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1.
J Appl Oral Sci ; 28: e20190042, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31778443

RESUMO

INTRODUCTION: Gap formation of composite resin restorations is a serious shortcoming in clinical practice. Polymerization shrinkage stress exceeds the tooth-restoration bond strength, and it causes bacterial infiltration within gaps between cavity walls and the restorative material. Thus, an intermediate liner application with a low elastic modulus has been advised to minimize polymerization shrinkage as well as gap formation. OBJECTIVE: The purpose of this in vitro study was to assess gap formation volume in premolars restored with different bulk-fill composites, with and without a resin-modified glass-ionomer cement (RMGIC) liner, using x-ray micro-computed tomography (micro-CT). METHODOLOGY: Sixty extracted human maxillary premolars were divided into six groups according to bucco-palatal dimensions (n=10). Standardized Class II mesio-occluso-distal cavities were prepared. G-Premio Bond (GC Corp., Japan) was applied in the selective-etch mode. Teeth were restored with high-viscosity (Filtek Bulk Fill, 3M ESPE, USA)-FB, sonic-activated (SonicFill 2, Kerr, USA)-SF and low viscosity (Estelite Bulk Fill Flow, Tokuyama, Japan)-EB bulk-fill composites, with and without a liner (Ionoseal, Voco GmbH, Germany)-L. The specimens were subjected to 10,000 thermocycles (5-55°C) and 50,000 simulated chewing cycles (100 N). Gap formation based on the volume of black spaces at the tooth-restoration interface was quantified in mm3 using micro-computed tomography (SkyScan, Belgium), and analyses were performed. Data were analyzed using repeated-measures ANOVA and the Bonferroni correction test (p < 0.05). RESULTS: The gap volume of all tested bulk-fill composites demonstrated that Group SF (1.581±0.773) had significantly higher values than Group EB (0.717±0.679). Regarding the use of a liner, a significant reduction in gap formation volume was observed only in Group SFL (0.927±0.630) compared with Group SF (1.581±0.773). CONCLUSION: It can be concluded that different types of bulk-fill composite resins affected gap formation volume. Low-viscosity bulk-fill composites exhibited better adaptation to cavity walls and less gap formation than did sonic-activated bulk-fill composites. The use of an RMGIC liner produced a significant reduction in gap formation volume for sonic-activated bulk-fill composites.


Assuntos
Resinas Compostas/química , Preparo da Cavidade Dentária/métodos , Materiais Dentários/química , Restauração Dentária Permanente/métodos , Imagem Tridimensional/métodos , Polimerização , Análise do Estresse Dentário , Humanos , Técnicas In Vitro , Teste de Materiais , Cimentos de Resina , Microtomografia por Raio-X
2.
J Appl Oral Sci ; 27: e20180631, 2019 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-31411263

RESUMO

OBJECTIVE: Extensive restorations in posterior teeth always bring doubts to the clinicians regarding the best protocol, mainly when structures of reinforcement were lost. OBJECTIVE: This study aimed to evaluate the effect of beveling on the fracture resistance and pattern of class II (MOD) restored teeth. METHODOLOGY: Ninety human premolars were randomly assigned into 9 groups: CTR (control/sound); NC (cavity preparation, non-restored); RU (restored, unbeveled); RTB (restored, entire angle beveling); RPB (restored, partial/occlusal beveling); EC (endodontic access/EA, non-restored); EU (EA, unbeveled); ETB (EA, entire angle beveling); EPB (EA, partial/occlusal beveling). Teeth were restored with Esthet X resin composite and stored in distilled water for 24 h before the inclusion in PVC cylinders. The axial loading tests were performed with 500 kgF at 0.5 mm/min crosshead speed until fracture of the specimens. Fracture resistance and pattern were accessed and data were analyzed using one-way ANOVA and Tukey's HSD test (α=0.05). RESULTS: Mean (±SD) failure loads ranged from 136.56 (11.62) to 174.04 (43.5) kgF in the groups tested without endodontic access. For endodontically accessed teeth, fracture resistance ranged from 95.54 (13.05) to 126.51 (19.88) kgF. Beveling of the cavosurface angle promoted the highest fracture resistance values (p<0.05) and prevented catastrophic fractures. CONCLUSIONS: Cavosurface angle beveling is capable of improving fracture resistance and pattern for both endodonticaly accessed and non-accessed teeth.


Assuntos
Dente Pré-Molar , Preparo da Cavidade Dentária/métodos , Restauração Dentária Permanente/métodos , Análise de Variância , Resinas Compostas/uso terapêutico , Humanos , Distribuição Aleatória , Valores de Referência , Reprodutibilidade dos Testes , Fatores de Risco , Fraturas dos Dentes , Dente não Vital , Resultado do Tratamento
3.
Microsc Res Tech ; 82(9): 1566-1574, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31199544

RESUMO

The purpose of this study was to comparatively evaluate the effects of different caries removal methods on microleakage success of class V adhesive restorations by means of light microscopy (stereomicroscope) and scanning electron microscopy (SEM) observations. Sixty-four human teeth with class V caries that measured with DIAGNOdent were used. The samples were divided into four groups (n = 16) randomly according to caries removing methods of conventional method, Carisolv, Papacarie, and Er,Cr:YSGG laser system. The self-etch Clearfil SE Bond and Clearfil Majesty Es-II were used as restoration materials. After thermal cycles of 2,000 (5 and 55°C) samples were immersed in a 50% wt/wt AgNO3. Samples were finally imaged and scored under light microscopy and SEM, respectively. The data were statistically analyzed using Kruskal-Wallis H, pairwise comparison and Wilcoxon's T tests at 5% significance level (p < .05). Statistical analysis demonstrated that there was no significant difference between microleakage scores in dentin regions but there were significant difference between the Papacarie and Er,Cr:YSGGlaser in terms of leakage scores in enamel sites. No statistically significant difference in leakage scores emerged between light microscopy and SEM.


