Comparative Evaluation of Platelet-rich Fibrin and Treated Dentin Matrix in Regenerative Endodontic Treatment of Nonvital Immature Permanent Teeth: A Randomized Clinical Trial.

AIM: Clinical and radiographic evaluation of the efficacy of platelet-rich fibrin (PRF) and treated dentin matrix (TDM) in regenerative endodontic treatment and periapical healing of nonvital immature permanent teeth with chronic apical periodontitis. MATERIALS AND METHODS: Twenty-four children aged between 7 and 11 years, each presenting with a nonvital immature permanent upper central incisor, were selected. They were randomly allocated into two groups (n = 12), group I (PRF) and group II (TDM). Baseline clinical findings were recorded, and preoperative cone-beam computed tomography (CBCT) was taken. Follow-up was done clinically for 15 months at 3-month intervals (3, 6, 9, 12, and 15 months), and CBCT was taken at the end of the 15-month follow-up. Root length, apical diameter, radiographic root area (RRA), and size of the periapical lesion were quantitively assessed at the end of follow-up period and compared to the preoperative CBCT. RESULTS: Clinical success was 100% in both groups by the end of the follow-up period. Radiographically, after a 15-month follow-up, there was a significant increase in root length and RRA, and there was also a significant reduction in apical diameter and lesion size within each group (p < 0.05). However, there was no statistically significant difference between both groups regarding the mean percentage of increase in root length and mean percentage of reduction of apical diameter (p > 0.05). On the other hand, PRF showed more increase in RRA and more reduction in lesion size, with a statistically significant difference between both groups (p < 0.05). CONCLUSION: Both PRF and TDM were clinically successful. Platelet-rich fibrin showed better radiographic outcomes and periapical healing. CLINICAL SIGNIFICANCE: Platelet-rich fibrin is a viable scaffold to aid further root development and resolution of periapical lesions of nonvital immature permanent teeth. Further studies with different forms of TDM are needed to assess the efficacy of TDM in regenerative endodontic treatment of nonvital immature permanent teeth. How to cite this article: Asal MA, Elkalla IH, Awad SM, et al. Comparative Evaluation of Platelet-rich Fibrin and Treated Dentin Matrix in Regenerative Endodontic Treatment of Nonvital Immature Permanent Teeth: A Randomized Clinical Trial. J Contemp Dent Pract 2024;25(6):563-574.

Assessment of the Effectiveness of Desensitizing Dentifrices on Management of Dental Hypersensitivity: An In Vitro Study.

AIM: The current study aimed to assess the efficiency of two desensitizing dentifrices on the management of dental hypersensitivity. MATERIALS AND METHODS: For the purpose of this investigation, 60 extracted human sound premolar teeth that were removed for orthodontic purposes were collected. On the buccal cervical areas, an inverted-cone bur was used to create cavities that were 2 mm deep and 3 mm wide. The blocks were submerged in 17% ethylenediaminetetraacetic acid (EDTA) for 40 minutes in order to ensure the complete dentin tubule opening. Following preparation, all samples were split into three groups, each containing 20 samples, Group A: Control, Group B: Dentifrice containing calcium sodium phosphosilicate, Group C: Dentifrice containing casein phosphopeptide-amorphous calcium phosphate (CPP-ACP). Scanning electron microscopy (SEM) was used to assess the occlusion of dentinal tubules. One-way analysis of variance (ANOVA) was used to assess the desensitization efficacy of dentifrices. At a p-value less than 0.05, statistical significance was determined. RESULT: Before application of different dentifrices, the maximum dentinal tubules opened in dentifrice containing CPP-ACP group (4.24 ± 0.10) followed by control group (4.18 ± 0.01) and dentifrice containing calcium sodium phosphosilicate (4.12 ± 0.06). And there was no significant difference between the different dentifrice groups (p > 0.001). After application of different dentifrices, the highest occlusion of dentinal tubules found in dentifrice containing CPP-ACP group (2.50 ± 0.05) followed by dentifrice containing calcium sodium phosphosilicate (2.84 ± 0.10) and control group (4.02 ± 0.07) and there was a highly significant difference between the different dentifrice groups (p < 0.001). CONCLUSION: On conclusion, dentifrice containing CPP-ACP exhibited the highest level of dentinal tubule occlusion in comparison to the control group and dentifrice containing calcium sodium phosphosilicate. CLINICAL SIGNIFICANCE: Dentinal hypersensitivity (DH) is a condition that is frequently experienced. With variable outcomes, a number of products are utilized in the management of DH. Need is felt in dentistry for a material that chemically reacts, physically occludes and adheres intimately to dentinal tubules to reduce the possibility of its recurrence. How to cite this article: Pulipaka S, Ramanna PK, Samson A, et al. Assessment of the Effectiveness of Desensitizing Dentifrices on Management of Dental Hypersensitivity: An In Vitro Study. J Contemp Dent Pract 2024;25(5):494-497.

