Biological effects of new chemical-mechanical caries removal products on human dental pulp stem cells.

AIM: The aim of this study was to compare the biological effects of four chemical caries removal materials and to assess their cytotoxicity using human dental pulp stem cells (hDPSCs). METHODS: The products evaluated are: 1 - Papain based product (BRIX 3000®); 2 - Papain/chloramine based products (NATURAL-CARE and Papacárie Duo®); and 3 - Chloramine based product (Cariesolut); The following in vitro experiments were carried out: IC50 measurement, cell metabolic activity (MTT) assay, cell migration, immunofluorescence experiment, cell apoptosis analysis, and reactive oxygen species (ROS) production analysis. Statistical analyses were performed using one-way ANOVA followed by Tukey's post hoc test (p<0.05). RESULTS: The IC50 values were: Brix 3000: 0.596%; Papacárie Duo: 0.052%; NATURAL CARE: 1.034%; and Cariesolut: 0.020%. The MTT assays showed non-adequate cell viability of all CMCR tested at 2% at 24, 48, and 72 h (p<0.001). The same behaviour was observed at 0.1% in the Papacárie Duo and Cariesolut groups. In contrast, 0.1% of Brix 3000 at all times and NATURAL CARE at 24h treated cells showed cell viability rates similar to the control group. At 0.01% only Brix 3000 did not show statistically significant differences at any time. Delayed cell migration was observed in all hDPSCs treated with Papacárie Duo and Cariesolut (p<0.01 and p<0.001). Phalloidin staining images showed a high confluence of cells in the presence of NATURAL CARE, similar to the control group. On the contrary, no cells were observed in Brix3000 and Cariesolut at 2% and 0.1% concentrations. Papacárie Duo showed cells at all concentrations, but hDPSCs treated at 0.01% exhibited better proliferation and spreading than those in the control group. Apoptosis assay showed that Brix 3000 at 0.1% and 0.01% had a percentage of live cells higher than 99%, with 68.4% live cells at 2%, 3.69% early apoptotic cells, and 27.9% late apoptotic cells. Conversely, the remaining materials showed abundant apoptotic cells, even at low concentrations. 0.1% and 0.01%of BRIX 3000 did not affect the ROS production levels, while 2% of BRIX 3000 counterparts significantly increased the percentage of CM-H2DCFDA positive cells. Again, all concentrations of Cariesolut showed significantly higher levels of ROS production than those observed in control cells. CONCLUSION: Our results suggest that Brix 3000 would be the most suitable material for chemical caries removal.

Scientific evidence on the efficacy of effervescent tablets for cleaning removable prostheses. A systematic review and meta-analysis.

STATEMENT OF PROBLEM: Scientific evidence to determine the optimal method of cleaning and disinfecting removable prostheses is lacking. PURPOSE: The purpose of this systematic review and meta-analysis was to evaluate the effectiveness of effervescent tablets in the cleaning and sanitizing of removable prostheses compared with other chemical and physical methods by assessing the reduction of biofilm, microbial levels, and material stability. MATERIAL AND METHODS: A systematic literature search and meta-analysis was conducted in August 2021 in the MEDLINE/PubMed, Cochrane, Embase, Scopus, and Web of Science databases. Randomized and nonrandomized controlled clinical trials published in English were included without publication year limits. A total of 23 studies were included in the systematic review and 6 in the meta-analysis, which had been registered in the international prospective register of systematic reviews (PROSPERO) database (CRD42021274019). The Cochrane Collaboration tool was used to assess the risk of bias of randomized clinical trials. The physiotherapy evidence database (PEDro) scale was used to analyze the internal validity of clinical trials by assessing the quality of the data obtained. The studies included in the meta-analysis were combined by using a random-effects model with the inverse variance method. Publication bias was analyzed by using the Duvall and Tweedie trim-and-fill method. RESULTS: With regard to biofilm reduction, the standardized mean difference estimated with the 4 studies combined in the meta-analysis was P=.012: mean difference=-1.92; 95% confidence interval=-3.45 to -0.38, indicating a "large" effect of the combination of brushing and effervescent tablet versus brushing alone. To estimate the reduction in the total bacteria levels in the 3 combined studies, a "large" effect size was obtained for the combination of brushing and using an effervescent tablet versus brushing alone, P<.001: mean difference=-4.43; 95% confidence interval=-8.29 to -0.55. Finally, when the 3 studies were combined to assess the reduction of Candida or fungal infection, a "moderate" effect size was obtained for the combination of brushing combined with the use of an effervescent tablet, P<.001: mean difference=-0.78; 95% confidence interval=-1.19 to -0.37. CONCLUSIONS: The combination of brushing and the use of effervescent tablets versus brushing alone had a significantly higher effect on reducing biofilm and bacterial counts and a moderate effect on reducing Candida. Regarding color and dimensional stability, few studies were found, with the results depending on the concentration of the product and the immersion time of the device.

