Peptide-assisted pre-bonding remineralization of dentin to improve bonding.

Bonding with dentin is a complex process involving physical and chemical adhesion where the adhesive must be able to penetrate and envelop collagen fibers. Acid etching clears the dentin of debris, which prevents adhesives to interact with dentin. However, it also demineralizes the outermost surface of dentin and exposes collagen fibers. The mineral-free collagen is susceptible to collapse after drying and to proteolytic or microbial attack, ultimately impairing the bonding with dentin. To address this, we have attempted a pre-bonding rapid remineralization approach to recover the mineral content of etched dentin. We have used a mineralization-promoting peptide and high calcium/phosphate concentration to achieve this in a clinically applicable timeframe. Partial remineralization was confirmed via SEM and XRD analyses. The mechanical properties and the stability of the partially remineralized dentin were investigated via microhardness, collagen hydrolysis and shrinkage tests. The bonding properties were investigated via shear bond strength (SBS) and microleakage tests. Pre-bonding remineralization of dentin with peptide for 10 min significantly increased the stiffness, resistance to hydrolysis and reduced shrinkage due to drying. SBS was increased with both an etch&rinse and a self-etch adhesive. However, pre-bonding remineralization resulted in reduced microleakage only with the etch&rinse adhesive. The described method is readily applicable to clinic since it is expected to add only 10 min to the procedure. Future in situ and/or in vivo studies will help to confirm the benefits observed in this in vitro study and allow optimize the parameters of the method.

Evaluation of different Apexification treatments of teeth with immature apices and apical periodontitis on the fractal dimensions of trabecular bone.

The aim of the present study was to investigate in the fractal dimension (FD) time-dependent changes of periapical bone after two different apexification treatments in teeth with immature apices and apical periodontitis. This study included 55 cases treated with apexification. Cases were divided into two groups: a calcium hydroxide group and a mineral trioxide aggregate group. In each case, the lesion area was evaluated by fractal analysis on periapical radiographs obtained before and 1-year after treatment via Image-J program. The FD of each region of interest on the radiographs was calculated using the fractal analysis method. The data were statistically analysed. In both groups, the FD values increased compare to initial at 1-year follow-up after treatment (P < .05). There was no statistically significant difference between the groups in terms of the time-dependent increase in FD values (P = 0.118). In the present study, time-dependent changes in FD were independent of the apexification method.

In vitro remineralization of primary teeth with a mineralization-promoting peptide containing dental varnish.

Mineralization-promoting peptides are attractive candidates for new remineralization systems. In previous studies, peptides have been applied as aqueous solutions, which is not a clinically relevant form. OBJECTIVE: This study aims to investigate the efficiency of a mineralization-promoting peptide, applied in varnish, on remineralizing artificial caries on primary teeth. METHODOLOGY: 55 primary molars were collected. Specimens were immersed in a demineralizing solution for 7 days and then, divided into 7 groups: Baseline: No-remineralization, Placebo: Blank colophony, F: Colophony 5% fluoride, P: Colophony 10% peptide, P+F: Colophony 5% fluoride and 10% peptide, Embrace: Embrace™ varnish, Durashield: Durashield™ varnish. A mixture of 35% w/v colophony varnishes were prepared in ethanol and applied accordingly. Specimens were immersed in a remineralization solution for 4 weeks and it was evaluated using PLM and SEM. Lesion depth reduction was examined by one-way ANOVA. RESULTS: There was no significant difference in mean lesion depths between baseline (147.04 ± 10.18 µm) and placebo groups (139.73 ± 14.92 µm), between F (120.95 ± 12.23 µm) and Durashield (113.47 ± 14.36 µm) groups and between P (81.79 ± 23.15 µm) and Embrace (90.26 ± 17.72 µm) groups. Lesion depth for the P+F group (66.95±10.59 µm) was significantly higher compared to all other groups. All groups contained samples with subsurface demineralized regions. Number of subsurface demineralized regions were higher in fluoride-containing groups. CONCLUSIONS: We conclude that the mineralization-promoting peptide (MPP3) is effective in this in vitro study and the peptide shows benefits over fluoride as it yields less subsurface demineralized regions.

