Dentin Exposure Research Articles

Study on bionic mineralization of dentin using gallic acid as a linker for calcium phosphate nanocluster formation and collagen modification

Dentin hypersensitivity and dental caries are prevalent symptoms and diseases in the oral cavity that markedly affect quality of life. The etiology of these conditions is directly or indirectly associated with the process of dentin demineralization and exposure. It is therefore imperative to identify an effective method for mineralizing demineralized dentin and sealing exposed dentin tubules. This study examines the potential of gallic acid, a polyphenol with a strong affinity for type I collagen, as a building block for calcium phosphate nanoclusters, with varying ratios of gallic acid to calcium. The objective is to utilize gallic acid as a linker to facilitate the docking, deposition, and mineralization of calcium phosphate nanoclusters and type I collagen. The study revealed that when the ratio of calcium to gallic acid was 0.05, calcium phosphate nanoclusters with an approximate particle size of 11.62 nm were formed. The nanoclusters were observed to effectively mineralize the intrafibrillar and interfibrillar spaces of type I collagen fibers, as well as the dentin itself. Following the mineralization treatment, the mechanical properties of the demineralized dentin were restored, and the depth of dentin tubule occlusion of 46.84 ± 12.83 μm, significantly reducing the permeability of dentin. This strategy demonstrates potential for clinical applications in the restoration of demineralized dentin and the treatment of dentin hypersensitivity.

Generational shift for clinical application of the QLF system for evaluating tooth wear

BackgroundNo study has quantitatively assessed tooth wear using a clinical quantitative light-induced fluorescence (QLF) system. This study aimed to compare fluorescence parameters (ΔFwear) between the research QLF system (QLF-D) and clinical QLF system (Qraycam Pro) and evaluate the validity of both systems in detecting dentin exposure from tooth wear. MethodsThirty-five human molars and premolars were collected. Two blinded examiners conducted evaluations. Images from QLF-D and Qraycam Pro were captured and analyzed by the first examiner to calculate ΔFwear, representing the maximum fluorescence intensity for occlusal wear. The stage of tooth wear was determined by the second examiner using the tooth wear index (TWI). The area of interest (AOI) was determined as the cusp without defects, such as caries or fractures. Only areas mutually agreed by both examiners were included in analysis. The Kruskal-Wallis test was conducted to assess differences in ΔFwear between two devices. ROC analysis evaluated the validity of both systems in determining dentin exposure using AUROC. ResultsThirty-eight AOIs were analyzed. ΔFwear significantly increased with higher TWI scores. Median ΔFwear for TWI scores (0, 1, and 2) were 6.9 %, 10.3 %, and 24.8 %, respectively, for QLF-D, and 5.7 %, 7.7 %, and 23.9 %, respectively, for Qraycam Pro. No significant differences in ΔFwear were observed between QLF-D and Qraycam Pro for any TWI score. The AUROC for both systems was 0.95. ConclusionΔFwear was comparable between QLF-D and Qraycam Pro and demonstrated high validity in detecting dentin exposure. These findings support the clinical application of the QLF for quantitative tooth wear assessment.

Efficacy and safety of TiF4 varnish in preventing erosive tooth wear in a rat animal model

An animal model was applied to develop erosive tooth wear (ETW) and to evaluate the efficacy and safety of titanium tetrafluoride (TiF4) in preventing ETW. Forty-eight male Wistar rats were divided into three groups (n = 16): TiF4 (2.45% F−), NaF (2.45% F−) and placebo varnishes. Eight from each group were subjected to erosive challenges (Sprite Zero) and the other received tap water, both ad libitum. After twenty-eight days, the mandibles were resected for histopathological gingival analysis, clinical and microscopic tooth evaluation by 3D confocal laser microscopy, scanning electron microscopy (SEM-EDX) and micro-Raman spectroscopy (MRS). Organs were evaluated with respect to fluoride content. No significant difference was found in F content in tissues. No histopathological damage was seen in gingiva. ETW was clinically more aggressive in rats from placebo group consuming Sprite compared to water (Q²=12.6, p < 0.01), in accordance with confocal images. TiF4 was superior in reducing cross-section area loss (0.036 ± 0.01µm2) compared to NaF and placebo, respectively (0.044 ± 0.01/0.063 ± 0.01µm2, ANOVA, p < 0.0001). Dentin exposure was detected by SEM in rats belonging to placebo consuming Sprite. Peaks compatible with typical apatite bands were visible. TiF4 reduces the progression of ETW without causing any relevant side-effect and the rats’ model was able to simulate ETW in vivo.