Cytocompatibility and bioactive potential of AH Plus Bioceramic Sealer: An in vitro study.

AIM: To assess the cytocompatibility and bioactive potential of the new calcium silicate cement-based sealer AH Plus Bioceramic Sealer (AHPbcs) on human periodontal ligament stem cells (hPDLSCs) compared with the epoxy resin-based sealer AH Plus (AHP) and the calcium silicate cement-based sealer Endosequence BC Sealer (ESbcs). METHODOLOGY: Standardized sample discs and 1:1, 1:2 and 1:4 eluates of the tested materials were prepared. The following assays were performed: surface element distribution via SEM-EDX, cell attachment and morphology via SEM, cell viability via a MTT assay, cell migration/proliferation via a wound-healing assay, osteo/cemento/odontogenic marker expression via RT-qPCR and cell mineralized nodule formation via Alizarin Red S staining. HPDLSCs were isolated from extracted third molars. Comparisons were made with hPDLSCs cultured in unconditioned (negative control) or osteogenic (positive control) culture media. Statistical significance was established at p < .05. RESULTS: A higher peak of Ca2 + was detected from ESbcs compared with AHPbcs and AHP in SEM-EDX. Both AHPbcs and ESbcs showed significantly positive results in the cytocompatibility assays (cell viability, migration/proliferation, attachment and morphology) compared with a negative control group, whilst AHP showed significant negative results. Both AHPbcs and ESbcs exhibited an upregulation of at least one osteo/odonto/cementogenic marker compared with the negative and positive control groups. Both ESbcs and AHPbcs showed a significantly higher calcified nodule formation than the negative and positive control groups, indicative of their biomineralization potential and were also significantly higher than AHP group. CONCLUSION: AH Plus Bioceramic Sealer exhibited a significantly higher cytocompatibility and bioactive potential than AH Plus and a similar cytocompatibility to that of Endosequence BC Sealer. Endosequence BC Sealer exhibited a significantly higher mineralization potential than the other tested sealers. The results from this in vitro study act as supporting evidence for the use of AH Plus Bioceramic Sealer in root canal treatment.

Scientific production on silicate-based endodontic materials: evolution and current state: a bibliometric analysis.

OBJECTIVES: To perform a bibliometric analysis on silicate-based biomaterials in endodontics; to elucidate the evolution and distribution of scientific production regarding research on these biomaterials, the authors and institutions involved, and the most used descriptors/keywords in this field. MATERIALS AND METHODS: A general advanced broad search was performed in Web of Science Core Collection, using the terms "Silicate" and "Endod*." By means of the "Analyze Results" and "Citation Analysis" tools from Web of Science, bibliometric data were extracted. Bibliometric networks on co-authorship and keyword co-occurrence were illustrated using VOSviewer software tool. RESULTS: Research in the field of silicate-based endodontic materials in endodontics has followed an exponential crescent tendency over the period between 1995 and 2020. Two major co-authorship networks lead the research production in the field, headed by Gandolfi MG and Prati C, and Rodríguez-Lozano FJ and Forner L; respectively. "Mineral trioxide aggregate," "MTA", "Biocompatibility," "Biodentine," and "In vitro" were the terms with the highest occurrence. The modal study type in this research area are laboratory studies, representing 77.7% of the total number of records. The relationship between keywords illustrates the recent tendency to assess biological properties of MTA and Biodentine, which could be extrapolated to other silicate-based materials. CONCLUSIONS: The results from the present study highlight the exponential increase and distribution of scientific production on silicate-based materials in endodontics, along with the modal keywords used as descriptors and the major authorship networks involved. The predominance of laboratory studies in this research field reinforces the need for clinical studies, to extrapolate the reported performance and characteristics of silicate-based materials into the clinical setting. CLINICAL RELEVANCE: The present study may aid the clinician's continuing education and evidence-based practice by providing knowledge and facilitating the literature search on the field of silicate-based biomaterials in endodontics.

