RESUMO
The objective of this study was to evaluate the occlusion potential of in-office desensitizing agents, and characterize the human dentin elements after acid exposure. Twelve human dentin discs were sectioned into four specimens each, and randomized into treatments (n = 20): no treatment (negative control); no treatment and 6% citric acid exposure (positive control); application of Gluma desensitizer (Heraeus Kulzer) or PRG Barrier Coat (Shofu), followed by 6% citric acid exposure. Occlusion and dentin surface characteristics were determined by scanning electron microscopy (SEM, n = 10), and elemental composition (at%), by energy-dispersive X-ray spectroscopy (EDS, n = 10). Three calibrated, blinded evaluators used SEM to categorize the occlusion potential: 1 = occluded, 2 = partially unoccluded, 3 = equally occluded/unoccluded, 4 = partially occluded, 5 = unoccluded. Data were analyzed by weighted kappa, Friedman, and Nemenyi tests (α = 0.05). For SEM, mean occlusion scores were higher for the PRG Barrier Coat than the positive control (p = 0.0235). Most specimens in the controls scored 4 or 5. The most frequent scores for PRG Barrier Coat were 1(60%) and 2(20%), while 30% of Gluma specimens scored 1 and 2. Gluma showed intratubular precipitation, while PRG Barrier Coat covered dentinal tubules totally or partially. For EDS, the K% was lower for Gluma than the negative control (p = 0.0046), with Si peaks in dentin treated with PRG Barrier Coat. The bioactive in-office desensitizing agent with S-PRG filler (PRG Barrier Coat) promoted dentin tubule occlusion, and persisted after exposure to acid.
Assuntos
Ácido Cítrico , Dessensibilizantes Dentinários , Dentina , Teste de Materiais , Microscopia Eletrônica de Varredura , Espectrometria por Raios X , Propriedades de Superfície , Dentina/efeitos dos fármacos , Dentina/química , Dessensibilizantes Dentinários/química , Dessensibilizantes Dentinários/farmacologia , Humanos , Propriedades de Superfície/efeitos dos fármacos , Ácido Cítrico/farmacologia , Ácido Cítrico/química , Glutaral/química , Glutaral/farmacologia , Sensibilidade da Dentina/tratamento farmacológico , Metacrilatos/química , Metacrilatos/farmacologia , Valores de Referência , Reprodutibilidade dos Testes , Estatísticas não ParamétricasRESUMO
This study evaluated the microtensile bond strength (µTBS) and fracture pattern of direct composite resin reinforced with polyethylene fiber (Ribbond®) on dentin substrate after thermomechanical cycling (TMC). Dentin blocks (dentin thickness=2 mm) were obtained from forty human third molars and randomly divided into four groups (n=10) according to type of restoration (composite resin with or without Ribbond®) and to whether they were or were not subjected to TMC (100,000 cycles of 50 N / 2 Hz / 1-minute baths of 5 and 55ºC). The 1-mm-thick square-shaped specimens were submitted to µTBS testing in a universal testing machine at 0.5 mm/min. The fracture patterns were assessed by stereoscopic magnifying glass (30X magnification). The µTBS (in MPa) and failure pattern data were subjected to the generalized linear model and G tests (a=0.05). Neither the polyethylene fiber nor TMC had any statistically significant effect (p=0.196 and p=0.136, respectively) on the µTBS of the composite resin to dentin. Adhesive failures were more prevalent in the composite resin group compared with the Ribbond-containing group when subjected to TMC. Additionally, the composite resin containing Ribbond® showed a higher proportion of cohesive failures in composite resin than the resin groups not containing this fiber, irrespective of TMC. It was concluded that reinforcing the direct layer of composite resin with Ribbond® polyethylene fiber did not influence the adhesive resistance to dentin, even when subjected to TMC. However, its incorporation did result in a higher frequency of cohesive failures in resin after TMC.
Assuntos
Resinas Compostas , Colagem Dentária , Dentina , Teste de Materiais , Resistência à Tração , Resinas Compostas/química , Humanos , Dentina/efeitos dos fármacos , Dentina/química , Colagem Dentária/métodos , Fatores de Tempo , Propriedades de Superfície , Polietileno/química , Reprodutibilidade dos Testes , Modelos Lineares , Adesivos Dentinários/química , Temperatura , Valores de Referência , Análise do Estresse Dentário , PolietilenosRESUMO
To evaluate the efficacy and safety of different wavelengths of high-power diode lasers for the treatment of dentin hypersensitivity by analyzing morphological changes and temperature variation. Human third molars were irradiated with five different commercially available lasers at wavelengths of 808 nm, 940 nm, 976 nm, and 980 nm, both with and without the use of a photoinitiator (activated charcoal). Temperature variations were monitored using thermocouples, and morphological changes were assessed through scanning electron microscopy. Lasers with wavelengths of 940 nm, 976 nm, and 980 nm, used without a photoinitiator, promoted dentinal tubule obliteration without causing thermal damage. Lasers with wavelengths of 808 nm, 940 nm, 976 nm, and 980 nm, when combined with a photoinitiator, resulted in even lower temperature variation compared to the non-photoinitiator groups, although no regular fused surface was observed. Diode laser parameters, except Group 1(808 nm without photoinitiator), are potentially safe for dentinal tubule obliteration. The use of a photoinitiator continues to be an effective strategy for minimizing temperature variations during irradiation.