Pongo's ecological diversity from dental macrowear analysis

AbstractObjectivesOrangutans are found in tropical rainforests of Borneo (Pongo pygmaeus) and Sumatra (Pongo abelii and Pongo tapanuliensis), and they are primarily considered frugivorous species. However, ecological studies reported differences in feeding behavior between these species. P. pygmaeus spend more time feeding on low‐quality foods, such as bark and tough vegetation than do P. abelii. The aim of this study is to investigate if there is any geographic variation in molar macrowear pattern between the two species.MethodsWe analyzed the macrowear pattern of second mandibular molars of 58 orangutan specimens combining dental topographic measurements (occlusal relief index, percentage of dentine exposure, and percentage of enamel wear) with the occlusal fingerprint analysis method.ResultsThe molar macrowear patterns of P. abelii and P. pygmaeus show no significant differences in most of the variables examined in this study. While P. pygmaeus molars are generally characterized by flatter occlusal morphology with slightly larger crushing and grinding areas than those of P. abelii, these differences are not statistically significant. However, we do observe a more variable wear in P. pygmaeus.ConclusionsSimilarities in molar macrowear patterns between the two species could be linked to overlapping long‐term diets, primarily composed of ripe and pulpy fruits. Dental macrowear is a cumulative process that occurs during the individual's lifetime, and it may be difficult to detect seasonal changes through its examination. Future studies could integrate tooth micro‐ and macrowear data for a better understanding of primate dental ecology.

Unveiling the Enigma of Molar Incisor Hypomineralisation: Causes, Consequences and Management Strategies

Abstract Molar incisor hypomineralisation (MIH) is a defect in the development of tooth enamel, affecting permanent first molars and incisors. This article explores MIH causes, consequences and management strategies for dental professionals. MIH is widespread, ranging from 2.4% to 40.2% globally. South America has the highest prevalence, while Africa has the lowest. Clinically, MIH presents as demarcated white, yellow or brownish opacities on the enamel surface. Affected teeth are fragile and prone to chipping, hypersensitivity and caries. MIH disrupts the tooth’s structure, increasing the risk of fractures, dentin exposure, pulp inflammation and rapid tooth decay. It can also lead to poor oral hygiene, aesthetic concerns and reduced quality of life for children. The causes of MIH are multifactorial and involve systemic or environmental factors during pre-natal or post-natal tooth development. Potential factors include childhood illnesses, antibiotic use, environmental toxins and Vitamin D deficiency. Early diagnosis and intervention are crucial for MIH management. Treatment options depend on the severity of the condition and may involve remineralisation, desensitisation, fluoride therapy, pit and fissure sealants, restorations or extractions. MIH is a common dental concern in children. Early management by dental professionals can help prevent complications and improve oral health outcomes.

A case of early childhood caries from a Medieval site in Southern Portugal: a multidisciplinary approach.

Dental caries is the most prevalent chronic infectious disease during childhood both in historical and contemporary times, but research focused on the oral health of non-adults from the past is still scant. As such, this study proposes a multidisciplinary approach to the differential diagnosis of severe dental lesions in a medieval non-adult skeleton. The skeleton of a three-year-old child recovered in the medieval necropolis of Cacela Velha (Portugal) was studied through macroscopic, radiological, elemental and stable isotope analyses. This individual exhibited enamel destruction and dentine exposure in both the maxillary and mandibular teeth, with the latter also showing changes in coloration. Elemental analysis showed that his skull presented lower values of Si, Cl, and Ca and higher of Cu compared to the control, while the concentration of P and S were significantly lower in the teeth. Early childhood caries is the most probable diagnosis for the dental lesions observed, apparently stemming from a reticulate of factors that include potential malnutrition, and the consumption of sugars in complementary feeding - even though historical sources point to the scarcity of sugar in Portugal during most of the Middle Ages.

