Conservative treatment for amelogenesis imperfecta: a case report.

Amelogenesis imperfecta is a hereditary condition that can alter the thickness, color, and shape of tooth enamel. Recent adhesive materials and techniques have provided less invasive treatment options. This case report presents the treatment of a patient whose anterior teeth had color alterations, white spots, pits, and shape defects. Using a more conservative technique, the mandibular and maxillary anterior teeth were restored using veneer direct composite restorations. After 6 years, the restorations demonstrated no deterioration, and no pathology was seen in association with the rehabilitation.

In vitro study of fracture load and fracture pattern of ceramic crowns: a finite element and fractography analysis.

PURPOSE: This in vitro study investigated the null hypothesis that metal-free crowns induce fracture loads and mechanical behavior similar to metal ceramic systems and to study the fracture pattern of ceramic crowns under compressive loads using finite element and fractography analyses. MATERIALS AND METHODS: Six groups (n = 8) with crowns from different systems were compared: conventional metal ceramic (Noritake) (CMC); modified metal ceramic (Noritake) (MMC); lithium disilicate-reinforced ceramic (IPS Empress II) (EMP); leucite-reinforced ceramic (Cergogold) (CERG); leucite fluoride-apatite reinforced ceramic (IPS d.Sign) (SIGN); and polymer crowns (Targis) (TARG). Standardized crown preparations were performed on bovine roots containing NiCr metal dowels and resin cores. Crowns were fabricated using the ceramics listed, cemented with dual-cure resin cement, and submitted to compressive loads in a mechanical testing machine at a 0.5-mm/min crosshead speed. Data were submitted to one-way ANOVA and Tukey tests, and fractured specimens were visually inspected under a stereomicroscope (20×) to determine the type of fracture. Maximum principal stress (MPS) distributions were calculated using finite element analysis, and fracture origin and the correlation with the fracture type were determined using fractography. RESULTS: Mean values of fracture resistance (N) for all groups were: CMC: 1383 ± 298 (a); MMC: 1691 ± 236 (a); EMP: 657 ± 153 (b); CERG: 546 ± 149 (bc); SIGN: 443 ± 126 (c); TARG: 749 ± 113 (b). Statistical results showed significant differences among groups (p < 0.05) represented by different lowercase letters. Metal ceramic crowns presented fracture loads significantly higher than the others. Ceramic specimens presented high incidence of fractures involving either the core or the tooth, and all fractures of polymer crown specimens involved the tooth in a catastrophic way. Based on stress and fractographic analyses it was determined that fracture occurred from the occlusal to the cervical direction. CONCLUSIONS: Within the limitations of this study, the results indicated that the use of ceramic and polymer crowns without a core reinforcement should be carefully evaluated before clinical use due to the high incidence of failure with tooth involvement. This mainly occurred for the polymer crown group, although the fracture load was higher than normal occlusal forces. High tensile stress concentrations were found around and between the occlusal loading points. Fractographic analysis indicated fracture originating from the load point and propagating from the occlusal surface toward the cervical area, which is the opposite direction of that observed in clinical situations.

How light sources and distance of the light tip influence water sorption, solubility, and biaxial flexural strength of a composite resin.

This study evaluated the water sorption (WS), solubility (SL), and biaxial flexural strength (BFS) of a resin composite based on different polymerization units, storage permeants (distilled water and 75% ethanol), and distances between the light's tip and the composite resin. Using a stainless steel mold, 80 specimens were made and separated in two independent groups, according to the duration of storage (7 days or 60 days). The specimens were photocured using either a QTH or LED light (both used at 600 mW/cm2 for 40 seconds), with the light's tip guide either 0 mm or 2 mm from the surface of the resin. In general, the 75% ethanol produced higher WS and SL values but lower BFS values compared to water. Both distances influenced the WS and SL values, especially when 75% ethanol was used (p < 0.05), although neither distance affected BFS values (p > 0.05). For nearly all groups, the WS, SL, and BFS in different solvents and at different distances for photocuring of the tested resin were not affected by the curing light used.

Finite element analysis of weakened roots restored with composite resin and posts.