Assuntos
Sensibilidade da Dentina , Lasers Semicondutores , Microscopia Eletrônica de Varredura , Humanos , Lasers Semicondutores/uso terapêutico , Sensibilidade da Dentina/radioterapia , Técnicas In Vitro , Polpa Dentária/efeitos da radiação , Dentina/efeitos da radiação , Temperatura , Temperatura Corporal/efeitos da radiação , Dente SerotinoRESUMO
OBJECTIVES: This study aimed to evaluate the effect of different irrigation protocols on the viability and metabolism of stem cells from the apical papilla (SCAP) using a new in vitro protocol that simulates the clinical situation. MATERIALS AND METHODS: Forty-eight bovine dentin cylinders were obtained and prepared to simulate teeth with incomplete rhizogenesis, positioned under a three-dimensional (3D) culture of SCAPs to mimic the apical papilla. The cylinders were divided into four groups (n = 8) according to the irrigating solution: Control; NaOCl (Sodium hypochlorite 1%); EDTA (17% ethylenediaminetetraacetic acid); and NaOCl + EDTA. Subsequently, the viability (Live/Dead n = 2) and metabolism (Alamar Blue n = 6) of the cells were assessed (ISO 10993). Data were analyzed using Kruskal-Wallis and Dunn tests (p < 0.05). RESULTS: In the 1 to 3 days period, Control and EDTA had significantly higher increases in metabolism compared to NaOCl and NaOCl + EDTA (p < 0.05). In the 3- to 7-day period, metabolism significantly decreased in NaOCl + EDTA compared to EDTA (p < 0.05) but was similar to Control and NaOCl. Additionally, significant differences were observed within groups Control, EDTA, and NaOCl + EDTA across the two periods (p < 0.05). CONCLUSIONS: The tested in vitro model allows for the analysis of the response of SCAPs to different irrigating solutions, simulating the clinical situation. Sodium hypochlorite 1% demonstrated high cytotoxicity to SCAPs, whose effects were partially reversed by 17% EDTA. CLINICAL RELEVANE: The methodology developed provides a tool for future investigations, allowing for the assessment of new irrigants and techniques that may optimize tissue regeneration.
Assuntos
Sobrevivência Celular , Ácido Edético , Irrigantes do Canal Radicular , Hipoclorito de Sódio , Células-Tronco , Irrigantes do Canal Radicular/farmacologia , Hipoclorito de Sódio/farmacologia , Animais , Ácido Edético/farmacologia , Bovinos , Sobrevivência Celular/efeitos dos fármacos , Células-Tronco/efeitos dos fármacos , Técnicas In Vitro , Papila Dentária/citologia , Papila Dentária/efeitos dos fármacos , Células Cultivadas , Ápice Dentário/efeitos dos fármacos , Ápice Dentário/citologia , Dentina/efeitos dos fármacosRESUMO
Guided bone regeneration (GBR) is an alternative treatment for craniofacial bone defects reconstruction through membrane barrier adaptation, such as demineralized dentin material membrane (DDMM). DDMM is used as a substitute for GBR material, which aligns with Green Economy principles, it has a good biological osteoinductive and osteoconductive effects, and its structure resembles bones. The balance of bone remodeling when experiencing craniofacial defects will be altered and allow changes to resorption activity, so the mechanisms of osteoclastogenesis and bone resorption are vital. OBJECTIVE: this article aims to analyze the expression of TNF-α, RANKL, and osteoclast cells count after application of DDMM as GBR in mandibular bone defects. METHODOLOGY: this is an experimental study with a post-test only control group design, which began with the randomization of 120 rats into five groups: K(-), without membrane implantation; K(+), PPCM; P1, DDMM; P2, DDMM + bone graft; P3, PPCM + bone graft. The expression of TNF-α, RANKL, and osteoclast cells count were observed, followed by analysis using a one-way ANOVA and post hoc Tukey HSD comparison test. RESULTS: there were significant differences in the expression of TNF-α, RANKL, and osteoclast cells count in all study groups (p=0.000). TNF-α showed a decreasing difference with the highest expression in the K(-) group on day 3 of 12.00±2.16. RANKL expression increased on day 14 and decreased on day 21 in all groups. The osteoclast cells count generally showed a critical period with the highest increase in the K(-) group on day 14 of 73.00±0.00. CONCLUSION: DDMM has the potential to be a superior membrane substitute compared to PPCM as GBR in alternative treatment for craniofacial bone defects reconstruction.