Rethinking Wear Rate Analysis: a New Dentin Exposure Proxy and its Applications to Ancient Chinese Populations

Assessing age through dentin exposure often leads to underestimated age due to assumptions of constant molar wear rate. New methods for age-related dentin exposure accrual could facilitate cross-population comparisons independent of dietary habits and sociocultural strategies. We analyzed 3D dentin exposure surfaces in four Chinese archaeological samples to reveal variations in dentin exposure rates linked to socioeconomic practices. Linear regression models of dentin exposure areas across molar rows showed significant correlations, with the first molars exhibiting steeper slopes and smaller intercepts compared to the second molars, which had intermediate values, and the third molars showing the highest intercepts and lowest slopes. The first molar contributed most to overall dentin exposure in the molar quadrant, while the second molar wore faster post-eruption. Among populations, Banlashan, predominantly agriculturalist; Houtaomuga, focused on fishing; and Jiayi, a nomadic hunting society, displayed similar wear rate patterns. In contrast, Dunping, a Bronze Age nomadic settlement situated on a high-altitude plateau, exhibited distinctively lower wear rates. These observed dentin exposure rates aligned with ecological and dietary constraints, enabling interpopulation comparisons using the proposed 3D dentin exposure proxy. Moreover, the statistical model allows for comparing wear rates across populations relative to dietary habits and potentially estimating age at death for isolated archaeological specimens, whether humans or animals. The precision of this physiological age estimation depends on the regression models used, necessitating further research with specimens of known age at death.

In situ deposition of amorphous zirconia to enhance corrosion and tribocorrosion resistance of dentin surface

With global aging and the prevalence of acidic diets, dentin exposure is becoming commonplace; thus, it is necessary to develop a treatment technology that combines resistance to wear, corrosion, and tribocorrosion. Herein, we present a promising treatment strategy that induces in situ deposition of amorphous zirconia on exposed dentin surface. The deposited amorphous zirconia bonds to dentin surface through strong chemical connection, and acts as a protective layer against acid attack and contact wear due to its acid-inertness and good mechanical properties. Consequently, the treated dentin surface exhibits encouraging corrosion and tribocorrosion performance. The deposit also provides antibacterial protection.

Effects of Endodontic Irrigants on Shear Bond Strength of Mild Universal Adhesives to Dentin

PurposeThe objective of this in vitro study was to evaluate the shear bond strength (SBS) of several universal adhesives to dentin treated with sodium hypochlorite (NaOCl), and NaOCl followed by ethylenediaminetetraacetic acid (EDTA). Materials and MethodsAdhese Universal, Scotchbond Universal, Prime & Bond Elect, Prime & Bond Active, and Optibond XTR were included in the study. SBS values were determined in self-etch mode with no pretreatment of the dentin, after a 20-minute exposure of the dentin to 6% NaOCl, and after a 20-minute exposure to NaOCl followed by a one-minute exposure to 17% EDTA. Experimental groups were repeated using a total-etch technique (except Optibond XTR). ResultsAdhesives in self-etch mode had significantly reduced SBS following dentin exposure to NaOCl (P < .05), while with a total-etch technique, only Prime & Bond Active was affected (P < .05). SBS in self-etch mode when NaOCl exposure was followed by EDTA were equal to or higher than negative control values (P < .05). For total-etch groups, Adhese Universal was negatively affected by NaOCl + EDTA exposure (P < .05). Prime & Bond Elect exhibited lower SBS following NaOCl + EDTA exposure when compared to just NaOCl exposure but was not different from the negative control (P < .05). ConclusionFor the adhesives tested, the use of 17% EDTA following NaOCl exposure negated the negative effects of NaOCl on SBS in self-etch mode. When used in total-etch mode, results varied significantly, with some adhesives performing better or worse depending on the specific testing condition.

Resistance of CAD/CAM composite resin and ceramic occlusal veneers to fatigue and fracture in worn posterior teeth: A systematic review.