Assuntos
Cárie Dentária/terapia , Preparo da Cavidade Dentária/métodos , Infiltração Dentária , Selantes de Fossas e Fissuras/farmacologia , Humanos , Microscopia , Microscopia Eletrônica de Varredura , Resultado do Tratamento
4.
Gen Dent ; 67(2): e7-e10, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30875313

RESUMO

The purpose of this in vitro study was to evaluate the influence of depth (3.0 vs 5.0 mm) of mesio-occlusodistal (MOD) cavity preparation and mechanical cycling on fracture resistance of maxillary premolars restored with resin-based composite (RBC). Seventy premolars were randomly divided into 7 groups (n = 10): NP, no cavity preparation (control); MOD3, 3.0-mm-deep MOD preparation, not restored; MOD3R, 3.0-mm-deep MOD preparation restored with RBC; MOD5, 5.0-mm-deep MOD preparation, not restored; MOD5R, 5.0-mm-deep MOD preparation restored with RBC; MOD3RC, 3.0-mm-deep MOD preparation restored with RBC and subjected to mechanical cycling; and MOD5RC, 5.0-mm-deep MOD preparation restored with RBC and subjected to mechanical cycling under the same conditions as MOD3RC. All specimens were tested using a universal testing machine, resulting in the following mean (SD) values: NP, 224.65 (35.66) kgf; MOD3, 58.92 (15.48) kgf; MOD3R, 95.58 (13.88) kgf; MOD5, 68.06 (10.12) kgf; MOD5R, 98.49 (13.16) kgf; MOD3RC, 83.68 (14.39) kgf; and MOD5RC, 54.25 (11.56) kgf. Analysis of variance and Tukey test showed no statistically significant difference among MOD3, MOD5, and MOD5RC; between MOD5 and MOD3RC; or among MOD3R, MOD5R, and MOD3RC (P > 0.05). MOD3RC had significantly greater fracture resistance than MOD5RC (P < 0.05). NP had the highest fracture resistance of all groups (P < 0.05). The results showed that the depth of the cavity preparation only influenced fracture resistance after mechanical cycling of the specimens.


Assuntos
Preparo da Cavidade Dentária , Restauração Dentária Permanente , Fraturas dos Dentes , Dente não Vital , Dente Pré-Molar , Resinas Compostas , Preparo da Cavidade Dentária/métodos , Restauração Dentária Permanente/métodos , Análise do Estresse Dentário , Humanos , Técnicas In Vitro , Estresse Mecânico
5.
J Endod ; 45(4): 442-446, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30827768

RESUMO

INTRODUCTION: The aim of this study was to investigate the influence of various apical preparation designs for surgical endodontics on stress concentrations in the mesial root of the mandibular molar under different experimental conditions using finite element analysis. METHODS: We designed 2 apical preparation groups according to whether an isthmus was present or not. Each group contained 4 subgroups according to the size of the apical preparation. We constrained the displacement of all nodes at the base of the supporting bone and applied a force of 150 N to the vertical axis. We analyzed stress generation and concentrations numerically for the groups and subgroups. RESULTS: In the subgroups, the von Mises and maximum principal stresses reduced gradually according to the enlargement of the prepared cavity. However, when the preparation extended excessively in the isthmus preparation groups, the situation reversed (ie, both von Mises and maximum principal stresses increased). CONCLUSIONS: Within the limitations of this study, the apical preparation design influenced the distribution of stress concentration. Unlike the overall pattern in which stress decreased as the amount of apical preparation increased, stress increased when the amount of residual dentin was extremely thin.


Assuntos
Preparo da Cavidade Dentária/métodos , Análise do Estresse Dentário , Endodontia , Análise de Elementos Finitos , Mandíbula , Dente Molar , Estresse Mecânico , Raiz Dentária , Modelos Dentários , Dentina/anatomia & histologia , Dentina/patologia , Dentina/cirurgia , Humanos , Raiz Dentária/anatomia & histologia , Raiz Dentária/patologia , Raiz Dentária/cirurgia
6.
Biomed Res Int ; 2019: 3126931, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30805363

