Dentin Surfaces Research Articles

The Effect of Actives in Desensitizing and Conventional Mouth Rinses Against Dentin Erosive Wear.

This study evaluated the effect of actives present in conventional and desensitizing mouth rinses on the control of dentin erosive tooth wear. Two hundred and seventy dentin specimens from human molars were prepared. The specimens were randomly allocated into 10 experimental groups (n=10): 4 corresponding to desensitizing mouth rinses, 4 to conventional mouth rinses, a negative control group (C-: distilled water), and a positive control group (C+: 500 ppm fluoride plus 800 ppm tin mouth rinse). Specimens were subjected to an erosion-abrasion cycling model: 5 min immersion in 0.3% citric acid and 60 min exposure to artificial saliva. This procedure was repeated 4x/day for 5 days. Immediately after the first and last erosive challenges, the specimens were brushed with a slurry of fluoride toothpaste for 15 s, with a total of 2 min exposure to the slurry. Afterward, the specimens were exposed to the mouth rinses. Dentin surface loss (SL, in µm) was determined by optical profilometry. Data were statistically analyzed by using Kruskal-Wallis and Dunn's tests (α=0.05). The only mouth rinses that presented significantly lower dentin SL than the C- was a desensitizing one containing sodium fluoride (220 ppm F-) with dipotassium oxalate (1.4%) and the C+ (p<0.001 and p=0.013, respectively), without significant differences between them (p>0.05). Dentin SL of the other groups did not significantly differ from the C- (p>0.05). The combination of sodium fluoride with dipotassium oxalate in a desensitizing mouth rinse showed a promising result against dentin erosive wear, matching the protection offered by a fluoride/tin mouth rinse.

Drug-loaded adhesive microparticles for biofilm prevention on oral surfaces.

The oral cavity, a warm and moist environment, is prone to the proliferation of microorganisms like Candida albicans (C. albicans), which forms robust biofilms on biotic and abiotic surfaces, leading to challenging infections. These biofilms are resistant to conventional treatments due to their resilience against antimicrobials and immune responses. The dynamic nature of the oral cavity, including the salivary flow and varying surface properties, complicates the delivery of therapeutic agents. To address these challenges, we introduce dendritic microparticles engineered for enhanced adhesion to dental surfaces and effective delivery of antifungal agents and antibiofilm enzymes. These microparticles are fabricated using a water-in-oil-in-water emulsion process involving a blend of poly(lactic-co-glycolic acid) (PLGA) random copolymer (RCP) and PLGA-b-poly(ethylene glycol) (PLGA-b-PEG) block copolymer (BCP), resulting in particles with surface dendrites that exhibit strong adhesion to oral surfaces. Our study demonstrates the potential of these adhesive microparticles for oral applications. The adhesion tests on various oral surfaces, including dental resin, hydroxyapatite, tooth enamel, and mucosal tissues, reveal superior adhesion of these microparticles compared to conventional spherical ones. Furthermore, the release kinetics of nystatin from these microparticles show a sustained release pattern that can kill C. albicans. The biodegradation of these microparticles on tooth surfaces and their efficacy in preventing fungal biofilms have also been demonstrated. Our findings highlight the effectiveness of adhesive microparticles in delivering therapeutic agents within the oral cavity, offering a promising approach to combat biofilm-associated infections.

A Novel Hierarchical Cross-Stream Aggregation Neural Network for Semantic Segmentation of 3-D Dental Surface Models.

