RESUMO
This non-controlled clinical study evaluated the masking effect of an infiltrant resin on mild molar incisor hypomineralization (MIH) lesions. Thirty MIH-affected anterior teeth with creamy/ white opacities from 12 children aged 6-15 years received the application of an infiltrant resin (Icon- DMG). Standard photographs were taken before (T1), immediately after (T2), and 1 week after (T3) resin infiltration. Two calibrated examiners qualitatively analyzed the color match using the Fédération Dentaire Internationale (FDI) scale. The binomial distribution test analyzed the scores of the color match at T1 with T2 and T3, and McNemar's test analyzed the scores of the color match between T2 and T3 (α=0.05). There was a significant increase in color match between T1 and T2 (p=0.0005), between T1 and T3 (p=0.0005), and between T2 and T3 (p=0.0019). It was concluded that infiltrant resin was effective in improving the esthetic appearance of creamy/white opacities on MIH-affected anterior teeth.
Assuntos
Hipomineralização Molar , Resinas Sintéticas , Criança , HumanosRESUMO
The aim of this laboratory study was to evaluate the pull-out force of a prefabricated fiberglass post (PP), relined fiberglass post (RP), or milled fiberglass post (MP) luted with Multilink N (MN), RelyX Unicem 2 (RXU2) or RelyX Ultimate (RU) to enlarged root canals. The thickness of the resin cements and the presence of voids in the resin cement film were observed. The root canals of 90 bovine incisors were enlarged, endodontically treated, and randomly divided into 9 groups (n=10) according to the post type and resin cement. The specimens were scanned using micro-CT to analyze the thickness of the resin cement and the presence of voids. The specimens were submitted to mechanical cyclic loading (500,000 cycles at 50 N load) and subjected to pull-out force testing. Two-way ANOVA and Tukey's test analyzed the pull-out force and resin cement thickness data. Kruskal-Wallis and Bonferroni tests analyzed the void scores. The interaction between factors (post × resin cement) was significant (p=0.0001) for the pull-out force. Higher pull-out forces were obtained for RP and MP compared to PP. The post factor was significant (p=0.0001) for resin cement thickness, which was higher for PP (1054 µm), followed by MP (301 µm) and RP (194 µm). More void formation occurred for PP, being less for RP, differing significantly among the posts. Post customization (RP and MP) decreased resin cement thickness and void formation, favoring a higher pull-out force. Resin cements requiring an adhesive application (MN and RU) favored higher pull-out force than self-adhesive resin cement (RXU2).
Assuntos
Colagem Dentária , Técnica para Retentor Intrarradicular , Animais , Bovinos , Cavidade Pulpar , Vidro , Teste de Materiais , Cimentos de Resina/uso terapêuticoRESUMO
STATEMENT OF THE PROBLEM: Full-coverage all-ceramic restorations are widely used. The impact of various classifications of luting agent on marginal discrepancies is not well understood. PURPOSE: The purpose of this study was to evaluate the cervical fit of all ceramic crowns (IPS e.maxPress, Cergogold, and In Ceram) on bovine teeth with two luting agents before and after cementation. MATERIALS AND METHODS: Ninety bovine incisors were embedded in resin. The coronal portions of the teeth were prepared to receive full-coverage crowns. Thirty crowns of 7.0 ± 0.5 mm height, 8.0 mm cervical diameter, and 4.2 mm incisal diameter were fabricated for each ceramic system. The crowns were seated on the teeth, and the marginal discrepancy was measured using a measuring microscope. Then, 15 crowns of each ceramic system were luted on the teeth with resin cement (Variolink II) or resin-modified glass ionomer cement (Rely X luting), and the marginal discrepancy was measured. The results were submitted to analysis of variance, t test and Tukey's test (p<0.05). RESULTS: The three ceramic systems showed cervical fits after cementation statistically inferior to cervical fits before cementation for the two cements. The IPS e.maxPress showed values for cervical fit statistically superior to Cergogold before cementation. No statistically significant difference was found between IPS e.maxPress and In Ceram and In Ceram and Cergogold. After cementation, no statistically significant difference was found for the three ceramics systems when luted with resin or resin-modified glass ionomer luting agents. CONCLUSIONS: Within the limitations of this study, it can be concluded that both cements studied increase the marginal discrepancy between the crown and the preparation for the three ceramic systems evaluated.