Comparative cytocompatibility of the new calcium silicate-based cement NeoPutty versus NeoMTA Plus and MTA on human dental pulp cells: an in vitro study.

OBJECTIVES: The aim of the present in vitro study is to determine the cytocompatibility of the recently introduced NeoPutty in contact with human dental pulp cells compared with its precursor NeoMTA Plus and the classic gold standard MTA Angelus. MATERIALS AND METHODS: Sample disks were obtained for each of the tested materials (5 mm diameter; 2 mm thickness; n = 30), along with 1:1, 1:2, and 1:4 material eluents. HDPCs were extracted and cultured with the tested materials (test groups) or in unconditioned medium (control group), and the following biocompatibility assays were performed: MTT assay, scratch wound assay, cell cytoskeleton staining assays, and cell attachment assessment via SEM. Additionally, material ion release and surface element composition were evaluated via ICP-MS and SEM-EDX, respectively. Each experimental condition was carried out three times and assessed in three independent experiments. Statistical significance was established at p < 0.05. RESULTS: 1:2 dilutions of all the tested materials exhibited a comparable cell viability to that of the control group at 48 and 72 h of culture (p < 0.05). The same was observed for 1:4 dilutions of the tested materials at 24, 48, and 72 h of culture (p > 0.05). All the tested materials exhibited adequate cytocompatibility in the remaining biocompatibility assays. MTA exhibited a significantly higher calcium ion release compared to NeoPutty and NeoMTA Plus (p < 0.05). CONCLUSION: The results from the present work elucidate the adequate cytocompatibility of NeoPutty, NeoMTA Plus, and MTA Angelus towards human dental pulp cells. CLINICAL RELEVANCE: Within the limitations of the present in vitro study, our results may act as preliminary evidence for its use in vital pulp therapy as a pulp capper. However, results need to be interpreted with caution until further clinical supporting evidence is reported.

Comparison of the effectiveness of professionally delivered and OTC whitening toothpastes. An in vitro study.

PURPOSE: To evaluate the effectiveness of five whitening toothpastes applied three times a day for 4 weeks. METHODS: 25 human extracted teeth were selected. Two peroxide-based dental bleaching pastes (professionally delivered): Enawhite 2.0 (En), Whitekin (Wk); and three over the counter whitening toothpastes: Opalescence whitening toothpaste (Op), Colgate max White expert White (Cg) Premium activated charcoal (Cr) were used. Teeth were brushed for 4 weeks, three times a day. Color was measured with a spectrophotometer according to the CIELab system. ΔEab, W* and ΔE00 values were calculated at baseline, at the end of the treatment, and 1 week after the end of treatment. Data analysis was performed using a generalized estimating equations model, evaluating the effect of treatment, time and interaction (P< 0.05). RESULTS: ΔEab values ranged from 5.01 for En to 3.22 for Wk after the 4-week treatment period. One week after the end of treatment, ΔEab ranged from 5.91 for Cr to 3.62 for Op (P> 0.05 between groups). The closest to pure white (W* differences between baseline and after 1 week from the end of treatment) was for En and Wk. ΔE00 values after 4 weeks of treatment ranged from 3.23 for En to 1.79 for Wk. One week after the end of treatment, the ΔE00 ranges were between 3.31 for Cr to 2.03 for Op (P> 0.05 between groups). CLINICAL SIGNIFICANCE: All the evaluated whitening toothpastes improved dental color values higher than those perceptible and acceptable at the 50:50 threshold.

Effect of highly concentrated bleaching gels on enamel microhardness and superficial morphology, and the recovery action of four remineralizing agents.