Severe tooth wear is related to substantial loss of tooth structure, with dentin exposure and significant loss (≥1/3) of the clinical crown. The objective of this systematic review was to summarize and analyze the scientific evidence regarding the mechanical performance of computer-aided design/computer-aided manufacturing (CAD/CAM) composite resin and CAD/CAM lithium disilicate ceramic occlusal veneers, in terms of fatigue and fracture resistance, on severely worn posterior teeth. Currently, occlusal veneers are an alternative for treating worn posterior teeth. Although scientific evidence demonstrates the good performance of lithium disilicate occlusal veneers, there are less brittle materials with a modulus of elasticity more similar to dentin than ceramics, such as resin CAD/CAM blocks. Therefore, it is important to identify which type of material is best for restoring teeth with occlusal wear defects and which material can provide better clinical performance. This review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A comprehensive search of the PubMed, Embase, Web of Science, Scopus, Cochrane, OpenGrey, Redalyc, DSpace, and Grey Literature Report databases was conducted and supplemented by a manual search, with no time or language limitations, until January 2022. We aimed to identify studies evaluating the fatigue and fracture resistance of CAD/CAM composite resin and ceramic occlusal veneers. The quality of the full-text articles was evaluated according to the modified Consolidated Standards of Reporting Trials (CONSORT) criteria for in vitro studies, and 400 articles were initially identified. After removing duplicates and applying the selection criteria, 6 studies were included in the review. The results demonstrated that the mechanical performance of CAD/CAM composite resin occlusal veneers is comparable to that of CAD/CAM lithium disilicate occlusal veneers in terms of fatigue and fracture resistance.

The Early Iron Age elite grave from the Kapiteljska njiva barrow cemetery (Novo mesto, Slovenia): an approach to dental profiling through non-invasive and minimally-invasive techniques.

Kapiteljska njiva is a prehistoric cemetery located in the town of Novo mesto in southern Slovenia. There is a long history of archaeological research at this site, as the first investigations date back to the end of the 19th century. In 2004, an Early Iron Age barrow XVI was investigated. The oldest surviving grave in the barrow is the central grave, numbered XVI/34, which according to its position and the richness of the grave goods, belongs to a woman of higher status. Most likely, she was the first member or initiator of a family that continued to bury its dead in the barrow for the next 300 years. There were no preserved skeletal elements; however, in the head part of the grave, remains of human teeth, mostly the tooth crowns and the shells of enamel from the tooth crowns, were found among the scattered amber beads of a necklace. Moreover, these tooth remains are one of the few human biological materials (mostly fragments of skull and long limb bones) unearthed in this cemetery, reflecting the influence of acidic soil from the burial site. This study aimed to create a dental profile of the deceased in a similar way as during a forensic investigation. The remains were examined macroscopically and stereo-microscopically. The morphological traits were scored following the ASUDAS protocol. Ancestry was estimated by entering these scores into a beta version of the web-based application rASUDAS. Brothwell's system was used for age at death estimation from occlusal attrition. Identification of sex was based on the analysis of sex-specific amelogenin isoforms in dental enamel by nanoflow liquid chromatography tandem mass spectrometry (nanoLC-MS/MS). The present study reveals that the dental remains from Kapiteljska njiva belong to the permanent dentition of a single individual and that only the right upper central incisor and third molar are completely absent. The remains of teeth exhibit a simple external morphology, characterised by the absence of morphological dental traits, with a notable exception of the two-rooted left lower canine. The probability of assigning this individual to the Western Eurasian ancestry group is 98%. According to the degree of dentine exposure on the occlusal surfaces of molars, the estimated age range is 17-25 years. Another line of evidence comes from the observation that the first signs of approximal attrition are present in lower third molars but absent in the only preserved upper counterpart, indicating that the age at which the lower third molars entered into occlusion represents a proxy of the individual's age at death. Data on the chronology of the lower third molar development and eruption in present-day European populations from forensic literature (Brkić et al. 2011; Olze et al. 2008; Selmanagić et al. 2013) and The London Atlas confirm the above age-range estimate. Caution is, however, needed in the interpretation of results, because reference data are not based on the population of the individual's origin. Proteomic analysis classified the individual as a female, which is in line with the archaeological evidence. No pathological lesions or indicators of systemic stress were identified; however, the absence of approximal attrition facets in upper anterior teeth indicates interdental spacing. The results of dental profiling are discussed in the context of historical background, today's clinical knowledge, and epidemiological data.

