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1.
Braz. j. oral sci ; 20: e210525, jan.-dez. 2021. ilus
Artigo em Inglês | LILACS, BBO - Odontologia | ID: biblio-1253928

RESUMO

Aim: Recent reports indicate that deproteinization of acid-etched dentin surface can extend penetration depth of adhesive agents. The main goal of the present research was to investigate the deproteinization effect of Nd:YAG and diode 940 lasers on acid-etched dentin and microleakage grade in class V composite restorations. Methods: 36 extracted human premolar teeth were selected to make standard buccal and lingual class V cavities. These samples were randomly split into three sub-groups: 1.Control group, in which composite was applied for restoration after etch and bonding process without deproteinization; 2.Nd:YAG laser group, in which the teeth were deproteinized with Nd:YAG laser after etching and painting internal surfaces of cavities with Van Geison stain and then composite restorations applied just as control group; 3.Diode laser group, in which the process was similar to Nd:YAG laser group, but instead, diode 940 laser was irradiated. The teeth were bisected into two equal longitudinal buccal and lingual halves. Marginal microleakage of samples was scored by using a stereomicroscope. Kruskal- Wallis, Mann-Whitney U and Fisher's statistical tests were employed for analysis of the obtained data. Results: A significant reduction in marginal microleakage was observed for both groups treated with laser (Nd:YAG and diode 940)compared to control (p=0.001 & p=0.047). There was no significant difference in marginal microleakage between Nd:YAG laser and diode 940groups (P = 0.333). Conclusion: Nd:YAG and diode 940 laser deproteinization of acid-etched dentin decreased the marginal microleakage of in-vitro class V resin composite restorations


Assuntos
Humanos , Condicionamento Ácido do Dente , Adesivos Dentinários , Infiltração Dentária , Lasers
2.
Biomed Res Int ; 2021: 3304553, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34337003

RESUMO

Background: Diet and lifestyle can destroy tooth structure due to the dissolution of enamel by acidic beverages. The present study evaluated the effect of CO2 laser irradiation and CPP-ACFP (casein phosphopeptide and amorphous calcium phosphate with fluoride) paste on the remineralization of enamel eroded by carbonated soft drinks. Methods: In the present in vitro study, 46 human sound premolar teeth were sectioned mesiodistally to achieve 84 samples. Fourteen samples were assigned to the positive control group (G1), and the remaining samples were immersed in 500 mL of cola drink for 2 minutes, followed by rinsing with distilled water for 10 seconds. This procedure was carried out three times to create erosive lesions. Then, the 60 eroded samples were randomly assigned to five groups of G2 to G6 in terms of the treatment as follows: negative control (G2), CO2 laser irradiation (G3), CPP-ACFP paste (G4), CO2 laser irradiation followed by CPP-ACFP paste application (G5), and CPP-ACFP paste application followed by CO2 laser irradiation (G6). The mean surface microhardness of the enamel surface was evaluated and determined at three points for each sample. Data were analyzed with one-way ANOVA and Tukey HSD tests (α = 0.05). Results: The highest and the lowest hardness values were recorded in the G1 (314 ± 12 kg/mm2) and G2 (213.7 ± 12 kg/mm2) groups, respectively. ANOVA revealed significant differences between the study groups (P < 0.001). Two-by-two comparisons showed significant differences between the G2 group and the other groups, indicating the efficacy of all the treatment modalities in tooth remineralization and rehardening procedures (P < 0.05). Only in group G6, the enamel microhardness was not significantly different from the G1 positive control group (P > 0.05). Conclusion: Considering the parameters used in the present study, CO2 laser irradiation or CPP-ACFP paste application alone increased eroded enamel's surface hardness; however, their sequential application was more effective in rehardening the eroded enamel's surface to near-normal levels.


Assuntos
Dióxido de Carbono/farmacologia , Caseínas/farmacologia , Esmalte Dentário/efeitos dos fármacos , Esmalte Dentário/efeitos da radiação , Fluoretos/farmacologia , Lasers de Gás , Fragmentos de Peptídeos/farmacologia , Erosão Dentária/patologia , Erosão Dentária/cirurgia , Dureza , Humanos
3.
J Lasers Med Sci ; 10(4): 275-282, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31875119