Accelerated Calcium Phosphate Mineralization by Peptides with Adjacent Oppositely Charged Residues.

Calcium phosphate mineralizing peptides are of special importance for dental and orthopedic applications, such as caries remineralization and improved osteointegration. Uncovering the mechanism of action for such peptides is an ongoing challenge with the aim of a better fundamental understanding of biomineralization processes and developing optimized peptides for clinical use. It has recently been reported that "adjacent oppositely charged residue" motifs are found abundantly in cation binding, inorganic surface binding, or biomineralization-related proteins and may play a key role in the biomineralization events. Despite their medical importance, the role of these motifs has not yet been investigated on calcium phosphate mineral systems. To investigate this, we have designed peptides with different structural properties and different numbers of adjacent oppositely charged residues. We have evaluated their effects on in vitro calcium phosphate mineralization kinetics and mineral properties. The kinetics of the mineralization increased proportionally with an increasing number of adjacent oppositely charged residues. Two peptides with relatively high structural stability and two adjacent oppositely charged residues resulted in faster mineralization and more crystalline mineral compared to a peptide with a higher structural degree of freedom that contained only acidic residues. The fastest mineralization and the highest mineral crystallinity were obtained with a peptide containing the highest number of adjacent oppositely charged residues and highest structural degree of freedom. Our findings and observations from previously identified natural or designed peptides indicate that, in addition to structural instability, adjacent oppositely charged residues play a role in the cation binding, inorganic surface binding, and biomineralization of peptides and require further investigation. Lastly, the peptide identified in this study is an agent with potential medical applications involving the treatment of mineralized tissues.

In vitro remineralization of primary teeth with a mineralization-promoting peptide containing dental varnish

Abstract Mineralization-promoting peptides are attractive candidates for new remineralization systems. In previous studies, peptides have been applied as aqueous solutions, which is not a clinically relevant form. Objective This study aims to investigate the efficiency of a mineralization-promoting peptide, applied in varnish, on remineralizing artificial caries on primary teeth. Methodology 55 primary molars were collected. Specimens were immersed in a demineralizing solution for 7 days and then, divided into 7 groups: Baseline: No-remineralization, Placebo: Blank colophony, F: Colophony 5% fluoride, P: Colophony 10% peptide, P+F: Colophony 5% fluoride and 10% peptide, Embrace: Embrace™ varnish, Durashield: Durashield™ varnish. A mixture of 35% w/v colophony varnishes were prepared in ethanol and applied accordingly. Specimens were immersed in a remineralization solution for 4 weeks and it was evaluated using PLM and SEM. Lesion depth reduction was examined by one-way ANOVA. Results There was no significant difference in mean lesion depths between baseline (147.04 ± 10.18 µm) and placebo groups (139.73 ± 14.92 µm), between F (120.95 ± 12.23 µm) and Durashield (113.47 ± 14.36 µm) groups and between P (81.79 ± 23.15 µm) and Embrace (90.26 ± 17.72 µm) groups. Lesion depth for the P+F group (66.95±10.59 µm) was significantly higher compared to all other groups. All groups contained samples with subsurface demineralized regions. Number of subsurface demineralized regions were higher in fluoride-containing groups. Conclusions We conclude that the mineralization-promoting peptide (MPP3) is effective in this in vitro study and the peptide shows benefits over fluoride as it yields less subsurface demineralized regions.