Assuntos
Regeneração Óssea , Dentina , Regeneração Tecidual Guiada , Mandíbula , Osteoclastos , Ligante RANK , Fator de Necrose Tumoral alfa , Animais , Regeneração Óssea/fisiologia , Regeneração Tecidual Guiada/métodos , Fator de Necrose Tumoral alfa/análise , Ligante RANK/análise , Masculino , Mandíbula/cirurgia , Reprodutibilidade dos Testes , Distribuição Aleatória , Ratos Wistar , Biomarcadores/análise , Análise de Variância , Membranas Artificiais , Fatores de Tempo , Resultado do Tratamento , Contagem de Células , Valores de Referência , Osteogênese/fisiologia , Transplante Ósseo/métodosRESUMO
The aim of this study was to assess the effect of a chlorhexidine digluconate solution (CHX) applied as an antiproteolytic agent for controlling erosive tooth wear or as part of the adhesive treatment on long-term bond strength to eroded dentin. Dentin specimens were abraded with a 600-grit silicon carbide (SiC) paper for 1 min (sound dentin - S), subsequently treated with 2% CHX for 1 min (with excess removed, followed by a 6-hour rest), and eroded by exposure to Coca-Cola for 5 min, three times a day, for 5 days (CHX-treated and eroded dentin - CHXE), or only eroded (eroded dentin - E). The specimens were acid-etched (15 s), rinsed (30 s), dried (15 s), and rehydrated with 1.5 µL of distilled water for 1 min, with excess removed (control - S.C/CHXE.C/E.C) or 2% CHX (S.CHX/CHXE.CHX/E.CHX). Adper Single Bond 2 was scrubbed twice on the surface for 15 s each and then light-cured for 10 s, and resin composite cores were built up. Specimens were sectioned into beams and microtensile bond strength was tested (µTBS; 0.5 mm/min) immediately or after 18-month aging. Failure modes were analyzed using a digital microscope. Data (µTBS/MPa) were analyzed by three-way ANOVA, followed by Tukey's test (α = 0.05). µTBS to E and CHXE, irrespective of the rehydration solution and aging period, were equivalent to each other and lower than that to S. CHX as the rehydration solution reduced immediate and long-term µTBS to S. Aging reduced µTBS. By controlling tooth wear or interface aging, CHX could not influence long-term bonding to eroded dentin.
Assuntos
Clorexidina , Colagem Dentária , Dentina , Teste de Materiais , Propriedades de Superfície , Erosão Dentária , Clorexidina/química , Clorexidina/farmacologia , Clorexidina/análogos & derivados , Dentina/efeitos dos fármacos , Dentina/química , Erosão Dentária/prevenção & controle , Colagem Dentária/métodos , Fatores de Tempo , Propriedades de Superfície/efeitos dos fármacos , Humanos , Reprodutibilidade dos Testes , Análise de Variância , Resistência à Tração , Valores de Referência , Adesivos Dentinários/química , Estatísticas não Paramétricas , Microscopia Eletrônica de Varredura , Bebidas Gaseificadas , Resinas Compostas/química , Cimentos DentáriosRESUMO
This study assessed the effect of composite resins, aggregated or not with S-PRG particles, and the use of toothpaste in controlling demineralization and bacterial growth. Human molars were distributed into 3 groups: control (CT) - sound teeth, Beautifil Bulk Restorative System (aggregated with S-PRG) (BB), Filtek One Bulk Fill (without S-PRG) (FB). Teeth destined for groups BB and FB previously received Class I preparations (4 × 4 × 4 mm), followed by single-increment restorations. All teeth were sectioned mesiodistally, with all specimens subjected to cariogenic challenge for 5 days, including microcosm biofilm formation. Half of each tooth was exposed to toothpaste (CTF, BBF, FBF). The loss of microhardness was assessed considering the initial microhardness as 100% on enamel, dentin, and composite resin substrates. Colony Forming Units (CFU/mL) were counted in 3 media. Data analysis used one-way ANOVA, Tukey HSD test, and paired t-test (α = 0.05). Toothpaste significantly reduced CFU/mL for total bacteria and genus Streptococcus (p < 0.05), with no significant difference for Streptococcus mutans. Enamel microhardness was positively affected by toothpaste. Both restorative systems controlled enamel demineralization, with FB and FBF outperforming BB and BBF. There was minor degradation of both composite resins, between 10% and 22%. Toothpaste effectively reduced microorganisms, irrespective of the composite resin. Regarding demineralization control, both restorative systems, with and without S-PRG particles, were effective on enamel.
Assuntos
Biofilmes , Resinas Compostas , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Resinas Compostas/farmacologia , Resinas Compostas/química , Humanos , Cremes Dentais/farmacologia , Cremes Dentais/química , Cárie Dentária/microbiologia , Cárie Dentária/prevenção & controle , Esmalte Dentário/efeitos dos fármacos , Esmalte Dentário/microbiologia , Desmineralização do Dente/prevenção & controle , Desmineralização do Dente/microbiologia , Dente Molar/efeitos dos fármacos , Dente Molar/microbiologia , Streptococcus mutans/efeitos dos fármacos , Streptococcus mutans/fisiologia , Streptococcus mutans/crescimento & desenvolvimento , Dureza , Dentina/microbiologia , Dentina/efeitos dos fármacosRESUMO
In the present study, chitosan microspheres (MSCH) loaded with different concentrations of simvastatin (2%, 5%, and 10%) were synthesized as a biomaterial for dentin tissue engineering. The microspheres were prepared by emulsion crosslinking method, and simvastatin was incorporated during the process. The microspheres were then physicochemically and morphologically characterized. Scanning electron microscopy and infrared spectroscopy confirmed the spherical morphology of synthesized microspheres and the chemical incorporation of simvastatin into MSCH, respectively. UV-visible absorption confirmed the controlled and continuous release pattern of the drug. To mimic the clinical application in vitro, the microspheres were applied onto three-dimensional (3D) cultures of human dental pulp cells (HDPCs). Cell viability, proliferation, and in situ-mineralized matrix deposition were evaluated. The results indicated no cytotoxic effects for all 3D cultures for all tested biomaterials, with cells being able to proliferate significantly over time. HDPCs showed a significant increase in the deposition of mineralization nodules when 3D cultures were in direct contact with chitosan microspheres in comparison to control; nevertheless, the highest expression was observed for MSCH encapsulated with 5% and 10% simvastatin, which was significantly higher than plain MSCH. Therefore, chitosan microsphere systems loaded with 5%-10% simvastatin provided the development of a controlled release system in bioactive dosages for dentin tissue engineering.