Co-doped titanium dioxide nanoparticles decrease the cytotoxicity of experimental hydrogen peroxide gels for in-office tooth bleaching.

OBJECTIVE: To evaluate the efficacy and cytotoxicity of experimental 6% and 35% hydrogen peroxide gels (HP6 or HP35) incorporated with titanium dioxide nanoparticles (NP) co-doped with nitrogen and fluorine and irradiated with a violet LED light (LT). METHODS: Bovine enamel-dentin disks adapted to artificial pulp chambers were randomly assigned to bleaching (n = 8/group): NC (negative control), NP, HP6, HP6 + LT, HP6 + NP, HP6 + NP + LT, HP35, HP35 + LT, HP35 + NP, HP35 + NP + LT, and commercial HP35 (COM). Color (ΔE00) and whiteness index (ΔWID) changes were measured before and 14 days after bleaching. The extracts (culture medium + diffused gel components) collected after the first session were applied to odontoblast-like MDPC-23 cells, which were assessed concerning their viability, oxidative stress, and morphology. The amount of HP diffused through the disks was determined. Data were analyzed by generalized linear models or Kruskal Wallis Tests (α = 5%).  RESULTS: HP6 + NP + LT exhibited ΔE00 and ΔWID higher than HP6 (p < 0.05) and similar to all HP35 groups. HP6 + NP + LT showed the lowest HP diffusion, and the highest cell viability (%) among bleached groups, preserving cell morphology and number of living cells similar to NC and NP. HP6 + LT, HP6 + NP, and HP6 + NP + LT exhibited the lowest cell oxidative stress among bleached groups (p < 0.05). HP35, HP35 + LT, and HP35 (COM) displayed the lowest cell viability. CONCLUSION: HP6 achieved significantly higher color and whiteness index changes when incorporated with nanoparticles and light-irradiated and caused lower cytotoxicity than HP35 gels. The nanoparticles significantly increased cell viability and reduced the hydrogen peroxide diffusion and oxidative stress, regardless of HP concentration. CLINICAL SIGNIFICANCE: Incorporation of co-doped titanium dioxide nanoparticles combined with violet irradiation within the HP6 gel could promote a higher perceivable and acceptable efficacy than HP6 alone, potentially reaching the optimal esthetic outcomes rendered by HP35. This approach also holds the promise of reducing cytotoxic damages and, consequently, tooth sensitivity.

Effects of self-etch adhesive agitation with diode laser on dentin bond strength.

The present study assessed the effect of active application of self-etch adhesives with diode laser irradiation on the shear dentin bond strength. Sixty bovine incisors, each embedded individually in hard plaster blocks, were divided into two groups based on the adhesive system used: Group 1 Adper Easy One and Group 2 Clearfil SE Protect. Based on the application technique of self-etch adhesives, each main group was further divided into three subgroups: passive application, active application with a micro-brush, and active application with a 976-nm diode laser tip (phototherapy active application). Shear bond strength tests were conducted using a universal testing machine and the data were analyzed by two-way ANOVA. Post hoc multiple comparisons were performed with the Tukey HSD test. Additionally, the statistical analysis of failure mode distribution was carried out using the chi-squared test (p < 0.05). While the adhesive system exhibited significant differences in shear dentin bond strengths, there were no significant differences in application techniques. Regardless of the application technique, Clearfil SE Protect demonstrated significantly higher dentin bond strength than Adper Easy One. In the present study, the utilization of phototherapy through a 976-nm diode laser for the active application of the tested self-etch adhesives demonstrated similar initial dentin bond strengths to conventional application methods.

Revolutionizing Bone Regeneration with Grinder-Based Dentin Biomaterial: A Systematic Review.