Assuntos
Cimentação/métodos , Cerâmica/química , Coroas , Adaptação Marginal Dentária , Porcelana Dentária/química , Silicatos de Alumínio/química , Animais , Bovinos , Resinas Compostas/química , Cimentos de Ionômeros de Vidro/química , Teste de Materiais , Compostos de Potássio/química , Cimentos de Resina/química , Propriedades de Superfície , Preparo Prostodôntico do Dente/métodosRESUMO
AIM: To evaluate the effect of unidirectional or woven glass fibre tapes inserted into MOD cavity preparations on the fracture resistance of root filled molar teeth. METHODOLOGY: Extracted human molar teeth were randomly divided into six groups (n = 15) : G1 - sound teeth, control; G2 - MOD cavity preparation; G3 - MOD + root canal treatment (Endo); G4 - MOD + Endo + composite resin restoration (Resin); G5 - MOD + Endo + unidirectional fibre (UF) + Resin; G6 - MOD + ;Endo + woven fibre (WF) + Resin. The teeth were subjected to a compressive fracture test in a universal testing machine. After testing, two failure modes were classified: pulp chamber floor or cusp. RESULTS: The highest and the lowest mean fracture strengths were found in sound teeth (G1) (4960N) and MOD + root canal treatment (G3) (612.84N), respectively, with significant differences from the other groups (P < 0.05). The remaining groups had statistically similar means. In G5 and G6, there was a tendency for fracture to occur in the pulp chamber floor compromising tooth integrity. CONCLUSIONS: The insertion of glass fibres into MOD cavity preparations and restoring them with composite resin was not different than molar teeth filled with composite resin only in terms of fracture resistance. Fibres placed into MOD cavities do not reinforce teeth.
Assuntos
Materiais Dentários/química , Restauração Dentária Permanente/métodos , Vidro/química , Dente Molar/patologia , Tratamento do Canal Radicular/métodos , Fraturas dos Dentes/fisiopatologia , Dente não Vital/terapia , Condicionamento Ácido do Dente , Bis-Fenol A-Glicidil Metacrilato/química , Resinas Compostas/química , Força Compressiva , Preparo da Cavidade Dentária/métodos , Esmalte Dentário/lesões , Cavidade Pulpar/lesões , Análise do Estresse Dentário/instrumentação , Cimentos de Ionômeros de Vidro/química , Guta-Percha/uso terapêutico , Humanos , Maleatos/química , Teste de Materiais , Dente Molar/lesões , Materiais Restauradores do Canal Radicular/uso terapêutico , Estresse MecânicoRESUMO
PURPOSE: To assess, in vitro, the tensile bond strength to dentin of the following adhesive systems: Single Bond (3M), One Coat Bond (Coltène), Clearfil Liner Bond 2 V (Kuraray) and Etch & Prime 3.0 (Degussa). MATERIALS AND METHODS: Thirty third molars, extracted according to therapeutic indication, were used. The roots were removed at the cement-enamel junction level and the crowns were sectioned in a mesial-distal direction, obtaining buccal and lingual halves. The dental portions were included in self-cured acrylic resin, abraded on a lathe under water spray and polished to 400 and 600 grit. The adhesive systems were applied on dentin according to manufacturers' instructions and resin-based composite (Z100) cones were bonded. For each adhesive system, 15 specimens were prepared, stored in distilled water at 37 degrees C during 24 hrs and submitted to tensile bond strength tests on a universal testing machine (EMIC DL-2000) at a crosshead speed of 0.5 mm/min. RESULTS: The mean tensile bond strength to dentin (MPa +/- SD) were statistically different (ANOVA, Tukey's tests, P < or = 0.01, shown by asterisks) from each other: (1) Clearfil Liner Bond 2 V* = 24.8 +/- 3.3; (2) One Coat Bond** = 20.4 +/- 2.0; (3) Single Bond** = 18.1 +/- 2.4; (4) Etch & Prime 3.0*** = 5.8 +/- 2.4.
Assuntos
Colagem Dentária , Adesivos Dentinários , Análise de Variância , Bis-Fenol A-Glicidil Metacrilato , Dentina , Difosfatos , Etanol , Humanos , Teste de Materiais , Metacrilatos , Dente Serotino , Distribuição Aleatória , Resistência à TraçãoRESUMO
The purpose of this study was to investigate the tensile bond strengths of three adhesive systems applied to dentin at refrigerated and room temperatures. Ninety bovine incisor teeth were obtained, embedded in self-cured acrylic resin, abraded on a lathe under water spray and polished to 400 and 600 grit to form standardized dentin surfaces before randomly assigning to six groups (n = 15). The adhesive systems Scotchbond Multi-Purpose, Single Bond and Prime & Bond NT were applied to dentin according to the manufacturers' instructions at refrigerated temperature (4 degrees C) and at room temperature (23 degrees C), before bonding resin-based composite (Z 100). The specimens were stored in distilled water at 37 degrees C for 24 hours and submitted to tensile bond strength tests on a universal testing machine (EMIC DL-2000) at a crosshead speed of 0.5 mm/min. The resulting data were statistically analyzed using analysis of variance and Tukey's test. No statistical differences were found when the adhesive systems were applied at refrigerated and room temperatures. Scotchbond Multi-Purpose and Single Bond had significantly stronger tensile bond strengths than Prime & Bond NT at room and refrigerated temperatures (p < 0.01). Scotchbond Multi-Purpose and Single Bond were statistically similar. No adverse effects upon tensile bond strength were observed when adhesive systems were taken directly from refrigerated storage.