Finite element analysis (FEA) was used to investigate the influence of different post systems on the stress distribution of weakened teeth under oblique-load application. A maxillary central incisor root obtained from a sound tooth was weakened by partial removal of dentin inside the root canal. Seven two-dimensional numerical models, one from the sound tooth and six from the weakened root restored with composite resin and post systems were created as follows - ST: sound tooth; CPC: cast CuAl post and core; SSP: stainless steel post + composite core; GP: fiberglass + composite core; CP: carbon fiber + composite core; ZP: zirconium dioxide post + composite core; TP: titanium post + composite core. The numerical models were considered to be restored with a leucite-reinforced all-ceramic crown and received a 45 masculine occlusal load (10 N) on the lingual surface.All the materials and structures were considered linear elastic, homogeneous, and isotropic, with the exception of fiberglass and carbon fiber posts which assumed orthotropic behavior. The numerical models were plotted and meshed with isoparametric elements, and the results were analyzed using von Mises and Sy stress criteria. When compared with the sound tooth, FEA revealed differences in stress distribution when post systems were used. Among the restored teeth, the use of CPC, SSP, ZP, and TP resulted in higher stress concentration in the post itself when compared to GP and CP. Therefore, results from the FEA images suggested that the use of non-metallic post systems could result in improved mechanical behavior for the weakened restored teeth.

Fracture resistance and stress distribution in endodontically treated maxillary premolars restored with composite resin.

PURPOSE: The aim of this study was to evaluate the effect of endodontic and restorative treatment on the fracture resistance of posterior teeth. MATERIALS AND METHODS: Fifty intact premolars were selected and randomly placed into five groups (n = 10): G1, intact teeth (control); G2, mesial-occlusal-distal (MOD) preparation; G3, MOD preparation restored with composite resin (Z-250, 3M ESPE); G4, MOD preparation and endodontic treatment; and G5, MOD preparation, endodontic treatment, and composite resin restoration. The specimens were submitted to an axial compression load in a mechanical test machine (EMIC), at a speed of 0.5 mm/min. Fracture patterns were analyzed at four levels. Five 2D numerical models were created by Ansys 10.0 for finite element analysis (FEA). RESULTS: Mean values of compressive strength for all groups were (Kgf): G1 (83.6 +/- 25.4); G2 (52.7 +/- 20.2); G3 (82.1 +/- 24.9); G4 (40.2 +/- 14.2); G5 (64.5 +/- 18.1). Statistical analysis (ANOVA and Tukey's test) showed that fracture resistance of G1 was significantly higher than that of G5, G2, and G4. Resistance of G3 was also higher than that of G2 and G4. Results showed that the tooth resistance is completely maintained when MOD preparation is restored with composite resin and partially recovered when MOD preparation associated with an endodontic access is restored in the same way. The endodontic treatment and composite resin restoration influenced stress distribution in the dental structure. CONCLUSIONS: Composite resin restoration plays an important role in recovering tooth strength. With regard to fracture mode, restoration and endodontic treatment increased the incidence of periodontal involvement, which was demonstrated by association with the finite element mechanical test method.

Effect of a bonding resin layer associated with a self-etching adhesive system on the bond strength of indirect restorations