A novel mussel-inspired desensitizer based on radial mesoporous bioactive nanoglass for the treatment of dentin exposure: An in vitro study

ObjectivesThe dentin exposure always leads to dentin hypersensitivity and the acid-resistant/abrasion-resistant stability of current therapeutic approaches remain unsatisfatory. Inspired by the excellent self-polymerization/adherence activity of mussels and the superior mineralization ability of bioactive glass, a novel radial mesoporous bioactive nanoglass coated with polydopamine (RMBG@PDA) was developed for prevention and management of dentin hypersensitivity. MethodsRadial mesoporous bioactive nanoglass (RMBG) was synthesized by the sol-gel process combined with the cetylpyridine bromide template self-assembly technique. RMBG@PDA was synthesized by a self-polymerization process involving dopamine and RMBG in an alkaline environment. Then, the nanoscale morphology, chemical structure, crystalline phase and Zeta potential of RMBG and RMBG@PDA were characterized. Subsequently, the ion release ability, bioactivity, and cytotoxicity of RMBG and RMBG@PDA in vitro were investigated. Moreover, an in vitro experimental model of dentin hypersensitivity was constructed to evaluate the effectiveness of RMBG@PDA on dentinal tubule occlusion, including resistances against acid and abrasion. Finally, the Young's modulus and nanohardness of acid-etched dentin were also detected after RMBG@PDA treatment. ResultsRMBG@PDA showed a typical nanoscale morphology and noncrystalline structure. The use of RMBG@PDA on the dentin surface could effectively occlude dentinal tubules, reduce dentin permeability and achieve excellent acid- and abrasion-resistant stability. Furthermore, RMBG@PDA with excellent cytocompatibility held the capability to recover the Young's modulus and nanohardness of acid-etched dentin. ConclusionThe application of RMBG@PDA with superior dentin tubule occlusion ability and acid/abrasion-resistant stability can provide a therapeutic strategy for the prevention and the management of dentin hypersensitivity.

Clinical performance of laminate veneers: A review of the literature.

This narrative review aimed to survey the clinical outcomes of laminate veneers (LVs), including their survival and success rates. An electronic search of MEDLINE/PubMed, Web of Science, Cochrane Library, and Google Scholar from 2000 to April 2023 was conducted using the keywords "laminate" OR "veneer" OR "porcelain" OR "feldspathic" OR "lithium disilicate" OR "composite resin" OR "zirconia" OR "survival" OR "success." Case reports, case series, reviews, abstracts, in vitro studies, and observational studies were excluded. Five researchers independently evaluated the titles and abstracts of all identified studies. A total of 55 studies were identified. None of the studies met the criteria for zirconia LVs. According to the studies in this review, LVs fabricated with feldspathic porcelain, leucite-reinforced glass ceramics (LRG), and lithium disilicate ceramics (LDS) exhibited satisfactory survival and success rates. Furthermore, hydrofluoric acid etching followed by silane priming of the surface of ceramic LVs is necessary for improved clinical outcomes. The extent of dentin exposure significantly decreases the success rate of ceramic LVs. An appropriate adhesive luting process is required to achieve the long-term success of ceramic LVs. Dentin exposure should be minimized or sealed during tooth preparation to achieve a reliable and durable bond between LVs and abutment teeth. Based on this narrative review of the literature, the use of silica-based ceramic feldspathic porcelain, LRG, and LDS is recommended for LVs.

Вивчення взаємозв’язку між гастро- езофагеальною рефлюксною хворобою, бруксизмом та ерозивними ураженнями твердих тканин зубів у практиці лікарів-стоматологів

