Quality of life and stability of tooth color change at three months after dental bleaching.

PURPOSE: Intracoronary bleaching is a minimally invasive, alternative treatment that addresses aesthetic concerns related to non-vital teeth discoloration. However, to the best of our knowledge, no studies have assessed the psychosocial impacts of such procedures on patients' aesthetic perceptions. The aim of this study was to evaluate aesthetic perceptions and the psychosocial impact of patients up to 3 months after their teeth had been bleached with hydrogen peroxide (35%) and carbamide peroxide (37%) using the walking bleach technique. METHODS: The patients were randomly divided into two groups according to the bleaching agent used: G1 = hydrogen peroxide 35% (n = 25) and G2 = carbamide peroxide 37% (n = 25). Non-vital bleaching was performed in four sessions. Color was objectively (ΔE) and subjectively (ΔSGU) evaluated. Aesthetic perception and psychosocial factors were evaluated before, 1 week and 1 month after the bleaching using the Oral Health Impact Profile (OHIP) and Psychosocial Impact of Dental Aesthetics Questionnaire (PIDAQ) questionnaires. RESULTS: The color change (ΔE) values at 1 month were G1 = 16.80 ± 6.07 and G2 = 14.09 ± 4.83. These values remained stable until the third month after treatment (p > 0.05). There was a decrease in the values of OHIP-aesthetics and PIDAQ after treatment versus baseline (p < 0.05). This status was maintained through the third month after treatment. CONCLUSIONS: Both agents were highly effective and had a positive impact on the aesthetic perception and psychosocial impact of patients, values that also remained stable over time. Non-vital bleaching yields positive and stable impacts on aesthetic perception and psychosocial factors. ClinicalTrials.gov identifier NCT02718183.

Long-term Performance of Refurbished Amalgam Restorations: 10-year Follow-up.

PURPOSE: This prospective, blinded clinical trial assessed the performance of amalgam restorations that were refurbished, replaced, or not treated. MATERIALS AND METHODS: Twenty-three patients were included, ages 18-80 years, with 63 amalgam restorations that had one or more defects in their clinical features, such as defective anatomic form, roughness and/or luster according to United State Public Health Service (USPHS) criteria. Restorations were randomly assigned to either refurbishment (A: n = 21), replacement (B: n = 21) or untreated (C: n = 21) groups. Two calibrated examiners evaluated the restorations at baseline (Kappa = 0.74) and after 10 years (Kappa = 0.84), according to eight parameters: anatomy, roughness, luster, secondary caries, marginal adaptation, occlusal contact, marginal staining and tooth sensitivity. Wilcoxon tests were performed for within-group comparisons, and Friedman tests were used for multiple within-group comparisons. The Mantel-Cox test was used to compare survival curves. RESULTS: After 10 years, 49 restorations (77.8%) were assessed (group A: n = 19; group B: n = 13; group C: n = 17). Over a decade, the three groups showed similar clinical performances for all studied parameters: anatomy (p = 0.410), roughness (p = 0.930), luster (p = 0.984), secondary caries (p = 1.0), marginal adaptation (p = 0.433), occlusal contact (p = 0.33), marginal staining (p = 0.470), and tooth sensitivity (p = 0.784). CONCLUSIONS: Amalgam restorations that have defective anatomic form, roughness and/or luster performed similarly for all studied parameters, whether they were refurbished, replaced or left untreated after 10 years in patients with low and intermediate caries risk. Most of the restorations were classified as clinically acceptable after ten years. Restorations in all three groups tended to deteriorate over time.

Antimicrobial Activity of Amphiphilic Triazole-Linked Polymers Derived from Renewable Sources.

Conventional engineered polymers are strong, stable, and can interact desirably within the human body in implants and medical devices. However, bacterial colonization of medical devices and implants constructed from these materials results in numerous hospital acquired infections (HAI) and deaths each year. Polytriazole based plastics containing triazole rings and fatty acid derivatives have been synthesized from biological sources without catalysts or solvents. In this study, three amphiphilic polytriazoles with varying triazole density and hydrophilic/hydrophobic segments demonstrated broad spectrum, contact antimicrobial properties against both Gram positive and negative bacteria. SEM analysis of bacteria killed by these polymers evidence membrane damage, indicating that these polymers act by direct contact with bacterial membranes. Surface hydrophobicity of these polymers increased with increasing triazole group density, which also improved the antimicrobial efficacy. This work demonstrates that amphiphilic polytriazoles have antimicrobial properties and that future utilization of triazole modified polymers may produce self-sterilizing materials which resist bacterial contamination and formation of antibiotic resistant organisms, ideal characteristics for medically relevant biomaterials.

Does refurbishing composites lead to short-term effects or long-lasting improvement?