Assuntos
Quitosana , Polpa Dentária , Dentina , Microesferas , Sinvastatina , Engenharia Tecidual , Sinvastatina/química , Sinvastatina/farmacologia , Quitosana/química , Humanos , Polpa Dentária/citologia , Polpa Dentária/metabolismo , Dentina/química , Dentina/metabolismo , Materiais Biocompatíveis/química , Células Cultivadas , Sobrevivência Celular/efeitos dos fármacosRESUMO
Investigate the impact of antimicrobial photodynamic therapy (aPDT) using different photosensitizers (PSs) such as indocyanine green (IG), curcumin (CC), and methylene blue (MB), with or without intracanal application of calcium hydroxide (CH), on the push-out bond strength of glass-fiber posts (GFPs) to intraradicular dentin, the chemical composition of the root substrate, and the sealing of the adhesive interface across different thirds of intraradicular dentin. A total of 112 bovine teeth underwent biomechanical preparation and were divided into eight experimental groups (n = 14 each): Negative control with deionized water; positive control with deionized water + CH; IG group with indocyanine green and infrared laser; IG + CH group; CC group with curcumin and blue LED; CC + CH group; MB group with methylene blue and red laser; and MB + CH group. The push-out bond strength was measured using a universal testing machine (n = 8), and scanning electron microscopy characterized the fracture patterns. Energy dispersive spectroscopy (n = 3) analyzed the chemical composition of the dentin substrate, while fluorescence confocal microscopy (n = 3) assessed the adhesive interface sealing between the resin cement and root dentin. Data were analyzed using two-way repeated measures ANOVA and the Tukey test for push-out bond strength and chemical composition comparison, with the Kruskal-Wallis and Dunn's tests (α = 0.05) for adhesive interface sealing. Significant bond strength differences were noted across root thirds and experimental groups (P < .05), with the IG + CH group showing the highest cervical bond strength and the IG group the lowest. Apical bond strength was highest in the CC group but lower in the NC and PC groups. Mixed failures predominated, except in the MB + CH group, where adhesive failures prevailed. Elemental composition varied among groups treated with different PSs and CH (P < .05), but interface quality, tag formation, and penetration depth showed no significant differences (P > .05). Laser-activated 500 mg/L CC combined with CH emerged as a clinically relevant option for root canal decontamination before GFPs luting. aPDT with different PSs and root canal depth influenced the push-out bond strength of GFPs and the chemical composition of root dentin. Curcumin-mediated aPDT at 500 mg/L proved effective, enhancing bond strength and sealing while maintaining consistent dentin composition across depths.
Assuntos
Hidróxido de Cálcio , Dentina , Vidro , Azul de Metileno , Fotoquimioterapia , Fármacos Fotossensibilizantes , Fotoquimioterapia/métodos , Hidróxido de Cálcio/química , Hidróxido de Cálcio/farmacologia , Bovinos , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/química , Animais , Dentina/efeitos dos fármacos , Dentina/química , Azul de Metileno/química , Vidro/química , Técnicas In Vitro , Curcumina/química , Curcumina/farmacologia , Colagem Dentária/métodos , Verde de Indocianina/química , Técnica para Retentor Intrarradicular , Anti-Infecciosos/farmacologia , Anti-Infecciosos/química , Raiz Dentária/efeitos dos fármacos , Raiz Dentária/químicaRESUMO
OBJECTIVES: This cross-sectional study aimed to evaluate the occurrence of Streptococcus spp., Streptococcus mutans, its serotypes (c, e, f, and k), collagen-binding genes (cnm/cbm), and Candida albicans in medium deep (D2) and deep (D3) dentin carious lesions of permanent teeth. MATERIALS AND METHODS: Carious dentin was collected from D2 (n = 23) and D3 (n = 24) lesions in posterior teeth from 31 individuals. DNA was extracted and analyzed using polymerase chain reaction (PCR). RESULTS: Streptococcus spp. exhibited a high prevalence in both D2 and D3 lesions, with a 100% occurrence rate in D3. Although S. mutans was prevalent in both lesion types, serotype distribution highlighted differences in complexity. Serotype e was the most frequently detected in D2 samples. Serotype c was absent in D2 but present in 19.0% of D3; serotype k was exclusively found in multi-serotype D3 alongside f, c, and e. The cbm gene and undetermined serotypes were detected only in D3. Candida albicans was not found in any samples, regardless of lesion depth. CONCLUSION: Dentinal lesions exhibited a complex array of S. mutans serotypes, with a notable prevalence of the genus Streptococcus and an overall S. mutans prevalence of approximately 35%. Candida albicans was absent. In addition, a high diversity of serotypes was observed, including multiple and indeterminate serotypes, along with the presence of the collagen-binding cbm gene. CLINICAL RELEVANCE: The identification of diverse Streptococcus mutans serotypes and the cbm gene in carious dentin from permanent teeth offers insights into microbial factors potentially linked to dentinal caries lesions. Additionally, the absence of Candida albicans suggests a limited role in this context.
