RESUMO
Root canal filling with zinc oxide-eugenol (ZOE) paste following primary tooth pulpectomy is a common practice in pediatric dentistry. This material offers high clinical and radiographic success rates. In some cases, however, it is not resorbed along with the root of the primary tooth. The aim of this study was to describe a case of prolonged retention of a primary maxillary incisor that was subjected to pulpectomy and filled with ZOE paste in order to characterize the aspects of root resorption using scanning electron microscopy.
Assuntos
Incisivo/ultraestrutura , Pulpectomia/métodos , Tratamento do Canal Radicular/métodos , Dente Decíduo/ultraestrutura , Criança , Cemento Dentário/ultraestrutura , Feminino , Seguimentos , Humanos , Microscopia Eletrônica de Varredura , Planejamento de Assistência ao Paciente , Materiais Restauradores do Canal Radicular/uso terapêutico , Reabsorção da Raiz/fisiopatologia , Ápice Dentário/ultraestrutura , Esfoliação de Dente/fisiopatologia , Extração Dentária/métodos , Cimento de Óxido de Zinco e Eugenol/uso terapêuticoRESUMO
AIM: Root conditioning is aimed at smear layer removal and at dental matrix collagen exposure, which may promote periodontal regeneration. This in vitro study assessed smear layer removal, collagen fiber exposure and the influence of PRP (platelet-rich plasma) application on adhesion of blood cells to the root surface using scanning electron microscopy (SEM). MATERIALS AND METHODS: Scaled root samples (n = 160) were set in five groups and conditioned with: group I - control group (saline solution); group II (EDTA 24%); group III (citric acid 25%); group IV (tetracycline hydrochloride 50 mg/ml); group V (sodium citrate 30%). Eighty samples were assessed using the root surface modification index (RSMI). The other eighty samples were set in two groups. The first group (n = 40) received PRP gel application with a soft brush and the second group (n = 40) received PRP application and then a blood drop. The fibrin clot formation was assessed in the first group and the blood cells adhesion was assessed in the second group using the BEAI (blood elements adhesion index). A previously trained, calibrated, and blind examiner evaluated photomicrographs. Statistical analysis was performed using the Kruskal-Wallis's and Dunn's tests. RESULTS: Group III attained the best results for RSMI and BEAI. Moreover, it was the only group showing fibrin clot formation. CONCLUSION: Citric acid was the most efficient conditioner for smear layer removal, collagen fiber exposure and blood cell adhesion. Moreover, it was the only group showing fibrin clot formation after PRP application. CLINICAL SIGNIFICANCE: This study demonstrated that root conditioning followed by PRP application may favor blood cell adhesion on root surface which may optimize periodontal healing.
Assuntos
Células Sanguíneas/fisiologia , Dentina/efeitos dos fármacos , Plasma Rico em Plaquetas , Camada de Esfregaço , Condicionamento de Tecido Mole Oral , Raiz Dentária/efeitos dos fármacos , Coagulação Sanguínea , Adesão Celular , Quelantes/farmacologia , Citratos/farmacologia , Ácido Cítrico/farmacologia , Cemento Dentário/efeitos dos fármacos , Cemento Dentário/ultraestrutura , Dentina/ultraestrutura , Ácido Edético/farmacologia , Fibrina/fisiologia , Humanos , Masculino , Microscopia Eletrônica de Varredura , Citrato de Sódio , Tetraciclina/farmacologia , Desmineralização do DenteRESUMO
This study evaluated the influence of material combinations used in the resin coating technique (RCT) on the marginal adaptation of indirect restorations with gingival margins in enamel (EM) and cement (CM). Eighty third-molars were used. Two cavities were prepared in each tooth. The cavities were distributed into 16 groups. Cavities with EM were filled with the following material combinations: G1: Single-Bond 2 (Sb2), G2: Sb2 + Bond/Scotchbond-Multipurpose (Sb2B), G3: Sb2 + Filtek-Flow Z350 (Sb2Fl), G4: Scotchbond-Multipurpose (SBMP), G5: Clearfil-S3 (CS3), G6: CS3 + Bond/Clearfil-SE Bond (CSE3B), G7: CS3 + Protect Liner F (CS3PL) and G8: Clearfil SE Bond + Protect Liner F (CSEBPL). The same combinations were applied to the cavities in CM: G9, G10, G11, G12, G13, G14, G15, G16, respectively. The fillings were performed with the Sinfony-System (3M/ESPE). After 24 h, the teeth were submitted to thermocycling (2,000 cycles, 5° to 55°C) and load-cycling (50,000 cycles, 50 N). Next, the Caries-Detector (Kuraray) was applied to the restoration margins. Images from the proximal margin were evaluated using the Image-Tool 3.0 software. The results were submitted to ANOVA and Tukey's test (α=0.05). The mean values (%) for the groups were: EM: G1=46.68, G2=15.53, G3=19.83, G4=27.53; G5=59.49, G6=25.13, G7=34.37, G8=15.20; CM: G9=38.38, G10=23.25, G11=26.97, G12=25.85, G13=37.81, G14=30.62, G15=29.17, G16=20.31. The highest percentages of marginal gap on EM or CM were found in the groups that did not use a liner. It can be concluded that the most appropriate RCT combinations were the groups that used a liner.