Bone tissue regeneration is a critical aspect of dental surgery, given the common occurrence of bone resorption leading to alveolar bone defects. The aim of this paper was to conduct a systematic review to provide a comprehensive summary of the evidence regarding the regenerative properties of dentin biomaterial. This systematic review was conducted through comprehensive searches in the PubMed, Scopus, and Web of Science databases, as well as an extensive exploration of the gray literature sources, including WorldCat, The New York Academy of Medicine Library, and Trip Database, following the established PRISMA protocol. Keywords such as tooth, dentin, grinder, and autograft guided the search, with a focus on a standardized procedure involving dentin grinders within laboratory, experimental, and clinical settings. Initially, a pool of 1942 articles was identified with 452 duplicates removed. An additional 1474 articles were excluded for not aligning with the predefined topics, and three more were excluded due to the unavailability of the full text. Ultimately, 13 articles met the strict inclusion criteria and were included in the review. The chemical composition of the dentin particles was similar to natural bone in terms of oxygen, carbon, calcium, phosphorus, sodium, and magnesium content, as well as in terms of the Ca/P ratio. In addition, the dentin also contained amide I and amide II structures, as well as aliphatic and hydroxyl functional groups. The chemically treated dentin was free of microorganisms. The dentin had characteristic tubules that opened after chemical treatment. At the cellular level, dentin released bone morphogenetic protein 2, induced significant cell growth, and stimulated the reorganization of the fibroblast cytoskeleton. Most clinical studies have focused on alveolar bone regeneration. After the transplantation of demineralized dentin particles, studies have observed new bone formation, a reduction in residual bone, and an increase in connective tissue. Clinical reports consistently indicate uncomplicated healing and recovery post-transplantation. However, there is a notable gap in the evidence concerning complication rates, patient-reported outcomes, and the presence of pro-inflammatory factors. In conclusion, dentin biomaterial emerges as a versatile bone substitute, demonstrating high biocompatibility and ease of acquisition. The preservation of its internal structure containing organic matter and growth factors enhances its potential for effective bone regeneration. Particularly, in dental surgery, dentin-derived materials present a promising alternative to traditional autologous bone autografts, offering the potential to reduce patient morbidity and treatment costs.

Efficacy of silver diamine fluoride (SDF) in arresting dentin caries against inter-kingdom biofilms of Streptococcus mutans and Candida albicans.

OBJECTIVES: To compare, in vitro, the efficacy of three proprietary silver diamine fluoride (SDF) products in mitigating progression of dentinal caries induced by an inter-kingdom, dual-species, bacterial-yeast biofilm. METHODS: Human dentin blocks were demineralized to create artificial caries lesions and randomized into three SDF test groups: Saforide, Topamine, T-SDF, and an aqueous control (n = 26 per group). After application of foregoing SDF variants, the blocks were incubated with Streptococcus mutans and Candida albicans for 24 h for biofilm development, and subsequently subjected to a microbe-induced, pH-cycling process for 7 days, to mimic the oral eco-system. The biofilm cell viability and surface topography were assessed by colony-forming units (CFUs) and scanning electron microscopy respectively. The lesion depth and mineral density were evaluated by micro-computer tomography. SDF precipitate and matrix-to-mineral ratio were evaluated by X-ray diffraction and Fourier transform infrared spectroscopy, respectively. Standard, accepted methodology was used for all these evaluations and procedures. RESULTS: After pH cycling, the SDF groups demonstrated comparable inhibition of the biofilm relative to the control. the log CFU of S. mutans for Saforide, Topamine, T-SDF, and control were 6.69±0.73, 6.48±0.56, 6.63±0.66, and 8.01±0.45, respectively. For C. albicans, the log CFU were 4.86±0.44, 4.72±0.53, 4.92±0.29, and 5.60±0.27, respectively. The log CFU of S. mutans and C. albicans in the SDF groups were significantly lower than the control group (p<0.001). Further, the lesion depth decreased by approximately 14.79±7.00% in the SDF groups, while it increased by 11.07±8.61% in the control (p<0.001), and the mineral density increased by 16.36±4.58% in the SDF group, as opposed to a 5.59±2.64% reduction in the control (p<0.001) implying their caries mitigating effect. These findings were corroborated by SEM images of the lesions. CONCLUSION: SDF significantly mitigated dentin caries due to an assault by a polymicrobial plaque biofilm whilst arresting mineral loss and lesion growth. There was no difference in the caries-arresting efficacy of the compared SDF variants.

Effects of sodium copper- and sodium iron-chlorophyllin primers on resin bonding to dentin.

