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Clinical Relevance Carious and eroded dentin represent clinical challenges. The use of a universal bonding system, in a self-etching mode, associated with chlorhexidine (CHX) seems to not improve its longevity. This may be attributed to the competition for calcium between the bonding agent functional monomer and CHX. SUMMARY Objectives: The purpose of this study was to explore the interaction between two calcium-dependent agents: 10-methacryloyloxydecyl-dihydrogen phosphate (MDP) and 2% chlorhexidine (CHX) digluconate in association with a self-etching universal bonding system. Methods and Materials: Flat dentin surfaces were obtained from 120 specimens (n=20/group) prepared from extracted sound human third molars and randomly divided into three groups according to the dentin substrate: sound ([S] control), artificial carious ([C] 6 h/demineralization + 18 h/remineralization for 5 days + 48 h/remineralization), and artificial eroded ([E] 3 cycles for 5 min/day for 5 days using orange juice). Before bonding procedures, one-half of the specimens from each group were pretreated with deionized water (W) and the other half with 2% chlorhexidine (CHX), forming six groups: S-W, S-CHX, C-W, C-CHX, E-W, and E-CHX. All specimens were restored with Adper Single Bond Universal (self-etching mode) and two increments of composite resin (Filtek Z-250), following the manufacturer’s instructions. Slices (0.8 mm) were obtained from the specimens and subjected to scanning electron microscopy (SEM) analysis and sticks (0.64 mm2) were obtained and subjected to a microtensile bond strength test (μTBS) in a universal testing machine (0.5 mm/min) after 24 hours and 6 months of storage. Failure modes were classified using optical microscopy (40×). Data was statistically analyzed by three-way ANOVA and Tukey tests (p Results: Substrate type was a statistically significant factor (p

The aim of this study was to explore the impact of the interaction between an MDP-based universal adhesive system in etch-and-rinse mode and two proteolytic inhibitors on the longevity of restorations bonded to artificially-affected-dentin substrates. 90 sound human third molars were randomly distributed into three groups according to the substrate: N-no challenges-control (stored in artificial saliva), ACD-artificial caries dentin (6 h DE + 18 h-RE/5 days + 48 h RE) and ERO-artificial erosion dentin (3 × 5 min/5 days with orange juice). They were further redistributed according to dentin pretreatment: W- water (control), CHX-2% digluconate chlorhexidine and E64- 5 μM E64-Trans-Epoxysuccinyl-L-Leucylamido-(4-guanidino) butane, which resulted in the following 9 groups (n = 10): N–W, N-CHX, N-E64, ACD-W, ACD-CHX, ACD-E64, ERO-W, ERO-CHX and ERO-E64. All specimens were restored with Adper Single Bond Universal (Etch-and-rinse mode)/Filtek Z250. Sticks (0.64 mm2) were obtained and subjected to microtensile test (μTBS) in a universal testing machine at 0.5 mm/min for 7-days, 6 and 18-month analyses. Failure modes were classified using optical microscopy (40X). Data were statistically analyzed by three-way ANOVA and Tukey tests (p

The incorporation of functional monomers and proteolytic inhibitors into adhesive systems have shown to be promising strategies to improve the longevity of adhesive restorations. The aim of this study was to evaluate the long-term bonding performance and anti-gelatinolytic effect of a 10-MDP-based universal adhesive system applied in combination with 2% chlorhexidine digluconate (CHX). For that, this study assessed the resin-dentin bond strength and the in situ gelatinolytic activity profile at the adhesive interface at initial and after 6 month of storage. One hundred and two sound human third molars were prepared and randomly divided into 3 groups according to the adhesive strategy: SB (two-step etch-and-rinse adhesive, Adper Single Bond 2, 10-MDP-free control group); SU-ER (Adper Single Bond Universal, 10-MDP containing universal adhesive applied on etch-and-rinse mode); and SU-SE (SU applied on self-etching mode). The groups were subdivided into two according to the dentin pretreatment: W - water or CHX- 2% chlorhexidine digluconate aqueous solution (SB-W; SB-CHX; SU-ER-W; SU-ER-CHX; SU-SE-W; SU-SE-CHX) and subsequently restored according to the manufacturer's instructions. Bond strength (n = 12) was assessed by a microtensile test (μTBS) (500N/0.5 mm/min) after 24h or after 6 months of storage. In situ zymography was performed to evaluate anti-gelatinolytic activity (n = 5). Resin-dentin samples were incubated with fluorescein-conjugated gelatin for 24 h at 37 °C and analyzed by confocal laser scanning microscopy. Fluorescence indicating gelatinolytic activity at hybrid layer zone and adjacencies was quantified using Image J. Data was analyzed by three-way ANOVA and Tukey post-hoc tests (p 0.05). Results: SU-SE showed the highest bond strength values, while similar results were observed for SU-ER and SB. No statistical significant differences were observed between pretreatment (CHX vs. W) or storage time (initial vs. 6 months of aging). For in situ zymography, fluorescence was detected in all groups and CHX pre-treatment was able to inhibit the gelatinolytic activity in all conditions. The 10-MDP-based universal adhesive system in self-etching mode was the strategy that showed the best bonding performance irrespective of its combination with chlorhexidine. Pre-treatment with CHX did not impair the bond strength when used in combination with 10-MDP and it may promote collagen stability overtime.