Assuntos
Resinas Compostas/química , Forramento da Cavidade Dentária/métodos , Adaptação Marginal Dentária , Materiais Dentários/química , Restauração Dentária Permanente/classificação , Condicionamento Ácido do Dente/métodos , Bis-Fenol A-Glicidil Metacrilato/química , Preparo da Cavidade Dentária/classificação , Cimentos Dentários/química , Cemento Dentário/ultraestrutura , Esmalte Dentário/ultraestrutura , Adesivos Dentinários/química , Corantes Fluorescentes , Humanos , Teste de Materiais , Polietilenoglicóis/química , Ácidos Polimetacrílicos/química , Cimentos de Resina/química , Rodaminas , Silanos/química , Estresse Mecânico , Propriedades de Superfície , Temperatura , Fatores de TempoRESUMO
This study evaluated the influence of material combinations used in the resin coating technique (RCT) on the marginal adaptation of indirect restorations with gingival margins in enamel (EM) and cement (CM). Eighty third-molars were used. Two cavities were prepared in each tooth. The cavities were distributed into 16 groups. Cavities with EM were filled with the following material combinations: G1: Single-Bond 2 (Sb2), G2: Sb2 + Bond/Scotchbond-Multipurpose (Sb2B), G3: Sb2 + Filtek-Flow Z350 (Sb2Fl), G4: Scotchbond-Multipurpose (SBMP), G5: Clearfil-S3 (CS3), G6: CS3 + Bond/Clearfil-SE Bond (CSE3B), G7: CS3 + Protect Liner F (CS3PL) and G8: Clearfil SE Bond + Protect Liner F (CSEBPL). The same combinations were applied to the cavities in CM: G9, G10, G11, G12, G13, G14, G15, G16, respectively. The fillings were performed with the Sinfony-System (3M/ESPE). After 24 h, the teeth were submitted to thermocycling (2,000 cycles, 5° to 55°C) and load-cycling (50,000 cycles, 50 N). Next, the Caries-Detector (Kuraray) was applied to the restoration margins. Images from the proximal margin were evaluated using the Image-Tool 3.0 software. The results were submitted to ANOVA and Tukey's test (α=0.05). The mean values (%) for the groups were: EM: G1=46.68, G2=15.53, G3=19.83, G4=27.53; G5=59.49, G6=25.13, G7=34.37, G8=15.20; CM: G9=38.38, G10=23.25, G11=26.97, G12=25.85, G13=37.81, G14=30.62, G15=29.17, G16=20.31. The highest percentages of marginal gap on EM or CM were found in the groups that did not use a liner. It can be concluded that the most appropriate RCT combinations were the groups that used a liner.
Este estudo avaliou a influência de diferentes combinações de materiais usados na técnica de selamento dentinário (TSD) sobre a adaptação marginal de restaurações indiretas, cujas margens gengivais localizam-se em esmalte (ME) ou cemento (MC). Oitenta terceiros molares foram selecionados e duas cavidades foram preparadas em cada dente, as quais foram distribuídas em 16 grupos. As cavidades com margem em esmalte foram forradas pelas seguintes combinações de materiais: G1: Single-Bond2 (Sb2), G2: Sb2 + Bond/Scotchbond-Multipurpose (Sb2B), G3: Sb2 + Filtek-Flow Z350 (Sb2Fl), G4: Scotchbond-Multipurpose (SBMP), G5: Clearfil-S3 (CS3), G6: CS3 + Bond/Clearfil-SE Bond (CSE3B), G7: CS3 + Protect Liner F (CS3PL), G8: Clearfil SE Bond + Protect Liner F (CSEBPL). As mesmas combinações foram aplicadas às cavidades com margens em cemento: G9, G10, G11, G12, G13, G14, G15, G16, respectivamente. As restaurações foram confeccionadas usando o sistema Sinfony (3M/ESPE). Após 24 h, os dentes restaurados foram submetidos à ciclagem térmica (2.000 ciclos - 5° a 55° C) e mecânica (50.000 ciclos, 50 N). Em seguida, Carie-Detector (Kuraray) foi aplicado sobre as margens das restaurações. As imagens obtidas da margem proximal foram avaliadas pelo software Image-Tool 3.0. Os resultados foram submetidos aos testes estatísticos ANOVA e Tukey (p<0,05). As médias (%) observadas para os grupos foram: ME: G1=46,68, G2=15,53, G3=19,83, G4=27,53; G5=59,49, G6=25,13, G7=34,37 e G8=15,20; MC: G9=38,38, G10=23,25, G11=26,97, G12=25,85, G13=37,81, G14=30,62, G15=29,17, G16=20,31. Os maiores valores de desadaptação marginal encontrados em ME e MC foram encontrados nos grupos que não utilizaram um "liner". Desta forma, pôde-se concluir que a combinação mais apropriada para a TSD é aquela que faz uso do "liner".