RESUMO

Objective: The aim of this study is to evaluate the effects of different fiber insertion techniques and thermomechanical aging on the fracture resistance of endodontically treated mandibular premolar teeth restored using bulk-fill composites. Materials and Methods: Eighty human mandibular premolar teeth were randomly divided into eight groups: Group IN, Group BF, Group PRF1, Group PRF2, Group IN-TMA, Group BF-TMA, Group PRF1-TMA ,and Group PRF2-TMA. Group IN (intact) and Group IN-TMA (intact but subjected to thermomechanical aging) served as control groups. In the other six groups, endodontic treatment was performed and standardized mesio-occluso-distal (MOD) cavities were prepared. In BF, PRF1, and PRF2, the cavities were restored with bulk-fill composite only, bulk-fill/Ribbond, and bulk-fill/additional Ribbond, respectively. In BF-TMA, PRF1-TMA, and PRF2-TMA, the teeth were subjected to thermomechanical aging after the restorations. All of the teeth were fractured on the universal testing machine. Fracture surfaces were analyzed with a stereomicroscope. Results: Control groups showed significantly higher fracture strengths than tested groups (P<0.05). No statistically significant difference was observed among the tested groups (P>0.05). Most of the favorable fractures were seen in PRF1, PRF2, and PRF2-TMA. Most of the unfavorable fractures were seen in BF-TMA. Conclusions: Although fiber insertion with different techniques did not increase the fracture strength of teeth restored with bulk-fill composites, it increased the favorable fracture modes. Thermomechanical aging did not change the fracture strength of the groups.


Assuntos
Resinas Compostas/uso terapêutico , Materiais Dentários/uso terapêutico , Resistência à Flexão/efeitos dos fármacos , Fraturas dos Dentes/terapia , Viscosidade/efeitos dos fármacos , Preparo da Cavidade Dentária/métodos , Restauração Dentária Permanente/métodos , Análise do Estresse Dentário/métodos , Humanos , Teste de Materiais/métodos , Polietilenos/uso terapêutico , Dente não Vital/terapia
7.
Niger J Clin Pract ; 22(1): 117-124, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30666030

RESUMO

Objective: The aim of this in-vivo study was to evaluate the long-term clinical survival of different deep dentin caries treatment options. Materials and Methods: : In total, 391 patients with at least one permanent tooth with clinically diagnosed deep dentin caries were inspected. Two hundred and fourteen patients were examined at recall visits. Inclusion criteria were teeth with deep caries lesions with pulp vitality but absence of spontaneous pain and periapical alterations. The subjects received either stepwise removal (SWR), complete caries removal (CCR), or direct pulp capping (DPC). The radiological and clinical exams were performed after a mean observation time of 62 months. Success was defined as pulp sensitivity to vitality test and absence of periapical lesions as well as a clinical symptom. Data were statistically analyzed using Kaplan-Meier and log-rank (Mantel-Cox) tests (α = 0.05). Results: Of the total 214 patients evaluated, 126 received SWR, 88 received CCR, and 67 received DPC treatment. One hundred and twenty-seven restorations were amalgam and 141 were composite. The mean observation period was 62 months. Survival rates were 85.7%, 90.9%, and 59.7% for SWR, CCR, and DPC, respectively (P = 0.001). Success rates of amalgam restorations (86.6%) were similar to composite restorations (83%), and both were found to be successful (P = 0.401). Conclusion: SWR treatment should be considered to preserve pulp vitality of deep dentin lesions instead of CCR or DPC. Clinical Relevance: SWR method for deep dentin caries management had acceptable results over 5 years.


Assuntos
Cárie Dentária/terapia , Preparo da Cavidade Dentária/métodos , Capeamento da Polpa Dentária/métodos , Restauração Dentária Permanente/métodos , Dentina/patologia , Adulto , Cárie Dentária/diagnóstico por imagem , Cárie Dentária/patologia , Materiais Dentários , Polpa Dentária/diagnóstico por imagem , Polpa Dentária/patologia , Polpa Dentária/fisiologia , Exposição da Polpa Dentária/patologia , Exposição da Polpa Dentária/prevenção & controle , Dentina/diagnóstico por imagem , Dentição Permanente , Feminino , Humanos , Masculino , Tratamento do Canal Radicular , Resultado do Tratamento
8.
J Prosthodont ; 28(1): e325-e331, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29508474

RESUMO

PURPOSE: Molar MOD (mesial-occlusal-distal) cavity preparation weakens relative cuspal stiffness by up to 63%, often resulting in cuspal fracture. This investigation inspects fracture resistance of MOD cavities restored using direct composite restoration. MATERIALS AND METHODS: 120 extracted, intact mandibular molars were selected. MOD cavities with different depth/wall thickness were prepared in 9 groups (n = 12): A: 3 mm/3.5 mm, B: 3 mm/2.5 mm, C: 3 mm/1.5 mm, D: 5 mm/3.5 mm, E: 5 mm/2.5 mm, F: 5 mm/1.5 mm, G: 7 mm/3.5 mm, H: 7 mm/2.5 mm, I: 7 mm/1.5 mm. Specimens with 7 mm deep cavities received root canal treatment. The teeth were restored with dental composite. Maximal fracture strength test was conducted. Intact natural teeth were used as control. For statistical analysis Kruskal-Wallis ANOVA with post-hoc pairwise comparisons was used (α = 0.05). RESULTS: Significant difference was indicated between the control and groups D, E, F, G, H, and I. No significant differences were found between the A, B, C groups and the control. Comparing the 5 and 7 mm cavity depth groups, there was no statistical difference between any of them. CONCLUSIONS: Within the limitations of this investigation, the following conclusions can be drawn regarding molar teeth with a MOD cavity: 3 mm or shallower cavities can be restored to the physiological fracture strength with direct composite restorations; 5 mm or deeper cavities cannot be restored to the physiological fracture strength with direct composite restorations. Cusp thickness does not significantly influence fracture strength in molar MOD cavities with a direct composite restoration.