Assuntos
Candida albicans , Cárie Dentária , Reação em Cadeia da Polimerase , Sorotipagem , Streptococcus mutans , Cárie Dentária/microbiologia , Candida albicans/genética , Streptococcus mutans/genética , Humanos , Estudos Transversais , Feminino , Masculino , Adulto , Dentina/microbiologia , ColágenoRESUMO
The amount of residual dentin thickness and tooth position in the dental arch is crucial to determine whether an intraradicular post should be used. This study aimed to compare stress distribution on the root dentin of an endodontically treated tooth rehabilitated with CAD/CAM milled glass fiber posts (MP), cast metal posts (CMP), or prefabricated posts (PP) with or without ferrule support, using the finite element method. MATERIALS AND METHODS: A human upper central incisor was selected, scanned, and treated endodontically. The canal was then prepared for post-placement and scanned again for the fabrication of digital posts. The geometries of MP and CMP were based on the measurements made by digital scanning of the root canal. In contrast, the geometry of PP was determined by technical drawings provided by the manufacturer, taking into account the post-space preparation and the cement. Six digital models were established: MP1 with ferrule support, MP2 without ferrule support; CMP1 with ferrule support, CMP2 without ferrule support; PP1 with ferrule support, and PP2 without ferrule support. The simulation was performed using the finite element method. RESULTS: Oblique forces were identified as more relevant to the metallic element compared to vertical forces. The presence of a ferrule was considered a protective factor for the remaining tooth structure. When the ferrule was absent, stresses were more evenly distributed in MP compared to CMP and PP. Posts with a higher modulus of elasticity were associated with higher and unequal stresses in the root dentin, which could predispose the tooth to fractures. CONCLUSIONS: As for the restoration set as a whole, it can be concluded that stress distribution on the root dentin was more evenly distributed on the milled post than on the other posts when a ferrule was absent, and the oblique forces were more detrimental to the tooth structure than vertical forces and that ferrule support was a protective factor for the remaining tooth structure. CLINICAL SIGNIFICANCE: The results of the study provide valuable information on how different types of intraradicular posts and the presence of a ferrule affect the stress distribution in dentin. In the absence of a ferrule, milled and customized computer-aided design/computer-aided manufacturing (CAD/CAM) glass fiber posts can exhibit better fracture resistance and adhesion strength than prefabricated fiberglass posts and metal posts.
Assuntos
Dentina , Análise de Elementos Finitos , Técnica para Retentor Intrarradicular , Humanos , Análise do Estresse Dentário , Dente não Vital , Vidro , Desenho Assistido por Computador , Incisivo , Estresse MecânicoRESUMO
This study investigated the effects of nonthermal atmospheric pressure plasma (NAPP) application and dentin rehydration with water (REHY) on bond strength (BS) of adhesives. Three etch-and-rinse adhesives were tested: Scotchbond Multi-Purpose (SBM / water-based primer + adhesive resin), Gluma Bond Universal (GBU / single-bottle containing acetone as organic solvent) and Prime&Bond Universal (PBU / single-bottle containing propanol as organic solvent). Adhesives were applied: 1- to phosphoric acid-etched dentin (Control), 2- after NAPP application for 45 seconds to etched dentin or 3- after REHY with water (10 seconds) of plasma-treated etched dentin. BS was performed using human molars and microtensile test, in which specimens were tested after 24 hours or one year (n=6). BS data were analyzed by three-way mixed ANOVA and Bonferroni's test (α=0.05). The morphology of etched dentin (n=3) and the dentin-adhesive interfaces (n=3) were evaluated using SEM. NAPP and REHY did not increase the BS of GBU and PBU. The BS of SBM to etched dentin not treated with NAPP (Control) reduced significantly after one year. The PBU adhesive showed the highest bond strength to dentin when the adhesives tested were applied after REHY. Phosphoric acid demineralized dentin to a depth of 5 mm that allowed the adhesive penetration into the dentinal tubules, forming the resin tags. Interfacial structures were maintained after one year. Argon plasma treatment was not beneficial in increasing the dentin bond strength of adhesives to etched-dentin at 24 hours. However, rehydration after plasma application prevented the bond strength reduction for three-step adhesive after one year.