The aim of this study was to evaluate the influence of a low-viscosity bonding resin applied over a self-etching adhesive system on the microtensile bond strength (µTBS) of indirect restorations. Comparisons were made using One Up Bond F (OB) self-etching adhesive system, Single Bond (SB) one-bottle adhesive system and Scotchbond Multi Purpose Plus (SMP) bonding component. Thirty bovine incisors were extracted and decoronated at the cementoenamel junction. The labial surfaces were ground so that superficial dentin and deep dentin were exposed. The specimens were randomized to three groups (n=10): G1- OB; G2- OB + SMP; G3- SB. In G2, a layer of the SMP bonding was applied over the OB adhesive system. Indirect composite restorations were bonded using dual-cure cement under 500 g load for 5 min. The specimens were serially sectioned with a bonding area of ± 1.0 mm² in 3 regions: enamel (E), superficial dentin (SD) and deep dentin (DD). The sticks were fixed with cyanoacrylate adhesive and submitted to µTBS test at a crosshead speed of 0.5 mm/min in a mechanical testing machine (EMIC DL 2000). The fractured specimens were examined under scanning electron microscopy to determine the failure mode. Data were analyzed by one-way ANOVA followed by Tukey's test (p<0.05). µTBS means (in MPa) were: G1/E: 15.5 ± 3.5b; G1/SD: 22.7 ± 7.6a; G1/DD: 19.4 ± 9.4a; G2/E: 15.9 ± 5.8b; G2/SD: 19.9 ± 6.9a; G2/DD: 15.3 ± 4.9a; G3/E: 23.2 ± 7.3a; G3/SD: 20.4 ± 8.2a; G3/DD: 19.1 ± 8.7a. The results showed that the use of a low viscosity bonding resin did not affect the µTBS means when associated with a self-etching adhesive system. The self-etching adhesive system was significantly more efficient in dentin than in enamel, while the one-bottle system was significantly more efficient in enamel when compared to the self-etching adhesive system.

Effect of a bonding resin layer associated with a self-etching adhesive system on the bond strength of indirect restorations.

The aim of this study was to evaluate the influence of a low-viscosity bonding resin applied over a self-etching adhesive system on the microtensile bond strength (microTBS) of indirect restorations. Comparisons were made using One Up Bond F (OB) self-etching adhesive system, Single Bond (SB) one-bottle adhesive system and Scotchbond Multi Purpose Plus (SMP) bonding component. Thirty bovine incisors were extracted and decoronated at the cementoenamel junction. The labial surfaces were ground so that superficial dentin and deep dentin were exposed. The specimens were randomized to three groups (n=10): G1- OB; G2- OB + SMP; G3- SB. In G2, a layer of the SMP bonding was applied over the OB adhesive system. Indirect composite restorations were bonded using dual-cure cement under 500 g load for 5 min. The specimens were serially sectioned with a bonding area of +/- 1.0 mm(2) in 3 regions: enamel (E), superficial dentin (SD) and deep dentin (DD). The sticks were fixed with cyanoacrylate adhesive and submitted to microTBS test at a crosshead speed of 0.5 mm/min in a mechanical testing machine (EMIC DL 2000). The fractured specimens were examined under scanning electron microscopy to determine the failure mode. Data were analyzed by one-way ANOVA followed by Tukey's test (p<0.05). microTBS means (in MPa) were: G1/E: 15.5 +/- 3.5b; G1/SD: 22.7 +/- 7.6a; G1/DD: 19.4 +/- 9.4a; G2/E: 15.9 +/- 5.8b; G2/SD: 19.9 +/- 6.9a; G2/DD: 15.3 +/- 4.9a; G3/E: 23.2 +/- 7.3a; G3/SD: 20.4 +/- 8.2a; G3/DD: 19.1 +/- 8.7a. The results showed that the use of a low viscosity bonding resin did not affect the microTBS means when associated with a self-etching adhesive system. The self-etching adhesive system was significantly more efficient in dentin than in enamel, while the one-bottle system was significantly more efficient in enamel when compared to the self-etching adhesive system.

Influência da confecção de canaleta e recobrimento com resina composta na resistência de união da colagem de fragmento dental / Influence of the chamfer on the bonding strenght of reattached dental fragments

Este estudo avaliou a influência da confecção da canaleta e posterior restauração com resina composta, na resistência de união da colagem de fragmento dental. Quarenta incisivos bovinos foram fraturados a 3 mm da junção cemento-esmalte e divididos em 4 grupos (n=10) nos quais a colagem do fragmento foi realizada com cimento resinoso dual após hibridização das superfícies de adesão. No grupo 1, foi feita somente a colagem, sem preparo adicional. Nos outros grupos as canaletas (0.7mm de profundidade)foram feitas e restauradas sobre a linha de união com diferentes localizações. Grupo 2, canaleta na facevestibular; grupo 3, canaleta na face lingual; grupo 4, canaleta nas faces vestibular e lingual. As amostras foram testadas usando dispositivo em forma de faca em máquina de ensaio mecânico(0.5mm/min) num ângulo de 90 na face lingual. Os valores em Kgf foram submetidos à análise estatística (?=0.05) e o teste de Kruskall-Wallis não mostrou diferença significativa entre os grupos (p=0.565)...