Accurate teeth delineation on 3-D dental models is essential for individualized orthodontic treatment planning. Pioneering works like PointNet suggest a promising direction to conduct efficient and accurate 3-D dental model analyses in end-to-end learnable fashions. Recent studies further imply that multistream architectures to concurrently learn geometric representations from different inputs/views (e.g., coordinates and normals) are beneficial for segmenting teeth with varying conditions. However, such multistream networks typically adopt simple late-fusion strategies to combine features captured from raw inputs that encode complementary but fundamentally different geometric information, potentially hampering their accuracy in end-to-end semantic segmentation. This article presents a hierarchical cross-stream aggregation (HiCA) network to learn more discriminative point/cell-wise representations from multiview inputs for fine-grained 3-D semantic segmentation. Specifically, based upon our multistream backbone with input-tailored feature extractors, we first design a contextual cross-steam aggregation (CA) module conditioned on interstream consistency to boost each view's contextual representation learning jointly. Then, before the late fusion of different streams' outputs for segmentation, we further deploy a discriminative cross-stream aggregation (DA) module to concurrently update all views' discriminative representation learning by leveraging a specific graph attention strategy induced by multiview prototype learning. On both public and in-house datasets of real-patient dental models, our method significantly outperformed state-of-the-art (SOTA) deep learning methods for teeth semantic segmentation. In addition, extended experimental results suggest the applicability of HiCA to other general 3-D shape segmentation tasks. The code is available at https://github.com/ladderlab-xjtu/HiCA.

Evaluating the Translucency, Surface Roughness, and Cytotoxicity of a PMMA Acrylic Denture Base Reinforced with Bioactive Glasses.

The colonisation of the surface of removable acrylic dentures by various types of microorganisms can lead to the development of various diseases. Therefore, the creation of a bioactive material is highly desirable. This study aimed to develop a denture base material designed to release bioactive ions into the oral environment during use. Four types of bioactive glasses (BAG)-S53P4, Biomin F, 45S5, and Biomin C-were incorporated into the PMMA acrylic resin, with each type constituting 20 wt.% (10 wt.% non-silanised and 10% silanised) of the mixture, while PMMA acrylic resin served as the control group. The specimens were subsequently immersed in distilled water, and pH measurements of the aqueous solutions were taken every seven days for a total of 38 days. Additionally, surface roughness and translucency measurements were recorded both after preparation and following seven days of immersion in distilled water. The cytotoxicity of these materials on human fibroblast cells was evaluated after 24 and 48 h using Direct Contact and MTT assays. Ultimately, the elemental composition of the specimens was determined through energy-dispersive X-ray (EDX) spectroscopy. In general, the pH levels of water solutions containing BAG-containing acrylics gradually increased over the storage period, reaching peak values after 10 days. Notably, S53P4 glass exhibited the most significant increase, with pH levels rising from 5.5 to 7.54. Surface roughness exhibited minimal changes upon immersion in distilled water, while a slight decrease in material translucency was observed, except for Biomin C. However, significant differences in surface roughness and translucency were observed among some of the BAG-embedded specimens under both dry and wet conditions. The composition of elements declared by the glass manufacturer was confirmed by EDX analysis. Importantly, cytotoxicity analysis revealed that specimens containing BAGs, when released into the environment, did not adversely affect the growth of human gingival fibroblast cells after 48 h of exposure. This suggests that PMMA acrylics fabricated with BAGs have the potential to release ions into the environment and can be considered biocompatible materials. Further clinical trials are warranted to explore the practical applications of these materials as denture base materials.

Obtaining data on the penetration of the chemical curing adhesive into the dentin when using different techniques of bond applying

A study aimed at obtaining tomographic data on the penetration of the chemical curing adhesive into the dentin when using different bond application techniques was carried out. High-quality aesthetics, durability, functionality and maximum preservation of hard dental tissues are the result of new adhesive preparation and improvement of the physico-chemical and optical properties of composites, therefore, the study of the optical properties of composites is relevant and promising. The paper presents the appearance of the spectrophotometer, an optical scheme is given and the technical characteristics of the device are given. Samples for studies made in various techniques are presented, and the measurement channel of the device is also shown, where samples were installed to measure the boundaries of the interaction of dental adhesive and dentin in depth. The spectral dependences of the absorption coefficient in the zone of the fixation boundaries of composite tabs with dentin and the boundary areas of the samples are obtained when using the adhesive according to the protocol described in the instructions; when applying with an additional 10-second exposure on the dentine before inflating; when rubbing of the adhesive into the dentine surface for 10 seconds before inflating. The data of the bond penetration into the dentin with usual techniques was revealed.