Introduction. A recent study found a relationship between bruxism, gastroesophageal reflux disease (GERD), and tooth loss, which may act in concert to attack tooth hard tissue both chemically (reflux) and mechanically (bruxism). Because bruxism is closely associated with symptomatic GERD, and patients with frequent bruxism symptoms tend to have GERD for long periods of time, dentists should consider assessment of GERD status as an integral part of the medical evaluation of bruxism, especially severe bruxism. The purpose of the study. To study the relationship between confirmed gastroesophageal reflux disease (GERD), bruxism, and erosive lesions of hard dental tissues in 119 patients aged 25–65. Research methods. 119 patients with confirmed GERD who applied to the Department of Orthopedic Stomatology, Digital Technologies and Implantology of the P. L. Shupyk National Hospital of Ukraine during 2021–2024 for the purpose of orthopedic treatment of the loss of hard tooth tissues took part in the study. Group 1 included 56 patients with a non-erosive form, and group 2 — 63 people with an erosive form of GERD. In turn, each of the research groups was further divided into subgroups A and B. Subgroup A included patients with a course of GERD up to 5 years, subgroup B — with a course of GERD more than 5 years. The control group included 17 patients without somatic pathology with a healthy oral cavity. The degree of loss of hard dental tissues was performed using the tooth wear index (TWI), and the assessment of the quality of life of patients with GERD and lesions of hard dental tissues was performed according to the OHIP-14 questionnaire (Oral Health Impact Profile). Statistical data analysis was performed using the STATISTICA program (StatSoft Inc., Tulsa, Oklahoma, USA). The results. In patients diagnosed with GERD, bruxism was found in 58.9% of patients of the 1st and 73.0% of the 2nd group. At the same time, in most cases in both groups, bruxism was detected in subgroups with GERD lasting more than 5 years. A slight loss of hard tissues was determined mainly in patients with GERD up to 5 years of age (3.6% in group 1 and 6.4% in group 2, respectively). The majority of patients of both groups with the course of GERD up to 5 years had a tooth wear index equal to 2 (30.4%—in the 1st and 19.0%— in the 2nd). At the same time, with a long course of GERD, 30.4% of patients of the 1st and 23.8% of patients of the 2nd group had pronounced loss of hard tissues of the teeth (IRR = 3). Complete loss of enamel with exposure of the pulp and exposure of secondary dentin was found in 12.5% of patients of the 1st group with a course of GERD for more than 5 years, in 25.4% of the 2nd (6.4% in subgroup A and in 19%—in subgroup B). According to all questions of the OHIP questionnaire, 14 patients with an erosive form and a long course of GERD had significantly worse indicators. Conclusion. We determined the connection between GERD, bruxism and erosive damage to the teeth. GERD was associated with all types of bruxism with different odds ratios. Long-term GERD led to pronounced loss of hard dental tissues (IRR = 3). It is necessary to emphasize the need for a multidisciplinary approach to the treatment of patients in this category, because somatic pathology can hide dental pathology, and vice versa. Keywords: gastroesophageal reflux disease, damage to hard dental tissues, bruxism, quality of life.

A novel clinical protocol for dentin hypersensitivity management based on regenerative dental gel associated with calcium: A case study in a patient with periodontal disease

Introduction: Dentin hypersensitivity (DH) is defined as pain caused by dentin exposure in response to various stimuli. Patients with periodontal disease (PD) frequently report DH due to root surface exposure or after periodontal treatment. Bioactive agents derived from calcium and/or silicon-based systems, such as REFIX technology, have been used to promote tooth regeneration, with focus on tooth sensitivity treatment. Case Report: Based on this, the efficacy of REFIX gel combined with calcium on the treatment of a DH was evaluated in a PD 45-year-old male patient. The patient’s right and left sides were randomly selected to use one of the prophylaxis dental protocols: REFIX dental gel/calcium (RDGCa) (experimental: 13, 14, 15 teeth) or Pumice Stone (PS) (control: 23, 24, 25 teeth). The products were applied using dental polishing brush during 10 seconds in each tooth surface. Schiff Air Index (SAI) for sensitive teeth (0–3) were performed by applying air jet to each tooth’s vestibular surface for 5 seconds after and before the prophylaxis. The patient reported pain and interruption of the stimulus before and after PS prophylaxis (SAI 3 and 3 respectively). There was a reduction in pain when RDGCa protocol was used (SAI 3—before/SAI 1—after). In this instance, the patient felt the stimulus but did not request to be interrupted. This contrasted with the outcomes of the initial stimulus as well as PS. Conclusion: The results showed that the RDGCa strategy was successful in lowering DH in PD patients.

Is dentin analogue material a viable substitute for human dentin in fatigue behavior studies?

