Tooth Dentin Research Articles

Effect of enzymatic chemo-mechanical agents on adhesion of composite resin to dentin of permanent teeth: an in vitro study.

To evaluate and compare the effect of two enzymatic chemo-mechanical caries removal agents with conventional caries removal using rotatory instruments on the adhesion of composite resin to dentin of permanent teeth. The sample comprised 30 permanent molars with caries lesions extending to the dentin, randomly distributed into three groups (n = 10 each): 1-Caries removal with rotary instruments (control group); 2-Caries removal with Papacárie Duo® (F&A Laboratório Farmacêutico, São Paulo, Brazil); 3-Caries removal with Brix 3000™ (Brix S.R.L., Carcarañá, Argentina). After caries removal, the specimens were rinsed and dried. Scotchbond Universal™ adhesive (3M, Saint Paul, Minnesota, USA) was actively applied in self-etch mode and light-cured. Resin composite increments were applied using a silicone mold (3 × 3 × 2mm) and light-cured. Shear bond strength (MPa), work-to-debonding (J/m2), and shear modulus (kPa) were evaluated. For statistical analysis, the level of significance was set at 5%. The control group presented significantly higher shear bond strength values (8.50 ± 2.69MPa) compared to the Brix 3000™ group (5.72 ± 1.55MPa, p = 0.008). There were no significant differences between Papacárie Duo® (6.66 ± 0.86MPa) and the other groups (p > 0.05). Regarding work-to-debonding, the Papacárie Duo® group had a significantly higher result (2944.41 ± 450.21J/m2) than the Brix 3000™ group (1189.41 ± 504.13J/m2, p < 0.001) and the control group (967.10 ± 270.01J/m2, p < 0.001). Concerning shear modulus, the control group showed a significantly higher result (558.67 ± 168.96kPa) than the Brix 3000™ group (339.79 ± 143.78kPa, p = 0.008) and the Papacárie Duo® group (223.04 ± 127.30kPa, p < 0.001). While the application of Papacárie Duo® did not negatively affect composite resin adhesion to dentin of permanent teeth, the application of Brix 3000™ reduced adhesive forces, potentially limiting its clinical use. Further investigations are warranted to elucidate the effects of these materials on dentin substrate, particularly through clinical studies.

Assessment of heavy metal contamination in groundwater and its implications for dental and public health

Groundwater contamination with heavy metals is a critical environmental issue, especially in regions heavily reliant on groundwater for drinking purpose. These metals can seep into groundwater from soil and rock weathering or through improper disposal of industrial waste and effluents. Access to safe drinking water is essential for maintaining public health. This study aimed to assess heavy metal contamination in groundwater and its implications for dental and public health. The objective of the study was to measure the concentration of the heavy metals in the dentine of extracted tooth of the study population. The study concurrently measured heavy metal concentrations in groundwater and tooth dentine samples, analyzing demographic profiles, heavy metal correlations, and underlying structures using Principal Component Analysis (PCA). The average level of heavy metals in the groundwater samples varied from 9.763 ± 3.362 μg/L for Cd to 3426.204 ± 875.264 μg/L for Fe. The mean concentrations (μg/g) in teeth dentine showed significant variations, with iron (Fe) ranging from 0.149 ± 0.03 μg/g in water purifiers to 4.62 ± 0.578 μg/g in local water sources. Similar variations were observed for other heavy metals across different water sources. Principal component analysis (PCA) revealed seven principal components, with the first two components explaining 96.1% of the total variance. The findings revealed varied concentrations of heavy metals across all water sources. Statistical analyses underscored the complex relationship between water sources and heavy metal contamination levels, highlighting the need for targeted interventions to improve water quality and mitigate health risks. The study highlights the urgent need for monitoring and mitigation efforts to ensure safe drinking water and mitigate health risks associated with heavy metal contamination.