Particle abrasion as a pre-bonding dentin surface treatment: A scoping review.

This scoping review aims to assess the influence of air abrasion with aluminum oxide and bioactive glass on dentin bond strength. An electronic search was conducted in three databases (PubMed, Cochrane Library, and Embase), on March 3rd, 2023, with previously identified MeSH Terms. A total of 1023 records were screened. Exclusion criteria include primary teeth, air abrasion of a substrate other than sound dentin, use of particles apart from aluminum oxide or bioactive glass, and studies in which bond strength was not assessed. Out of the 1023 records, title and abstract screening resulted in the exclusion of 895 and 67 studies, respectively, while full-text analysis excluded another 25 articles. In addition, 5 records were not included, as full texts could not be obtained after requesting the authors. Two cross-references were added. Thus, 33 studies were included in this review. It is important to emphasize the absence of standardization of air abrasion parameters. According to 63.6% of the studies, air abrasion does not influence dentin bond strength. Moreover, 30.3% suggest improving bonding performance, and 6.1% advocate a decrease. Air abrasion with aluminum oxide does not enhance or impair dentin bond strength. The available data on bioactive glass are limited, which hinders conclusive insights. Dentin air abrasion is a widely applied technique nowadays, with numerous clinical applications. Despite the widespread adoption of this procedure, its potential impact on bonding performance requires a thorough analysis of the existing literature.

Interpretation of the effect of using whitening toothpastes through a literature review

Advertising and marketing play a crucial role in the perception of the effectiveness of whitening toothpastes. The study's aim was to interpret the effect of using whitening toothpastes through a literature review. This study adopted a hermeneutic perspective to interpret the collected data. The implemented methodology was observational, descriptive, cross-sectional, and retrospective. A search was conducted in the PubMed and Google Scholar databases in English, as well as SciELO, Scopus, and Elsevier in Spanish, using key terms in both languages. Ultimately, 25 articles offering valuable and relevant information for the study were analyzed. The study revealed that whitening toothpastes, specifically Colgate Maxwhite, Colgate Luminous White, and Crest with peroxide, stand out for their ability to significantly improve color and provide an effective polish to the dental surface, compared to other brands that do not achieve these results. Additionally, the importance of selecting toothpastes with a Relative Dentin Abrasivity (RDA) index of less than 250 to prevent dental sensitivity and enamel damage is emphasized. Although no significant differences were found in the enamel's microhardness among the pastes evaluated, Crest appears to offer superior resistance on the external surface of the dental tissue. The study's major conclusion underscores the need for an informed choice of whitening toothpastes, prioritizing those with evidence of efficacy in improving dental color and maintaining a low abrasivity index to protect dental health

Evaluating the advancements in a recently introduced universal adhesive compared to its predecessor

Background/purposeThe dental adhesive market is constantly evolving to meet the demands of dentists and patients, but new products and upgrades should be rigorously evaluated before being used in clinical practice. This study investigated the physicomechanical properties and dentin bonding efficacy of a newly upgraded universal adhesive compared to its predecessor. Materials and methodsTwenty-four molars were divided into four groups (n = 6/group) based on adhesive (new vs. predecessor) and application mode [self-etch (SE) vs. etch-and-rinse (ER)] for evaluating their dentin microtensile bond strength (μTBS), failure pattern, and bonding interface. Additional thirty-six molars’ crowns were perpendicularly sectioned to obtain flat mid-coronal dentin discs. The opposing dentin surfaces of each disc received contrasting treatments (new/predecessor adhesive applied in SE/ER mode), resulting in six interventions. The bonded discs (n = 6/intervention) were used to assess the adhesives’ survival probability employing a double-sided μTBS test. The other physicomechanical properties examined were adhesives’ oxygen inhibition layer (OIL), viscosity, hardness, elastic modulus, degree of conversion (DC), and in-situ DC. ResultsBoth adhesive versions showed similar μTBS (P > 0.05), failure pattern (P > 0.05), and survival probability (P > 0.008). ER mode promoted resin tag formation and exhibited a slender adhesive layer for both adhesives. The newer adhesive version showed a thinner adhesive layer in general with narrower OIL (P < 0.001), less viscosity (P < 0.001), higher hardness (P < 0.05), elastic modulus (P < 0.05), DC (P < 0.001), and in-situ DC (P < 0.001). ConclusionWhile the newly updated adhesive had superior physicomechanical properties with more fluidity, its dentin bonding efficacy and survival probability were comparable to its predecessor.