Clinical Relevance This article presents the dental restoration of a young female patient complaining of erosive dental wear using a three-step restorative technique, an alternative approach with some novel adjustments. SUMMARY For successful tooth wear treatment, determining the etiological systemic and local factors is the main priority before deciding on effective and long-term preventive and/or therapeutic restorative approaches. In addition to professional intervention, achieving optimal outcomes requires patients to control their diet and/or gastric issues, thus minimizing the wear process. However, continuous wear constitutes the most challenging scenario, mainly when it affects young patients’ dentitions. This article describes the dental restoration of posterior teeth with reestablishment of occlusal vertical dimension before treating the anterior teeth, while educating the patient and providing medical monitoring. The three-step restorative technique seems to be properly applicable in cases of significant dental compromise due mainly to erosive wear and is based on direct procedures, which can assure a reliable and feasible approach.

Objectives Enzyme inhibitors minimize the degradation of unprotected collagen of dentin promoted by matrix metalloproteinases (MMPs) and cysteine cathepsins (CCs). As the evidence of their effect on the root canal is limited, this study aimed to evaluate the role of EDTA, chlorhexidine and E-64 as antiproteolytic agents on the bond strength (BS) of glass-fiber posts in root canals. Materials and methods Ninety-six bovine roots were distributed in groups for each time point (n = 8). Adper Scotchbond Multipurpose (MP)/ RelyX ARC system was used to lute the post according to the treatment: negative control (NC)- water, EDTA- 17% ethylenediaminetetraacetic acid, CHX- 2% digluconate chlorhexidine, E-64-5- 5 μM E-64, E-64-10- 10 μM E-64 and positive control (PC)- MP associated with activator/ catalyst. Then, slices were subjected to push-out test (0.5 mm/min) after 24 h/6 mons. Data were analyzed by three-way ANOVA/Tukey tests. Failure modes were analyzed (40×). Results The factors treatment, time, root canal third and the interaction between treatment and time were statistically significant. At 24 h, no negative interactions were observed among the root dentin, bonding system and post. At 6 mons, CHX improved the BS for middle and apical root thirds. Conclusions CHX was able to promote beneficial BS after 6 mons, which was not noted for any other tested enzyme inhibitors.

Objectives Because of its ability to act as an antiproteolytic agent, the effect of sodium trimetaphosphate (STMP) against specific enzymes extracted from sound dentin and its performance under acidic challenge on demineralized dentin were investigated. Methods The antiproteolytic potential of STMP (0.5%, 1.0%, and 1.5%) was assessed in triplicate by zymography. For the evaluation of remineralization activity, 50 bovine-root dentin specimens were selected and randomly divided into 5 groups (n = 10). Three areas were determined for each specimen: 1) control (no treatment); 2) demineralized (artificial caries-like challenge); 3) treated (demineralized and subjected to pH-cycling for 7 days, and treated for 10 min with 1.5% STMP, 1.5% STMP + calcium hydroxide (Ca[OH]2), 1.5% STMP + sodium fluoride (NaF), NaF, or deionized H2O). The dentin specimens were analyzed for superficial hardness (SH) and cross-sectional hardness (CSH) at different depths (10, 30, 50, 70, 90, 110, and 220 μm) using a Knoop penetrator (10 g/10 s). Statistical analyses were performed with analysis of variance (ANOVA) and Tukey tests (p Results The zymographic analysis showed that 1.5% STMP promoted complete inhibition of gelatinolytic activity. Therefore, 1.5% STMP was investigated in association with supplemented calcium or fluoride; a combination of 1.5% STMP and Ca(OH)2 significantly increased the mechanical properties of the treated dentin. Conclusion 1.5% STMP serves as an antiproteolytic agent against matrix metalloproteinases extracted from human dentin. Furthermore, when supplemented with Ca(OH)2, 1.5% STMP may potentially induce remineralization. Clinical significance STMP can be introduced as a novel strategy that combines enzymatic inhibition and remineralizing potential, which can serve to strengthen dentin and improve stability. STMP may have potential in the treatment of demineralized dentin lesions, especially when supplemented with calcium.