This study evaluated the effects of two chlorophyll derivatives, sodium copper chlorophyllin (Cu-Chl) and sodium iron chlorophyllin (Fe-Chl), on the bond strength between a self-curing luting agent (4-META/MMA-TBB resin) and dentin. Five aqueous primers containing 35% 2-hydroxyethylmethacrylate with 0.007% Cu-Chl, 0.07% Cu-Chl, 0.007% Fe-Chl, 0.07% Fe-Chl, or neither Cu-Chl nor Fe-Chl (no-Chl) were prepared. The extracted human dentin surfaces were etched with 10% phosphoric acid (10PA), primed, and bonded to a resin block using the 4-META/MMA-TBB resin. A conventional etching agent (10-3) and 10PA without primer (PA/no-primer) were used as controls. The microtensile bond strength was determined after 48 h. The arithmetic medians for 20 stick specimens were calculated and statistically analyzed using a nonparametric Steel-Dwass test (α = 0.05). The maximum bond strength was achieved in the 0.007% Cu-Chl group, followed by those in the 0.07% Cu-Chl, 0.07% Fe-Chl, 10-3, 0.007% Fe-Chl, no-Chl, and PA/no-primer groups. No significant difference was observed between 0.007% Fe-Chl, 0.07% Fe-Chl, and 10-3. The bond strength to dentin etched with 10PA was influenced by the type and concentration of the chlorophyll derivatives applied. Cu-Chl rather than Fe-Chl should be useful as a component of surface treatment agents for bonding 4-META/MMA-TBB resin to dentin.

Masking discolored substrates with resin composites: effect of layering strategies.

This study aimed to evaluate the masking ability of different resin composite (RC) layering techniques over discolored substrates. Layering strategies were tested (n=10), using different RCs: flowable opaque, white dentin, A1 dentin, A1 body, and A1 enamel (Filtek Z350XT; 3M ESPE). Bilayer and trilayer RC combinations resulted in final thicknesses of 1 mm, 1.5 mm, and 2 mm. Substrates tested were: A1 (reference), A3, A4, B3, C2, and C4 (Filtek Z350XT Dentin; 3M ESPE). Color differences (∆E00) were measured for the RC layers over discolored substrates with the CIEDE2000 formula. The results were compared statistically (One-way ANOVA) and descriptively (acceptability=1.77 and perceptibility=0.81 thresholds). The layering strategy influenced the ∆E00 of RCs over all substrates (P<0.001). The 1 mm bilayer group combining 0.5 mm of dentin and 0.5 mm of enamel led to ∆E00 below AT for substrates A3 and B3; the 1.5 mm bilayer group combining A1 dentin (1 mm) and enamel (0.5 mm) provided ∆E00 below AT for substrates A3, A4, and C2 and ∆E00 below PT for B3; for substrate C4, the 2 mm trilayer group combining flowable opaque (0.2 mm), A1 dentin (1.3 mm) and enamel (0.5 mm) provided ∆E00 below PT, and the 1.5 mm trilayer groups (flowable opaque + 0.8 mm dentin or body + enamel) led to ∆E00 below AT. Resin Composites were effective in masking discolored substrates. The most adequate layering strategy depended on substrate shade.

Current landscape of research on whitening toothpastes and their effects on dental hard tissue.

PURPOSE: To explore the latest trends in research on whitening toothpaste and to present the issues and future perspectives of these studies. METHODS: An initial PubMed search was performed, followed by a meticulous manual review. A total of 543 papers were initially retrieved, and 54 final research papers were selected and analyzed through a manual review. RESULTS: The number of studies on whitening toothpastes has significantly increased, and while initial studies primarily focused on the efficacy of various whitening toothpastes, recent studies have shifted towards investigating the potential effects on dental hard tissues such as enamel and dentin. Common active ingredients used in these whitening toothpastes include hydrogen peroxide, activated charcoal, and blue covarine. Most studies have used commercial toothpastes with fixed ingredients rather than experimentally manufactured toothpaste, and it was noted that toothpastes from specific major manufacturers were frequently used. CLINICAL SIGNIFICANCE: Whitening toothpastes should be treated as separate entities based on their active ingredients, and more standardized experimental designs are required for better comparisons. Accurate analysis and labeling of other components of toothpaste are also essential.

Charcoal dentifrices: A laboratory study of their safety and efficacy.