BACKGROUND: Dental bleaching is a common clinical practice. The aim of this study is to investigate the effect of 35% hydrogen peroxide (HP) bleaching gel on the morphology and microhardness of enamel, and to analyze the effect of four remineralizing agents. METHODS: One hundred blocks were prepared. The enamel surfaces were bleached with 35% HP in one session. The specimens were divided into four remineralization treatment groups (n = 25). G1: Tooth Mousse, G2: Remin-Pro, G3: Colgate Pro-Relif, G4: Mirafluor. The remineralizing protocol was applied 3 min per day for one week. Vickers microhardness (HV) measurements and SEM observations were performed at baseline, after bleaching, and after remineralizing treatment in all groups. Statistical analyses were performed using the paired t-test and ANOVA. RESULTS: After bleaching, SEM showed an increase of irregularities on the surface of the samples. Enamel microhardness decreased a mean of 47.7 HV, equivalent to a mean decrease of 18.3% (p < 0.05). After remineralization, the HV increased in all groups between 16 and 33% (p < 0.01), recovering the initial microhardness of enamel samples. SEM images revealed a higher quantity of superficial mineral deposits in groups 1 and 2 compared to the rest of the groups. CONCLUSIONS: The application of remineralizing products generates a significant increase in enamel microhardness. Tooth Mousse-treated samples showed a greater microhardness recovery, followed by Remin Pro. The superficial morphology of the samples reflects the results obtained in the HV tests.

A pilot study to assess oral colonization and pH buffering by the probiotic Streptococcus dentisani under different dosing regimes.

Bacterial colonization in the oral cavity is critical for efficient action of probiotics. However, limited colonization rates have been reported in many clinical trials. The aim of this pilot clinical study was to evaluate the colonization efficiency of Streptococcus dentisani under different dosing schedules and pre-treatment conditions. Eleven adult volunteers enrolled in the study. A professional ultrasound cleaning was performed in quadrants 1 and 4. The probiotic was applied in all four quadrants at a total dose of 1010 CFUs, administered in a buccoadhesive gel for 5 min, either in a single dose (n = 5) or daily for a week (n = 6). Dental plaque and saliva samples were collected at baseline and after 14 and 28 days of first application. Amounts of S. dentisani and the cariogenic organism Streptococcus mutans were measured by qPCR and salivary pH was measured by reflectometry. There was a significant increase in S. dentisani cells at day 14 but not at day 28 under both dosing schedules. A non-significant higher colonization was found in the half-mouth with previous professional cleaning as compared to the intact half. There was a significant increase in salivary pH at day 14 (p = 0.024) and day 28 (p = 0.014), which was stronger in multi-dose patients, and a significant decrease in S. mutans at day 28 (p < 0.01). The results indicate that S. dentisani is transiently able to colonize the oral cavity and that it buffers oral pH, especially after multiple dosing. Future randomized, placebo-controlled clinical trials should evaluate its use to prevent tooth decay.

Bleaching efficacy of at home 16% carbamide peroxide. A long-term clinical follow-up study.

OBJECTIVE: To assess the whitening efficacy of a 16% carbamide peroxidase (CP) gel after 42 months of clinical follow-up. MATERIALS AND METHODS: A retrospective clinical study was carried out involving 95 participants. CP 16% was applied for 90 minutes a day for 4 weeks using individualized trays. Tooth color was assessed using spectrophotometry at baseline, 1 week after the end of treatment, and every 6 months until completing 42 months of follow-up. Color parameters were compared using analysis of variance for repeated measures. The analysis by teeth groups was performed using two-way ANOVA. RESULTS: The mean baseline L* was 81.7 ± 5.2 versus 83.6 ± 8.8 after 42 months (P<.01). L* showed a decrease of 2.3 after 30 months. The values corresponding to a* before treatment were 0.4 ± 1.1 versus -1.0 ± 1.0 after 42 months (P<.01). The initial values corresponding to b* were 23.4 ± 3.3 versus 15.8 ± 1.3 after 42 months (P<.01). Values of ΔE00 and ΔE, at the end of the treatment were 4.6 ± 1.2 and 7.8 ± 1.8, respectively. Teeth groups remained stable after 42 months of follow-up. CONCLUSIONS: The home application of 16% CP gel for 90 minutes a day for 4 weeks using individualized trays resulted in whitening that remained stable over the 42 months of follow-up. CLINICAL SIGNIFICANCE: Treatment with 16% CP is an effective and safe tooth whitening procedure, and the color obtained remains stable over the long term.

Risk factors associated with new caries lesions in permanent first molars in children: a 5-year historical cohort follow-up study.