This study aimed to compare the fatigue performance of a lithium disilicate ceramic cemented on different substrates (human dentin and glass fiber-reinforced epoxy resin - GFRER), treated with different types of conditioning (CTR - without surface conditioning; HF5 - 5% hydrofluoric acid; HF10 - 10% hydrofluoric acid; H3PO4 - phosphoric acid 37%; SAND - sandblasting with aluminum oxide). The occlusal surface of human molars (DENT group) (n = 15) was ground for dentin exposure and the root portion was cut, then the dentin slice (2.0 mm thick) was conditioned with 37% phosphoric acid and a dual-curing dental adhesive was applied. The GFRER in a round-rod format was cut into discs (Ø = 10 mm, 2.0 mm thick). Lithium disilicate glass ceramic blocks (IPS e.max CAD, Ivoclar, Schaan, Liechtenstein) were shaped into a cylinder format and cut, resulting in 90 discs (Ø = 10 mm, 1.5 mm thick). The substrate materials of each group were etched according to the groups and the ceramic was etched with 5% hydrofluoric acid for 30 s. A silane coupling agent was applied over the cementation surface in ceramic and GFRER surfaces and a dual cement was used for cementation (ceramic/GFRER or dentin). The disc/disc sets were submitted to thermocycling (25,000 cycles + storage for 6 months), and then tested in step-wise accelerated cyclic fatigue test. The failure pattern and topography were analyzed and the roughness and contact angle were measured before and after surface treatment. The DENT group presented the lowest load to failure values and number of cycles to failure in fatigue (637.33 N; 118.333), showing no statistical similarity with any of the other tested groups (p < 0.05). The topographic analysis showed that all proposed surface treatments modified the substrate surface when compared to the CTR group. All of the fractographical inspections demonstrated failure by radial crack. Considering the roughness analysis, the post-etched DENT group showed similar roughness to all groups of GFRER materials with their surface treated, except for SAND, which showed greater roughness and statistically different from the other groups. The DENT group (49.5) showed statistically different post-conditioning contact angle values from the HF10 group (96.5) and similar to the other groups. The glass fiber-reinforced epoxy resin was not able to simulate the results presented by the human dentin substrate when cemented to lithium disilicate regarding fatigue failure load and number of cycles for failure, regardless of the surface treatment. Lithium disilicate cemented on dentin analogue overestimates the load values for fatigue failure.

Assessment of Nanoscale Configuration of Dentin in Non-carious Cervical Lesions.

Introduction Non-carious cervical lesions (NCCLs) are structural deformities or tissue loss in the cervical region of teeth, which are closer to the gum linethat do not result from caries (tooth decay). On the tooth enamel at the gingival margin, these lesions are frequently seen as V- or U-shaped notches. The causes of NCCLs are multifaceted and involve intricate relationships between chemical, mechanical, and biological elements. The slow loss of enamel and dentin in the cervical area occurs due to mechanical causes like abrasive toothbrushing and occlusal tension, as well as chemical variables such as erosive acidic food components. As NCCLs advance, dental discomfort, aesthetic issues, and impaired tooth function may result. The aim of this study was to assess the nanoscale configuration of dentin in non-carious cervical lesions using scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS). Methodology Sterilized teeth samples were selected from the extracted tooth repository of Saveetha Dental College and Hospitals, Chennai. Tooth samples were thinly sliced using a diamond bur. The sliced teeth were examined using a scanning electron microscope. Ionic configuration was assessedusing EDS and elemental analysis. Results The findings showed the nanoscale morphology and elemental configurations present. Elemental mapping showed specific elemental localization in the affected area. Conclusion NCCLs can be attributed as a predominant factor leading to gingival recession causing dentin exposure and hypersensitivity. NCCLs can also threaten the integrity of dentin; therefore, early diagnosis of non-carious cervical lesions is crucial to ensure proper treatment plan and therapeutic regimens.

Sensory nerves, but not sympathetic nerves, promote reparative dentine formation after dentine injury via CGRP-mediated angiogenesis: An in vivo study.