Assuntos
Preparo da Cavidade Dentária , Restauração Dentária Permanente , Dente Molar/cirurgia , Fraturas dos Dentes/etiologia , Preparo da Cavidade Dentária/efeitos adversos , Preparo da Cavidade Dentária/métodos , Falha de Restauração Dentária , Restauração Dentária Permanente/efeitos adversos , Restauração Dentária Permanente/métodos , Análise do Estresse Dentário , Humanos , Técnicas In Vitro , Fraturas dos Dentes/prevenção & controle
9.
J Prosthodont ; 28(2): e524-e529, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29533499

RESUMO

PURPOSE: To examine the fracture resistance of premolars restored with CAD/CAM lithium disilicate mesio-occlusal-distal (MOD) inlays and onlays of different cavity designs. MATERIALS AND METHODS: Two widths of occlusal isthmus (75%, 100% of intercuspal distance) and three designs of cuspal coverage (none, palatal, complete) were used for the preparation of MOD inlays and onlays in the extracted maxillary premolars. Sixty lithium disilicate restorations were milled and bonded into the cavities. After 24 hours of water storage, the specimens were loaded until fracture, and the fracture loads (N) were measured. Any evidence of cracks and fractures on the tested specimens were examined to classify failure patterns. RESULTS: Mean fracture load values for the tested groups were as follows: 664.4 ± 214.7 N (group A), 659.3 ± 391.2 N (B), 681.9 ± 258.1 N (C), 938.1 ± 862.0 N (D), 841.7 ± 375.4 N (E), and 994.2 ± 486.3 N (F). The width of occlusal isthmus did not significantly affect the fracture loads among all the groups. Within groups with identical isthmus width, the fracture loads showed no significant difference depending on the designs of cuspal coverage. The majority of specimens showed either type III or IV fracture mode. CONCLUSIONS: Within limitations of this study, the bonded restorations of premolars with CAD/CAM-generated lithium disilicate were reliable, regardless of cavity preparation design.


Assuntos
Projeto Auxiliado por Computador , Preparo da Cavidade Dentária/métodos , Falha de Restauração Dentária , Restauração Dentária Permanente/métodos , Restaurações Intracoronárias , Fraturas dos Dentes/etiologia , Dente Pré-Molar , Cerâmica , Porcelana Dentária , Análise do Estresse Dentário , Humanos , Técnicas In Vitro , Microscopia Eletrônica de Varredura , Propriedades de Superfície
10.
Lasers Med Sci ; 34(1): 23-34, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29982880

RESUMO

The purpose of this study was to evaluate the thickness and qualitative characteristics of the hybrid layer after two cavity preparation methods, using Er:YAG laser in QSP mode and conventional carbide burs. Additionally, two different adhesive techniques were investigated using etch-and-rinse and self-etch adhesive systems. Sixty sound human third molars were used and were randomly divided into four groups (n = 15). In the first two groups, large (4 mm length, 3 mm wide, and 3 mm deep) class I cavities were prepared using Er:YAG laser (2.94 µm) in QSP mode, while in the other two groups, the cavities were prepared using carbide burs. After cavity preparations, two different adhesive techniques with GLUMA® 2 Bond (etch-and-rinse) and Clearfil™ Universal Bond Quick (self-etch) were applied. For the qualitative evaluation of the formed hybrid layer, photomicrographs were taken using SEM, and elemental semi-quantitative analysis was performed using EDS to confirm the extent of the hybrid layer. One-way ANOVA was applied to verify the existence of statistically significant differences, followed by Tukey test for post hoc comparisons (Bonferroni corrected), and the level of significance was set at a = 0.05. The laser-treated groups exhibited higher hybrid layer thickness than bur-treated groups (p < 0.001). Between the laser-treated groups, etch-and-rinse technique presented higher hybrid layer thickness than self-etch technique (p < 0.001), while between the bur-treated groups, no significant differences were detected (p = 0.366). Er:YAG laser cavity preparations in QSP mode may be advantageous for adhesion of composite restorations, but more data are necessary to confirm its clinical effectiveness.