Effect of ethanolic extract of propolis on antibacterial and microshear bond strength of glass-ionomer restorations to dentin

ObjectivesThis study was conducted to evaluate the effect of ethanolic extract of propolis on antibacterial and microshear bond strength of glass ionomer restorations to dentin. Materials and methodsConventional glass ionomer cement (Equia forte, GC Tokyo, Japan), resin-modified glass ionomer (Fuji II LC, GC Tokyo, Japan) and propolis powder (dried extract from honey bees) materials were used in this study. Both conventional glass ionomer and resin-modified glass ionomer were modified by two different concentrations of ethanolic extract of propolis (10 % and 25 % EEP). For antibacterial test, Streptococcus mutans strain was spread on agar petri dishes using a sterile swab. Discs of both glass ionomer restorative materials (without adding EEP, with 10 % EEP and with 25 % EEP) were fabricated within the agar plates. Antibacterial activity was evaluated by measuring the inhibition zones around each disc. For microshear bond strength test, 60 healthy human permanent molars were prepared by cutting occlusal surface and expose the dentin at the height of contour of all teeth then conditioned using poly acrylic acid conditioner, both glass ionomer restorative materials (without adding EEP, with 10 % EEP and with 25 % EEP) were mixed and applied on conditioned dentin surface by using tygon tube. Microshear bond strength was evaluated by the universal testing machine. ResultsTwo-way ANOVA test revealed that both glass ionomer type and different concentrations of EEP had significant effect on the antibacterial test results and microshear bond strength values (p < 0,05). Glass ionomer restorative material with 25%EEP had the highest antibacterial values whereas glass ionomer restorative material without modifications (control groups) had the lowest values. Resin-modified glass ionomer without any modification (control group) had the highest bond strength while resin-modified glass ionomer with 25%EEP had the lowest bond strength. ConclusionsIncorporation of ethanolic extract of propolis to glass ionomer restorative material increases the antibacterial effects of both conventional GIC and RMGI. Inspite of this advantage, it seems that it has deleterious effect on microshear bond strength to dentin.

Dental-dedicated MRI, a novel approach for dentomaxillofacial diagnostic imaging: technical specifications and feasibility.

MRI is a noninvasive, ionizing radiation-free imaging modality that has become an indispensable medical diagnostic method. The literature suggests MRI as a potential diagnostic modality in dentomaxillofacial radiology. However, current MRI equipment is designed for medical imaging (eg, brain and body imaging), with general-purpose use in radiology. Hence, it appears expensive for dentists to purchase and maintain, besides being complex to operate. In recent years, MRI has entered some areas of dentistry and has reached a point in which it can be provided following a tailored approach. This technical report introduces a dental-dedicated MRI (ddMRI) system, describing how MRI can be adapted to fit dentomaxillofacial radiology through the appropriate choice of field strength, dental radiofrequency surface coil, and pulse sequences. Also, this technical report illustrates the possible application and feasibility of the suggested ddMRI system in some relevant diagnostic tasks in dentistry. Based on the presented cases, it is fair to consider the suggested ddMRI system as a feasible approach to introducing MRI to dentists and dentomaxillofacial radiology specialists. Further studies are needed to clarify the diagnostic accuracy of ddMRI considering the various diagnostic tasks relevant to the practice of dentistry.