OBJECTIVE: The objective of this study is to analyze the factors associated with the occurrence of caries in the permanent teeth (PT) and in the permanent first molar (PFM) 5 years after their eruption. MATERIAL AND METHODS: Children born in 2005 and enrolled in a community dental program were included. The inclusion criteria were: age 10 years in 2015; the availability of clinical dental history (CDH) data from before eruption of the PT and a follow-up period of 5 years after eruption of the PT. A total of 206 children were enrolled. Risk factors evaluated were: caries experience in the mother, educational level of the mother, frequent drug use, systemic diseases, eating habits, brushing frequency, presence of molar incisor hypomineralization (MIH) in PT, and caries in deciduous teeth (DT). Associations between explanatory factors and the DMF-T (decayed, missing, filled teeth in PT) and DMFT-M (DMF in PFM) indexes, independently considering cavitated or cavitated and non-cavitated caries as outcomes, were evaluated by poisson regression with robust variance analysis. RESULTS: In the multivariate analysis, a cariogenic diet, especially soft drinks, was associated to high DMF-T and DMFT-M scores when both cavitated and non-cavitated caries were considered. A brushing frequency < 1 a day was significantly associated to high DMF-T scores. The presence of df-t (decayed and filled temporary teeth) score > 0 and MIH conditioned high DMF-T or DMFT-M values, considering cavitated or cavitated and non-cavitated caries. CONCLUSIONS: The intake of sweets and soft drinks, brushing frequency, caries in DT, and MIH in PT were the best predictors of caries in PT. CLINICAL RELEVANCE: Control of risk factors in early childhood is important for preventing caries in PT.

Color stability of nanohybrid resin-based composites, ormocers and compomers.

OBJECTIVE: The aim of this study is to evaluate the color stability of two nanohybrid resin-based composites, two organic modified ceramic resin composites (ormocers) and a compomer, following their immersion during 4 weeks in four usual drinks. MATERIAL AND METHODS: Forty discs of each of the following materials were prepared: GrandioSO (GR), Esthet X (EX), Dyract EXTRA (DY), Ceram X duo (CX), and Admira Fusion (AD). The discs were polished and stored in distilled water during 24 h at 37 °C. Color according to the CIEL*a*b* scale was recoded. Ten randomly selected samples of each material were immersed in red wine (RW), coffee (CF), cola (CK), and distilled water (DW). The color was recorded after 1, 7, 21 and 28 days of immersion. The ΔE values between the baseline color and each of the study timepoints were calculated. The data were analyzed based on the Kruskal-Wallis test, Wilcoxon test, and Mann-Whitney U test. RESULTS: After 1 day of immersion, all the materials showed ΔE > 3.3, except EX, CF, and CX in CK. RD was the most staining beverage (ΔE 15.36 to 31.09). EX and CX were significantly less stained than the rest of the materials (p < 0.05). CONCLUSIONS: All the staining solutions produced darkening beyond clinically acceptable limits. EX and CX were the materials who experimented less staining, followed by GD. AD and DY were the materials more stained. RW was the drink that produced more staining, followed by CF and CK. CLINICAL RELEVANCE: After 24 h of immersion in all the solutions, equivalent to 1 month of exposure in the mouth, the evaluated materials showed clinically unacceptable ΔE values.

Effect of Hydrogen and Carbamide Peroxide in Bleaching, Enamel Morphology, and Mineral Composition: In vitro Study.

AIM: The aim of the study was to evaluate the bleaching effect, morphological changes, and variations in calcium (Ca) and phosphate (P) in the enamel with hydrogen peroxide (HP) and carbamide peroxide (CP) after the use of different application regimens. MATERIALS AND METHODS: Four groups of five teeth were randomly assigned, according to the treatment protocol: HP 37.5% applied for 30 or 60 minutes (HP30, HP60), CP 16% applied for 14 or 28 hours (CP14, CP28). Changes in dental color were evaluated, according to the following formula: ΔE = [(La-Lb)2+(aa-ab)2 + (ba-bb)2]1/2. Enamel morphology and Ca and P compositions were evaluated by confocal laser scanning microscope and environmental scanning electron microscopy. RESULTS: ΔE HP30 was significantly greater than CP14 (10.37 ± 2.65/8.56 ± 1.40), but not between HP60 and CP28. HP60 shows greater morphological changes than HP30. No morphological changes were observed in the groups treated with CP. The reduction in Ca and P was significantly greater in HP60 than in CP28 (p < 0.05). CONCLUSION: Both formulations improved tooth color; HP produced morphological changes and Ca and P a gradual decrease, while CP produced no morphological changes, and the decrease in mineral component was smaller. CLINICAL SIGNIFICANCE: CP 16% applied during 2 weeks could be equally effective and safer for tooth whitening than to administer two treatment sessions with HP 37.5%.