Influence of different cavity disinfectants on composite adhesion to dentin of primary teeth: an in vitro study

Influence of different cavity disinfectants on composite adhesion to dentin of primary teeth: an in vitro study

Evaluation of ultrasonic and mechanical methods for assessing dentin demineralization in children's permanent teeth in vitro

Relevance. With the advent of advanced methods for functional diagnostics, dentists have gained new opportunities for detecting carious lesions. However, the diagnostic sensitivity of these methods requires further investigation.Purpose. To evaluate the condition of intact and demineralized dentin in children's permanent teeth using both ultrasonic and mechanical methods.Materials and methods. Divided cross-section" models were created from premolars extracted from children for orthodontic purposes. After a 20-day exposure to a demineralizing buffer solution with a pH of 4.5, both the intact and demineralized dentin cross-sections were tested using ultrasonic and mechanical methods.Results. Statistically significant differences were observed in the mean ultrasonic signal speed C between two independent sample groups: intact dentin (Group 1) and demineralized dentin (Group 2), based on Mann-Whitney U-test calculations (p = 0.01). In Group 2, the mean value of C was 27% lower compared to Group 1. Additionally, significant differences were found in the mean ultimate strength σ between two independent groups: intact dentin (Group 3) and demineralized dentin (Group 4), with Group 4 showing a 29.5% reduction in the mean σ value, according to Mann-Whitney U-test calculations (p = 0.01).Conclusion. Demineralization leads to significant changes in both the ultrasonic and mechanical properties of dentin. Statistical analysis of the laboratory test results using the "divided cross-section" model supports the effectiveness and diagnostic sensitivity of the methods applied for evaluating the extent of dentin demineralization.

The Potential of Silver Diamine Fluoride in Non-Operative Management of Dental Caries in Primary Teeth: A Systematic Review

Background and Objectives: Dental caries has seen an increase in untreated cases, leading to significant health and quality-of-life impacts, necessitating innovative approaches like the promising non-operative management with silver diamine fluoride. This study aimed to evaluate the mechanisms of action of silver diamine fluoride on arresting dental caries in primary teeth. Materials and Methods: A systematic search was conducted across MEDLINE (PubMed), Google Scholar, and Wiley Online Library, including both in vivo and in vitro studies published from 1 January 2017 to 16 October 2022. The Cochrane Risk of Bias Tool assessed bias in in vivo studies, while the Quality Assessment Tool for In Vitro Studies evaluated the methodological quality of in vitro studies. Results: Nineteen publications met the inclusion criteria. Two studies indicated that silver diamine fluoride application significantly alters oral microflora, contributing to caries arrest. Additionally, two studies reported increased mineral density and mineral content in demineralised primary teeth, emphasising silver diamine fluoride’s role in promoting remineralisation. Three studies demonstrated significant improvements in surface microhardness, enhancing tooth resistance. However, no significant qualitative changes in bacterial species composition were noted. Modified silver diamine fluoride application techniques, including light curing or laser irradiation, enhanced efficacy, with light curing notably increasing surface microhardness. Based on a limited number of studies, no statistically significant differences in clinical effectiveness were observed with higher silver diamine fluoride concentrations or extended application durations. Conclusions: Silver diamine fluoride effectively induces quantitative changes in oral microflora and enhances the microhardness and mineral density of enamel and dentine in primary teeth, with modified application methods showing potential for improved outcomes.

Bone strength and residual compressive stress in apatite crystals

Residual stresses are omnipresent in composite materials due to fabrication processes. Residual compressive stresses were recently also observed to develop in collagen fibrils during mineralization and residual strains have been reported in a range of bony materials spanning tooth dentin to mammalian and fish bones. Treatments by heat or by irradiation show that compressive residual stresses up the 100 MPa can be released in the mineral by inducing damage to the collagen fibers. This mini-review assembles some of the knowledge about residual stresses in bony nanocomposites and uses a composite model to argue that residual stresses play a major role in enhancing the strength of bone.