Knowledge of general dentists, endodontists and pediatric dentists about the management on dental traumas: a survey in turkey / Conhecimento de dentistas clínicos-gerais, endodontistas e pediatras sobre o manejo de traumas dentários: uma pesquisa na Turquia

Objective: The purpose of this study was to determine endodontists, pedodontists and general dentists' knowledge of management of dental trauma. Material and methods: A web-based survey including 13 questions was prepared using Google forms, and a link to the survey was sent to the general dentists, endodontists and paediatric dentists via social media. The questionnaire asked for information regarding the age, gender, state of education, type of institution and knowledge levels about dental traumas. A total of 258 questionnaires were returned, and the One-Way Anova for practitioners' knowledge and the statistical analysis of the relationship between gender, vocational training and training by using Mann-Whitney U tests for participants. Results: As a result of statistical analysis, although there was no statistical difference between pedodontists and endodontists in their knowledge levels, it was found that both occupational groups had higher knowledge level than general dentists (p = 0,0001). While there was a significant difference between practitioners at university and oral and dental health hospital (p = 0.0001), there was no difference between practitioners in university hospital and private office (p = 0.065). Conclusions:In conclusion, general dentists had knowledge of inadequate dental trauma management and the knowledge level of dentists working at oral and dental hospital was lowe (AU)

Objetivo: O objetivo deste estudo foi determinar o conhecimento de dentistas clínicos gerais endodontistas, odontopediatras sobre o tratamento de traumatismos dentários. Material e métodos: Uma pesquisa na Web, incluindo 13 perguntas, foi preparada utilizando os formulários do Google. Um link para a pesquisa foi enviado aos dentistas clínicos gerais, endodontistas e odontopediatras via mídia social. O questionário solicitou informações sobre idade, sexo, estado da educação, tipo de instituição e níveis de conhecimento sobre traumas dentários. Um total de 258 questionários foram devolvidos e o One-way ANOVA foi utilizado para avaliar o conhecimento dos profissionais e a análise estatística da relação entre gênero, treinamento vocacional e treinamento foi realizada utilizando o teste de Mann-Whitney. Resultados: como resultado da análise estatística, embora não tenha havido diferença estatística entre pediatra e endodontista em seus níveis de conhecimento, verificou-se que ambos os grupos ocupacionais apresentaram maior nível de conhecimento que os dentistas em geral (p = 0,0001). Embora tenha havido uma diferença significativa entre os profissionais da universidade e o hospital de saúde bucal e odontológico (p = 0,0001), não houve diferença entre os profissionais do hospital universitário e consultório particular (p = 0,065). Conclusões: Em conclusão, os dentistas clíncos-gerais tinham conhecimento de tratamento inadequado do traumatismo dentário e o nível de conhecimento dos dentistas que trabalhavam nos hospitais odontológicos era menor. (AU)

Efficacy of different remineralization agents on treating incipient enamel lesions of primary and permanent teeth.

AIMS AND OBJECTIVES: The aim of this study was to compare the in vitro efficacy of different remineralization (RM) agents on RM of artificial caries by evaluating the density, light reflection, and the crystal size of the newly formed mineral in primary and permanent teeth. MATERIALS AND METHODS: Caries-free primary and permanent molars were divided into seven groups (n = 20) and treated with: G1 - Deionized water, G2 - Colgate Cavity Protection, G3 - Sensodyne Rapid Relief, G4 - GC MI Paste Plus, G5 - Clinpro Tooth Creme, G6 - Clinpro 5000, and G7 - Sensodyne Repair and Protect. Lesion depths were evaluated using laser fluorescence (DIAGNOdent), and polarized light microscopy (PLM), and the minerals were evaluated using X-ray diffractometry (XRD). RESULTS: The highest decrease in laser fluorescence readings was observed in G6 for both primary and permanent teeth. No significant difference was observed between G2, G4, G5, and G6 in permanent teeth and G4 and G6 in primary teeth (P > 0.05). In PLM analyses, lesions depths were found to be lower in G6 compared to the other groups. No significant difference was observed between G2, G4, and G6 (P < 0.05). XRD evaluation showed that the newly formed mineral in G6 was denser and highly crystallized compared to the other groups. CONCLUSION: This in vitro study demonstrated that Clinpro 5000 is more efficient in remineralizing incipient enamel lesions compared to the other agents tested.