Intratubular penetration in post cementing: A comparative study between a total etching system and a self-etching cement.

PURPOSE: To analyze the penetration depth and percentage perimeter with penetration of two fiber post cementing systems using confocal laser scanning microscopy (CLSM). METHODS: 20 maxillary incisors were shaped with the Mtwo system and filled using lateral condensation and TopSeal mixed with fluorescein. Fiber posts were cemented. The samples were divided into two groups of 10 teeth each, according to the post cementing technique used: Prime&Bond NT combined with Rebilda DC using a total dentin etching technique (Group 1); or BisCem a self-adhesive cement (Group 2). Rhodamine B was incorporated in the adhesive systems. Cross-sections were prepared, with the selection of three sections (coronal, middle and apical thirds). CLSM was used to measure the percentage perimeter of the root canal showing penetration of the endodontic cement and of the adhesive system in the dentin tubules, together with the maximum penetration depth. The nonparametric Mann-Whitney U-test was used to compare the data referred to each of the three tooth sections between the two study groups. The Friedman test was used to compare the variables by coronal, middle and apical thirds within each group. RESULTS: Greater penetration was recorded with the BisCem system in all thirds, with statistically significant differences in the case of the middle and apical thirds (P = 0.001). The percentage perimeter with penetration was also greater in all thirds with the BisCem system, though without significant differences between the two groups. Penetration depth and percentage were found to decrease in the coronal to apical direction in both groups.

Sociodemographic and Behavioural Factors Affecting the Oral-Health-Related Quality of Life as Measured with the Child-OIDP Index in Adolescents.

PURPOSE: Environmental factors modulate oral-health-related quality of life (OHRQoL). The aim of this study was to analyse sociodemographic and behavioural factors affecting the OHRQoL in Spanish adolescents, by using the Child-OIDP (Child-Oral Impacts on Daily Performances) index. MATERIALS AND METHODS: A cross-sectional study was conducted in 337 adolescent schoolchildren aged 13-15 years. A questionnaire on sociodemographic, behavioural and oral self-perception factors was administered with the Child-OIDP questionnaire. Descriptive statistics, Kruskal-Wallis and Mann-Whitney U-tests, as well as a regression model were used in the data analysis. RESULTS: The overall mean Child-OIDP index was 3.28±6.55. It was statistically significantly higher in females than in males (p < 0.001). Mothers having a managerial job showed statistical association with worse OHRQoL (p < 0.001). Caries experience and history of dental trauma were not associated with the oral-health-related quality of life (p > 0.05). Halitosis statistically significantly affected the activities of daily living (p < 0.001). Perceived dental problems, dental treatment needs, self-assessment of oral health status and satisfaction with oral health were associated with the impact index (p < 0.05). CONCLUSION: Mothers who were managers, female sex, presence of halitosis, and perceived dental treatment needs were the most important predictors of the impact index, while dietary habits, oral hygiene, and dental visits did not affect it. Knowledge of these factors will help dental professionals to apply adequate preventive and therapeutic measures.

Effect of Bleaching Agents on Composite Resins with and without Bis-GMA: An In Vitro Study.

The objective was to evaluate the change in color, hardness, and roughness produced by carbamide peroxide (CP) at two different concentrations on two resins. The 16% or 45% CP was applied to 66 resin discs with and without Bis-GMA. The color was measured with a spectrophotometer, and ΔEab and ΔE00 were calculated. Microhardness tester and SEM were used. In both composites, the a* and b* coordinates tended to be red and yellow, respectively, and were significant in the Bis-GMA group (p < 0.05). The ΔEab and ΔE00 were higher in the composite with Bis-GMA, regardless of the treatment received (p < 0.05). The microhardness was reduced in both composites regardless of the PC concentration compared to the control (p < 0.05). The 45% CP reduced the microhardness in the resin group with Bis-GMA compared to 16% CP (p < 0.001) but was not significant in the resin without Bis-GMA (p = 1). An increase in roughness was directly proportional to the concentration of CP, and it was more notable in the composite without Bis-GMA. The composite with Bis-GMA showed a greater tendency to darken than the one without Bis-GMA. The surface hardness of the composite was reduced in both composites and was not influenced by CP concentration in the composite without Bis-GMA. Bleaching is a common procedure nowadays. It is important to know how CP affects composites to establish a prognosis of the treatments in terms of color change, roughness, and hardness.