RESUMO

Introduction: Some studies have shown that laser irradiation on unpolymerized adhesives can improve composite-dentin adhesion. The aim of the present study was to evaluate the effect of the diode laser (810 nm) on the microleakage of multi-mode adhesive systems at enamel and dentin margins of composite restorations. Methods: Classic class V boxes were prepared on 48 sound premolar teeth and randomly divided into 6 groups (n=16). In the control groups, Scotchbond Universal (SBC), G-Premio (GBC), and Ambar U (AMC) were used by a self-etch mode. In the test groups (SBL, GBL, ABL), the 810 nm diode laser was irradiated (1 W) for 10 seconds before the polymerization of the adhesive. The boxes were restored by the resin composite. After finishing and polishing, the samples were thermocycled (5°C to 55°C) for 1000 cycles and then immersed in 0.1% methylene blue dye (48 hours). Dye penetration through the gingival and occlusal margins was measured by Stereomicroscope. The data were analyzed at the 5% significance level using Kruskal-Wallis and Mann-Whitney U tests. Results: Significant differences were found between the control and test groups (P < 0.05). The occlusal margins of the SBL and GBL groups and the cervical margin of the SBL group exhibited the lowest microleakage (P < 0.05). The AM control group showed maximum microleakage at cervical and occlusal margins. Conclusion: The irradiation of the 810 nm diode laser on the unpolymerized universal adhesive systems in a self-etch mode caused a significant reduction in enamel and dentin marginal microleakage of composite restorations.

4.
Dent Med Probl ; 56(2): 143-148, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31274252

RESUMO

BACKGROUND: The cross-linking of collagen fibers in the hybrid layer has been suggested as a way to create more durable bonds. OBJECTIVES: This study evaluated the effect of visible light-activated riboflavin (RF) as a cross-linking agent on the durability of the dentin microtensile bond strength (µTBS) in a 2-step self-etch (SE) adhesive system. MATERIAL AND METHODS: The occlusal surfaces of 21 human premolar teeth were ground down to expose the dentin, and were then randomly divided into 3 groups. The Clearfil® SE Bond was used in the control group. In the RF/BL group, a 0.1 wt% aqueous solution of RF was applied to the dentin surface before applying the adhesive and irradiating with blue light (BL) for 2 min. In the 3rd group, the RF-P/BL group, the RF powder was added to the adhesive primer (P) at a concentration of 0.1 wt%. The teeth were built up using composite resin. After thermocycling, 14 resin-dentin beams from each group were prepared and stored in water for 3 months. The µTBS was determined and the data was analyzed using a linear model with a generalized estimating equation (GEE) (p = 0.05). RESULTS: The highest and the lowest µTBS belonged to the control group (41.15 ±3.50 MPa) and the RF-P/BL group (19.84 ±3.80 MPa), respectively. The mean µTBS in the control group was significantly higher than in the RF/BL and RF-P/BL groups (p < 0.001), but no significant difference was found between the RF/BL and RF-P/BL groups (p = 0.598). CONCLUSIONS: Pre-treatment of dentin surfaces with RF activated with BL had a negative impact on the µTBS of the Clearfil SE Bond as a 2-step SE adhesive.


Assuntos
Colagem Dentária , Adesivos Dentinários , Riboflavina , Cimentos Dentários , Dentina , Humanos , Cimentos de Resina , Riboflavina/farmacologia , Estresse Mecânico , Resistência à Tração
5.
J Dent (Shiraz) ; 20(1): 30-36, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30937334

RESUMO

Statement of the Problem: Laser can influence bonding mechanism by increasing the penetration depth of adhesive in smear layer. The effect of 940 nm diode laser on microtensile bond strength of adhesive to dentin has not been investigated in previous studies. Purpose: The aim of this study was to evaluate the effect of 940 nm diode laser irradiation on microtensile bond strength of Single Bond 2 to dentin. Materials and Method: Thirty sound premolars extracted for orthodontic reasons were randomly divided into five groups as follows: G1 or control: etching+ Single Bond2 (SB); G2: diode laser (940 nm wavelength, 1W power, continuous mode)+ etching+ SB; G3: etching+ laser irradiation+ SB; G4: etching+ SB+ laser irradiation+ adhesive curing; G5: etching+ laser irradiation+ SB +laser irradiation +adhesive curing. After the bonding procedure, Z250 composite resin was applied on the dentin surface in three layers of 2 mm thickness. After 24 hours of immersion in distilled water at 37°C and thermocycling for 1000 thermal cycles, the teeth were sectioned into 1mm2 sticks. The microtensile bond strength was measured using a universal testing machine. Bond strength (MPs) was analyzed by one-way ANOVA followed by HSD post hoc Tukey's test (α=0.05). Results: G4 (38.35±8.99) showed the significant highest bond strength compared to other groups (p= 0.000). G5 (25.16±6.14) showed significantly higher bondstrength than the control group (18.85±4.79) (p= 0.032).Bond strength of G2 (23.39±6.07) and G3 (22.85±5.11) groups was the same and similar to that in the control group (p> 0.05). Conclusion: Based on the results of this study, it may be concluded that dentin surface irradiation with 940 nm diode laser after adhesive application and prior to curing can significantly increase the bond strength of composite to dentin.