Changes in the composition and mechanical properties of dentin in mouse models of diabetes

ObjectivesThis study employed mouse models of type 1 (T1D) and type 2 (T2D) diabetes to characterize the changes in tooth dentin composition and its mechanical properties. MethodsThirty-two mice were used in this study and divided into T1D, T2D and corresponding control groups. Mandibles were extracted 12 weeks after the onset of diabetes, and dentin from the first molars was evaluated in varying regions of the root. The composition was assessed using Raman Spectroscopy. Nanoindentation and Vickers indentation were employed to study the mechanical properties of the tissue. Statistical significance was evaluated by two-way analysis of variance with respect to the diabetic group and region of the tooth (p ≤ 0.05). ResultsIn the T2D model, the mineral-to-collagen ratio, hardness, and storage modulus of the intertubular dentin were significantly reduced compared to tissue from the controls, especially in the cervical regions of the tooth. The reduction in the mineral-to-collagen ratio was also observed in the T1D model, but changes in nanomechanical properties were not evident. However, the bulk hardness of the teeth in the T1D model was lower than in the littermate controls. Optical microscopy revealed significant wear of the tooth crowns in both models of diabetes, which appear to result from parafunctional activities. ConclusionThis study suggests that both type 1 and type 2 models of diabetes are associated with detrimental changes in dentin. Clinical significanceBetter understanding of how diabetes affects dentin and the contributing mechanisms will be key to improving treatments for people with diabetes.

A Comparative Study to Explore the Variability of Heavy Metal Concentration in the Teeth of Residents of Non-gated Versus Gated Societies.

Human populations face increasing exposure to heavy metals, which pose significant health risks. Dental tissues, such as dentin and enamel, provide a reliable biomarker for assessing long-term heavy metal exposure due to their stable nature. This study aims to explore the variability of heavy metal concentrations in the teeth dentine of residents living in gated versus non-gated societies near the Yamuna Riveraround the Jamia Millia Islamia, New Delhi, India. Sixty-nine participants were enrolled, 27 from gated societies and 42 from non-gated societies. Participants underwent elective dental extraction,following whichheavy metal concentrations were measured in extracted tooth dentine using atomic absorption spectrophotometry. Demographic data including age, gender, tooth types, and drinking water sources were recorded. Statistical analysis included Mann-Whitney's test, Spearman correlation heatmap, and principal component analysis (PCA). Residents of non-gated societies exhibited significantly (p< 0.005) higher mean concentrations of heavy metals compared to gated societies except for cadmium (p = 0.495). Subgroup analysis based on drinking water sources revealed significant (p<0.001) variations in heavy metal concentrations, suggesting the influence of water quality on environmental exposure. PCA provided insights into underlying trends and correlations among heavy metal variables. This study provides valuable insights into heavy metal contamination among residents living near the Yamuna River, highlighting disparities in exposure based on residential environment and drinking water sources. Participants from non-gated societies exhibited higher mean concentrations of heavy metals compared to those from gated societies, emphasizing the influence of socio-economic factors, urban infrastructure and environmental management practices on heavy metal accumulation. The study's findings underscore the need for targeted interventions to address heavy metal exposure across diverse population groups, improve water quality standards, and enhance access to safe drinking water.

The influence of different radiotherapy doses on the mechanical properties and microstructure of the enamel and dentin of human premolar teeth.