In vitro biocompatibility of ammonia-free silver fluoride products on human dental pulp stem cells.

OBJECTIVES: Silver fluoride (SF) is a preventive and therapeutic option for dental pathological processes involving structural alterations of the hard tissues, either during their formation or those caused by caries or other pathological reasons. This study aimed to compare the biological properties of two commercial SF products, one of them with ammonium (Riva Star; SDF) and the other ammonium-free (Riva Star Aqua; AgF), both with or without potassium iodide (KI), by the assessment of the cytotoxicity of the materials' eluates. METHODS: Human dental pulp stem cells (hDPSCs) were obtained from healthy 18-23-year-old donors. Three dilutions were prepared for the tested materials (0.005%, 0.0005%, and 0.0001%). The following groups were assessed: (AgF, AgF+KI, SDF, SDF+KI, KI, negative control). A series of cytocompatibility assays were performed: MTT assay, IC50 assay, wound healing (migration) assay, cell cytoskeleton staining, analysis of cell apoptosis and necrosis, and reactive oxygen species production. The normality in the distribution of the data was previously confirmed via a Q-Q plot. Statistical significance was tested using one way ANOVA and Tukey's post hoc test. RESULTS: The incorporation of KI improved the cytocompatibility of both SF products in terms of viability, migration, morphology, apoptosis, and reactive oxygen species production. This difference was higher in the AgF group. The lowest dilutions of SF+KI and AgF+KI showed a similar cytocompatibility to that of the control group (MTT assay (p > 0.05 after 24, 48, and 72 h of culture); migration assay (p > 0.05 after 24, 48, and 72 h of culture); reactive oxygen species production (p > 0.05 after 72 h of culture). SIGNIFICANCE: Riva Star Aqua shows lower cytotoxicity than Riva Star on hDPSCs. It can be considered as a good alternative in the conservative treatment of dental caries and in the preservation and remineralisation of viable dentine tissue.

3D Graphene/silk fibroin scaffolds enhance dental pulp stem cell osteo/odontogenic differentiation.

OBJECTIVES: The current in vitro study aims to evaluate silk fibroin with and without the addition of graphene as a potential scaffold material for regenerative endodontics. MATERIAL AND METHODS: Silk fibroin (SF), Silk fibroin/graphene oxide (SF/GO) and silk fibroin coated with reduced graphene oxide (SF/rGO) scaffolds were prepared (n = 30). The microarchitectures and mechanical properties of scaffolds were evaluated using field emission scanning electron microscopy (FESEM), pore size and water uptake, attenuated total reflectance fourier transformed infrared spectroscopy (ATR-FTIR), Raman spectroscopy and mechanical compression tests. Next, the study analyzed the influence of these scaffolds on human dental pulp stem cell (hDPSC) viability, apoptosis or necrosis, cell adhesion, odontogenic differentiation marker expression and mineralized matrix deposition. The data were analyzed with ANOVA complemented with the Tukey post-hoc test (p < 0.005). RESULTS: SEM analysis revealed abundant pores with a size greater than 50 nm on the surface of tested scaffolds, primarily between 50 nm and 600 µm. The average value of water uptake obtained in pure fibroin scaffolds was statistically higher than that of those containing GO or rGO (p < 0.05). ATR-FTIR evidenced that the secondary structures did not present differences between pure fibroin and fibroin coated with graphene oxide, with a similar infrared spectrum in all tested scaffolds. Raman spectroscopy showed a greater number of defects in the links in SF/rGO scaffolds due to the reduction of graphene. In addition, adequate mechanical properties were exhibited by the tested scaffolds. Regarding biological properties, hDPSCs attached to scaffolds were capable of proliferating at a rate similar to the control, without affecting their viability over time. A significant upregulation of ALP, ON and DSPP markers was observed with SF/rGO and SF/GO groups. Finally, SF/GO and SF/rGO promoted a significantly higher mineralization than the control at 21 days. SIGNIFICANCE: Data obtained suggested that SF/GO and SF/rGO scaffolds promote hDPSC differentiation at a genetic level, increasing the expression of key osteo/odontogenic markers, and supports the mineralization of the extracellular matrix. However, results from this study are to be interpreted with caution, requiring further in vivo studies to confirm the potential of these scaffolds.