6.
Front Dent ; 16(6): 407-414, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-33089241

RESUMO

Objectives: It has been reported that bulk-fill composites simplify tooth restoration with no adverse effect on the success rate. This study sought to assess the cuspal deflection of premolars with mesio-occluso-distal (MOD) cavities restored with bulk-fill and conventional posterior composite resins. Materials and Methods: This in-vitro experimental study was conducted on 64 human maxillary premolars. MOD cavities were prepared on teeth and restored with Filtek P60 conventional composite and Filtek Bulk Fill flowable, X-tra fill, and X-tra base bulk-fill composites in four groups (n=16). Distance between the cusp tips was measured before, five minutes, 24 hours, 48 hours, and one week after restoration. The data were analyzed using repeated-measures analysis of variance (ANOVA) and Tukey's test (α=0.05). Results: The mean±standard deviation (SD) of cuspal deflection at five minutes after the restoration was 13.5±5.3, 12.2±3.5, 11.3±4.4, and 10.4±3.7 µm for Filtek P60, Filtek Bulk Fill, X-tra fill, and X-tra base, respectively. ANOVA showed that bulk-fill composites did not cause a significant reduction in cuspal deflection compared to P60 (P>0.05). Cuspal deflection in all groups significantly decreased with time (P<0.05). Conclusion: Bulk-fill composites have no superiority over P60 in the reduction of cuspal deflection. The cuspal deflection was variable at different time points in all groups and decreased over time.

7.
Dent Med Probl ; 55(1): 29-34, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30152632

RESUMO

BACKGROUND: Bitewing radiography is an important modality useful for the evaluation of teeth in patients of various ages and in different stages of tooth eruption. Clinical examination of proximal surfaces for caries may result in false negative results, especially in tight contact areas. Thus, radiography, as an adjunct to clinical examination, is used as a routine diagnostic modality for caries detection. OBJECTIVES: The objective of this study was to assess the in vitro effect of changing the horizontal angulation of X-ray beam on the detection of proximal enamel caries in bitewing radiographs. MATERIAL AND METHODS: This in vitro study was conducted on 150 caries-free human premolars (code: p/16/35/9/210). The teeth were randomly divided into 3 groups (n = 50). Group 1 served as the control group and no carious lesions were induced in this group. Teeth in groups 2 and 3 were immersed in demineralizing solution for 2 and 4 months, respectively. After induction of caries and its radiographic confirmation, the teeth were mounted in wax in groups of 3 and bitewing radiographs were obtained at 0°, 5°, 10° and 15° horizontal angles. RESULTS: The sensitivity values of bitewing radiographs at 0°, 5°, 10° and 15° horizontal angles were 88%, 90%, 88%, 92% in group 2 and 88%, 94%, 94% and 94% in group 3, respectively. The specificity values of bitewing radiographs at 0°, 5°, 10° and 15° horizontal angles were 92%, 86%, 84% and 76%. The accuracy of bitewing radiographs at 0°, 5°, 10° and 15° horizontal angles was 89.3%, 90%, 88.7% and 87.3%, respectively. The highest diagnostic accuracy was obtained at 5° horizontal angle for caries detection; however, the difference in this regard among the tested horizontal angles was not statically significant (p = 0.846). CONCLUSIONS: Based on the results of this study, changing the horizontal angulation has no significant effect on the detection of proximal enamel caries in bitewing radiographs.


Assuntos
Cárie Dentária/diagnóstico por imagem , Esmalte Dentário/diagnóstico por imagem , Radiografia Interproximal/métodos , Humanos , Técnicas In Vitro , Sensibilidade e Especificidade
8.
J Dent (Tehran) ; 15(1): 30-40, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29971119