PURPOSE: To compare charcoal-containing dentifrices (CDs) to non-charcoal containing dentifrices (NCDs) through the following experiments: potentially available fluoride, 1-minute fluoride release, pH, cytotoxicity, heavy metals, enamel fluoride uptake (EFU) and relative dentin abrasivity (RDA). METHODS: Nine fluoride dentifrices; six CDs and three NCDs were tested (n= 3) for available fluoride, the amount of fluoride released within 1 minute, pH cytotoxicity, heavy metals, EFU and RDA. Four CDs and 1 NCD contained sodium fluoride (NaF) as the active ingredient whereas two dentifrices contained stannous fluoride (SnF2; 1 CD and 1 NCD), and two dentifrices contained disodium monofluorophosphate (Na2FPO3, or Na2MFP; 1 CD and 1 NCD). Available samples were homogenized and diluted to 1-in-100 in deionized water (DIW). Release samples were prepared as 1-in-4 homogenized dilutions by mass in DIW. Available and release samples were measured in triplicate (n= 3) via fluoride ion-selective electrode (F-ISE) and ion chromatography (IC). ANSI/ADA 130 was followed for pH. L929 cells were cultured using the lactate dehydrogenase (LDH) assay and ISO 10993-5 Annex C MTT cytotoxicity test. Heavy metals testing was performed using a hydrofluoric acid digestion sample preparation method followed by inductively coupled plasma mass spectrometry (ICP-MS) detection. EFU was performed on enamel specimens that underwent treatment with a CD slurry (1-in-4 dilution) following Test Method #40 of FDA Monograph 21. RDA was performed following ISO 11609 Annex A and the Hefferren method. Data was analyzed using one-way ANOVA followed by post-hoc tests (α= 0.05). RESULTS: Available fluoride for all nine dentifrices was between ~93-102% of the labeled amount. The amount of fluoride released after 1 minute of homogenous mixing ranged between 75-107% of the labeled amount. The pH values of the nine dentifrices ranged from 6.5 to 7.7. Charcoal did not significantly contribute to cytotoxicity in L929 cells. The concentrations of each heavy metal (Hg, Cd, As and Pb) present in each of the nine dentifrices were < 1 ppm, indicating trace amounts. The CDs were not significantly more abrasive than the NCDs. The SnF2 CD had the highest EFU value (644.2 ±131.7 ppm) followed by the NaF CD and the Na2MFP CD at 492.2± 69.5 ppm and 140.1± 28.1 ppm, respectively. CLINICAL SIGNIFICANCE: Charcoal-containing dentifrices were not found to be significantly more abrasive or cytotoxic than non-charcoal-containing dentifrices. Charcoal and non-charcoal-containing dentifrices were also found to be comparable through experiments determining their fluoride content, pH, enamel fluoride uptake and heavy metals.

Effects of salivary contamination on the shear bond strengths of universal adhesives to dentin.

PURPOSE: To evaluate the shear bond strength (SBS) of resin composite to dentin contaminated with artificial saliva (AS) containing mucin and amylase using an experimental method controlling the volume of saliva and adhesive in a defined surface area. METHODS: Flat bonding surfaces were prepared on extracted human molars (320 grit surface). Using adhesive tape, a 4.5 mm bonding window was prepared on the dentin surfaces. Groups (n= 12) were prepared using the etch & rinse (ER) or self-etch (SE) modes for Adhese Universal (ADH), Scotchbond Universal Plus (SBU), and Prime & Bond active (PBA) dental adhesives (DA). For the control (C) groups, the adhesives were applied per the manufacturers' instructions with 2.0 µl or 3.0 µl of the adhesive. For the saliva-contaminated groups, 1.0 µl of artificial saliva with mucin was applied in the bonding window either dried or allowed to remain wet before the application of either 2.0 µl or 3.0 µl of the adhesive. After the adhesive film was air dried and light cured using an Ultradent bonding fixture, Spectrum TPH3 was bonded to the prepared surfaces. After water storage for 24 hours at 37°C, the specimens were debonded and shear bond strength (SBS) was calculated (MPa). A Kruskal-Wallis test with Bonferroni correction was used to determine group differences (P< 0.05). Scanning electron microscopy (SEM) was performed to visualize the interfacial surfaces prepared using an ion-etching technique. RESULTS: Mean SBS for the three adhesives were similar in both ER and SE modes to uncontaminated dentin surfaces for all the control groups. For dentin contaminated with dried or wet saliva, both the surface condition and the adhesive system were significant factors at a confidence level of 95%. For the dried saliva test groups, ADH and PBA with 3.0 µl of adhesive generated similar SBS values to controls while SBU generated lower values. Lower values were generated when using 2.0 µl of adhesive for the three adhesives in SE and ER modes except for PBA in the ER mode. Using wet saliva and 3.0 µl of adhesive ADH and SBU generated lower SBS values while PBA generated similar values to controls. Under SEM, morphology at the adhesive dentin interfaces was similar among the adhesives to uncontaminated dentin but notable differences were observed for SBU and ADH for both wet and dried saliva-contaminated surfaces. CLINICAL SIGNIFICANCE: Salivary contamination differentially affects shear bond strength and the morphology of the bonded interface of universal adhesives to dentin. These differences are specific to the adhesive tested and are influenced by using the etch and rinse or self-etch strategies and the volume of adhesive used. When concerned about salivary contamination clinically, maximizing the volume of adhesive on the substrate may help mitigate the deleterious effects of saliva contamination.

The effect of a universal cleaning agent on the bonding performance of a self-adhesive cement to contaminated dentin surfaces.