The effect of the chamfer and posterior restoration using composite resin on the bond strength of dental reattachment was evaluated. Forty bovine teeth were fractured 3 mm above the cement-enamel junction, divided in 4 groups (n=10) and the fragments were reattached with a dual resin cement afterhybridization of the bonding surfaces. In the group 1 the reattachment was done without additional preparation but in the other groups chamfers (0.7 mm depth) were made and restored with composite resin along the bond line in different locations. Group 2, chamfer on the buccal aspect; group 3, chamferon the lingual aspect; group 4, chamfer on both buccal and lingual aspects. Specimens were sheared using a spade blade in a test machine (0.5 mm/min) at 90° to the lingual surface. The data (Kgf) were submitted to statistical analysis (?=0.05) and the Kruskall-Wallis test showed no significant differences among the groups (p=0.565)...

Avaliação clínica de clareamento caseiro com gel de peróxido de carbamida industrializado e manipulado em farmácia / Tooth bleaching clinical evaluation with industrialized and drugstore manipulated carbamide peroxide gel

Este trabalho objetivou avaliar clinicamente o uso de clareamento dental caseiro com peróxido de carbamida 10% industrializado e manipulado. Quarenta pacientes foram selecionados com indicação de receber clareamento caseiro e divididos em dois grupos: G1- peróxido de carbamida 10% com Carbopol manipulado em drogaria e G2- peróxido de carbamida 10% com Carbopol industrializado (Whiteness-FGM-Joinvile-SC-Brasil). A análise se baseou nos parâmetros: variação do grau de escurecimento dental por meio de escala de cores (Vita Classic); satisfação pessoal do paciente; sensibilidade pós-operatória, irritação gengival e vitalidade pulpar. Os dados obtidos foram analisados qualitativamente mediante distribuição por freqüência. Os resultados foram: alteração de cor após uma semana de uso do gel clareador: G1- redução de um nível de saturação e G2- redução de dois níveis de saturação e após duas semanas de uso do gel clareador; satisfação do paciente: G1- 68,0% e G2- 82,7%; sensibilidade pós-operatória: G1- 40,0% e G2- 10,0%; irritação gengival: G1-10,0% e G2- 5,0%. Não houve alteração na vitalidade pulpar com o uso dos dois produtos analisados. Pôde-se concluir que os dois materiais apresentaram desempenhos diferenciados, sendo o produto industrializado o mais eficiente para o uso clínico.

The aim of this study was to realize the clinical follow-up of vital tooth bleaching realized with manipulated and industrialized 10% carbamide peroxide gel. Forty patients were selected with indication to receive tooth bleaching and divided in two groups: G1-Twenty patients received drugstore manipulated 10% carbamide peroxide with carbopol, and G2- twenty patients received industrialized 10% carbamide peroxide (Whiteness-FGM-Joinvile-SC-Brasil). The analysis if based on the parameters: degree of tooth discoloration before and after treatment, using Vita shade guide; personal satisfaction of patients; post-operative tooth sensibility; gingival irritation and pulp vitality. The data were analyzed qualitatively by frequency distribution. The results showed: color alteration after one week of use of the gel: G1- reduction of a level of saturation and G2- reduction of two levels of saturation; e after two weeks of use of the gel: satisfaction of the patient: G1- 68.0% and G2- 82,7%; post-operative tooth sensibility: G1- 40.0% and G2- 10,0%; gingival irritation: G1-10,0% and G2- 5,0%. It did not have alteration in the pulp vitality with the use of the two analyzed products. It can conclude that the manipulated and industrialized 10% carbamide peroxide showed different results, been industrialized gel more efficient to clinical usage.