RESUMO

Objectives: Laser irradiation, as an adjunct to root canal preparation, may increase the success rate of endodontic treatments. This study aimed to assess the effect of neodymium-doped yttrium aluminum garnet (Nd:YAG) and diode lasers on the apical seal of the root canals filled with AH Plus® and mineral trioxide aggregate (MTA)-based sealers. Materials and Methods: This in-vitro experimental study was conducted on 96 single-rooted, single-canal extracted human teeth with closed apices. The root canals were prepared by using ProTaper® rotary instruments and were randomly divided into six groups (n=16): 940-nm diode laser and AH Plus® sealer (group 1), Nd:YAG laser and AH Plus® sealer (group 2), AH Plus® sealer (group 3), 940-nm diode laser and MTA-based sealer (group 4), Nd:YAG laser and MTA-based sealer (group 5), MTA-based sealer (group 6), as well as positive and negative control groups. A bacterial leakage model was used for microleakage assessment. Qualitative assessment was done by using a scanning electron microscope (SEM). Data were analyzed by two-way analysis of variance (ANOVA) at the significance level of 0.05. Results: There were statistically significant differences between the experimental and control groups (P=0.002). The laser-treated groups showed a lower apical microleakage compared to the non-laser-treated groups, although the difference was not statistically significant (P>0.05). No significant differences were noted between the two lasers in terms of the apical microleakage, irrespective of the type of sealer (P>0.05). Conclusions: Laser irradiation, as an adjunct to root canal preparation, has no significant effect on the level of apical microleakage.

9.
J Lasers Med Sci ; 9(2): 144-148, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30026901

RESUMO

Introduction: It has been suggested that the application of casein phosphopeptide-amorphous calcium phosphate paste (CPP-ACP) and CO2 laser irradiation on enamel could increase the resistance of enamel to caries and acid attacks. The aim of the current study was to compare the influence of CPP-ACP paste application and irradiation of CO2 laser on microhardness of demineralized enamel. Methods: Thirty sound maxillary extracted premolars were selected. The crowns were cut at the cervical line and were split into facial and palatal halves. Specimens were mounted in selfcure acrylic blocks in such way that the enamel surface was exposed to 4×4 mm. After a pH cycling of the specimens, they were randomly divided into 4 groups (n=15), as follows: CG: Control group, LAS: CO2 laser, CP: CPP-ACP and LASCP: laser combined CPP-ACP treatment. The Vickers microhardness of the specimens was measured (500 g load, 5 seconds, 3 points). Data were analyzed using one-way ANOVA and post hoc Tukey tests (α =0.05). Results: The lowest mean Vickers microhardness value was observed in CG group (192.57±50.87 kg/mm2 ) and the highest in LASCP group (361.86±22.22 kg/mm2 ). There were significant differences between groups (P<0.001). The pairwise comparison of the groups revealed that there were significant differences between these groups: CG versus LAS, CP, LASCP (P<0.05) and LASCP versus LAS and CP (P<0.05). No significant difference between LAS group versus CP group (P>0.05) was observed. Conclusion: The results of the current study revealed that CO2 laser and CCP-ACP were effective for improvement of enamel hardness value after demineralization. Incorporation of CO2 laser irradiation and CCP-ACP paste application provides additional remineralizing potential for demineralized enamel.

10.
J Conserv Dent ; 21(2): 162-168, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29674818

RESUMO

Background and Objectives: Image processing and enhancement filters can significantly improve the diagnostic value of digital radiographs. Evidence shows that increasing the contrast and filtering improve the diagnostic accuracy for caries detection. This study sought to assess the diagnostic accuracy of original and enhanced digital radiographs for the detection of approximal and occlusal caries. Subjects and Methods: In this experimental study, incipient carious lesions were artificially created on 120 proximal and occlusal surfaces of human extracted permanent molar and premolar teeth. After mounting the teeth in wax, digital radiographs were obtained using photostimulable phosphor plates and enhanced by enhancement filters 1, 2, and 3 with/without denoising. Two oral and maxillofacial radiologists blinded to filtering viewed the radiographs and filled out a chart. A definite diagnosis was made by a pathologist by observing the samples under a stereomicroscope (gold standard). Data were analyzed using SPSS software version 16. Interobserver agreement was calculated using kappa statistics. Chi-square test was used to assess the correlation between qualitative variables. Results: Assessment of sensitivity, specificity, accuracy, positive predictive value, and negative predictive value showed that enhancement filter 2 without denoising was the most efficient and original radiographs (filter free) were the least efficient radiographs for the detection of carious and sound surfaces. Application of filters significantly increased the accuracy of caries detection on digital radiographs. The lowest diagnostic accuracy was noted for the detection of enamel lesions on original radiographs (52%). Enhancement filter 2 plus denoising was the best filter for the detection of these lesions (79.25%). No significant difference was noted among different filters for detection of carious and sound surfaces but enhanced, and original radiographs were significantly different in visualization and detection of caries (P < 0.05). Conclusion: Application of enhancement filters, particularly enhancement filter 2 with/without denoising, increases the accuracy of caries detection on digital radiographs.

