversely, Adper Single Bond 2 showed significantly lower bond strength values when bonded to simulated caries-affected dentin. Load-cycling did not influence bond strength for any of the tested materials, while carious challenge resulted in a significant decrease in microtensile bond strengths of Adper Single Bond 2, but not of Vitremer restorations.

Exploring factors associated with traumatic dental injuries in preschool children: a Poisson regression analysis.

OBJECTIVE: This cross-sectional study aimed to investigate the factors associated with dental trauma in preschool children using Poisson regression analysis with robust variance. SUBJECTS AND METHODS: The study population comprised 888 children aged 3- to 5-year-old attending public nurseries in Canoas, southern Brazil. Questionnaires assessing information related to the independent variables (age, gender, race, mother's educational level and family income) were completed by the parents. Clinical examinations were carried out by five trained examiners in order to assess traumatic dental injuries (TDI) according to Andreasen's classification. One of the five examiners was calibrated to assess orthodontic characteristics (open bite and overjet). Multivariable Poisson regression analysis with robust variance was used to determine the factors associated with dental trauma as well as the strengths of association. Traditional logistic regression was also performed in order to compare the estimates obtained by both methods of statistical analysis. RESULTS: 36.4% (323/888) of the children suffered dental trauma and there was no difference in prevalence rates from 3 to 5 years of age. Poisson regression analysis showed that the probability of the outcome was almost 30% higher for children whose mothers had more than 8 years of education (Prevalence Ratio = 1.28; 95% CI = 1.03-1.60) and 63% higher for children with an overjet greater than 2 mm (Prevalence Ratio = 1.63; 95% CI = 1.31-2.03). Odds ratios clearly overestimated the size of the effect when compared with prevalence ratios. CONCLUSIONS: These findings indicate the need for preventive orientation regarding TDI, in order to educate parents and caregivers about supervising infants, particularly those with increased overjet and whose mothers have a higher level of education. Poisson regression with robust variance represents a better alternative than logistic regression to estimate the risk of dental trauma in preschool children.

Patient's perception on mini-screws used for molar distalization / Percepção dos pacientes quanto ao uso de mini-implantes para distalização de molares

Purpose: The objective of this study was to evaluate and compare the perceived pain intensity, side effects and discomfort related to the moment of placement, during mechanics and removal of a mini-screw for molar distalization in orthodontic treatment.Methods: The sample consisted of 30 adult patients with a mean age of 30 years old, with class II malocclusion subdivision right or left. A mini-screw was installed in each patient, in the maxillary arch to provide a molar distalization. The patients answered a questionnaire to assess their opinions on the treatment. Results: Ninety percent of the patients chose mini-screws over pre-molar extraction (orthodontic camouflage), or the use of an extra-oral appliance (Kloehn cervical traction) or another non-compliance treatment to class II. Aphthous ulcer was the side effect most frequent after placement of the mini-screw (30%). The greatest discomfort was felt during infiltration anesthesia (27%), though 23% reported no discomfort during placement. Eighty-three percent of the patients reported no pain during placement, which may be associated with the degree of satisfaction with the treatment (100%) and recommendation of the procedure to other patients (100%). Conclusion: Mini-screws were well accepted by the patients and were efficient for molar distalization when utilized in association with orthodontic treatment for Class II malocclusion.

Objetivo: O objetivo desse estudo foi avaliar e comparar a intensidade de dor, os efeitos colaterais e o desconforto sentido pelo paciente relacionado à colocação do mini-implante, durante a mecânica e na remoção do mesmo, durante a distalização de molares no tratamento ortodôntico. Métodos: A amostra foi composta por 30 pacientes adultos com uma média de idade de 30 anos, com maloclusão Classe II subdivisão direita ou esquerda. Um mini-implante foi instalado em cada paciente, no arco superior para conseguir a distalização de molar. Os pacientes receberam um questionário a respeito de sua opinião sobre o tratamento. Resultados: Noventa por cento dos pacientes escolheram colocar os mini-implantes ao invés de realizar extração de molares (camuflagem ortodôntica), fazer o uso de um aparelhoextraoral (Aparelho extraoral de Kloehn) ou fazer uso de qualquer outro tratamento alternativo para classe II. A úlcera aftosa foi o efeito colateral com a maior incidência após a inserção do mini-implante (30%). O maior desconforto foi sentido durante a infiltração anestésica (27%), embora 23% relataram não ter sentido desconforto durante o tratamento. Um total de 83% dos pacientes não relatou dor durante o tratamento, o que pode ser associado com o grau de satisfação com o tratamento (100%) e a recomendação desse procedimento a outros pacientes (100%). Conclusão: Os mini-implantes foram bem aceitos pelos pacientes e foram eficientes para a distalização de molares quando utilizados em associação com o tratamento ortodôntico para correção da maloclusão de Classe II.