Assuntos
Argônio , Colagem Dentária , Dentina , Gases em Plasma , Humanos , Colagem Dentária/métodos , Gases em Plasma/química , Argônio/química , Resistência à Tração , Adesivos Dentinários/química , Teste de Materiais , Cimentos Dentários/química , Condicionamento Ácido do Dente , Água/química , Microscopia Eletrônica de Varredura , Cimentos de Resina/química , Ácidos Polimetacrílicos/química , Bis-Fenol A-Glicidil Metacrilato , Análise do Estresse Dentário , GlutaralRESUMO
The aim of this study was to verify the biomodifying action of 6.5% grape seed extract solutions, with different pH, when applied on dentin collagen. Dentin bars (1.7 mm x 6.0 mm x 0.5 mm) were demineralized for 5 hours in 10% phosphoric acid, and distributed into the following groups: acid solution (pH=4.42); neutral (pH=6.96); alkaline (pH=11.92) and distilled water (pH=6.75). Three-point flexural test (n=10) and mass variation (n=10) were assessed at different periods (baseline, after biomodification, 7 and 14 days of remineralizing solution storage). For qualitative analysis, similar dentin bars were prepared and analyzed using Fourier transform infrared spectroscopy (FT-IR) and Raman Spectroscopy (FT-Raman) before and after 1 hour of immersion in biomodifying solution with different pH. Data were subjected to Shapiro-Wilk normality tests, followed by two-way ANOVA for repeated measures and Tukey's post-test (p<0.05). Alkaline solution was effective in increasing the modulus of elasticity, showing a decrease after 7 days and subsequent stabilization after 14 days of storage. Acid solution group showed a greater increase in the modulus of elasticity immediately after biomodification, but it was not stable over storage. Regarding mass variation, only the acid solution showed an increase in mass after biomodification and 14 days of storage. In relation to FT-IR and FT-Raman, all solutions showed interaction with collagen at some level. Therefore, pH of the solution directly influences the action of the grape seed extract, with satisfactory results being found in both acidic and alkaline solutions.
Assuntos
Colágeno , Dentina , Extrato de Sementes de Uva , Análise Espectral Raman , Concentração de Íons de Hidrogênio , Extrato de Sementes de Uva/farmacologia , Extrato de Sementes de Uva/química , Dentina/efeitos dos fármacos , Dentina/química , Espectroscopia de Infravermelho com Transformada de Fourier , HumanosRESUMO
OBJECTIVES: This study aimed to investigate cracked teeth and vertical root fracture observable on micro-CT images of extracted roots of mandibular incisors, after fiber post removal. MATERIALS AND METHODS: Thirty mandibular incisors were selected with any degree of slight incisal wear inspected with the aid of a stereomicroscope under 12x magnification, in order to have a group of young adult specimens according to the criteria of Hugoson et al. A sample of twelve mandibular incisors were selected, aged between 20 and 30 years old, with similar dentine volume and thickness. The specimens were scanned in a micro-computed tomography (micro-CT) device and submitted to root canal shaping, root canal filling, post space preparation, post placement and post removal. RESULTS: From a total of six experimental endodontic timepoints until post removal of 12 mandibular incisors, 64,800 cross-sectional images were analyzed and no vertical root fracture (VRF) or cracked tooth were detected. CONCLUSIONS: Micro-CT assessment after ex vivo fiber post removal did not detect vertical root fracture or cracked tooth formation in the root canal walls of mandibular incisors. CLINICAL RELEVANCE: This study highlighted that fiber post removal per se was not able to propagate VRF or cracked tooth formation or promoted any interruption of the integrity of human root dentin.
Assuntos
Incisivo , Técnica para Retentor Intrarradicular , Fraturas dos Dentes , Microtomografia por Raio-X , Humanos , Incisivo/lesões , Incisivo/diagnóstico por imagem , Fraturas dos Dentes/diagnóstico por imagem , Adulto , Raiz Dentária/diagnóstico por imagem , Raiz Dentária/lesões , Técnicas In Vitro , Mandíbula/diagnóstico por imagem , Dentina/diagnóstico por imagem , Dentina/lesões , Adulto Jovem , Síndrome de Dente Quebrado/diagnóstico por imagemRESUMO
This study compared the effects of different final irrigation protocols on the mechanical properties and structural integrity of root dentine. One-hundred eight teeth were instrumented and irrigated with sodium hypochlorite (NaOCl) using conventional irrigation (CI). Teeth were distributed into four groups based on final irrigation protocols: Control Group (CG): 17%EDTA/CI + H2O; G1: 2.5%NaOCl/Passive Ultrasonic Irrigation (PUI) + EDTA/PUI + NaOCl/PUI (60s each); G2: EDTA/PUI + NaOCl/PUI (30s each); G3: EDTA/PUI + NaOCl/PUI + H2O/PUI + CHX/PUI (30s each). Four tests were conducted: three-point flexural strength test, Scanning Electron Microscopy analysis, microhardness assessment, and the push-out bond strength (POBS) of the filling material to the root dentine. Data were analyzed using ANOVA and Tukey tests (Flexural strength), and Student t-test (Microhardness). Erosion scores and POBS were analyzed by Kruskal-Wallis and Dunn tests (α = 0.05). Results indicated no significant differences in flexural strength (p > 0.05) among groups. CG exhibited the lowest erosion scores in the cervical third. In the middle third, CG had lower scores than G1 and G2, while in the apical third, CG had lower scores than G1 (p < 0.05). Microhardness values decreased following the protocols (p < 0.05), except for the CG (p > 0.05). G2 displayed higher POBS values in the middle and apical thirds (p < 0.05). The protocols did not significantly influence the flexural strength of root dentine. However, they did affect microhardness and promoted greater erosion. The best results for POBS were observed when the final irrigation involved the sequential use of EDTA and NaOCl employing PUI for 30 seconds in each solution.