PURPOSE: To evaluate the clinical performance of refurbished resin composite restorations compared to untreated (negative control) restorations over a period of 10 years. METHODS: 26 subjects (having a total of 52 composite restorations) were recruited. All restorations in the refurbished group showed clinical features rated bravo according to modified USPHS criteria. Untreated restorations were those that had been deemed acceptable (alpha or bravo rated); these were used as controls. Two examiners performed assessments at baseline and during the 5th and 10th years after the intervention. Wilcoxon tests were performed for within-group comparisons, Friedman tests were used for multiple within-group comparisons, and Mann Whitney tests were used for between-groups comparisons. Kaplan-Meier survival curves were calculated, and the Mantel-Cox test was used to compare curves. P < 0.05 was considered statistically significant. RESULTS: In both groups, 10-year scores were significantly different from baseline scores in all clinical parameters except secondary caries. There were no statistically significant differences in the survival analysis of groups (log-rank test, P = 0.376). Refurbishing treatment improved the anatomy, roughness, luster, and marginal adaptation of restorations with a short-term effect, with most properties rated acceptable after 10 years of clinical service. The clinical characteristics were similar for all groups at the 10th year.

Rol del 10-metacriloxidecilfosfato dihidrogenado en el cambio de paradigma de los sistemas adhesivos integrados en la dentina / The Role of 10-methacryloyloxydecyl dihydrogen phosphate in the paradigm of change to adhesive systems integrated to dentin

La aplicación de adhesivos dentarios autograbantes que contienen 10-metacriloxidecilfosfato dihidrogenado supera la resistencia a la biodegradación de la interfase adhesiva de los sistemas tradicionales de grabado total. El mecanismo de acción se basa en la formación de múltiples nanocapas de calcio unido a 2 moléculas 10-metacriloxidecilfosfato dihidrogenado sobre la dentina; estas múltiples capas de 3,5 nm son las que protegerían las fibras colágenas del fenómeno de hidrólisis. Las nanocapas explicarían su alta estabilidad en el tiempo y la fortaleza de la unión, probadas tanto en estudios clínicos como de laboratorio. La interacción con la hidroxiapatita sucede con ácidos de pH bajos, pero mayores que los tradicionales, por lo que surge la necesidad de recomendar el grabado selectivo previo del esmalte. El uso de metacriloxidecilfosfato dihidrogenado permite el cambio de filosofía adhesiva desde el grabado total a la integración adhesiva de la dentina.

Applying self-etching dental adhesives containing 10-MDP overcomes the resistance to biodegradation of the adhesive interface of traditional total etch. The mechanism of action is based on the formation of multiple nano-layers of calcium and two molecules of 10-MDP on the dentin surface. These multiple layers of 3.5 nm protect the collagen fibers from hydrolysis phenomenon. The nano-layer explains its high stability and bond strength over time, tested both by clinical and laboratory studies. Hydroxyapatite interaction occurs with acids of low pH, but are higher than traditional, thus increasing the need to recommend the previous selective etching of the enamel. The use of MDP allows a change of philosophy from the total-etch adhesive to adhesive integration of the dentin.

Influence of type of bur and acid etching on dentin hydraulic conductance.

The aim of this study was to compare ex vivo filtration rate (hydraulic conductance) in human dentin discs mechanically treated with diamond and carbide burs of different grain size with or without acid etching. Method: 60 healthy third molars, recently extracted from patients aged 18-30 years, were cleaned, disinfected (0.1% thymol) and embedded in epoxy resin blocks. Dentin discs were obtained by cutting the occlusal surface with cylindrical rotary instruments, forming nine groups containing 12 specimens each: 1: fine grain (FG); 2: medium grain (MG); 3: coarse grain (CG); 4: carbide (C) burs; 5: FG with acid etching (AE); 6: MG with AE; 7: CG with AE; 8: C with AE; 9: only AE. Hydraulic conductance was determined in the experimental model under constant pressure of 200mm H2O. No difference in hydraulic conductance was observed among dentin discs treated with different types of burs (p = 0.5). Differences were found in the hydraulic conductance of etched and non-etched dentin discs (p < 0.001). The type of mechanical bur treatment does not affect dentin hydraulic conductance. Acid etching significantly increases dentin hydraulic conductance.

Influence of type of bur and acid etching on dentin hydraulic conductance. / Influence of type of bur and acid etching on dentin hydraulic conductance.

The aim of this study was to compare ex vivo filtration rate (hydraulic conductance) in human dentin discs mechanically treated with diamond and carbide burs of different grain size with or without acid etching. Method: 60 healthy third molars, recently extracted from patients aged 18-30 years, were cleaned, disinfected (0.1

thymol) and embedded in epoxy resin blocks. Dentin discs were obtained by cutting the occlusal surface with cylindrical rotary instruments, forming nine groups containing 12 specimens each: 1: fine grain (FG); 2: medium grain (MG); 3: coarse grain (CG); 4: carbide (C) burs; 5: FG with acid etching (AE); 6: MG with AE; 7: CG with AE; 8: C with AE; 9: only AE. Hydraulic conductance was determined in the experimental model under constant pressure of 200mm H2O. No difference in hydraulic conductance was observed among dentin discs treated with different types of burs (p = 0.5). Differences were found in the hydraulic conductance of etched and non-etched dentin discs (p < 0.001). The type of mechanical bur treatment does not affect dentin hydraulic conductance. Acid etching significantly increases dentin hydraulic conductance.