Assuntos
Humanos , Resinas Compostas/química , Adaptação Marginal Dentária , Forramento da Cavidade Dentária/métodos , Materiais Dentários/química , Restauração Dentária Permanente/classificação , Condicionamento Ácido do Dente/métodos , Bis-Fenol A-Glicidil Metacrilato/química , Preparo da Cavidade Dentária/classificação , Cimentos Dentários/química , Cemento Dentário/ultraestrutura , Esmalte Dentário/ultraestrutura , Adesivos Dentinários/química , Corantes Fluorescentes , Teste de Materiais , Polietilenoglicóis/química , Ácidos Polimetacrílicos/química , Cimentos de Resina/química , Rodaminas , Estresse Mecânico , Propriedades de Superfície , Silanos/química , Temperatura , Fatores de TempoRESUMO
Although in vitro studies have shown encouraging results for root surface conditioning with demineralizing agents, in vivo studies have failed to show its benefits in periodontal healing. This can be attributed to several factors, among which, the hypermineralization of dental surface. Therefore, this in vitro study compared, using scanning electron microscopy (SEM), the effect of root surface conditioning with different conditioners (1% and 25% citric acid, 24% EDTA and 50 mg/mL tetracycline hydrochloride) in impacted teeth and in teeth that had their roots exposed to the oral environment. One trained examiner assessed the SEM micrographs using a root surface modification index. There was a tendency of more root surface modification in the group of impacted teeth, suggesting that the degree of root mineralization influences its chemical demineralization.
Assuntos
Colágeno/ultraestrutura , Dentina/ultraestrutura , Aplainamento Radicular/métodos , Camada de Esfregaço , Raiz Dentária/ultraestrutura , Adulto , Quelantes/uso terapêutico , Ácido Cítrico/administração & dosagem , Ácido Cítrico/uso terapêutico , Colágeno/efeitos dos fármacos , Cálculos Dentários/patologia , Cemento Dentário/efeitos dos fármacos , Cemento Dentário/ultraestrutura , Dentina/efeitos dos fármacos , Ácido Edético/uso terapêutico , Hemorragia Gengival/patologia , Humanos , Microscopia Eletrônica de Varredura , Pessoa de Meia-Idade , Bolsa Periodontal/patologia , Tetraciclina/uso terapêutico , Raiz Dentária/efeitos dos fármacos , Dente Impactado/patologiaRESUMO
UNLABELLED: The aim of this study was to analyze the structural characteristics of the mineralized dental tissues--enamel, dentin and cementum--in primary teeth and to correlate the histological aspects observed in function of the dental type--single-rooted or multi-rooted. METHOD: Eighteen human primary noncarious teeth were sectioned in facial-lingual (single-rooted) and mesio-distal direction (multi-rooted). One to three samples from each tooth were obtained. The samples were prepared by the ground technique and analyzed under light microscopy at different magnifications. A quantitative and descriptive analysis of the morphology of the mineralized tissues was performed. RESULTS: Spindles, tufts and lamellae were consistently observed mainly in the occlusal surface of the primary molars. The scalloped pattern of the dentinoenamel junction was not always present. The same was seen for zones of interglobular dentin. Dead tracts in dentin and tertiary dentin were observed mainly in single-rooted teeth below areas of dental attrition. Areas of cellular and acellular cementum were observed in the two dental types. CONCLUSIONS: Primary teeth have some structural peculiarities and these should be investigated concerning the clinical repercussion.
Assuntos
Cemento Dentário/ultraestrutura , Esmalte Dentário/ultraestrutura , Dentina/ultraestrutura , Calcificação de Dente/fisiologia , Criança , Pré-Escolar , Cemento Dentário/fisiologia , Esmalte Dentário/fisiologia , Dentina/fisiologia , Humanos , Raiz Dentária/anatomia & histologia , Dente Decíduo/fisiologia , Dente Decíduo/ultraestruturaRESUMO
Although in vitro studies have shown encouraging results for root surface conditioning with demineralizing agents, in vivo studies have failed to show its benefits in periodontal healing. This can be attributed to several factors, among which, the hypermineralization of dental surface. Therefore, this in vitro study compared, using scanning electron microscopy (SEM), the effect of root surface conditioning with different conditioners (1% and 25% citric acid, 24% EDTA and 50 mg/mL tetracycline hydrochloride) in impacted teeth and in teeth that had their roots exposed to the oral environment. One trained examiner assessed the SEM micrographs using a root surface modification index. There was a tendency of more root surface modification in the group of impacted teeth, suggesting that the degree of root mineralization influences its chemical demineralization.
Apesar de estudos in vitro terem demonstrado resultados favoráveis ao condicionamento da superfície radicular com agentes desmineralizantes, estudos in vivo não mostraram seus benefícios na cicatrização periodontal. Isto pode ser atribuído a vários fatores, entre os quais, a hipermineralização da superfície dental. Portanto, este estudo in vitro comparou, usando microscopia eletrônica de varredura, o efeito do condicionamento da superfície radicular com diferentes condicionadores (1% e 25% de ácido cítrico, EDTA 24% e 50 mg/mL de cloridrato de tetraciclina) em dentes impactados e dentes que tinham suas raízes expostas ao meio bucal. Um examinador treinado avaliou as microscopias eletrônicas de varredura utilizando um índice de modificação da superfície radicular. Houve uma tendência de maior modificação da superfície radicular no grupo de dentes impactados, sugerindo que o grau de mineralização da raiz influencia a sua desmineralização química.