PURPOSE: This study examined the effect of using KATANA Cleaner (KC) containing 10-methacryloyloxydecyl dihydrogen phosphate (MDP) salt on the micro-shear bond strength (µSBS) of a self-adhesive cement to uncontaminated and contaminated dentin. METHODS: Dentin samples were categorized into four contamination conditions (no contamination, saliva, blood, saliva/blood mixed) and subjected to two decontamination methods (water rinse and KC use), forming eight groups. Scanning electron microscope images representing each group were obtained. One sample representing each group was analyzed by Raman Spectroscopy. Composite resin was bonded to the sample dentin surfaces with a self-adhesive resin cement. After 5,000 thermal cycles, the µSBS test was performed. The data were analyzed statistically (α= 0.05). RESULTS: The lowest µSBS value was observed in the water-rinsed mixed contamination group, while the highest was in the KC-treated uncontaminated group. KC-treated groups exhibited significantly higher µSBS values compared to water-rinsed groups for each contamination type (P< 0.05), indicating the efficacy of KC in enhancing bond strength. CLINICAL SIGNIFICANCE: There are limited studies using the new MDP salt-containing cleaner on dentin. In this study, contamination of dentin tissue with saliva, blood, and saliva/blood mixture was simulated and the effects of water rinsing and MDP salt-containing cleaner (KATANA Cleaner) on bond strength were tested as decontamination methods. The results showed that the use of a cleaner containing MDP salt increased the bond strength to dentin tissue under both non-contaminated and contaminated conditions.

Use of autologous dentin matrix in bone defects augmentation - a literature review.

A number of regenerative materials are currently used to regenerate or preserve the alveolar pro- cess. One of these is autogenous dentin matrix. With many valuable properties such as easy availability, simple preparation, low cost, low risk of disease transmission and no risk of triggering an immune response against the graft, autogenous dentin matrix appears to be a very good material of choice. The following article is intended to provide an overview of the use of autogenous dentin matrix.

Substrate-Mediated Regulation of Src Expression Drives Osteoclastogenesis Divergence.

BACKGROUND/OBJECTIVES: Glass, bone, and dentin are commonly applied substrates for osteoclast cultures; however, the impact of these substrates on osteoclastogenesis remains underexplored. This study aimed to address a significant gap in understanding how different substrates influence the process of osteoclastogenesis. METHODS: RAW 264.7 cells were cultured and induced with RANKL on glass, bone, and dentin slides. Histological and molecular techniques were used to identify patterns and differences in osteoclast behavior on each substrate. RESULTS: Osteoclasts cultured on glass slides possessed the greatest number of nuclei and the highest expression levels of ACP5 (TRAP) and CTSK, with osteoclasts on bone and dentin slides displaying progressively lower levels. Src expression was also most pronounced in osteoclasts on glass slides, with decreased levels observed on bone and dentin. This variation in Src expression likely contributed to differences in cytoskeletal remodeling and oxidative phosphorylation (OXPHOS), resulting in substrate-dependent divergences in osteoclastogenesis. CONCLUSIONS: Glass slides were the most favorable substrate for inducing osteoclastogenesis, while bone and dentin slides were less effective. The substrate-induced expression of Src played a fundamental role in shaping the phenotypic divergence of osteoclasts. These insights fill important knowledge gaps and have significant implications for the development and selection of in vitro models for bone-related diseases and drug screening platforms.

Long-term hybrid stability and matrix metalloproteinase inhibition by fucosterol in resin-dentin bonding biomechanics.

Fucosterols have been widely studied for their antioxidant, anticancer, and anti-inflammatory properties. However, they have not yet been studied in the field of dentistry. This study aimed to determine whether pretreatment of dentin with fucosterol before resin restoration enhances bond stability in resin-dentin hybrid layers. After applying 0.1, 0.5, and 1.0 wt% fucosterol to demineralized dentin, microtensile bond strength (MTBS) and nanoleakage tests were performed before and after collagenase aging, and the surface was observed using scanning electron microscope (SEM). The fucosterol-treated group showed better bond strength and less nanoleakage both before and after collagenase aging, and the corresponding structures were confirmed using SEM. MMP zymography confirmed that the activity of MMPs was relatively low along the concentration gradient of fucosterol, and the FTIR analysis confirmed the production of collagen crosslinks. In addition, fucosterol exhibits cytotoxicity against Streptococcus mutans, the main cause of dental decay. The results of this study suggest that fucosterol pretreatment improves bond strength and reduces nanoleakage at the resin-dentin interface, possibly through a mechanism involving collagen cross-link formation via the inhibition of endogenous and exogenous MMP activity. This study demonstrates the potential of fucosterol as an MMP inhibitor in dentin, which contributes to long-term resin-dentin bond stability and can be used as a restorative material.