Nanostructural changes in dentine caused by endodontic irrigants.

OBJECTIVE: To study nanostructural dentinal changes produced by endodontic irrigants. STUDY DESIGN: Experimental study. Nanoindentations were performed on peritubular (PD) and intertubular dentine (ID) with an atomic force microscopy. Stiffness and adhesion force were determined before and after application of 5.25% sodium hypochlorite (NaOCl) and 17% ethylenediaminetetraacetic acid (EDTA). Normalized differences before and after treatment for stiffness and adhesion forces were calculated. A paired T-test was used to compare stiffness and adhesion force before and after irrigants application. RESULTS: After treatment with EDTA there was a 29.80% reduction in stiffness in ID and a 63.53% reduction in PD. Adhesion force was reduced by 21.22% and 8.21% respectively. After treatment with 5.25% NaOCI stiffness was reduced by 2.49% in ID and increased by 15.01% in PD. Adhesion force increased by 25.11% and 23.97% respectively. CONCLUSIONS: 17% EDTA reduced stiffness and adhesion force in ID and PD. Treatment with NaOCI at 5.25% had no significant effect on stiffness but did affect adhesion force in ID and PD.

The Effect of Antioxidants on Dentin Bond Strength after Application of Common Endodontic Irrigants: A Systematic Review.

The purpose of this systematic review was to evaluate how an antioxidant treatment would influence the immediate bond strength of dental adhesives to endodontically treated dentine. Scientific evidence was researched in five databases using selected descriptors. Two independent reviewers conducted the investigation and assessed the data and methodological quality of the studies. Inclusion and exclusion criteria were specified for article selection; only studies in English and published between 2001 and 2022 were evaluated. A total of 18 studies were selected and analysed. According to most studies, the irrigation procedure and substrate preparation in endodontic therapy may affect the immediate bond strength. Antioxidants can improve bond strength and adhesion following the use of the most frequently used irrigants in root canal treatments. Therefore, antioxidant treatment can be considered a proper technique to enhance the bond strength of endodontically treated teeth.

Effect of calcium silicate-based endodontic sealers on tooth color: A 3-year in vitro experimental study.

Objective: To analyze the change in tooth color produced by two hydraulic and one resin-based sealers by means of spectrophotometry for 3 years. Methods: Forty maxillary anterior teeth were selected (n = 10 per group). Root canals were prepared by rotary instrumentation and irrigation was performed with NaOCl, which was also used in the final irrigation, followed by saline and activated with Endoactivator. Root canals were then filled using single cone technique. Negative control (NC): gutta-percha filling; Positive control: gutta-percha and AH Plus; experimental groups: gutta-percha and Bioroot RCS/TotalFill BC Sealer. Gutta-percha was cut 2 mm below the cementoenamel junction, the pulp chamber was sealed with flowable composite. The teeth were kept in PBS. Color was measured in the cervical and incisal halves before root canal treatment (RCT), one and six months after RCT, and after one, two and three years, with the Vita EasyShade spectrophotometer; positioned using an individualized splint. ΔEab and ΔE00 were calculated. Two-way ANOVA repeated measures test followed by Bonferroni post-test were performed to analyze the ΔL, Δa*, Δb*, ΔEab, and ΔE00, considering treatment groups and evaluation periods. Statistical significance was set at p < 0.05. Results: In the incisal half, in decreasing order of darkening, the groups at three years were ordered according to the ΔEab: AH Plus > NC > TotalFill > Bioroot. ΔE00 values were: 1.38 ± 0.61 NC, 2.37 ± 0.70 AH Plus, 1.86 ± 0.60 BioRoot and 1.53 ± 0.85 TotalFill. In the cervical half, the ΔEab values, showed the same descending order, except for Bioroot and TotalFill which alternated the order. The ΔE00 values were 1.86 ± 0.61 NC, 3.01 ± 0.70 AH Plus,1.89 ± 0.58 Bioroot and 1.65 ± 0.41 TotalFill, with no significant differences between groups and times in both locations. Conclusions: All groups presented some degree of discoloration. Lightness and b* component were the most influential. Calcium silicate-based cements (Bioroot RCS and TotalFill BC Sealer) produced acceptable levels of discoloration at the end of follow-up.