Assuntos
Adulto , Humanos , Pessoa de Meia-Idade , Colágeno/ultraestrutura , Dentina/ultraestrutura , Aplainamento Radicular/métodos , Camada de Esfregaço , Raiz Dentária/ultraestrutura , Quelantes/uso terapêutico , Ácido Cítrico/administração & dosagem , Ácido Cítrico/uso terapêutico , Colágeno/efeitos dos fármacos , Cálculos Dentários/patologia , Cemento Dentário/efeitos dos fármacos , Cemento Dentário/ultraestrutura , Dentina/efeitos dos fármacos , Ácido Edético/uso terapêutico , Hemorragia Gengival/patologia , Microscopia Eletrônica de Varredura , Bolsa Periodontal/patologia , Tetraciclina/uso terapêutico , Raiz Dentária/efeitos dos fármacos , Dente Impactado/patologiaRESUMO
OBJECTIVE: To assess microleakage in conservative class V cavities prepared with aluminum-oxide air abrasion or turbine and restored with self-etching or etch-and-rinse adhesive systems. MATERIALS AND METHODS: Forty premolars were randomly assigned to 4 groups (I and II: air abrasion; III and IV: turbine) and class V cavities were prepared on the buccal surfaces. Conditioning approaches were: groups I/III - 37% phosphoric acid; groups II/IV - self-priming etchant (Tyrian-SPE). Cavities were restored with One Step Plus/Filtek Z250. After finishing, specimens were thermocycled, immersed in 50% silver nitrate, and serially sectioned. Microleakage at the occlusal and cervical interfaces was measured in mm and calculated by a software. Data were subjected to ANOVA and Tukey's test (α=0.05). RESULTS: Marginal seal provided by air abrasion was similar to high-speed handpiece, except for group I. There was SIGNIFICANT difference between enamel and dentin/cementum margins for to group I and II: air abrasion. The etch-and-rinse adhesive system promoted a better marginal seal. At enamel and dentin/cementum margins, the highest microleakage values were found in cavities treated with the self-etching adhesive system. At dentin/cementum margins, high-speed handpiece preparations associated with etch-and-rinse system provided the least dye penetration. CONCLUSION: Marginal seal of cavities prepared with aluminum-oxide air abrasion was different from that of conventionally prepared cavities, and the etch-and-rinse system promoted higher marginal seal at both enamel and dentin margins.
Assuntos
Abrasão Dental por Ar/métodos , Preparo da Cavidade Dentária/métodos , Infiltração Dentária/classificação , Condicionamento Ácido do Dente/métodos , Óxido de Alumínio/química , Resinas Compostas/química , Colagem Dentária , Preparo da Cavidade Dentária/instrumentação , Cemento Dentário/ultraestrutura , Esmalte Dentário/ultraestrutura , Equipamentos Odontológicos de Alta Rotação , Adaptação Marginal Dentária , Polimento Dentário , Restauração Dentária Permanente/métodos , Dentina/ultraestrutura , Adesivos Dentinários/química , Humanos , Teste de Materiais , Metacrilatos/química , Ácidos Fosfóricos/química , Coloração pela Prata , Propriedades de Superfície , TemperaturaRESUMO
OBJECTIVE: To assess microleakage in conservative class V cavities prepared with aluminum-oxide air abrasion or turbine and restored with self-etching or etch-and-rinse adhesive systems. Materials and Methods: Forty premolars were randomly assigned to 4 groups (I and II: air abrasion; III and IV: turbine) and class V cavities were prepared on the buccal surfaces. Conditioning approaches were: groups I/III - 37 percent phosphoric acid; groups II/IV - self-priming etchant (Tyrian-SPE). Cavities were restored with One Step Plus/Filtek Z250. After finishing, specimens were thermocycled, immersed in 50 percent silver nitrate, and serially sectioned. Microleakage at the occlusal and cervical interfaces was measured in mm and calculated by a software. Data were subjected to ANOVA and Tukey's test (α=0.05). RESULTS: Marginal seal provided by air abrasion was similar to high-speed handpiece, except for group I. There was SIGNIFICANT difference between enamel and dentin/cementum margins for to group I and II: air abrasion. The etch-and-rinse adhesive system promoted a better marginal seal. At enamel and dentin/cementum margins, the highest microleakage values were found in cavities treated with the self-etching adhesive system. At dentin/cementum margins, high-speed handpiece preparations associated with etch-and-rinse system provided the least dye penetration. CONCLUSION: Marginal seal of cavities prepared with aluminum-oxide air abrasion was different from that of conventionally prepared cavities, and the etch-and-rinse system promoted higher marginal seal at both enamel and dentin margins.