Immunorecognition of Streptococcus mutans secreted proteins protects against caries by limiting tooth adhesion

IntroductionChildhood caries, a prevalent chronic disease, affects 60–90 % of children in industrialized regions, leading to lesions in both primary and permanent teeth. This condition precipitates hospital admissions, emergency room visits, elevated treatment costs, and missed school days, thereby impeding the child's academic engagement and increasing the likelihood of caries into adulthood. Despite multiple identified risk factors, significant interpersonal variability remains unexplained. The immune system generates a unique antibody repertoire, essential for maintaining a balanced and healthy oral microbiome. Streptococcus mutans is a primary contributor to the development of caries. MethodsEmploying mass spectrometry, we investigated the S. mutans proteins targeted by antibodies in children both with and without caries, delineating a fundamental suite of proteins discernible by the immune systems of a majority of individuals. Notably, this suite was enriched with proteins pivotal for bacterial adhesion. To ascertain the physiological implications of these discoveries, we evaluated the efficacy of saliva in thwarting S. mutans adherence to dental surfaces. ResultsAntibodies in most children recognized a core set of ten S. mutans proteins, with additional proteins identified in some individuals. There was no significant difference in the proteins identified by children with or without caries, but there was variation in antibody binding intensity to some proteins. Functionally, saliva from caries-free individuals, but not children with caries, was found to hinder the binding of S. mutans to teeth. These findings delineate the S. mutans proteome targeted by the immune system and suggest that the inhibition of bacterial adherence to teeth is a primary mechanism employed by the immune system to maintain oral balance and prevent caries formation. ConclusionsThese findings enhance our knowledge of the immune system's function in oral health maintenance and caries prevention, shedding light on how immunoglobulins interact with S. mutans proteins. Clinical SignificanceTargeting S. mutans proteins implicated in bacterial adhesion could be a promising strategy for preventing childhood caries.

Peri-implant Parameters of Dental Implants Inserted in Prefabricated Microvascular Fibular Flaps: A Retrospective Study.

To assess the peri-implant and flap parameters of the prefabricated microvascular fibula flap and determine the dental implant survival rate. This retrospective study investigated a cohort of subjects who received prefabricated microvascular fibula flaps at two highly specialized tumor reconstruction centers. The subjects had all suffered atrophy or a large segmental defect of the jaws due to tumor resection or injury. Two independent surgeons determined the dental implant survival rate and assessed the peri-implant parameters and flap parameters during clinical follow-up. In total, 41 subjects were treated with a prefabricated fibula flap between 1999 and 2012. Of these, 17 subjects (10 male, 7 female) with a total of 62 dental implants were examined. The other 24 subjects were unavailable for assessment and had to be excluded. Ten of the 62 dental implants (16.1%) had to be removed due to peri-implantitis before the follow-up assessment. Follow-up assessments were performed at intervals ranging from 2 to 12 years (mean: 7.2 years) after fibula flap transplantation. The dental implant survival rate was found to be 83.9%. A total of 208 dental surfaces were assessed. Overall, 96% of all surfaces had a pocket depth (PD) of ≤ 4 mm and 4% had a pocket depth of > 5 mm. An attachment level (AL) of 3 mm was measured in 48.5% of implants and ≥ 5 mm was measured in 15.9% of implants. Dental implants with a PD > 4 mm showed a significantly higher plaque index (PI) (75%; P = .0057), papillary bleeding index (PBI) (62.5%; P = .0094), and radiologic bone loss (P = .0014) compared to dental implants with a PD ≤ 4 mm. Reconstructive surgery using microvascular fibula flaps represents an alternative tool for oral rehabilitation in subjects suffering from a large segmental defect in the maxillary or mandibular bone compared to the conventional method. However, it appears that the different ossification processes that develop the fibula and the jawbones affect dental implant survival.