Effect of silver diamine fluoride application on the microtensile bond strength of three commonly used restorative materials in primary teeth: An ultrastructural study.

INTRODUCTION: Caries in primary teeth rapidly advances owing to its thin structure, thereby requiring restoration. However, restorations often fail due to various causes such as secondary caries and reduced microtensile bond strength (µTBS), which calls for the use of antimicrobial agents such as silver diamine fluoride (SDF). AIM: This study aims to measure and analyse the effect of SDF application on the µTBS of three regularly used restorative materials to dentin of primary teeth as well as compare the types of bond failure interfaces under SEM. MATERIALS AND METHODS: The study comprised 60 samples equally divided into six groups among three restorative materials, namely, glass ionomer cement (GIC, Groups I and II), resin-modified glass ionomer cement (RMGIC, Groups III and IV), and composite resin (Groups V and VI) with subdivisions of A and B, where A represented samples with SDF application and B represented samples without SDF application. RESULTS AND OBSERVATIONS: It was observed that µTBS of RMGIC to sound and carious dentin irrespective of SDF application was found to be statistically significant (P < 0.05), and when GIC, RMGIC, and composite resins were compared to both sound and carious dentin irrespective of SDF application, it was statistically significant (P < 0.05). SEM analysis revealed predominantly cohesive failures among all the groups. CONCLUSION: Based on the results, it was concluded that SDF has no adverse effect on the µTBS of GIC, RMGIC, and composite resin to both carious and sound dentin of primary teeth.

A novel injectable boron doped-mesoporous nano bioactive glass loaded-alginate composite hydrogel as a pulpotomy filling biomaterial for dentin regeneration.

BACKGROUND: Different materials have been used as wound dressings after vital pulp therapies. Some of them have limitations such as delayed setting, difficult administration, slight degree of cytotoxicity, crown discoloration and high cost. Therefore, to overcome these disadvantages, composite scaffolds have been used in regenerative dentistry. This study aims to construct and characterize the physicochemical behavior of a novel injectable alginate hydrogel loaded with different bioactive glass nanoparticles in various concentrations as a regenerative pulpotomy filling material. METHODS: Alginate hydrogels were prepared by dissolving alginate powder in alcoholic distilled water containing mesoporous bioactive glass nanoparticles (MBG NPs) or boron-doped MBG NPs (BMBG NPs) at 10 and 20 wt% concentrations. The mixture was stirred and incubated overnight in a water bath at 50 0 C to ensure complete solubility. A sterile dual-syringe system was used to mix the alginate solution with 20 wt% calcium chloride solution, forming the hydrogel upon extrusion. Then, constructed hydrogel specimens from all groups were characterized by FTIR, SEM, water uptake percentage (WA%), bioactivity and ion release, and cytotoxicity. Statistical analysis was done using One-Way ANOVA test for comparisons between groups, followed by multiple pairwise comparisons using Bonferroni adjusted significance level (p < 0.05). RESULTS: Alginate/BMBG loaded groups exhibited remarkable increase in porosity and pore size diameter [IIB1 (168), IIB2 (183) (µm)]. Similarly, WA% increased (~ 800%) which was statistically significant (p < 0.05). Alginate/BMBG loaded groups exhibited the strongest bioactive capability displaying prominent clusters of hydroxyapatite precipitates on hydrogel surfaces. Ca/P ratio of precipitates in IIA2 and IIB1 (1.6) were like Ca/P ratio for stoichiometric pure hydroxyapatite (1.67). MTT assay data revealed that the cell viability % of human gingival fibroblast cells have declined with increasing the concentration of both powders and hydrogel extracts in all groups after 24 and 48 h but still higher than the accepted cell viability % of (˃70%). CONCLUSIONS: The outstanding laboratory performance of the injectable alginate/BMBGNPs (20 wt%) composite hydrogel suggested it as promising candidate for pulpotomy filling material potentially enhancing dentin regeneration in clinical applications.

Effects of lactic acid etching on immediate and aged bond strength of resin-dentin bonding interface.