Assuntos
Humanos , Abrasão Dental por Ar/métodos , Preparo da Cavidade Dentária/métodos , Infiltração Dentária/classificação , Condicionamento Ácido do Dente/métodos , Óxido de Alumínio/química , Resinas Compostas/química , Colagem Dentária , Equipamentos Odontológicos de Alta Rotação , Adaptação Marginal Dentária , Polimento Dentário , Preparo da Cavidade Dentária/instrumentação , Cemento Dentário/ultraestrutura , Esmalte Dentário/ultraestrutura , Restauração Dentária Permanente/métodos , Adesivos Dentinários/química , Dentina/ultraestrutura , Teste de Materiais , Metacrilatos/química , Ácidos Fosfóricos/química , Coloração pela Prata , Propriedades de Superfície , TemperaturaRESUMO
OBJECTIVE: To evaluate the gingival marginal seal in class II composite restorations using different restorative techniques. MATERIAL AND METHODS: Class II box cavities were prepared in both proximal faces of 32 sound human third molars with gingival margins located in either enamel or dentin/cementum. Restorations were performed as follows: G1 (control): composite, conventional light curing technique; G2: composite, soft-start technique; G3: amalgam/composite association (amalcomp); and G4: resin-modified glass ionomer cement/composite, open sandwich technique. The restored specimens were thermocycled. Epoxy resin replicas were made and coated for scanning electron microscopy examination. For microleakage evaluation, teeth were coated with nail polish and immersed in dye solution. Teeth were cut in 3 slices and dye penetration was recorded (mm), digitized and analyzed with Image Tool software. Microleakage data were analyzed statistically by non-parametric Kruskal-Wallis and Mann-Whitney tests. RESULTS: Leakage in enamel was lower than in dentin (p<0.001). G2 exhibited the lowest leakage values (p<0.05) in enamel margins, with no differences between the other groups. In dentin margins, groups G1 and G2 had similar behavior and both showed less leakage (p<0.05) than groups G3 and G4. SEM micrographs revealed different marginal adaptation patterns for the different techniques and for the different substrates. CONCLUSION: The soft-start technique showed no leakage in enamel margins and produced similar values to those of the conventional (control) technique for dentin margins.
Assuntos
Resinas Compostas/química , Colagem Dentária , Adaptação Marginal Dentária , Materiais Dentários/química , Restauração Dentária Permanente/métodos , Condicionamento Ácido do Dente , Bis-Fenol A-Glicidil Metacrilato/química , Corantes , Amálgama Dentário/química , Preparo da Cavidade Dentária/classificação , Cemento Dentário/ultraestrutura , Esmalte Dentário/ultraestrutura , Infiltração Dentária/classificação , Polimento Dentário , Restauração Dentária Permanente/classificação , Dentina/ultraestrutura , Adesivos Dentinários/química , Cimentos de Ionômeros de Vidro/química , Humanos , Teste de Materiais , Microscopia Eletrônica de Varredura , Cimentos de Resina/química , Propriedades de Superfície , Temperatura , Fatores de TempoRESUMO
OBJECTIVE: To compare the adhesion and maturation of blood components on chemically conditioned root surfaces. METHOD AND MATERIALS: Clinical root samples of human teeth were obtained (n = 150) and manually scaled. Five groups of 30 samples were treated as follows: (1) saline solution irrigation (control); (2) 24% EDTA gel; (3) 25% citric acid solution; (4) tetracycline solution (50 mg/mL); and (5) 30% sodium citrate solution. After these treatments, 15 samples of each group received a blood drop and were analyzed by SEM. The remaining 15 had their surface morphology evaluated for collagen fibrils exposure by SEM. Photomicrographs were analyzed according to the score of adhesion of blood components. Kruskal-Wallis and Dunn multiple comparison tests were employed. RESULTS: The control group was characterized by the absence of blood elements on the surface. The best result was observed in the citric acid group, which had a dense fibrin network with blood elements adhered. The EDTA group showed a moderate fibrin network formation. In contrast, a scarce fibrin network and a few cells were present in the tetracycline samples, and an absence of blood elements was found on sodium citrate specimens. The citric acid group was statistically different from the control group (P < .01). No differences were found among the control, EDTA, tetracycline, and sodium citrate groups (P > .05). CONCLUSION: Under these experimental conditions, citric acid is indicated to stabilize clots on the root surface, which act as a scaffold for connective tissue cell development.