11.
Lasers Med Sci ; 33(2): 287-293, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29082462

RESUMO

Low-level laser therapy (LLLT) is a non-invasive modality to promote osteoblastic activity and tissue healing. The aim of this study was to evaluate the efficacy of LLLT for improvement of dental implant stability. This randomized controlled clinical trial was performed on 80 dental implants placed in 19 patients. Implants were randomly divided into two groups (n = 40). Seven sessions of LLLT (940 nm diode laser) were scheduled for the test group implants during 2 weeks. Laser was irradiated to the buccal and palatal sides. The same procedure was performed for the control group implants with laser hand piece in "off" mode. Implant stability was measured by Osstell Mentor device in implant stability quotient (ISQ) value immediately after surgery and 10 days and 3, 6, and 12 weeks later. Repeated measures ANOVA was used to compare the mean ISQ values (implant stability) in the test and control groups. Statistical test revealed no significant difference in the mean values of implant stability between the test and control groups over time (P = 0.557). Although the mean values of implant stability changed significantly in both groups over time (P < 0.05). Although the trend of reduction in stability was slower in the laser group in the first weeks and increased from the 6th to 12th week, LLLT had no significant effect on dental implant stability.


Assuntos
Implantes Dentários , Lasers Semicondutores , Terapia com Luz de Baixa Intensidade/métodos , Adulto , Feminino , Humanos , Masculino , Osseointegração , Fatores de Tempo
12.
Braz. j. oral sci ; 16: e17048, jan.-dez. 2017. ilus
Artigo em Inglês | LILACS, BBO - Odontologia | ID: biblio-883768

RESUMO

Objective: this study aimed to assess the effect of treatment of phosphoric acid etched dentin surface with 5% bromelain enzyme and Nd:YAG laser prior to the use of etch and rinse adhesive systems on microleakage margins of class V composite restorations. Materials and Methods: sixty sound premolar teeth were selected. Standard class V cavities were prepared in the buccal and lingual surfaces of each teeth. Preparation in that way 1 mm of the cavity was above and 1 mm of it was below the cementoenamel junction. The teeth were then randomly divided into three groups including 20 teeth(40cavities in each gorup). Two ethanol base etch and rinse system (Adper Single Bond and OptiBond Solo) was applied in each group. In the control group, cavities were etched with 37% phosphoric acid. Adper Single Bond was applied to 20 and OptiBond Solo was applied to the remaining 20 cavities and they were restored with Z250 composite (n=40). The same procedures were performed in bromelain and Nd:YAG laser groups with the difference that prior to the application of adhesive, aqueous 5% bromelain was applied in bromelain group while Nd:YAG laser was irradiated in laser group. All teeth were thermocycled and their apices were sealed with sticky wax. The tooth surfaces were coated with nail varnish except for 1 mm around the restoration margins, and the teeth were then immersed in fuchsine and sectioned by a diamond disc into mesial and distal halves. Marginal microleakage at both sides was determined and scored under a stereomicroscope at x40 magnification. Then data were analyzed using the Kruskal Wallis and Mann Whitney tests (α=0.05). Results: according the result of Mann Whitney test, Cervical margins showed significantly higher microleakage than the occlusal margins (P=0.000) but no significant difference was noted in microleakage of occlusal (P=0.362) or gingival (P=0.147) margins among the three groups by Kruskal Wallis test. Conclusion: in conclusion, application of proteolytic agents(5% bromelain solution and Nd:YAG laser) on acid-etched dentin surface prior to the application of adhesive has no significant effect on marginal microleakage of class V composite restorations (AU)


Assuntos
Humanos , Bromelaínas , Infiltração Dentária , Lasers
13.
J Lasers Med Sci ; 8(1): 36-41, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28912942

RESUMO

Introduction: The purpose of the present study was to evaluate the different concentrations of sodium hypochlorite activated with laser in removing of the smear layer in the apical, middle, and coronal segments of root canal walls by scanning electron microscopy analysis. Methods: Sixty single-rooted human mandibular teeth were decoronated to a standardized length. The samples were prepared by using Race rotary system to size 40, 0.04 taper and divided into 4 equal groups (n = 15). Group 1, irrigated with EDTA 17% and 5.25% NaOCl, groups 2, 3 and 4, 1%, 2.5%, and 5% NaOCl activated with Nd:YAG laser, respectively. Teeth were split longitudinally and subjected to scanning electron microscope (SEM). Data were analyzed by Kruskal-Wallis, Mann-Whitney tests. P value of <0.05 was considered statistically significant. Results: Five percent NaOCl LAI (laser-activated irrigation) showed best smear layer removal in test groups and the difference was statistically significant (P < 0.001). Control group (EDTA 17% and 5.25% NaOCl irrigation) showed significantly better outcomes in comparative with test groups (P < 0.001). In the apical third, compared to coronal and middle third, the canal walls were often contaminated by inorganic debris and smear layer. Conclusion: All different concentrations of sodium hypochlorite activated with laser have a positive effect on removing of smear layer. Sodium hypochlorite activated with laser removed smear layer more effectively at the coronal and middle third compared to the apical third.