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.

Differential bonds degradation of two resin-modified glass-ionomer cements in primary and permanent teeth.

OBJECTIVES: To evaluate the effect of chemical degradation on bond strength of resin-modified glass-ionomer cements bonded to primary and permanent dentin. METHODS: Class I cavities of permanent and primary extracted human molars were restored with two resin-modified glass-ionomer cements: Fuji II LC and Vitremer, and stored in water for 24h. Half samples were immersed in 10% NaOCl aqueous solution for 5h. Teeth were sectioned into beams and tested for microtensile bond strengths. Results were analyzed with multiple ANOVA and Tukey's tests (p<0.05). Analysis of debonded surfaces was performed by SEM. RESULTS: 24h bond strengths for Vitremer and Fuji II LC were similar. For Fuji II, bond strength values were higher for primary than for permanent dentin. Vitremer bond strength was similar for both. Chemical degradation did not affect Fuji II LC bond strength to dentin. However, decreases in bond strength were found for Vitremer groups after NaOCl immersion. Signs of glass ionomer-dentin interaction were evident by SEM analysis for Fuji II LC specimens. CONCLUSIONS: Vitremer and Fuji II presented similar bond strength at 24. Vitremer dentin bonds were prone to chemical degradation. Fuji II LC-dentin bonds showed typical features of glass-ionomer dentin interaction at the bonded interfaces, and were resistant to in vitro degradation.

Esthetic and functional dental rehabilitation in a patient with gastroesophageal reflux.

Gastroesophageal reflux disease (GERD) is a common disorder of the gastrointestinal tract in children and adults. The purpose of this report is to describe the case of a patient with GERD and the effects of the disease on the oral cavity, as well as to discuss functional and esthetic rehabilitation using composite resin. The authors also conducted a review of the literature on GERD etiopathogenesis, clinical signs and symptoms, diagnostic methods, and treatment.

Effect of chlorhexidine-thymol varnish on caries lesion development in first permanent molars.

OBJECTIVE: The aim of this study was to investigate the caries prevention efficacy of chlorhexidine-thymol (CHX-T) varnish on newly erupted permanent first molars. METHODS: Fifty-seven six- to eight-year-old school children were included in a program of sequential CHX-T varnish application. For inclusion, they had to have at least two homologous, newly erupted first permanent molars with visually sound occlusal surfaces. A clinical examination was used to determine the molar eruption stage, biofilm presence, and whole caries status. There were 99 pairs of molars in the study population. A split-mouth design was used where each child randomly had one first molar treated with six applications of CHX-T varnish, and the other with a placebo varnish, every 15 days for 75 days. The children were then revaluated for caries one year following the conclusion of treatment. RESULTS: Fourteen pairs of teeth presented incipient enamel caries lesions in both molars (one CHX-T and one placebo varnish), four developed lesions in the placebo-treated molars only, and eight developed lesions in CHX-T varnish-treated molar only. No significant statistical differences were found between the two groups with regard to caries increment (p = 0.20). CONCLUSION: Six applications of CHX-T varnish had no protective effect against caries development.

Microtensile bond strength of contemporary adhesives to primary enamel and dentin.