Dental pulp is richly innervated by nerve fibres, which are mainly involved in the sensation of pain. Aside from pain sensation, little is known regarding the role of dental innervation in reparative dentine formation. We herein generated a mouse model of experimental dentine injury to examine nerve sprouting within the odontoblast and subodontoblastic layers and investigated the potential effects of this innervation in reparative dentinogenesis. Mouse tooth cavity model (bur preparation + etching) was established, and then nerve sprouting, angiogenesis and reparative dentinogenesis were determined by histological and immunofluorescent staining at 1, 3, 7, 14 and 28 days postoperatively. We also established the mouse-denervated molar models to determine the role of sensory and sympathetic nerves in reparative dentinogenesis, respectively. Finally, we applied calcitonin gene-related peptide (CGRP) receptor antagonist to analyse the changes in angiogenesis and reparative dentinogenesis. Sequential histological results from dentine-exposed teeth revealed a significant increase in innervation directly beneath the injured area on the first day after dentine exposure, followed by vascularisation and reparative dentine production at 3 and 7 days, respectively. Intriguingly, abundant type H vessels (CD31+ Endomucin+ ) were present in the innervated area, and their formation precedes the onset of reparative dentine formation. Additionally, we found that sensory denervation led to blunted angiogenesis and impaired dentinogenesis, while sympathetic denervation did not affect dentinogenesis. Moreover, a marked increase in the density of CGRP+ nerve fibres was seen on day 3, which was reduced but remained elevated over the baseline level on day 14, whereas the density of substance P-positive nerve fibres did not change significantly. CGRP receptor antagonist-treated mice showed similar results as those with sensory denervation, including impairments in type H angiogenesis, which confirms the importance of CGRP in the formation of type H vessels. Dental pulp sensory nerves act as an essential upstream mediator to promote angiogenesis, including the formation of type H vessels, and reparative dentinogenesis. CGRP signalling governs the nerve-vessel-reparative dentine network, which is mostly produced by newly dense sensory nerve fibres within the dental pulp.

Guided Tissue Regeneration in Class IV External Cervical Resorption: A Case Report

External cervical resorption (ECR) is a type of dental resorption that originates from the loss of the cementum's protective layer. The direct exposure of dentin to the periodontal ligament may lead to the invasion of clastic cells through an entry point on the external root surface into the dentinal tissue, causing resorption. Depending on the extension of ECR, different treatments are proposed. Although the literature presents distinct materials and methods for restoring ECR areas, an existing gap is related to care in the treatment of the supporting periodontal tissue. Guided tissue regeneration (GTR)/guided bone regeneration includes the stimulation of bone formation in bone defects using different types of membranes (resorbable and nonresorbable), regardless of its association with bone substitutes or grafts. Despite the benefits of guided bone regeneration, the application of this method in cases of ECR is still under-explored in the literature. Thus, the present case report uses GTR with xenogenic material and polydioxanone membrane in a case of class IV ECR. The success of the present case is related to the correct diagnosis and treatment plan. Complete debridement of resorption areas and restoration with biodentine were effective in tooth repair. GTR contributed to the stabilization of supporting periodontal tissues. The association of the xenogeneic bone graft with the polydioxanone membrane proved to be a viable option for restoring the health of the periodontium.

Dental topography of the Oligocene anthropoids Aegyptopithecus zeuxis and Apidium phiomense: Paleodietary insights from analysis of wear series

Fossil primate dietary inference is enhanced when ascertained through multiple, distinct proxies. Dental topography can be used to assess changes in occlusal morphology with macrowear, providing insight on tooth use and function across the lifespans of individuals. We measured convex Dirichlet normal energy—a dental topography metric reflecting occlusal sharpness of features such as cusps and crests—in macrowear series of the second mandibular molars of two African anthropoid taxa from ∼30 Ma (Aegyptopithecus zeuxis and Apidium phiomense). Wear was quantified via three proxies: occlusal dentine exposure, inverse relief index, and inverse occlusal relief. The same measurements were calculated on macrowear series of four extant platyrrhine taxa (Alouatta, Ateles, Plecturocebus, and Sapajus apella) to provide an analogical framework for dietary inference in the fossil taxa. We predicted that Ae. zeuxis and Ap. phiomense would show similar patterns in topographic change with wear to one another and to extant platyrrhine frugivores like Ateles and Plecturocebus. The fossil taxa have similar distributions of convex Dirichlet normal energy to one another, and high amounts of concave Dirichlet normal energy ‘noise’ in unworn molars—a pattern shared with extant hominids that may distort dietary interpretations. Inverse relief index was the most useful wear proxy for comparison among the taxa in this study which possess disparate enamel thicknesses. Contrary to expectations, Ae. zeuxis and Ap. phiomense both resemble S. apella in exhibiting an initial decline in convex Dirichlet normal energy followed by an increase at the latest stages of wear as measured by inverse relief index, lending support to previous suggestions that hard-object feeding played a role in their dietary ecology. Based on these results and previous analyses of molar shearing quotients, microwear, and enamel microstructure, we suggest that Ae. zeuxis had a pitheciine-like strategy of seed predation, whereas Ap. phiomense potentially consumed berry-like compound fruits with hard seeds.