14.
Braz Dent J ; 28(1): 85-91, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28301024

RESUMO

Secondary caries is the most common cause of dental restoration failures. This study aimed to compare the diagnostic accuracy of conventional and digital intraoral radiography and cone beam computed tomography (CBCT) for detection of recurrent caries around composite restorations. mesio-occluso-distal (MOD) cavities were prepared using bur on 45 extracted sound human molar teeth. The teeth were divided into 3 groups. In the control group, cavities were restored with composite resin after etching and bonding (n=15). In Group 2, 500-µm thick wax was placed over the buccal, lingual and gingival walls and the cavities were restored with composite resin. Group 3 specimens were subjected to pH cycling and artificial caries were created on the buccal, lingual and gingival walls. The cavities were restored with composite. Conventional and digital photo-stimulable phosphor (PSP; Optime) radiographs and two CBCTs images (NewTom 3G and Cranex 3D) were obtained from them. Presence or absence of caries in the cavity walls was assessed on these images. Data were analyzed using Kappa statistic. The diagnostic accuracy of CBCT was significantly higher than that of digital and conventional intraoral radiography (p<0.05). The accuracy was 0.83, 0.78, 0.55 and 0.49 for CBCT Cranex 3D, CBCT NewTom 3G, conventional and digital intraoral radiography, respectively. CBCT has a higher diagnostic accuracy than digital and conventional intraoral radiography for detection of secondary caries around composite restorations.


Assuntos
Resinas Compostas , Tomografia Computadorizada de Feixe Cônico/métodos , Cárie Dentária/diagnóstico , Restauração Dentária Permanente , Cárie Dentária/terapia , Humanos , Radiografia Dentária Digital/métodos , Recidiva , Sensibilidade e Especificidade
15.
Braz. dent. j ; 28(1): 85-91, Jan.-Feb. 2017. tab, graf
Artigo em Inglês | LILACS | ID: biblio-839115

RESUMO

Abstract Secondary caries is the most common cause of dental restoration failures. This study aimed to compare the diagnostic accuracy of conventional and digital intraoral radiography and cone beam computed tomography (CBCT) for detection of recurrent caries around composite restorations. mesio-occluso-distal (MOD) cavities were prepared using bur on 45 extracted sound human molar teeth. The teeth were divided into 3 groups. In the control group, cavities were restored with composite resin after etching and bonding (n=15). In Group 2, 500-μm thick wax was placed over the buccal, lingual and gingival walls and the cavities were restored with composite resin. Group 3 specimens were subjected to pH cycling and artificial caries were created on the buccal, lingual and gingival walls. The cavities were restored with composite. Conventional and digital photo-stimulable phosphor (PSP; Optime) radiographs and two CBCTs images (NewTom 3G and Cranex 3D) were obtained from them. Presence or absence of caries in the cavity walls was assessed on these images. Data were analyzed using Kappa statistic. The diagnostic accuracy of CBCT was significantly higher than that of digital and conventional intraoral radiography (p<0.05). The accuracy was 0.83, 0.78, 0.55 and 0.49 for CBCT Cranex 3D, CBCT NewTom 3G, conventional and digital intraoral radiography, respectively. CBCT has a higher diagnostic accuracy than digital and conventional intraoral radiography for detection of secondary caries around composite restorations.


Resumo A causa mais comum de falha das cáries dentais são as cáries secundárias. Este estudo objetivou comparar a acurácia diagnóstica da radiografia intraoral digital e convencional com a tomografia computadorizada de feixe cônico (TCFC) para a detecção de cáries recorrentes em torno restaurações com compósitos. Cavidades mésio-oclusais-distais (MOD) foram produzidas com broca em 45 molares hígidos humanos extraídos. Os dentes foram dividdos em 3 grupos. No grupo controle, as cavidades foram restauradas com compósito após condicionamento e colagem (n=15). No Grupo 2, foi aplicada uma camada de cera de 500 µm de espessura sobre as paredes bucais, linguais e gengivais; as cavidades foram então restauradas com resina composta. No Grupos 3, as amostras foram submetidas a ciclagem de pH e criação artificial de cáries sobre as paredes bucais, linguais e gengivais; as cavidades foram então restauradas com resina composta. Radiografias convencional e digital com fósforo foto-estimulável (PSP, Optima) e duas imagens em TCFC (NewTom 3G e Granex 3D) foram obtidas de cada amostra. A presença ou não de cáries foi avaliada nestas imagens. Os dados foram analisados por estatística Kappa. A acurácia diagnóstica da TCFC foi significantemente (p<0,05) maior que na radiografia intraoral convencional e digital. A acurácia foi de 0,83, 0,78, 0,55 e 0,49, respectivamente para TCFC Cranex 3D, TCFC NewTom 3G, a radiografia intraoral convencional e digital. A TCFC tem maior acurácia diagnóstica que a radiografia intraoral convencional e digital para detecção de cáries secundárias em torno de restaurações com compósito.