Radiation therapy is applied in the treatment of head and neck cancer patients. However, oral-health-related side effects like hyposalivation and ahigher prevalence of caries have been shown. This study aims to assess the influence of different radiotherapy doses on the mechanical properties, roughness, superficial microstructure, and crystallinity of the enamel and dentin of human premolar teeth. Specimens (n = 25) were categorized into five groups based on the radiation dose received (0, 10, 30, 50, and 70 Gy). The enamel and dentin of these specimens were subjected to amicrohardness tester, profilometer, atomic force microscopy (AFM), scanning electron microscopy (SEM), and X‑ray diffraction (XRD) before and after different irradiation doses and compared to hydroxylapatite in each group. The data were analyzed using repeated-measures analysis of variance (ANOVA). Therapeutic radiation doses of 30, 50, and 70 Gy led to adecrease in the microhardness and an increase in the average roughness of the enamel, and rougher surfaces were observed in the mixed three-dimensional images. Moreover, in the dentin, asimilar outcome could be observed for more than 10 Gy. The main crystalline phase structure remained hydroxylapatite, but the crystallinity decreased and the crystalline size increased above 10 Gy. The superficial micromorphology revealed granulation, fissures, and cracks in adose-dependent manner. Radiation below 70 Gy had little effect on the hydroxylapatite concentration during the whole experiment. Above aradiation dose of 30 Gy, the micromorphology of the tooth enamel changed. This occurred for dentin above 10 Gy, which indicates that dentin is more sensitive to radiotherapy than enamel. The radiation dose had an effect on the micromorphology of the hard tissues of the teeth. These results illustrate the possible mechanism of radiation-related caries and have guiding significance for clinical radiotherapy.

ZnO and antimonene-based surface plasmon resonance sensor for enamel, dentin, and cementum layer detection in human teeth

ZnO and antimonene-based surface plasmon resonance sensor for enamel, dentin, and cementum layer detection in human teeth

Comparing the Effect of two different deproteinizing agents on shear bond strength and resin dentin interface in dentin of primary teeth (In-vitro study)

Comparing the Effect of two different deproteinizing agents on shear bond strength and resin dentin interface in dentin of primary teeth (In-vitro study)

Proximity to metal-emitting sites and metal concentrations in tooth dentin among children from the St. Louis Baby Tooth Study

Proximity to metal-emitting sites and metal concentrations in tooth dentin among children from the St. Louis Baby Tooth Study

Influence of Different Application Modes of a Universal Adhesive System on the Bond Strength of Bulk-Fill Composite Resin to Enamel and Dentin in Primary Teeth.

The objective of this study was to assess how the application mode of a universal adhesive system affects the microshear bond strength (μSBS) of bulk-fill and conventional composite resins to enamel and dentin in primary teeth. A total of 80 caries-free primary second molars were randomly assigned to eight experimental groups (n = 10) based on the bonding substrate (enamel or dentin), the application mode of the universal adhesive system (etch and rinse [E&R], or self-etch [SE]), and the type of composite resin used (bulk-fill or conventional). After bonding the composite resin to enamel or dentin, the μSBS of the bonded composite resins was measured. The mean μSBS value of bulk-fill composite resin was significantly higher than that of conventional composite resin for both enamel and dentin substrates, regardless of the application mode (p < 0.001). An interaction effect between the bonding substrate and the application mode of the adhesive system was observed, indicating a significant relationship (p < 0.001). The highest μSBS values for primary teeth enamel were achieved using the E&R mode with bulk-fill composite resin, while for dentin specimens, the SE mode with bulk-fill composite resin yielded the highest μSBS values. The μSBS of the E&R group was significantly higher than that of the SE group for enamel specimens (p < 0.001), whereas the μSBS of the SE group was significantly higher than that of the E&R group for dentin specimens (p < 0.001). Bulk-fill composite resin demonstrated higher μSBS in comparison to conventional composite resin. The universal adhesive system exhibited superior performance in the SE mode compared to the E&R mode on primary dentin. Pre-etching the enamel before the application of the universal adhesive enhanced the μSBS to primary teeth enamel, highlighting the importance of selectively acid etching the enamel of primary teeth.