Assuntos
Cárie Dentária/cirurgia , Preparo da Cavidade Dentária/métodos , Lasers de Estado Sólido/uso terapêutico , Dentina/efeitos da radiação , Dentina/ultraestrutura , Humanos , Espectrometria por Raios X
11.
Dent Mater J ; 38(1): 96-100, 2019 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-30381630

RESUMO

This study investigated the effect of bulk-fill composites on proximal contact tightness (PCT) of composite restorations using different matrix systems. 150/standardized-MO-ivorine cavity preparations were divided into 5 groups; Smart Dentin Replacement (SDR), SonicFill (SF), Tetric EvoCeram Bulk-Fill (TEB), G-ænial Universal Flo (GF) and Tetric EvoCeram (TE). Each group was subdivided into 3 sub-groups (n=10); Dixieland band in Tofflemire retainer, FenderMate and Palodent plus matrix systems. PCT was measured 24 h post-curing using Tooth Pressure Meter. PCT means were calculated and statistically-analyzed using ANOVA and Tukey's post-hoc test (p<0.05). Means and SD of PCT for Tofflemire subgroup were: 1.75(0.13), 3.21(0.1), 3.06(0.19), 2.49(0.21) and 3.18(0.1) for (SDR), (SF), (TEB), (GF) and (TE), respectively. Using FenderMate, values were: 1.87(0.08), 3.35(0.12), 3.17(0.16), 2.64(0.1) and 3.26(0.11) for (SDR), (SF), (TEB), (GF) and (TE), respectively, while with Palodentplus; 3.16(0.17), 4.23(0.11), 4.1(0.1), 3.46(0.17) and 3.98(0.1) for (SDR), (SF), (TEB), (GF) and (TE), respectively. ANOVA revealed significant differences (p<0.05) between all samples except between (SF), (TEB) and (TE) and also significant difference between Palodentplus and two subgroups. Effect of bulk-fill composites on PCT is material dependent. Separation ring is recommended for proper PCT.


Assuntos
Resinas Compostas/química , Preparo da Cavidade Dentária/métodos , Materiais Dentários/química , Adaptação Marginal Dentária , Adesivos Dentinários , Humanos , Técnicas In Vitro , Teste de Materiais , Dente Molar , Propriedades de Superfície
12.
BMJ Open ; 8(12): e022952, 2018 12 14.
Artigo em Inglês | MEDLINE | ID: mdl-30552261

RESUMO

INTRODUCTION: Selective (incomplete/partial) carious tissue removal is suitable for treating deep carious lesions in teeth with vital, asymptomatic pulps. In the periphery of a cavity, removal to hard dentin is performed, while in pulpo-proximal areas, leathery or soft dentin is left to avoid pulp exposure. As the decision of what contains 'soft' or 'leathery' dentin is subjective, using self-limiting burs which help to standardise the hardness of the remaining dentin, has been suggested to increase the reliability of carious tissue removal. The trial compares subjectively measured selective carious tissue removal in deep lesions in primary teeth with objectively measured selective removal with a self-limiting bur (Polybur, Komet). METHODS AND ANALYSIS: A community-based single-blind clustered randomised controlled superiority trial nested into a larger evaluation is performed. Recruitment for this trial has been concluded. We have recruited 115 children aged 6-8 years with ≥1 vital primary molar with a deep dentin lesion. The unit of randomisation was the child, with all eligible molars per child treated identically. Treatment was performed in a mobile dental unit. Subjective and objective carious tissue removal was performed at random. Teeth were restored using glass ionomer cement (Equia Forte, GC). Our primary outcome will be the time until complications occur, evaluated via multilevel survival analysis. Secondary outcomes will be the time until extraction is needed, subjective satisfaction of the child with the treatment (measured using a Likert scale) and cost-effectiveness. Re-examination will be performed after 12, 24 and 36 months (the final examination is expected in 2020). ETHICS AND DISSEMINATION: This trial has been approved by the Ethics Committee of the Health Sciences of the University of Brasília (CAAE 51310415.0.0000.0030). Trial results will be published in peer-reviewed journals and presented on conferences. TRIAL REGISTRATION NUMBER: NCT02754466.


Assuntos
Tratamento Dentário Restaurador sem Trauma/métodos , Cárie Dentária/terapia , Preparo da Cavidade Dentária/instrumentação , Polímeros , Criança , Análise por Conglomerados , Preparo da Cavidade Dentária/métodos , Estudos de Equivalência como Asunto , Feminino , Seguimentos , Humanos , Masculino , Método Simples-Cego
13.
Niger J Clin Pract ; 21(12): 1549-1556, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30560816

RESUMO

The management of deeply carious lesion could be accomplished conservatively by two techniques: an indirect single-step and stepwise techniques. The former involves incomplete removal of carious dentin and then application of a well-sealed permanent restoration. While the latter involves incomplete removal of caries and then reentry after a period to remove the residual caries, after changing its environment. The aim of this article was to review the dental literature concerning the conservative methods available to treat deeply carious teeth. A literature search was done using electronic databases "PubMed," "Google Scholar," and "Cochrane Database" for articles in English. Several keywords were used: conservative treatment, deep caries, deeply carious lesion, indirect pulp capping (IPC), and stepwise excavation. This review mentions two operative methods for conservative treatment of deeply carious lesions, namely, IPC, including criteria for case selection and success and failure of the deeply carious lesion, and an account on various used materials. Both single-step and stepwise IPC techniques could be used for managing deeply carious lesions with maintaining pulp vitality; more longitudinal studies are needed to determine which technique is preferable to be used.