Evaluation of wettability characteristics and adhesion of resin composite to photo-polymerized pulp-capping materials with and without bioactive glass / Avaliação das características de molhabilidade e adesão da resina composta aos materiais fotopolimerizáveis com e sem vidro bioativo

Objective: This study evaluated the wettability and adhesive properties of three different photopolymerized resin-based pulp-capping materials with or without bioactive glass (BAG). Material and Methods: Cylindrical specimens (5 per group) were prepared from photo-polymerized pulp-capping materials (TER-TheraCal LC, BIN-Biner LC, and CAL-CalciPlus LC containing BAG). After surface finishing, contact angle measurements were made (θ)using the sessile drop method and surface free energy was calculated. For shear test, cylindrical acrylic blocks (N = 30) (diameter: 6 mm; height: 1 m) in the center were filled with the pulp-capping materials (N = 10 per group) flattened using a metal spatula and photo-polymerized. The specimens were stored at 37 °C in 100% humidity for 24 h prior to the bonding procedures. An adhesive system (CLEARFIL SE BOND, Kuraray) was applied on the material surfaces and photo-polymerized for 20 s. Then, resin composite material (Filtek Z250, 3M ESPE) was bonded on the substrate materials using translucent plastic molds (internal diameter: 2 mm; height: 2 mm). The specimens were photopolymerized with an LED photo-polymerization unit for 20 s. After polymerization, the specimens were stored at 37 °C, at 100% humidity for 24 h. Shear force was applied at the pulp-capping material and the resin composite interface In a universal testing machine (1 mm/min).Data were analyzed using 1-way ANOVA and Tukey`s tests at the significance level of 0.05. Results: Contact angle values showed significant difference between the 3 materials with group CAL presenting the lowest (35.35 ± 12.89) and group BIN the highest values (74.77 ± 13.56) (p < 0.05). Significantly lower surface energy was observed with BIN (36.22) (p 0.05). Group BIN (9.12 ± 3.45) showed significantly lower (p < 0.05) mean bond strength than those of TER (11.56 ± 5.67) and CAL (12.66 ± 4.34) (p > 0.05). Most of the observed modes of failures in all groups were of mixed type of failures. Conclusion: The bioglass used in Calciplus LC did not adversely affect the wettability, surface energy and adhesive properties. (AU)

Objetivo: Este estudo avaliou as propriedades de molhabilidade e adesivas de três diferentes materiais capeadores pulpares fotopolimerizaveis à base de resina, com ou sem vidro bioativo (BAG). Material e Métodos: Amostras cilíndricas (5 por grupo) foram preparadas a partir de materiais capeadores pulpares fotopolimerizáveis (TER-TheraCal LC, BIN-Biner LC e CAL-CalciPlus LC contendo BAG). Após o acabamento da superfície, as medidas do ângulo de contato foram feitas (θ) usando o método de gota séssil e a energia livre da superfície foi calculada. Para o ensaio de cisalhamento, blocos de acrílico cilíndricos (N = 30) (diâmetro: 6 mm; altura: 1 m) foram preenchidos no centro com os materiais de capeamento pulpar (N = 10 por grupo) achatados usando uma espátula metálica e fotopolimerizados. Os espécimes foram armazenados a 37 ° C em 100% de umidade por 24 h antes dos procedimentos de colagem. Um sistema adesivo (CLEARFIL SE BOND, Kuraray) foi aplicado nas superfícies do material e fotopolimerizado por 20 segundos. Em seguida, o material de resina composta (Filtek Z250, 3M ESPE) foi colado nos materiais do substrato utilizando moldes de plástico translúcido (diâmetro interno: 2 mm; altura: 2 mm). Os espécimes foram fotopolimerizados com um dispositivo de fotopolimerização de LED por 20 s. Após a polimerização, os espécimes foram armazenados a 37 °C, a 100% de umidade por 24 h. A força de cisalhamento foi aplicada no material capeador e na interface da resina composta em uma máquina universal de ensaios (1 mm / min). Os dados foram analisados por meio do teste de ANOVA e teste de Tukey ao nível de significância de 0,05. Resultados: Os valores do ângulo de contato mostraram diferença significativa entre os 3 materiais com o grupo CAL apresentando os menores valores (35,35 ± 12,89) e o grupo BIN os maiores valores (74,77 ± 13,56) (p < 0,05). Uma energia de superfície significativamente menor foi observada com o BIN (36,22) (p 0,05). O grupo BIN (9,12 ± 3,45) apresentou resistência de união média significativamente menor (p 0,05). A maioria dos modos de falhas observados em todos os grupos eram de tipo misto de falhas. Conclusão: O biovidro utilizado no Calciplus LC não afetou negativamente a molhabilidade, energia superficial e propriedades adesivas. (AU)

Fracture Resistance of Incisal Fragments Following Reattachment With Different Techniques in Simulated Crown Fractures.