Tracking Childhood Lead Exposure in Early Industrial Romanians

Childhood lead exposure has been linked to severe adverse health outcomes throughout life. Measurements of lead in teeth have established that individuals living in contaminated environments show higher levels compared to individuals living further away, although less is known about when individuals are most susceptible to these exposures. We examined lead (Pb208) concentrations (ppm) in teeth over the first 2.5 years of life in 16 children born in the late 19th to early 20th century throughout Romania. This period of intense industrialization was characterized by increases in mining, coal burning, and oil refining—activities that contaminate air, water, and food with Pb. We hypothesized the distance from an operational mine or oil refinery, or being born in a city, would be positively associated with cumulative dentine Pb exposure (CDPE). We also predicted that Pb exposures would peak in the first six months of life when gastrointestinal (GI) absorption of Pb is likely highest. Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) of sectioned tooth dentine followed by Bayesian statistical analyses revealed that living 30 km or more from a mine or oil refinery did not explain CDPE. However, being born in a city explained 42% of CDPE. All individuals showed maximum Pb exposures after six months of age, likely due to contaminated solid food and/or non-milk liquids. This research demonstrates how tooth formation can be coupled with comprehensive elemental mapping to analyse the context and timing of early-life neurotoxicant exposures, which may be extended to well-preserved teeth from clinical and historic populations.

Weighted Gene Co-expression Network Analysis (WGCNA) of Wnt Signaling Related to Periodontal Ligament Formation: A Bioinformatics-Based Analysis.

Introduction The Wnt signaling pathway is crucial for tooth development, odontoblast differentiation, and dentin formation. It interacts with epithelial cadherin (E-cadherin) and beta-catenin in tooth development and periodontal ligament (PDL) formation. Dysregulation of Wnt signaling is linked to periodontal diseases, requiring an understanding of therapeutic interventions. Weighted gene co-expression network analysis (WGCNA) can identify co-expressed gene modules. Our study aims to identify hub genes in WGCNA analysis of Wnt signaling-based PDL formation. Methods The study used a microarray datasetGSE201313 from the National Center for Biotechnology Information (NCBI) Gene Expression Omnibus to analyze the impact of DMP1 expression on XLH dental pulp cell differentiation and PDL formation. The standardized dataset was used for WGCNA analysis, which generated a co-expression network by calculating pairwise correlations between genes and constructing an adjacency matrix. The topological overlap matrix (TOM) was transformed into a hierarchical clustering tree and then cut into modules or clusters of highly interconnected genes. The module eigengene (ME) was calculated for each module, and the genes within this module were identified as hub genes. Gene ontology (GO) and KEGG pathway enrichment analysis were performed to gain insights into the biological functions of the hub genes. The integrated Differential Expression and Pathway analysis (iDEP) tool (http://bioinformatics.sdstate.edu/idep/; South Dakota State University, Brookings, USA) was used for WGCNA analysis. Results The study used the WGCNA package to analyze 1,000 differentially expressed genes, constructing a gene co-expression network and generating a hierarchical clustering tree and TOM. The analysis reveals a scale-free topology fitting index R2 and mean connectivity for various soft threshold powers, with an R2 value of 5. COL6A1, MMP3, BGN, COL1A2, and FBN2 are hub genes implicated in PDL development. Conclusion The study identified key hub genes, including COL6A1, MMP3, BGN, and FBN2, crucial for PDL formation, tissue remodeling, and cell-matrix interactions, guiding future therapeutic strategies.

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

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). 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. 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. 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. 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.

The Potential Effect of Bisphosphonate on Teeth Enamel and Dentin Formation in Both Normal and Osteoporotic Albino Rats

The Potential Effect of Bisphosphonate on Teeth Enamel and Dentin Formation in Both Normal and Osteoporotic Albino Rats

Assessment of Autogenous Tooth Dentin Graft with Allogenic Bone Graft in the Preservation of Alveolar Ridge: A Clinicoradiographic Study