UNLABELLED: The purpose of this study was to assess bond strength of three self-etching and two total-etch adhesive systems bonded to primary tooth enamel and dentin. MATERIALS AND METHODS: Forty extracted primary human molars were selected and abraded in order to create flat buccal enamel and occlusal dentin surfaces. Teeth were assigned to one of the adhesive systems: Adper Scotch Bond Multi Purpose, Adper Single Bond 2, Adper Prompt L-Pop, Clearfil SE Bond and AdheSE. Immediately to adhesive application, a composite resin (Filtek Z250) block was built up. After 3 months of water storage, each sample was sequentially sectioned in order to obtain sticks with a square cross-sectional area of about 0.72 mm2. The specimens were fixed lengthways to a microtensile device and tested using a universal testing machine with a 50-N load cell at a crosshead speed of 0.5 mm/min. Microtensile bond strength values were recorded in MPa and compared by Analysis of Variance and the post hoc Tukey test (a = 0.05). RESULTS: In enamel, Clearfil SE Bond presented the highest values, followed by Adper Single Bond 2, AdheSE and Adper Scotch Bond Multi Purpose, without significant difference. The highest values in dentin were obtained with Adper Scotch Bond Multi Purpose and all other adhesives did not present significant different values from that, except Adper Prompt L-Pop that achieved the lowest bond strength in both substrates. Adper Scotch Bond Multi Purpose and Adper Single Bond 2 presented significantly lower values in enamel than in dentin although all other adhesives presented similar results in both substrates. CONCLUSIONS: contemporary adhesive systems present similar behaviors when bonded to primary teeth, with the exception of the one-step self-etching system; and self-etching systems can achieve bond strength values as good in enamel as in dentin of primary teeth.

Resistência à degradação de restaurações em dentina sadia e afetada por cárie de dentes decíduos submetidas a desafios mecânico e cariogênico / Resistance to degradation of restorations on sound and affected dentin of primary teeth submitted to mechanical and carious challenges

Este estudo objetivou investigar a resistência à degradação de restaurações de cimento de ionômero de vidro modificado por resina (CIVMR) e adesivo/resina composta sobre dentina sadia e afetada por cárie de dentes decíduos submetidas a desafio cariogênico e ciclagem mecânica, por meio de teste de microtração e nanoinfiltração. Cavidades oclusais tipo Classe I foram preparadas em 60 molares decíduos esfoliados. Metade dos dentes foi submetida ao processo de indução de cárie artificial, por meio de ciclagem de pH. Os dentes foram aleatoriamente restaurados com um dos dois materiais: um CIVRM (Vitremer®) e um sistema adesivo de condicionamento total (Adper Single Bond 2®) seguido de resina composta (Filtek Z100®). Após 24 horas de armazenagem em água a 37°C, as amostras dos grupos controle seguiram para os procedimentos de teste, enquanto as demais foram re-divididas e submetidas a dois métodos de desafio: desafio cariogênico (ciclagem de pH) e ciclagem mecânica (50.000 ciclos, 90 N, 3 Hz). Para os testes, os dentes foram seccionados em fatias seriadas de aproximadamente 1mm de espessura, das quais uma foi separada para o teste de nanoinfiltração e as demais foram seccionadas no sentido perpendicular de forma a obter espécimes em formato de palito com 1 mm² de área, que foram fixados a uma máquina de ensaios universal e submetidos ao teste de microtração. Os valores nominais de resistência de união foram registrados em MPa e analisados por meio de ANOVA e testes de comparações múltiplas de Games-Howel (α=0,05). As fatias designadas para o teste de nanoinfiltração foram impermeabilizadas com esmalte exceto nas interfaces e imersos em nitrato de prata amoniacal por 24 horas para evidenciação dos espaços nanométricos e sinais de degradação nas interfaces...

This study aimed to investigate the resistance to degradation of resin modified glass ionomer cement (RMGIC) and adhesive/composite restorations on sound and caries-affected dentin of primary teeth subjected to carious challenge and load-cycling, by means of microtensile test and nanoleakage. Occlusal class I cavities were prepared on sixty sound exfoliated second primary molars. Half teeth were submitted to pH-cycling to induce artificial caries lesion. Teeth were randomly restored with one of the two materials: (1) a RMGIC (Vitremer®) and a (2) a total-etch adhesive system (Adper Single Bond 2®) followed by composite resin (Filtek Z100®). After storage in distilled water 37°C for 24 hours, sample from control groups followed to test procedures while the other ones were re-divided and submitted to two different aging methods: carious challenge (pH-cycling) and load-cycling (50 000 cycles, 90N, 3Hz). For testing, teeth were sectioned into about 1mm slabs, from which, one was separated for nanoleakage testing and the others were perpendicularly sectioned into 1mm² beams that were tested to failure in tension in a universal testing machine. Data on microtensile bond strengths were registered in MPa and analyzed by ANOVA and Games-Howell multiple-comparisons tests (α=0.05). Slabs meant for nanoleakage testing were coated with nail varnish except for the bonded interfaces, and immersed in ammoniacal AgNO3 for 24 hours in order to disclose nanometer-sized spaces and degradation signs within interfaces. After immersion in photodeveloping solution, bonded sections were prepared and observed under SEM...