Assuntos
Condicionamento Ácido do Dente/métodos , Coagulação Sanguínea/efeitos dos fármacos , Quelantes/uso terapêutico , Dentina/efeitos dos fármacos , Raiz Dentária/efeitos dos fármacos , Células Sanguíneas/ultraestrutura , Adesão Celular/efeitos dos fármacos , Citratos/uso terapêutico , Ácido Cítrico/uso terapêutico , Colágeno/ultraestrutura , Cemento Dentário/efeitos dos fármacos , Cemento Dentário/ultraestrutura , Raspagem Dentária , Dentina/ultraestrutura , Ácido Edético/uso terapêutico , Fibrina/efeitos dos fármacos , Fibrina/ultraestrutura , Humanos , Teste de Materiais , Microscopia Eletrônica de Varredura , Aplainamento Radicular , Método Simples-Cego , Camada de Esfregaço , Cloreto de Sódio , Citrato de Sódio , Tetraciclina/uso terapêutico , Raiz Dentária/ultraestruturaRESUMO
OBJECTIVE: To evaluate the gingival marginal seal in class II composite restorations using different restorative techniques. MATERIAL AND METHODS: Class II box cavities were prepared in both proximal faces of 32 sound human third molars with gingival margins located in either enamel or dentin/cementum. Restorations were performed as follows: G1 (control): composite, conventional light curing technique; G2: composite, soft-start technique; G3: amalgam/composite association (amalcomp); and G4: resin-modified glass ionomer cement/composite, open sandwich technique. The restored specimens were thermocycled. Epoxy resin replicas were made and coated for scanning electron microscopy examination. For microleakage evaluation, teeth were coated with nail polish and immersed in dye solution. Teeth were cut in 3 slices and dye penetration was recorded (mm), digitized and analyzed with Image Tool software. Microleakage data were analyzed statistically by non-parametric Kruskal-Wallis and Mann-Whitney tests. RESULTS: Leakage in enamel was lower than in dentin (p<0.001). G2 exhibited the lowest leakage values (p<0.05) in enamel margins, with no differences between the other groups. In dentin margins, groups G1 and G2 had similar behavior and both showed less leakage (p<0.05) than groups G3 and G4. SEM micrographs revealed different marginal adaptation patterns for the different techniques and for the different substrates. CONCLUSION: The soft-start technique showed no leakage in enamel margins and produced similar values to those of the conventional (control) technique for dentin margins.
Assuntos
Humanos , Resinas Compostas/química , Colagem Dentária , Adaptação Marginal Dentária , Materiais Dentários/química , Restauração Dentária Permanente/métodos , Condicionamento Ácido do Dente , Bis-Fenol A-Glicidil Metacrilato/química , Corantes , Polimento Dentário , Amálgama Dentário/química , Preparo da Cavidade Dentária/classificação , Cemento Dentário/ultraestrutura , Esmalte Dentário/ultraestrutura , Infiltração Dentária/classificação , Restauração Dentária Permanente/classificação , Adesivos Dentinários/química , Dentina/ultraestrutura , Cimentos de Ionômeros de Vidro/química , Teste de Materiais , Microscopia Eletrônica de Varredura , Cimentos de Resina/química , Propriedades de Superfície , Temperatura , Fatores de TempoRESUMO
OBJECTIVE: To describe the ultrastructure of the interface between periodontal tissues and titanium mini-implants in rat mandibles. MATERIALS AND METHODS: A titanium mini-implant was placed between the buccal roots of the mandibular first molar of 24 adult rats. After 21, 30, 45, 60, 90, and 120 days of implantation, the mandibular portion was removed and fixed in cacodylate-buffered 2% glutaraldehyde + 2.5% formaldehyde. The material was decalcified and processed for scanning and transmission electron microscopy. RESULTS: Ultrastructural analysis revealed a thin cementum-like layer at longer times after implantation at the areas in which the periodontal ligament was in contact with the implant. CONCLUSIONS: The alveolar bone and the periodontal ligament reorganized their constituents around the implant, and a thin cementum-like layer was formed at longer times after implantation at the areas in which the periodontal ligament was in contact with the implant.
Assuntos
Implantes Dentários , Materiais Dentários , Mandíbula/cirurgia , Ligamento Periodontal/ultraestrutura , Titânio , Processo Alveolar/ultraestrutura , Animais , Colágeno/ultraestrutura , Cemento Dentário/ultraestrutura , Materiais Dentários/química , Masculino , Mandíbula/ultraestrutura , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Dente Molar/anatomia & histologia , Procedimentos de Ancoragem Ortodôntica/instrumentação , Osseointegração/fisiologia , Osteoblastos/ultraestrutura , Osteócitos/ultraestrutura , Osteogênese/fisiologia , Ratos , Ratos Wistar , Propriedades de Superfície , Fatores de Tempo , Titânio/química , Raiz Dentária/anatomia & histologiaRESUMO
Age estimation by counting incremental lines in cementum added to the average age of tooth eruption is considered an accurate method by some authors, while others reject it stating weak correlation between estimated and actual age. The aim of this study was to evaluate this technique and check the influence of periodontal disease on age estimates by analyzing both the number of cementum lines and the correlation between cementum thickness and actual age on freshly extracted teeth. Thirty one undecalcified ground cross sections of approximately 30 µm, from 25 teeth were prepared, observed, photographed and measured. Images were enhanced by software and counts were made by one observer, and the results compared with two control-observers. There was moderate correlation ((r)=0.58) for the entire sample, with mean error of 9.7 years. For teeth with periodontal pathologies, correlation was 0.03 with a mean error of 22.6 years. For teeth without periodontal pathologies, correlation was 0.74 with mean error of 1.6 years. There was correlation of 0.69 between cementum thickness and known age for the entire sample, 0.25 for teeth with periodontal problems and 0.75 for teeth without periodontal pathologies. The technique was reliable for periodontally sound teeth, but not for periodontally diseased teeth.