Assuntos
Humanos , Resinas Compostas , Tomografia Computadorizada de Feixe Cônico/métodos , Cárie Dentária/diagnóstico , Restauração Dentária Permanente , Cárie Dentária/terapia , Radiografia Dentária Digital/métodos , Recidiva , Sensibilidade e Especificidade
16.
Lasers Med Sci ; 31(5): 985-9, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27126410

RESUMO

The aim of the present study was to evaluate the success rate of failed implants re-implanted after surface treatment with CO2 laser. Despite the widespread use of dental implants, there are many incidents of failures. It is believed that lasers can be applied to decontaminate the implant surface without damaging the implant. Ten dental implants that had failed for various reasons other than fracture or surface abrasion were subjected to CO2 laser surface treatment and randomly placed in the maxillae of dogs. Three failed implants were also placed as the negative controls after irrigation with saline solution without laser surface treatment. The stability of the implants was evaluated by the use of the Periotest values (PTVs) on the first day after surgery and at 1, 3, and 6 months post-operatively. The mean PTVs of treated implants increased at the first month interval, indicating a decrease in implant stability due to inflammation followed by healing of the tissue. At 3 and 6 months, the mean PTVs decreased compared to the 1-month interval (P < 0.05), indicating improved implant stability. The mean PTVs increased in the negative control group compared to baseline (P < 0.05). Independent t-test showed that the mean PTVs of treated implants were significantly lower than control group at 3 and 6 months after implant placement (P < 0.05). Based on the PTVs, re-implantation of failed implants in Jack Russell Terrier dogs after CO2 laser surface debridement is associated with a high success rate in terms of implant stability.


Assuntos
Implantação Dentária Endo-Óssea/métodos , Retenção em Prótese Dentária , Lasers de Gás/uso terapêutico , Terapia com Luz de Baixa Intensidade/métodos , Animais , Cães , Masculino , Maxila , Osseointegração/efeitos da radiação , Distribuição Aleatória , Cicatrização
17.
J Lasers Med Sci ; 7(3): 152-158, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-28144434

RESUMO

Introduction: This study aimed to compare the microshear bond strength of composite to enamel treated with Erbium-Doped Yttrium Aluminum Garnet (Er:YAG) laser using a self-etch one step bonding agent. Methods: Seventy-six enamel surfaces were prepared from 38 sound human third molar teeth. Specimens were randomly divided into four groups of 18. The enamel surface in half the specimens was irradiated with Er:YAG laser. One extra specimen from each group was evaluated under a scanning electron microscope (SEM). Composite micro-cylinders were bonded to the specimen surfaces using OptiBond All-In-One (OB) adhesive agent and stored in distilled water for 24 hours. Half the specimens were thermocycled (2000 cycles) and stored in distilled water at 37°C for three months (TW). The microshear bond strength of composite to enamel was measured using a universal testing machine at a crosshead speed of 1 mm/min. The fractured surfaces were evaluated under a stereomicroscope at ×40 magnification to determine the mode of failure. Data were analyzed using repeated measures analysis of variance (ANOVA) and t test. Results: The mean values (±standard deviation) were 17.96 ± 2.92 MPa in OB group, 22.29 ± 4.25 MPa in laser + OB group, 18.11 ± 3.52 MPa in laser + OB + TW group and 9.42 ± 2.47 MPa in OB + TW group. Repeated measures ANOVA showed that laser irradiation increased the microshear bond strength (P < 0.001). Bond strength decreased when the samples were thermocycled and stored for three months (P < 0.001). The interaction effect of water storage and laser treatment on bond strength was significant (P < 0.05). Conclusion: Enamel surface preparation with Er:YAG laser is recommended to enhance the durability of the bond of self-etch bonding systems to enamel.