Assuntos
Tratamento Conservador/métodos , Cárie Dentária/terapia , Preparo da Cavidade Dentária/efeitos adversos , Preparo da Cavidade Dentária/métodos , Exposição da Polpa Dentária/etiologia , Cárie Dentária/microbiologia , Exposição da Polpa Dentária/prevenção & controle , Restauração Dentária Permanente/métodos , Dentina/patologia , Humanos , Resultado do Tratamento
14.
J Contemp Dent Pract ; 19(9): 1100-1104, 2018 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-30287711

RESUMO

AIM: The placement of composite in teeth is not an easy task and it poses many challenges. Microleakage is one of the factors that affects the success of any composite restoration. It influences the longevity of dental restorations. The present study was aimed to evaluate and compare microleakage of two restorative composites resins in class II cavities using confocal laser scanning microscopy (CLSM). MATERIALS AND METHODS: This was an in vitro study, which included 20 permanent mandibular first molar. On each tooth, 40 class II cavities were prepared with a carbide bur. The teeth were then randomly divided into two groups of 10 each. Group I included teeth in which SonicFill Bulk Fill composite was used. Group II included teeth in which Tetric EvoCeram Bulk Fill composite was used. The microleakage was measured using confocal microscopy at 10* magnification in the fluorescent mode by a scoring system. RESULTS: Estimation was done at cervical and occlusal levels, wherein group I included 10 teeth which were restored with SonicFill Bulk Fill composite and group II included 10 teeth which were restored with Tetric EvoCeram Bulk Fill composite. Microleakage was quantified on scoring basis, which was consecutively based on the dye penetration at different levels. Data thus obtained statistically revealed that microleakage was comparatively more in group II as compared with group I. In addition, it was somewhat similar on both cervical as well as occlusal regions. The difference was significant (p = 0.05). Comparison was also done at cervical and occlusal levels using Wilcoxon signed-rank test, which showed significant levels of differences (p > 0.05). CONCLUSION: There is more microleakage in Tetric EvoCeram Bulk Fill composite as compared with SonicFill Bulk Fill composite. CLINICAL SIGNIFICANCE: No material seems to totally eliminate microleakage in class II situations with gingival margin ended in dentine. However, CLSM is a useful tool in microleakage evaluation that could be used successfully to estimate the severity of microbial penetrations and material of choice as well.


Assuntos
Resinas Acrílicas , Resinas Compostas , Cárie Dentária , Preparo da Cavidade Dentária/métodos , Infiltração Dentária , Restauração Dentária Permanente/métodos , Microscopia Confocal , Poliuretanos , Humanos , Técnicas In Vitro , Mandíbula , Dente Molar
15.
Oper Dent ; 43(6): 656-664, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30142038

RESUMO

This study determined the influence of shrinkage and viscosity of flowable composite liners on the cervical microleakage of Class II restorations using micro-CT. Seven composites of varying viscosities were selected and included five giomers (Shofu Beautifil II [BF], Flow Plus F00 and F03 [F00 and F03], Flow F02 and F10 [F02 and F10]) and 2 nano-filled composites (3M-ESPE Filtek Z350 [Z350] and Filtek Z350 Flowable [Z350F]). Polymerization shrinkage (n=7) was assessed with the Acuvol volumetric shrinkage analyzer while complex viscosity was determined with the advanced rheometric expansion system at 25°C. Standardized Class II restorations incorporating 1-mm horizontal layers of different flowable liners and 3-mm oblique layers of BF or Z350 were subjected to a silver nitrate test for 24 hours and examined using micro-CT. Microleakage was determined at 0.1-mm intervals from the buccal to lingual surfaces providing 30 sites per specimen and scored accordingly. Statistical analysis was performed with the one-way ANOVA, Kruskal-Wallis test, and Spearman's rho correlation at a significance level of p<0.05. Mean volumetric shrinkage ranged from 5.33±0.17% to 2.35±0.02% for F02 to Z350, respectively. The flowable materials had significantly higher shrinkage than did their sculptable counterparts (BF and Z350). Complex viscosities ranged from 9.65 to 4.20 (Z350 and F10, respectively) at a frequency of 10 rad/s and from 8.16 to 3.28 (Z350 and F03, respectively) for 100 rad/s. Giomer restorations had significantly less leakage than did those restored with nano-filled composites. No microleakage was observed with restorations lined with F02 or F10. The use of flowable liners reduced cervical microleakage of Class II restorations. Interfacial integrity of Class II restorations was significantly correlated with liner viscosity, filler volume, and shrinkage.


Assuntos
Resinas Compostas/química , Forramento da Cavidade Dentária/instrumentação , Preparo da Cavidade Dentária/métodos , Infiltração Dentária , Microtomografia por Raio-X , Dente Pré-Molar , Bis-Fenol A-Glicidil Metacrilato , Restauração Dentária Permanente/métodos , Humanos , Técnicas In Vitro , Teste de Materiais , Polimerização , Viscosidade
16.
Indian J Dent Res ; 29(4): 459-464, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30127197