Introduction: The aim of the present study was to evaluate and compare the effect of acidetching and Er, Cr:YSGG laser treatment before the reattachment of incisal fragments in coronal fractures of permanent incisor teeth. Methods: Sixty-six sound human maxillary incisors were randomly divided into 3 groups (n=22). Teeth were embedded in self-cure acrylic resins by leaving one-third of the crowns out, and uncomplicated crown fractures were obtained using an Instron testing device. The fragments were reattached using 3 different procedures and a hybrid resin composite (Z250): Group I: Acid etching + Prime & Bond NT; Group II: Er,Cr:YSGG + Prime & Bond NT; Group III: Er,Cr:YSGG + Acid etching + Prime & Bond NT. The percentages of shear bond strengths were determined by comparing fracture strengths of sound and reattached teeth for 3 groups. All data were analyzed statistically with Kruskal-Wallis H test. Results: Mean fracture strengths of the reattached fragments were between 51.02% and 62.93% of that of the sound teeth in all groups. Group I had significantly higher percentages of shear bond strength values (P<0.05) when compared to group II and group III. No significant difference (P>0.05) was found between group II and group III. Conclusion: The findings of the present study show that Er,Cr:YSGG laser irradiation prior to the reattachment of incisal fragments has a negative effect on fracture strength.

Shear bond strength of different restorative materials to mineral trioxide aggregate and Biodentine.

SIGNIFICANCE OF STUDY: Mineral trioxide aggregate (MTA) and Biodentine (calcium silicate-based materials) have great importance in dentistry. There is no study comparing the bond strength of Biodentine and MTA for composite, compomer, and compomer or resin-modified glass ionomer (RMGIC). Although many advantages of Biodentine over MTA; in this study, MTA has shown better shear bond strength (SBS) to restorative materials. AIM: Recently, a variety of calcium silicate-based materials are often used for pulp capping, perforation repair, and endodontic therapies. After those treatment procedures, teeth are commonly restored with composite resin, (RMGIC materials in pediatric dentistry. The aim of this study was to evaluate the SBS of composite resin (Filtek™ Z250; 3M ESPE, USA), compomer (Dyract XP; LD Caulk/Dentsply, USA), and resin-modified glass ionomer (Photac-Fil Quick Aplicap; 3M ESPE, USA) to white MTA and Biodentine. MATERIALS AND METHODS: Ninety acrylic cylindrical blocks were prepared and divided into two groups (n = 45). The acrylic blocks were randomly allocated into 3 subgroups; Group-1A: MTA + composite (Filtek™ Z250), Group-1B: MTA + compomer (Dyract XP), Group-1C: MTA + RMGIC (Photac-Fil Quick Aplicap), Group-2A: Biodentine + composite, Group-2B: Biodentine + compomer, Group-2C: Biodentine + RMGIC. The specimens were mounted in Universal Testing Machine. A crosshead speed 1 mm/min was applied to each specimen using a knife-edge blade until the bond between the MTA/Biodentine and restorative material failed. Failure modes of each group were evaluated under polarized light microscope at ×40 magnification. RESULTS: There was no statistically significant difference between MTA + Composite resin with MTA + Compomer; and MTA + RMGIC with Biodentine + RMGIC (P > 0.05). There were statistically significant differences between other groups (P < 0.05). CONCLUSIONS: The results of the present study displayed that although many advantages of Biodentine over MTA; MTA has shown better SBS to compomer and composite resin materials than Biodentine.