Adaptação marginal e resistência à fratura de coroas totais executadas em diferentes sistemas / Marginal adaptation and fracture resistance of metal-ceramic and metal-free prosthetic unit crowns made with different systems

O objetivo deste trabalho foi avaliar a adaptação marginal e a resistência à fratura de coroas totais metalocerâmicas e de coroas sem reforço de infra-estrutura metálica, utilizando-se diferentes sistemas restauradores. Foram selecionadas 48 raízes de dentes bovinos com diâmetros e formas semelhantes, seccionadas com 15 mm de comprimento. Após tratamento endodôntico e alívio do conduto pinos metálicos com 12 mm de comprimento foram fixados com cimento de fosfato de zinco e um preenchimento coronário de resina composta micro-híbrida foi construído com 3 mm de altura e convergência axial de aproximadamente 6 graus. O término foi o ombro arredondado com 1,0 mm de largura. As amostras preparadas e seus respectivos modelos foram aleatoriamente distribuídos em 6 grupos com 8 amostras cada. Os grupos foram assim divididos: GRUPO A - coroas metalocerâmicas convencionais; GRUPO B - coroas metalocerâmicas modificadas; GRUPO C - coroas cerâmicas reforçadas por dissilicato de lítio (Empress 2); GRUPO D - coroas cerâmicas reforçadas por leucita (Cergogold); GRUPO E - coroas cerâmicas reforçadas por leucitafluorapatita; GRUPO F - coroas de cerômero (Targis). As coroas foram fabricadas seguindo-se as recomendações técnico-laboratoriais dos fabricantes para o seu material. No seu formato final as coroas apresentaram espessura axial aproximada de 1,0 mm no terço gengival e espessura oclusal de 2 mm. A inclinação oclusal das coroas foi controlada através de uma referência padronizada...

Aplicaçäo tópica de flúor - efeito sobre a porcelana dental / Topic fluoride aplication - effect on dental porcelain

Este trabalho se propôs a avaliar o efeito do flúor neutro e flúor fosfato acidulado sobre a porcelana dental através da análise da rugosidade superficial e variaçäo da massa. 70 amostras foram confeccionadas com as porcelanas Vita VMK-68 e Ivoclar IPS Classic. Essas amostras foram pesadas em balança analítica e analisadas em rugosímetro. Posteriormente foram imersas em grupos de 5 no flúor neutro e acidulado nos períodos de 4 minutos, 60 minutos e 24 horas. Em seguida foram lavadas, secas em estufa e reavaliadas. Os resultados demonstraram que o flúor fosfato acidulado produziu efeito estatisticamente significante na reduçäo da massa e aumento da rugosidade em ambas as porcelanas; o fator tempo produziu efeito cumulativo para o flúor acidulado. O flúor neutro näo produziu efeito sobre a porcelana dental sendo portanto uma alternativa viável na aplicaçäo tópica de flúor como método preventivo da cárie dental em pacientes portadores de prótese metalocerâmica

Materiais restauradores que liberam flúor / Restoring materials that release fluoride

Necessitando encontrar mecanismos que atuassem em nível da microbiota oral, tem-se na atualidade que o flúor exerce um papel importante na prevençäo da cárie, pois atua näo só em nível da microbiota oral, mas também na formaçäo de uma camada protetora do esmalte. Assim, materiais odontológicos restauradores, que liberam certa quantidade de flúor estäo sendo desenvolvidos e aprimorados para que funcionem de maneira efetiva nos mecanismos de prevençäo da cárie. Esta revisäo literária explanará o estado atual destes materiais

Remoçäo de manchas da superfície dental através da microabrasäo dos esmalte: relato de caso clínico / Dental surface stains removal with microabrasion enamel: case report

A remoçäo de manchas e pequenas irregularidade da superfície do esmalte pela técnica d microabrasäo tem apresentado resultados excelentes. É uma alternativa que quase dispensa a utilizaçäo de material restaurador, preservando a estética natural e pode ser feita em uma sessäo. O caso clínico aqui relatado mostra a remoçäo de manchas da superfície dental através de uma variaçäo da técnica original proposta por Croll, visando diminuir o tempo de trabalho e mantendo a qualidade dos resultados