To investigate the effects of lactic acid etching on the immediate and aged bond strength of the resin-dentin bonding interface, the resin-dentin bonding interface was evaluated 24 hours and 6 months later. A total of 42 isolated third molars were randomly divided into 6 experimental groups according to different lactate concentration (35%, 40%, 45%) and acid etching time (30 s, 45 s), with 37% phosphoric acid etching 15 s as a control. In each group, dentin samples were etched under different acidic conditions and bonded with Adper Single Bond 2 (3M ESPE) as directed. The immediate group was immediately stored in deionized water at 37 °C for 24 h, and the aging group was stored in artificial saliva at 37 °C for 6 months. Immediate and aged bond strengths were measured by a micro-tensile tester, and the specimen fracture surface was observed under a microscope. 14 isolated third molars were randomly divided into 7 groups, and each group was etched with acid. Collagen fibers morphology in dentin was examined after gradient dehydration with ethanol by scanning electron microscopy (SEM). Statistically, there was no difference between the resin-dentin immediate bonding strength of 35% lactic acid for 30 s and 37% phosphoric acid for 15 s, but the aged bond strength was greater than that of the phosphoric acid group. According to scanning electron microscope observations, the collagen fiber morphology in 35% and 40% lactate etching dentin 30 s groups was relatively intact compared with other groups. In conclusion, 35% lactic acid etching of dentin 30 s ensures both immediate and aged resin-dentin bond strength.

Molar enamel-dentine junction shape of Pliobates cataloniae and other Iberian pliopithecoids.

The phylogenetic relationships of the small-bodied catarrhine Pliobates cataloniae (∼11.6 Ma, NE Iberian Peninsula) have been controversial since its original description. However, the recent report of additional dentognathic remains has supported its crouzeliid pliopithecoid status. Based on the available hypodigm, the molar enamel-dentine junction (EDJ) shape of P. cataloniae is compared with that of other pliopithecoids from the same basin as well as both extinct and extant hominoids to further evaluate its pliopithecoid affinities. We also quantitatively compare the EDJ shape among these taxa by means of landmark-based three-dimensional geometric morphometrics using principal component analysis (PCA), canonical variate analysis, and between-group PCA. Permutation tests are performed to test whether Pliobates variation exceeds that of extant hominoid genera. Results indicate that Pliobates is similar in molar EDJ shape to other pliopithecoids, particularly crouzeliids. The variation displayed by Pliobates upper molars is less marked at the EDJ level than at the outer enamel surface, probably owing to differential enamel wear and intraspecific differences in enamel thickness. Multivariate analyses of EDJ shape show that all pliopithecoids (including Pliobates) cluster together in the PCAs, canonical variate analyses, and between-group PCAs and occupy a different portion of the morphospaces from extinct and extant hominoids. Posterior and typicality probabilities strongly support the classification of Pliobates as a pliopithecoid, wheras permutation tests fail to reject the single-genus hypothesis for the P. cataloniae hypodigm. We conclude that P. cataloniae is a crouzeliid pliopithecoid, as recently supported by cladistic analyses of craniodental characters, and that previous cladistic results that supported a stem hominoid status are attributable to postcranial convergences with crown hominoids. Our results further highlight the potential of three-dimensional geometric morphometrics analyses of the EDJ shape for better informing fossil primate alpha-taxonomy by means of quantitatively testing hypotheses about tooth shape variation.

Comparing the remineralization potential of undemineralized dentin powder versus chicken eggshell powder on artificially induced initial enamel carious lesions: an in-vitro investigation.

BACKGROUND: White spot lesions are a widespread undesirable effect, especially prevalent during fixed orthodontic treatments. The study compared the in vitro enamel remineralization potential of undemineralized dentin matrix (UDD) versus chicken eggshell powder (CESP) for artificially induced enamel lesions. METHODS: 100 caries-free and sound maxillary premolars were randomly divided into four groups each contain 25 teeth: Group I (Baseline): No treatment was done to the enamel surface. Group II (Negative control ): The enamel surface of the teeth underwent demineralization using demineralizing solution to create artificial carious lesions then kept in artificial saliva. Group III (CESP treated): After demineralizing the tooth surface, the teeth have been suspended in the CESP remineralizing solution. Group IV (UDD treated): After enamel demineralization, the teeth were suspended in UDD remineralizing solution. The remineralization potential was assessed by Vickers microhardness testing, scanning electron microscopic examination (SEM), and energy dispersive X-ray (EDX). RESULTS: The current study demonstrated an increase in the mean microhardness of CESP and UDD-treated groups; however, It was nearer to the baseline level in the UDD group. SEM imaging revealed greater enamel remineralization in the UDD group compared to the remaining groups. The UDD group disclosed complete coverage for the prismatic enamel compared to the CESP group, which revealed a partially remineralized enamel surface. Interestingly, the Ca/P ratio increased significantly in the CESP group compared to the negative control group. In contrast, a higher significant increase in the mean Ca/P ratios was recorded in the UDD group compared to the test groups. CONCLUSION: biomimetic UDD and CESP powder should be utilized to treat enamel early carious lesions. However, UDD demonstrated the most significant remineralization potential.