Assuntos
Determinação da Idade pelos Dentes/métodos , Cemento Dentário/ultraestrutura , Doenças Periodontais/patologia , Adolescente , Adulto , Idoso , Humanos , Aumento da Imagem/métodos , Processamento de Imagem Assistida por Computador/métodos , Pessoa de Meia-Idade , Variações Dependentes do Observador , Odontometria/métodos , Fotografação/métodos , Adulto JovemRESUMO
The aim is to verify, under scanning electron microscopy, the occurrence of apical root resorption in anterior and posterior teeth with chronic and radiographically visible periapical lesions. Thirty-two teeth were extracted, the apical thirds (n = 39) were removed, and prepared to analyse the external apical root surface. All specimens presented irregular areas of root resorption with different depths, located mainly around the apical foramen. Teeth with chronic periapical lesions present areas of external apical root resorption with irregular surface and different depths located mainly around the apical foramen. Root resorptions may show different configurations and destroy the apical root structure more or less extensively.
Assuntos
Microscopia Eletrônica de Varredura , Doenças Periapicais/patologia , Ápice Dentário/ultraestrutura , Raiz Dentária/ultraestrutura , Doença Crônica , Cemento Dentário/ultraestrutura , Dentina/ultraestrutura , Microanálise por Sonda Eletrônica , Humanos , Reabsorção da Raiz/patologiaRESUMO
OBJECTIVE: The aim of this study was to examine if there are qualitative differences in the appearance of external root resorption patterns of primary teeth undergoing physiologic resorption and permanent teeth undergoing pathological root resorption in different conditions. MATERIAL AND METHODS: A total of 40 teeth undergoing external root resorption in different conditions were divided into 4 groups and prepared for examination under scanning electron microscopy at magnifications ranging from 20x to 1000x. Group I: 10 primary molars exfoliated due to physiologic root resorption; Group II: 10 permanent teeth with periapical granulomas showing signs of resorption; Group III:10 permanent teeth therapeutically extracted during the course of orthodontic therapy with evidence of resorption, and Group IV: 10 permanent teeth associated with odontogenic tumors that showed evidence of resorption. RESULTS: In Group I, the primary teeth undergoing resorption showed smooth extensive and predominantly regular areas reflecting the slow ongoing physiologic process. In Group II, the teeth with periapical granulomas showed the resorption was localized to apex with a funnel shaped appearance in most cases. Teeth in Group III, which had been subjected to a short period of light orthodontic force, showed the presence of numerous resorption craters with adjoining areas of cemental repair in some cases. Teeth associated with odontogenic tumors in Group IV showed many variations in the patterns of resorption with extensive loss of root length and a sharp cut appearance of the root in most cases. CONCLUSION: Differences were observed in the patterns of external root resorption among the studied groups of primary and permanent teeth under physiologic and pathological conditions.
Assuntos
Microscopia Eletrônica de Varredura , Reabsorção da Raiz/patologia , Raiz Dentária/ultraestrutura , Ameloblastoma/patologia , Dente Pré-Molar/ultraestrutura , Cemento Dentário/ultraestrutura , Polpa Dentária/ultraestrutura , Dentina/ultraestrutura , Humanos , Incisivo/ultraestrutura , Dente Molar/ultraestrutura , Ortodontia Corretiva , Granuloma Periapical/patologia , Tecido Periapical/ultraestrutura , Ápice Dentário/ultraestrutura , Esfoliação de Dente/patologia , Dente Decíduo/ultraestruturaRESUMO
OBJECTIVE: The aim of this study was to examine if there are qualitative differences in the appearance of external root resorption patterns of primary teeth undergoing physiologic resorption and permanent teeth undergoing pathological root resorption in different conditions. MATERIAL AND METHODS: A total of 40 teeth undergoing external root resorption in different conditions were divided into 4 groups and prepared for examination under scanning electron microscopy at magnifications ranging from 20x to 1000x. Group I: 10 primary molars exfoliated due to physiologic root resorption; Group II: 10 permanent teeth with periapical granulomas showing signs of resorption; Group III:10 permanent teeth therapeutically extracted during the course of orthodontic therapy with evidence of resorption, and Group IV: 10 permanent teeth associated with odontogenic tumors that showed evidence of resorption. RESULTS: In Group I, the primary teeth undergoing resorption showed smooth extensive and predominantly regular areas reflecting the slow ongoing physiologic process. In Group II, the teeth with periapical granulomas showed the resorption was localized to apex with a funnel shaped appearance in most cases. Teeth in Group III, which had been subjected to a short period of light orthodontic force, showed the presence of numerous resorption craters with adjoining areas of cemental repair in some cases. Teeth associated with odontogenic tumors in Group IV showed many variations in the patterns of resorption with extensive loss of root length and a sharp cut appearance of the root in most cases. CONCLUSION: Differences were observed in the patterns of external root resorption among the studied groups of primary and permanent teeth under physiologic and pathological conditions.