Assuntos
Dentina , Ácido Edético , Resistência à Flexão , Teste de Materiais , Microscopia Eletrônica de Varredura , Irrigantes do Canal Radicular , Preparo de Canal Radicular , Hipoclorito de Sódio , Dentina/efeitos dos fármacos , Dentina/química , Hipoclorito de Sódio/química , Irrigantes do Canal Radicular/química , Humanos , Ácido Edético/química , Estatísticas não Paramétricas , Análise de Variância , Preparo de Canal Radicular/métodos , Resistência à Flexão/efeitos dos fármacos , Valores de Referência , Reprodutibilidade dos Testes , Propriedades de Superfície/efeitos dos fármacos , Fatores de Tempo , Raiz Dentária/efeitos dos fármacos , Raiz Dentária/química , Testes de Dureza , Irrigação Terapêutica/métodos , Colagem Dentária/métodos , Erosão Dentária/prevenção & controle , Clorexidina/químicaRESUMO
This study evaluated conventional and alternative irrigation solutions combined with ultrasonic irrigant activation (UIA) against Fusobacterium nucleatum (F. nucleatum) and its endotoxin (LPS) in main root canal and dentinal tubules, using a new intratubular infection model. Seventy dentin cylinders were infected with F. nucleatum for seven days under anaerobic conditions and treated with 2.5% sodium hypochlorite (NaOCl), limewater + 2.5% NaOCl, and 10% ethanolic propolis extract (EEP), administered by syringe irrigation (SI) or UIA. Microbiological samples were collected before and after irrigation to determine CFU ml-1 and LPS levels. Confocal microscopy assessed bacterial membrane damage with Live/Dead staining. Irrigation solutions effectively reduced CFU ml-1. UIA caused greater damage to the bacterial membranes and reduced LPS levels. The ultrasonic activation of 10% EEP and limewater + 2.5% NaOCl were comparable to 2.5% NaOCl (p > 0.05). UIA improved the effectiveness of solutions, suggesting potential for alternative substances. Randomized clinical trials using these protocols are recommended.
Assuntos
Cavidade Pulpar , Endotoxinas , Fusobacterium nucleatum , Irrigantes do Canal Radicular , Fusobacterium nucleatum/efeitos dos fármacos , Irrigantes do Canal Radicular/farmacologia , Cavidade Pulpar/microbiologia , Hipoclorito de Sódio/farmacologia , Humanos , Própole/farmacologia , Ultrassom , Dentina/microbiologia , Infecções por Fusobacterium/tratamento farmacológico , Infecções por Fusobacterium/microbiologiaRESUMO
A promising approach for managing root caries is the use of cross-linking agents to stabilize collagen. However, despite testing various natural and synthetic agents in vitro, their efficacy remains uncertain. The aim of this review was to examine which cross-linking agent performs better in reducing root caries lesion depth and the release of hydroxyproline, which is a marker of collagen degradation. Studies evaluating the impact of cross-linking agents on dentin were included, while studies performed on enamel surface/cell cultures and studies evaluating collagenase inhibitors were excluded, among others. A comprehensive search covered eight databases, and study quality was assessed using the QUINN Tool for in vitro dental studies. Synthesis of the results was done using a Bayesian network meta-analysis to compare agents. Fifty studies involving 31 cross-linking agents were included for qualitative synthesis. The network meta-analysis for lesion depth involved 284 samples across 36 comparisons and ranked cross-linking agents in terms of their caries lesion depth-reducing effect (from best to worst): naringin > quercetin > riboflavin > proanthocyanidins > hesperidin > glutaraldehyde > cranberry > grape seed extract > untreated controls. Only naringin, quercetin, proanthocyanidins, and glutaraldehyde showed statistically significant efficacy over untreated controls. Cranberry extract excelled in reducing hydroxyproline release, followed by proanthocyanidins. In conclusion, proanthocyanidins positively affected both outcomes, suggesting they are prime candidates for translational research. Clinical studies are now essential to evaluate their real-world effectiveness against root caries. PROSPERO-CRD42023404911.