Abstract Background: Alveolar ridge is dynamic in nature. Preservation of residual alveolar ridge is always desirable. Bone grafts and platelet concentrates can be used for socket preservation. Maintenance of bone volume is essential and various ridge augmentation techniques are used for desirable functional and esthetic outcomes. Aim: Evaluation and comparison of the efficacy of autogenous dentin block versus allograft block in preserving alveolar ridge dimension with 6-month follow-up. Materials and Methods: Twenty subjects indicated for tooth extraction were randomly divided into three groups. In Group I, autogenous dentin graft with platelet-rich fibrin (PRF) membrane was used as socket filling material, Group II: allogenic bone graft with PRF membrane, or Group III: control group (socket left ungrafted). Clinical and radiographic examinations were done using periodontal probe and cone-beam computed tomography. Results: On intragroup comparison of socket size, the mean for Group I was found to be 33.270 mm2 at baseline and 25.358 mm after 12 months for Group II was found to be 53.250 mm2 at baseline and socket fill was 41.875 mm2 at 12 months. Group III was found to be 43.483 mm2 at baseline, and socket fill was 15.063 mm2 at 12 months. On intergroup comparison, the values were found to be statistically nonsignificant both at baseline (12 months postoperatively. The crestal bone loss was 0.975 for Group I, 1.075 for Group II, and 2.925 mm for Group III. Crestal bone loss was seen highest in Group III and lowest for Group I. The mean percentage of socket fill was found to be 80.01% for Group I, 76.13% for Group II, and 34.03% for Group I. Conclusion: A significant amount of radiographic socket fill was appreciated over 12 months in all the three groups. The percentage of socket fill in Group I was 80.01% and in Group II was 76.13% and the difference between them was statistically nonsignificant. Statistically significant socket fill was seen for both Group 1 and Group 2.

Efficacy of silver diamine fluoride on immediate and delayed adhesive strength of resin composite to sound dentin of permanent teeth: an in vitro study

Objectives: How silver diamine fluoride affected the immediate and prolonged adhesive resin composite's resistance to sound dentin of permanent premolars. Procedures: Three groups were identified (total number=30). The manufacturer's recommendations were followed while applying adhesive resin to the dentin surfaces in Group A after they had been etched. In Group B and C, dentin surfaces were treated with silver diamine fluoride and 0.05% NaF respectively. Then etched and bonded as for the control group. Then resin composite build-ups were created. Following this, each group was divided into two subgroups (for each group n=5), subgroup 1 underwent a shear bond strength test by universal test machine after 24 hrs, subgroups 2 the test was done after thermocycling process (300 cycles). The mode of failure was also examined. Results: The type of dentin surface treated with SDF solution was significantly affect shear bond strength (p=0.000) for both periods (immediate and prolonged). However, there were no significant difference between NaF group and control group on shear bond strength (p&lt;0.05) in immediate and prolong periods. On other hand there were statistically no significant differences between immediate and prolonged shear bond strength in SDF group (p=0.850), NaF group (p=0.637) and control group(p=0.794) When dentin surfaces were treated with silver diamine fluoride , there were more adhesive failures not as 0.05% NaF and control group which showed more mixed failures. Conclusion: silver diamine fluoride significantly reduced bond strength of etch and rinse adhesive system. Pretreatment with NaF maintained the shear bond strength of the adhesive to dentin after 300 thermal cycles.

Differnts Effectiveness of 10,600 nm Carbon Dioxide Laser on Enamel Surface

Besides having a modest penetration depth, a carbon dioxide laser operating at 10,600 nm has a strong absorption affinity for water. It's useful for coagulation of bleeding and soft-tissue surgery. Also, its absorption properties are consistent with hydroxyapatite, a mineral found in tooth enamel and dentin. This article examines the current research on the impacts of 10,600 nm Carbon Dioxide Laser on enamel surfaces. When compiling this review's data, we restricted our attention to articles that were made available online. For this study, we utilized the following search terms on "Google Scholar" and "PubMed" websites: CO2 Laser (10,600 nm), Demineralized enamel, Microhardness, enamel erosion, remineralization, fluoride. Only publications written in English from 2005 through June 2023 were included in this review. Priority was given to original articles and clinical research. Conclusion: The 10,600 nm CO2 laser is widely accepted in caries prevention. CO2 lasers have been the subject of much research but have yet to be used in therapeutic settings. Effective laser energy transmission to enamel allows for the transformation of carbonated hydroxyapatite into the purer hydroxyapatite of enamel. The laser enhances fluorides and other caries-preventive ingredients' effectiveness. As a result, resin bonds better to tooth enamel.