Rhodamine B (RB) is commonly used to evaluate dental polymers, including dental bonding systems (DBS). For reliability assessments, its effect should not only allow visualization of the dentin-polymer interface but also must not interfere with the bonding of the DBS to dentin as measured by the microtensile bond strength and hardness tests.Flat human dentin surfaces were prepared and randomly distributed (n = 10) into six groups: Adper Scotchbond Multi-Purpose (MP) or Clearfil SE Bond (SE) in concentrations of none/control, 0.02 or 0.1 mg/mL. These combinations were prepared through ethanol dissolution to improve their penetration into the dentin. All specimens were fabricated with Filtek Z250 (n = 10) and prepared for a microtensile bond test (μTBS) (0.5 mm/min) after 7 days and 6 months. The failure modes were determined using a stereomicroscope (×40). For the hardness test, flat human dentin blocks were prepared and treated as previously described (n = 6). The specimens were stored at 37 °C/48 h and were tested (Knoop indenter - 25 gF/10 s). Data were analyzed with two-way ANOVA and Tukey tests for multiple comparisons (α = 0.05). The effect of time was evaluated using the Student t-test.For 7-day μTBS, both the DBS and RB concentrations were significant factors (p 0.01). After 6 months, only the RB concentration was significantly different. Adhesive failures were prevalent for all groups. Regarding hardness, the DBS differed only with the use of 0.10 mg/mL of RB.Ethanol-dissolved rhodamine B in concentrations of 0.02 and 0.10 mg/mL in non-simplified adhesives can affect the physical-mechanical properties of functional monomer-based systems rather more than those of BisGMA systems.

SUMMARY Objectives: The aim of this study was to evaluate the effect of proteolytic inhibitors on the bond strength of a universal adhesive system (etch-and-rinse mode) applied to artificial carious and eroded dentin. Methods: Ninety molars were prepared and randomly divided into three groups according to the substrate: N, no challenges; ACD, artificial carious dentin simulation and ERO, artificial erosion simulation with orange juice. All groups were redivided into three subgroups according to the dentin pretreatment: W, water; CHX, 2% digluconate chlorhexidine; and E-64 (trans-epoxysuccinyl-L-leucylamido-[4-guanidino] butane), 5 μM E-64 inhibitor. They constituted a total of nine groups (n=10): N-W, N-CHX, N-E64, ACD-W, ACD-CHX, ACD-E64, ERO-W, ERO-CHX, and ERO-E64. All specimens were restored with Adper Single Bond Universal/Filtek Z250. Beams (0.64 mm2) were obtained and subjected to the microtensile test (μTBS) in a universal testing machine at 0.5 mm/min. The failure mode of the interfaces was determined by optical microscopy (40× magnification). Data were statistically analyzed by three-way analysis of variance and Tukey tests (p