Assuntos
Reagentes de Ligações Cruzadas , Hidroxiprolina , Cárie Radicular , Hidroxiprolina/análise , Cárie Radicular/tratamento farmacológico , Humanos , Metanálise em Rede , Técnicas In Vitro , Dentina/efeitos dos fármacos , Flavanonas/farmacologia , Flavanonas/uso terapêutico , ColágenoRESUMO
No intuito de preservar a estrutura dentária, remanescentes de dentina afetada por cárie podem ser deixados após remoção do tecido cariado. O uso de soluções antimicrobianas é uma alternativa para reduzir ou eliminar bactérias após o preparo cavitário. Além disso, métodos de remoção de cárie, menos invasivos que o tradicional uso de brocas, vêm sendo desenvolvidos, tais como os com lasers de alta potência. No contexto de redução microbiana, tanto os lasers de alta potência (efeito fototérmico), quanto os lasers de baixa potência associados a fotossensibilizadores (terapia fotodinâmica antimicrobiana) podem ser utilizados. O objetivo deste estudo in vitro foi avaliar o uso dos lasers ou clorexidina na redução microbiana em lesões de cárie artificialmente desenvolvidas. Sessenta discos de dentina humana foram analisados de acordo com o tratamento da superfície (n=10): G1 - sem tratamento; G2 - digluconato de clorexidina a 2%; G3 - laser de alta potência Er:YAG (2,94 ?m) ; G4 - laser de alta potência Er,Cr:YSGG (2,78 ?m); G5 - aPDT 1 (laser de baixa potência 660 nm + azul de metileno a 0,01%); G6 - aPDT 2 (laser de baixa potência 660 nm + azul de metileno a 0,005%). A dentina afetada por cárie foi induzida por um modelo artificial desenvolvido com S. Mutans, com profundidade de lesão de aproximadamente 260 ?m. A dentina cariada foi coletada com auxílio de uma broca esférica Carbide estéril, antes e após os tratamentos propostos. Para padronização da coleta, foi feita a inserção de todo o diâmetro da ponta ativa broca (0,5 mm) no tecido dentinário. O desfecho primário foi a redução de bactérias, realizada pela contagem de unidades formadoras de colônia (UFC). Para comparar o desempenho dos tratamentos foi aplicado o teste de Kruskal Wallis, complementado pelo teste dms, para identificação das diferenças significativas, considerando nível de significância de 5%. De acordo com os resultados, houve redução microbiana para todos os grupos experimentais avaliados, porém, sem diferença estatística significativa entre eles (p=0,1133). Dessa forma, todos os tratamentos propostos foram eficazes na redução microbiana.
Assuntos
Dentina , LasersRESUMO
OBJECTIVE: Self-etching dental adhesives bond with dentin through chemical reactions with calcium. This study assessed bond strength (BS) using microtensile (µTBS) and microshear (µSBS) tests on sound and post-radiotherapy dentin, with dental adhesives containing different functional monomers. METHODS: Sound dentin (SD) and post-radiotherapy irradiated dentin (ID) were tested with two adhesive systems: Clearfil SE Bond (SE, 10-MDP-based) and FL Bond II (FL, containing carboxylic and phosphonic monomers with S-PRG bioactive particles). The tests occurred initially (24 h) and six months later; fracture mode was also analyzed (40x). Ninety-six human molars were randomly assigned (n = 12), and half were irradiated with a 70 Gy radiation dose. For µTBS test, teeth were bonded, restored and sectioned them into beams (0.64 mm2). The µSBS test used filled transparent cylindrical matrices with resin composite and light-cured them after dental adhesive applications. Three-way ANOVA and Tukey's test (p < 0.05) analyzed the data. RESULTS: µTBS showed a significant substrate x adhesive interaction (p < 0.001), while µSBS was significant for all factors (p = 0.006). SE and FL performed better on SD and ID, respectively, in the µTBS test. As for µSBS, SE showed higher values on ID (p < 0.05). Lower BS values occurred for SD-FL and ID-SE after six months. CONCLUSION: Dental adhesive performance varied based on substrate type and test method. FL was more stable for ID in µTBS, while SE excelled in µSBS. CLINICAL RELEVANCE: As post-radiotherapy irradiated dentin becomes more vulnerable, self-etching systems based on functional monomer and bioactive ingredients may exhibit appropriate bonding to this altered substrate.
Assuntos
Colagem Dentária , Análise do Estresse Dentário , Adesivos Dentinários , Teste de Materiais , Cimentos de Resina , Resistência à Tração , Humanos , Adesivos Dentinários/química , Adesivos Dentinários/efeitos da radiação , Cimentos de Resina/química , Cimentos de Resina/efeitos da radiação , Colagem Dentária/métodos , Técnicas In Vitro , Dentina/efeitos da radiação , Resistência ao Cisalhamento , Dente Molar , Propriedades de SuperfícieRESUMO
This study evaluated the effect of actives present in conventional and desensitizing mouth rinses on the control of dentin erosive tooth wear. Two hundred and seventy dentin specimens from human molars were prepared. The specimens were randomly allocated into 10 experimental groups (n=10): 4 corresponding to desensitizing mouth rinses, 4 to conventional mouth rinses, a negative control group (C-: distilled water), and a positive control group (C+: 500 ppm fluoride plus 800 ppm tin mouth rinse). Specimens were subjected to an erosion-abrasion cycling model: 5 min immersion in 0.3% citric acid and 60 min exposure to artificial saliva. This procedure was repeated 4x/day for 5 days. Immediately after the first and last erosive challenges, the specimens were brushed with a slurry of fluoride toothpaste for 15 s, with a total of 2 min exposure to the slurry. Afterward, the specimens were exposed to the mouth rinses. Dentin surface loss (SL, in µm) was determined by optical profilometry. Data were statistically analyzed by using Kruskal-Wallis and Dunn's tests (α=0.05). The only mouth rinses that presented significantly lower dentin SL than the C- was a desensitizing one containing sodium fluoride (220 ppm F-) with dipotassium oxalate (1.4%) and the C+ (p<0.001 and p=0.013, respectively), without significant differences between them (p>0.05). Dentin SL of the other groups did not significantly differ from the C- (p>0.05). The combination of sodium fluoride with dipotassium oxalate in a desensitizing mouth rinse showed a promising result against dentin erosive wear, matching the protection offered by a fluoride/tin mouth rinse.