Utilização do sistema de anestesia computadorizada The Wand® em odontopediatria / Use of the computed anesthetic system The Wand® in pediatric dentistry

Introdução: O comportamento positivo do paciente infantil depende, entre outras variáveis, do controle da dor com a anestesia local. Objetivo: Neste contexto realizou-se uma revisão de literatura sobre a utilização da anestesia computadorizada em odontopediatria. Este sistema anestésico tem como principal objetivo reduzir o desconforto causado pela anestesia, por meio do controle de dois fatores que influenciam no sucesso da anestesia local: a pressão e o volume do l¡quido anestésico. Conclusão: A maioria dos trabalhos revisados demonstrou que o sistema computadorizado The Wand© é superior a anestesia tradicional, quando as técnicas modificadas são utilizadas.

Introduction: The positive behavior of the pediatric patient depends, among other variables, on pain control with local anesthetics.Purpose: In this context, a review of literature was performed regarding the use of computed anesthesia in Pediatric Dentistry.This anesthetic system has as its main goal minimizing the discomfort caused by conventional anesthesia, by controlling two factors that influence the success of local anesthesia: the pressure and volume of the anesthetic liquid. Conclusions: Most retrieved studies demonstrated that the computed anesthetic system The Wand© has a better performance than conventional anesthesia, when the modified techniques are used.

Inhibition of demineralization adjacent to tooth-colored restorations in primary teeth after 2 in vitro challenges.

PURPOSE: As clinical diagnosis of secondary caries is the most common reason for restoration replacement, fluoride-releasing restorative materials have been developed to address this problem. The purposes of this study were to verify demineralization inhibition produced by 5 restorative materials submitted to two methods of in vitro cariogenic challenge and verify whether these methods influence material behavior by means of polarized light microscopy and microhardness. METHODS: Class V cavities were prepared on buccal surfaces of 100 extracted primary molars and randomly restored with 1 of the 4 fluoride-releasing materials, Fuji IX, Vitremer, Dyract, Tetric Ceram, and Filtek Z250 as control material (N=10). Specimens were submitted to in vitro caries induction by two different methods, acid gel immersion, and pH cycling. Teeth submitted to gel were then sectioned and prepared for polarized light microscopy in water, while teeth cycled were prepared for microhardness evaluation. RESULTS: Polarized light microscopy: Means of demineralization areas (microm(2)) differed significantly, depending on the restorative material. Tukey's test revealed the smallest demineralization areas adjacent to Fuji IX and Vitremer restorations, with no difference between them (P>.05). The greatest demineralization area mean values were verified using Dyract and Filtek Z250, without differences between them (P>.05). Microhardness: Glass ionomer cements (GICs) performed better on the area of great cariogenic challenge, closer to the surface, than other materials indicating minor mineral loss during pH cycling. The compomer Dyract presented similar performance to GICs and composite resin Tetric Ceram, but it was better than Filtek Z250. CONCLUSION: The experimental model of caries lesion induction may influence material performance. GICs, however, are superior in preventing in vitro demineralization independently of the method.

Low-level-laser therapy as an alternative treatment for primary herpes simplex infection: a case report.

Gingivostomatitis is the most common primary and symptomatic clinical manifestation of HSV-1 infection. Painful oral lesions appear as ulcerative erosions on the gingiva, palate, buccal mucosa, and tongue, leading to eating and drinking difficulties with an evolution between 10-14 days. This paper describes a case of a 19-month-old boy with severe painful Gingivostomatitis lesions. Low level laser therapy (LLLT) was used with an immediate outcome.