RESUMO

Context: Dental students commonly face the problem of overhanging proximal margins and unsatisfactory proximal contact points (PCPs) while restoring Class II cavities in posterior teeth. Various matrix band systems are used in dental clinics to avoid such problems. Aims: The aim of this study is to compare the effects of two matrix band systems, circumferential matrix system and sectional matrix system on the PCPs and contours when restoring Class II cavities in posterior teeth. Settings and Design: This was a randomized controlled clinical trial done at College of Dentistry, Qassim University, Saudi Arabia. Subjects and Methods: Total 1200 Class II cavities in teeth were selected for this study. Treatment was done by senior undergraduate students. Cavities were randomly divided into two groups. Group 1: Total 600 cavities were restored using circumferential band system. Group 2: Total 600 cavities were restored using sectional band system. Teeth were restored either with the composite or the amalgam restoration. Contact points were evaluated. The presence or absence of proximal overhangs was assessed. Overhanging margins were categorized as positive overhangs, negative overhangs, and absent overhangs. Statistical Analysis Used: To identify the relationship between matrix band systems and other factors, Chi-square tests (χ2-tests) and Z-tests were used. Pearson correlation coefficient was computed and logistic regression analysis was carried out to assess variables that can affect proximal margins and contact points of final restorations. Results: All optimum contacts 389 (100%) were found in restorations done using sectional band system. A highly significant association was found between open contact points and negative overhanging margins with the use of circumferential matrix band system (P < 0.00). Conclusion: Sectional matrix band system has been found superior to circumferential matrix band system.


Assuntos
Cárie Dentária/terapia , Preparo da Cavidade Dentária/métodos , Restauração Dentária Permanente/métodos , Bandas de Matriz , Estudantes de Odontologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Distribuição de Qui-Quadrado , Resinas Compostas , Amálgama Dentário , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Resinas Sintéticas , Arábia Saudita , Faculdades de Odontologia , Adulto Jovem
17.
Indian J Dent Res ; 29(4): 465-469, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30127198

RESUMO

Context: Studies have been conducted to measure the fracture resistance of restored teeth with the current restorative materials. However, most of those studies disregard the cavity size as an influencing variable. Aims: To evaluate the fracture resistance of prepared and restored maxillary premolars with medium and large preparations. Materials and Methods: Seventy superior and sound premolars were randomly divided: G1 (control) - sound tooth; G2, G3, and G4 received a Class II mesial-occlusal-distal (MOD) preparation with an occlusal box width 1/3 of the intercuspal distance, and were restored with Filtek Z350 XT, IPS Empress Direct, and Charisma Diamond, respectively; G5, G6, and G7 received a Class II MOD preparation with an occlusal box width 2/3 of the intercuspal distance, and were restored with Filtek Z350 XT, IPS Empress Direct, and Charisma Diamond, respectively. After storage in water, at 37°C, the specimens were subjected to a fracture test under compression in a universal testing machine where the loads were applied vertically and at a speed of 0.5 mm/min. Statistical Analysis Used: Data were analyzed with two-way ANOVA and Tukey's multiple comparison post hoc test (P < 0.05). Results: G1 presented a fracture resistance significantly higher (P = 0.005) than any other experimental groups. Among the experimental groups, only G5 showed a significantly low fracture resistance (P = 0.019) when compared to the other groups. For the other resins, the change in intercuspal distance from 1/3 to 2/3 the intercuspal distance did not significantly reduce the fracture resistance (P > 0.05). Conclusions: The cavity preparation weakens the remaining tooth structure; however, its resistance could be partially restored using direct adhesive restorations.


Assuntos
Dente Pré-Molar , Preparo da Cavidade Dentária/métodos , Cimentos Dentários , Restauração Dentária Permanente/métodos , Resistência à Flexão , Fraturas dos Dentes/prevenção & controle , Resinas Compostas , Materiais Dentários , Humanos , Teste de Materiais , Maxila , Resinas Sintéticas
18.
Dent Mater ; 34(10): 1426-1439, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30119841

RESUMO

OBJECTIVES: To measure the spatial distribution of crystallographic strain in tooth enamel induced by the photo-polymerisation of a dimethacrylate resin based composite cavity restoration. METHODS: Six sound first premolar teeth, allocated into two groups (n=3), were prepared with mesio-occlusal distal cavities. The enamel was machined at the point of maximum convexity on the outer tooth to create a vertical fin of thickness 100µm and 0.5mm depth to allow for synchrotron X-ray diffraction measurements. 2D diffraction patterns were used to determine crystallite orientation and quantify changes in the hydroxyapatite crystal lattice parameters, before and after photo-polymerisation of a composite material placed in the cavity, to calculate strain in the respective axis. The composite was photo-polymerised with either relatively high (1200mWcm-2, group 1) or low (480mWcm-2, group 2) irradiances using LED or quartz halogen light sources, respectively. A paired t-test was used to determine significant differences in strain between irradiance protocols at ɑ=0.001. RESULTS: Photo-polymerisation of the composite in the adjacent cavity induced significant changes in both the crystallographic c and a axes of the enamel measurement area. However the magnitude of strain was low with ∼0.1% difference before and after composite photo-polymerisation. Strain in enamel was not uniformly distributed and varied spatially as a function of crystallite orientation. Increased alignment of crystallites perpendicular to the cavity wall was associated with higher c axis strain. Additionally, strain was significantly greater in the c (p<0.001) and a axis (p<0.001) when using a high irradiance photo-polymerisation protocol. SIGNIFICANCE: Although cuspal deflection is routinely measured to indirectly assess the 'global' effect of composite shrinkage on the tooth-restoration complex, here we show that absolute strains generated in enamel are low, indicating strain relief mechanisms may be operative. The use of low irradiance protocols for photo-polymerisation resulted in reduced strain.