The effect of sodium trimetaphosphate (STMP) as an antiproteolytic and remineralizing agent on demineralized dentin was evaluated in vitro. The inhibitory potential of STMP at 0.5, 1.5, 3.5, and 5% against recombinant matrix metalloproteinases (MMPs) MMPs-2 and -9 was assessed by zymography. To investigate its remineralization potential, 40 bovine root specimens were obtained and subjected to a demineralization protocol to produce caries-like dentin lesions. After that, dentin surfaces were divided into 3 areas: (1) mineralized (no treatment); (2) demineralized; and (3) demineralized/treated with STMP and submitted to a pH-cycling associated or not with STMP (1.5, 3.5, or 5% STMP, 10 min of treatment). After that, superficial hardness (SH) and cross-sectional hardness (CSH) were determined. Polarized light microscopy (PLM) was used to qualitatively evaluate mineralization within the caries-like lesions. The zymographic analysis showed that STMP solution is a potent inhibitor of the gelatinolytic activity of MMPs-2 and -9 depending on the dose, since the lowest concentration (0.5%) partially inhibited the enzyme activity, while the higher concentrations completely inhibited enzyme activity. Regarding remineralization effect, only 1.5% STMP solution enhanced both the SH and CSH. PLM showed that the area treated with 1.5% STMP presented similar birefringence as mineralized sound dentin. In conclusion, 1.5% STMP solution is effective as an antiproteolytic agent against MMPs and promotes dentin remineralization.

This study evaluated the impact of orange juice on the bond strength (BS) of dentin bonding systems (DBSs) to enamel surface after simulation with an in situ/ ex vivo erosive cycling. One hundred and ninety two bovine enamel fragments (4x4x2mm) were obtained and randomized regarding superficial microhardness and distributed to palatal devices for 8 volunteers, in three phases (one for each DBS), containing 8 blocks, which were, allocated in 4 pairs. Daily, these pairs were subjected extraorally to the following conditions: CONT- neither erosive nor abrasive challenge; ERO- erosive challenge only; ABR- abrasive challenge only and ERO + ABR- with erosive and abrasive challenges. Erosive cycles (immersion in orange juice, 3 times/day/5 min/5 days) or/and abrasive challenges (electric toothbrush, 3 times/day/1 min/5 days) were performed. After these cycles, all specimens were restored with the adhesive systems Adper Scotchbond Multi Purpose (MP), Adper Single Bond 2 (SB) or Clearfil SE Bond (SE), and the composite resin Filtek Z250. After 7 days, sticks (area ≅1 mm2) were obtained and subjected to the microtensile bond strength test (μTBS) at 0.5 mm/min. Data was statistically analyzed by ANOVA and Tukey tests (a=0.05). Failure modes were determined using a digital microscope (40´). DBS was the only statistical significant factor. SE was the unique DBS not affected in any challenge, whereas MP and SB performed according to the scenario. The adhesive and mixed failures were predominant in all groups. Overall performance suggested that BS to enamel after erosive /abrasive challenged by orange juice was not affected and it was material-dependent. Resumo Este estudo avaliou o impacto de suco de laranja na resistência de união (RU) de sistemas adesivos dentinários (SAD) à superfície do esmalte após a simulação com uma ciclagem erosiva in situ/ex vivo. Cento e noventa e dois fragmentos de esmalte bovino (4x4x2mm) foram obtidos e randomizados considerando a microdureza superficial, e distribuídos em dispositivos palatinos para 8 voluntários, em três fases (uma para cada SAD), contendo 8 blocos, os quais foram alocados em 4 pares. Diariamente, esses pares eram submetidos às seguintes condições extraoralmente: CONT- sem desafio erosivo ou abrasivo; ERO- desafio erosivo somente; ABR- desafio abrasivo somente; e ERO+ABR- com desafio erosivo e abrasivo. A ciclagem erosiva (imersão em suco de laranja, 3 vezes/dia/5 min/5 dias) e/ou ciclagem abrasiva (escova dentária elétrica, 3 vezes/dia/1 min/5 dias) foram feitas. Após estas ciclagens, todos os espécimes foram restaurados com os sistemas adesivos Adper Scotchbond Multi Purpose (MP), Adper Single Bond 2 (SB) ou Clearfil SE Bond (SE), e com a resina composta Filtek Z250. Após 7 dias, palitos (área ≈1 mm) eram obtidos e submetidos ao teste de resistência de união por microtração (μTBS) a 0,5 mm/min. Os dados foram estatisticamente analisados por ANOVA e teste de Tukey (a=0,05). Os modos de fratura foram determinados utilizando um microscópio digital (40×). SAD foi o único fator estatisticamente significante. SE foi o único SAD não afetado por qualquer desafio, enquanto o MP e o SB apresentaram um desempenho de acordo com o cenário. As fraturas do tipo mista e adesiva foram predominantes em todos os grupos. O desempenho geral sugeriu que RU ao esmalte após desafio erosivo/abrasivo por suco de laranja não foi afetada e foi material-dependente.