Assuntos
Humanos , Microscopia Eletrônica de Varredura , Reabsorção da Raiz/patologia , Raiz Dentária/ultraestrutura , Ameloblastoma/patologia , Dente Pré-Molar/ultraestrutura , Cemento Dentário/ultraestrutura , Polpa Dentária/ultraestrutura , Dentina/ultraestrutura , Incisivo/ultraestrutura , Dente Molar/ultraestrutura , Ortodontia Corretiva , Granuloma Periapical/patologia , Tecido Periapical/ultraestrutura , Ápice Dentário/ultraestrutura , Esfoliação de Dente/patologia , Dente Decíduo/ultraestruturaRESUMO
PURPOSE: The purpose of this study was to investigate anatomically the cementoenamel junctions (CEJs) of primary teeth by observation of the morphological relationship among enamel, cementum, and dentin. METHODS: One hundred five human extracted primary teeth were analyzed by scanning electron microscopy. The teeth were divided into 7 groups, each with 15 primary teeth, as follows: maxillary central incisors (group 1); maxillary lateral incisors (group 2); maxillary canines (group 3); maxillary molars (group 4); mandibular incisors (group 5); mandibular canines (group 6); and mandibular molars (group 7). The entire cervical region was analyzed, especially concerning regularity of the CEJ, for establishment of the type of enamel-cementum relationship (cementum over enamel, the edge-to-edge relationship between cementum and enamel, and presence of gaps with exposure of dentinal tubuli). RESULTS: All circumferences represented by CEJs exhibit an interchange and combination of 3 types of relationships: (1) cementum over enamel; (2) enamel and cementum in the edge-to-edge relationship; and (3) the presence of a gap between the enamel and cementum with dentin exposure. There was no predominance as to the dental groups. CONCLUSIONS: All primary teeth exhibited the 3 morphological tissue interrelation types along the circumference of the cementoenamel junction. The irregularity and fragility of cementoenamel junction structures indicate that this region is weak and should be handled with care and protected during application of chemicals and utilization of clamps, dental instruments, and restorative materials.
Assuntos
Colo do Dente/anatomia & histologia , Dente Decíduo/anatomia & histologia , Pré-Escolar , Cemento Dentário/ultraestrutura , Esmalte Dentário/ultraestrutura , Dentina/ultraestrutura , Humanos , Microscopia Eletrônica de Varredura , Colo do Dente/ultraestruturaRESUMO
The aim of this study was to evaluate the influence of thermal stress on the marginal integrity of restorative materials with different adhesive and thermal properties. Three hundred and sixty Class V cavities were prepared in buccal and lingual surfaces of 180 bovine incisors. Cervical and incisal walls were located in dentin and enamel, respectively. Specimens were restored with resin composite (RC); glass ionomer (GI) or amalgam (AM), and randomly assigned to 18 groups (n=20) according to the material, number of cycles (500 or 1,000 cycles) and dwell time (30 s or 60 s). Dry and wet specimens served as controls Specimens were immersed in 1% basic fuchsine solution (24 h), sectioned, and microleakage was evaluated under x40 magnification. Data were analyzed by Kruskal-Wallis and Mann-Whitney tests: thermal cycling regimens increased leakage in all AM restorations (p<0.05) and its effect on RC and GI restorations was only significant when a 60-s dwell time was used (p<0.05). Marginal integrity was more affected in AM restorations under thermal cycling stress, whereas RC and GI ionomer restoration margins were only significantly affected only under longer dwell times.
Assuntos
Adaptação Marginal Dentária , Materiais Dentários/química , Restauração Dentária Permanente , Animais , Bovinos , Corantes , Resinas Compostas/química , Amálgama Dentário/química , Preparo da Cavidade Dentária/classificação , Cemento Dentário/ultraestrutura , Esmalte Dentário/ultraestrutura , Infiltração Dentária/classificação , Dentina/ultraestrutura , Cimentos de Ionômeros de Vidro/química , Distribuição Aleatória , Corantes de Rosanilina , Estresse Mecânico , Propriedades de Superfície , Temperatura , Fatores de TempoRESUMO
The purpose of this study was to evaluate morphological characteristics of teeth with hypercementosis that are relevant to endodontic practice. Twenty-eight extracted teeth with hypercementosis had their root apexes analyzed by scanning electron microscopy (SEM). The teeth were divided according to tooth groups and type of hypercementosis. The following aspects were examined under SEM: the contour and regularity of the root surface; presence of resorption; presence and number of apical foramina, and the diameter of the main foramen. The progression of club shape hypercementosis was directly associated with the presence of foramina and apical foramen obstruction. Cases of focal hypercementosis presented foramina on the surface, even when sidelong located in the root. Circular cementum hyperplasia form was present in 2 out of 3 residual roots, which was the highest proportion among the tooth types. The detection of a large number of foramina in the apical third of teeth with hypercementosis or even the possible existence of apical foramen obliteration contributes to understand the difficulties faced during endodontic treatment of these cases.