Assuntos
Resinas Compostas/química , Preparo da Cavidade Dentária/métodos , Esmalte Dentário/química , Durapatita/química , Síncrotrons , Dente Pré-Molar , Resinas Compostas/efeitos da radiação , Cristalografia por Raios X , Esmalte Dentário/efeitos da radiação , Infiltração Dentária , Durapatita/efeitos da radiação , Humanos , Processamento de Imagem Assistida por Computador , Técnicas In Vitro , Polimerização , Estresse Mecânico , Difração de Raios X
19.
J Appl Oral Sci ; 26: e20180004, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30133672

RESUMO

Objective This study aimed to evaluate the effect of the cavity preparation and ceramic type on the stress distribution, tooth strain, fracture resistance and fracture mode of human molar teeth restored with onlays. Material and Methods Forty-eight molars were divided into four groups (n=12) with assorted combinations of two study factors: BL- conventional onlay preparation with boxes made from leucite ceramic (IPS-Empress CAD, Ivoclar Vivadent); NBL- conservative onlay preparation without boxes made from leucite ceramic; BD- conventional onlay preparation with boxes made from lithium disilicate glass ceramic (IPS e.max CAD, Ivoclar Vivadent); NBL- conservative onlay preparation with boxes made from lithium disilicate glass ceramic cuspal deformation (µS) was measured at 100 N and at maximum fracture load using strain gauge. Fracture resistance (N) was measured using a compression test, and the fracture mode was recorded. Finite element analysis was used to evaluate the stress distribution by modified von Mises stress criteria. The tooth strain and fracture resistance data were analyzed using the Tukey test and two-way ANOVA, and the fracture mode was analyzed by the chi-square test (α=0.05). Results The leucite ceramic resulted in higher tooth deformation at 100 N and lower tooth deformation at the maximum fracture load than the lithium disilicate ceramic (P<0.001). The lithium disilicate ceramic exhibited higher fracture resistance than the leucite ceramic (P<0.001). The conservative onlay resulted in higher fracture strength for lithium disilicate ceramic. Finite element analysis results showed the conventional cavity preparation resulted in higher stress concentration in the ceramic restoration and remaining tooth than the conservative onlay preparation. The conservative onlays exhibited increased fracture resistance, reduced stress concentration and more favorable fracture modes. Conclusion Molars restored with lithium disilicate CAD-CAM ceramic onlays exhibited higher fracture resistance than molars restored with leucite CAD-CAM ceramic onlays.


Assuntos
Silicatos de Alumínio/química , Cerâmica/química , Projeto Auxiliado por Computador , Preparo da Cavidade Dentária/métodos , Porcelana Dentária/química , Restaurações Intracoronárias/métodos , Fraturas dos Dentes , Resinas Acrílicas/química , Análise de Variância , Resinas Compostas/química , Falha de Restauração Dentária , Análise do Estresse Dentário , Módulo de Elasticidade , Análise de Elementos Finitos , Humanos , Teste de Materiais , Dente Molar , Poliuretanos/química , Valores de Referência , Reprodutibilidade dos Testes , Estatísticas não Paramétricas
20.
Braz Dent J ; 29(3): 268-274, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29972453

RESUMO

The aim was to evaluate the influence of different dentin preparation mode in the smear layer characteristics (SL), hybrid layer (HL), and microtensile bond strength (µTBS) to dentin with two resin cements. The occlusal dentin of 120 third molars was exposed. The teeth were divided into 4 groups (n=30) according to the dentin preparation mode: 1- fine grain diamond bur; 2- coarse grain diamond bur; 3- multi laminate carbide steel bur; and, 4- ultrasonic CV Dentus diamond bur. Each treated dentin group was divided into 2 sub-groups (n=15) according to the resin cement: (1) RelyX U200 and (2) RelyX ARC. Resin composite blocks were cemented on dentin. After storage at 37o C for 24 h, beams with a cross section area of 1.0 mm2 were obtained, and tested in a universal testing machine at a crosshead speed of 0.5 mm/min. Two additional teeth for each sub-group were prepared to analyze the SL and HL on a scanning electron microscopy. According to Kruskal-Wallis test and Dunn tests, there was no significant difference in µTBS among the rotary instruments within each resin cement group. RelyX ARC obtained higher µTBS values compared to RelyX U200 (p<0.05). RelyX ARC formed evident HL, which was not observed for RelyX U200. The dentin mode preparation did not influence the µTBS of the resin cements. The SL was different for all instruments. The cementing agent is more determinant in the hybrid layer formation and bond strength to dentin than the instruments applied on dentin.


Assuntos
Colagem Dentária , Preparo da Cavidade Dentária/métodos , Adesivos Dentinários/química , Dentina/química , Cimentos de Resina/química , Resistência à Tração , Bis-Fenol A-Glicidil Metacrilato , Análise do Estresse Dentário , Humanos , Microscopia Eletrônica de Varredura , Dente Serotino/química , Polietilenoglicóis , Ácidos Polimetacrílicos , Camada de Esfregaço
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