18.
J Dent (Tehran) ; 12(9): 686-94, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27148380

RESUMO

OBJECTIVES: Because of poor bond between resin cement and zirconia ceramics, laser surface treatments have been suggested to improve adhesion. The present study evaluated the effect of CO2 and Nd:YAG lasers on the shear bond strength (SBS) of resin cement to zirconia ceramic. MATERIALS AND METHODS: Ninety zirconia disks (6×2 mm) were randomly divided into six groups of 15. In the control group, no surface treatment was used. In the test groups, laser surface treatment was accomplished using CO2 and Nd:YAG lasers, respectively (groups two and three). Composite resin disks (3×2 mm) were fabricated and cemented to zirconia disks with self-etch resin cement and stored in distilled water for 24 hours. In the test groups four-six, the samples were prepared as in groups one-three and then thermocycled and stored in distilled water for six months. The SBS tests were performed (strain rate of 0.5 mm/min). The fracture modes were observed via stereomicroscopy. Data were analyzed with one and two-way ANOVA, independent t and Tukey's tests. RESULTS: The SBS values of Nd:YAG group (18.95±3.46MPa) was significantly higher than that of the CO2 group (14.00±1.96MPa), but lower than that of controls (23.35±3.12MPa). After thermocycling and six months of water storage, the SBS of the untreated group (1.80±1.23 MPa) was significantly lower than that of the laser groups. In groups stored for 24 hours, 60% of the failures were adhesive; however, after thermocycling and six months of water storage, 100% of failures were adhesive. CONCLUSION: Bonding durability of resin cement to zirconia improved with CO2 and Nd:YAG laser surface treatment of zirconia ceramic.

19.
Restor Dent Endod ; 39(4): 296-302, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25383349

RESUMO

OBJECTIVES: It is difficult to achieve adhesion between resin cement and zirconia ceramics using routine surface preparation methods. The aim of this study was to evaluate the effects of CO2 and Er:YAG laser treatment on the bond strength of resin cement to zirconia ceramics. MATERIALS AND METHODS: In this in-vitro study 45 zirconia disks (6 mm in diameter and 2 mm in thickness) were assigned to 3 groups (n = 15). In control group (CNT) no laser treatment was used. In groups COL and EYL, CO2 and Er:YAG lasers were used for pretreatment of zirconia surface, respectively. Composite resin disks were cemented on zirconia disk using dual-curing resin cement. Shear bond strength tests were performed at a crosshead speed of 0.5 mm/min after 24 hr distilled water storage. Data were analyzed by one-way ANOVA and post hoc Tukey's HSD tests. RESULTS: The means and standard deviations of shear bond strength values in the EYL, COL and CNT groups were 8.65 ± 1.75, 12.12 ± 3.02, and 5.97 ± 1.14 MPa, respectively. Data showed that application of CO2 and Er:YAG lasers resulted in a significant higher shear bond strength of resin cement to zirconia ceramics (p < 0.0001). The highest bond strength was recorded in the COL group (p < 0.0001). In the CNT group all the failures were adhesive. However, in the laser groups, 80% of the failures were of the adhesive type. CONCLUSIONS: Pretreatment of zirconia ceramic via CO2 and Er:YAG laser improves the bond strength of resin cement to zirconia ceramic, with higher bond strength values in the CO2 laser treated samples.

20.
J Conserv Dent ; 17(3): 220-4, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24944443

RESUMO

AIM: This study evaluated the effect of 10% ascorbic acid on the bond strength between fiber post and composite resin core after applying 24% hydrogen peroxide. MATERIALS AND METHODS: Twenty-four hydrogen peroxide-treated fiber posts were divided into 4 groups (n = 6). Group 1 was the control group with no treatment. In groups 2-4, post surfaces were treated with 10% v ascorbic acid solution for 10, 30 and 60 minutes, respectively. Cores were built up using flowable composite resin. Two sticks were prepared from each specimen. Microtensile bond strength test was performed for each stick. Failure modes of sticks were evaluated under a stereomicroscope (×20). Surface morphologies of two fractured sticks from each group were assessed by SEM. STATISTICAL ANALYSIS: Data were analyzed using one-way ANOVA and Tukey HSD tests (α = 0.05). RESULTS: The highest microtensile bond strength was observed in Group 4 (20.55 ± 2.09) and the lowest in Group 1 (10.10 ± 0.55). There were significant differences in microtensile bond strength between all the groups (P < 0.05). CONCLUSION: It is concluded that ascorbic acid application increased the microtensile bond strength between the hydrogen peroxide treated fiber post and composite resin core. The increase is dependent on the duration of exposure to the antioxidant.

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