Performance of self-etching adhesives on caries-affected primary dentin treated with glutaraldehyde or silver diamine fluoride

Objectivesto evaluate the quality and stability of adhesive interfaces established by self-etching adhesives on caries-affected primary dentin (CAD) treated with glutaraldehyde (GA) or silver diamine fluoride (SDF). Methods42 primary molars were exposed to a microbiological caries-inducing protocol and divided into 6 groups according to the adhesive system (Clearfil SE - CL or FL Bond II - FL) and pretreatment (water, GA or SDF) applied on CAD. One tooth from each group was analyzed for surface modification using infrared spectroscopy. Crowns were restored with resin composite (n = 36) and cut into beams and slices. The beams were subjected to microtensile testing, Raman spectroscopy and SEM after 24 h and 6 months of storage. The slices were analyzed using Micro-Raman spectroscopy to determine the diffusion zone thickness (DZ) in each period. Data were analyzed by ANOVA and Tukey or Kruskal-Wallis and Dunn tests (α = 0.05%). ResultsSDF reduced the immediate bond strength for both adhesives. The control groups showed a decrease in BS after 6 months in artificial saliva. GA increased immediate DZ for FL, while SDF had the opposite effect on CL. GA decreased the DZ for FL at 6 months. There was a predominance of adhesive failures with areas of cohesive dentin fractures within control groups. SignificanceModifications caused by dentin surface treatments may directly affect the performance of adhesive systems and the quality and stability of adhesive restorations.

Effects of glass fibers reinforced and non-reinforced composite resin on fracture behavior of severely destructed primary incisors and restored with post and core system

ObjectiveTo evaluate fracture resistance and failure type of coronally rehabilitated primary incisors with EverX Flow or Grandio Core post and core with or without fiber post. Materials and MethodsForty-eight extracted maxillary primary incisors were root canal treated and obturated with Metapex. The coronal 4-mm of Metapex was removed to create 3-mm intracanal post space. Next, coronal enamel and radicular dentin surfaces were acid-etched, and a bonding agent was applied and light-cured. Based on intracanal post and 2-mm height core buildup materials, specimens were divided equally (n = 12) into 4 groups as follow; Group I (EverX Flow), Group II (Grandio Core), Group III (Fiber post, and EverX Flow), and Group IV(Fiber post and Grandio Core). The coronal restorations were finalized to 4-mm height using G-aenial Anterior composite and specimens were tested for fracture resistance. Force required to induce fracture was recorded and failure type was examined. ResultsFracture resistance of Fiber post and EverX Flow group was statistically significant high than other tested groups. However, fracture resistance of EverX Flow group showed non-statistically significant difference from that of Fiber post and Grandio Core group. Regarding failure type, no specimen presented root fracture, and all failures were favorable and repairable. ConclusionEverX flow post and core with or without fiber post enhanced fracture resistance of restored primary incisors compared to Grandio Core alone. Clinical relevanceEverX flow post and core system with or without fiber post could be a promising restorative option for severely destructed primary incisors.

Enhancing dentin bonding quality through Acetone wet-bonding technique: a promising approach.

Objective: This paper aimed to assess the impact of the acetone wet-bonding (AWB) technique on dentin bonding and to investigate its potential underlying mechanisms. Materials and Methods: Caries-free third molars were sliced, ground, etched, water-rinsed. Then the specimens were randomly allocated to four groups according to the following pretreatments: 1. water wet-bonding (WWB); 2. ethanol wet-bonding (EWB); 3. 50% (v/v) acetone aqueous solution (50%AWB); 4. 100% acetone solution (AWB). Singlebond universal adhesive was then applied and composite buildups were constructed. The microtensile bond strength (MTBS), failure modes and interface nanoleakage were respectively evaluated after 24h of water storage, 10,000 times of thermocycling or 1-month collagenase ageing. In situ zymography and contact angle were also investigated. Results: Acetone pretreatment preserved MTBS after thermocycling or collagenase ageing (p < 0.05) without affecting the immediate MTBS (p > 0.05). Furthermore, AWB group manifested fewer nanoleakage than WWB group. More importantly, the contact angle of the dentin surfaces decreased significantly and collagenolytic activities within the hybrid layer were suppressed in AWB group. Conclusion: This study suggested that the AWB technique was effective in enhancing the dentin bond durability by increasing the wettability of dentin surface to dental adhesives, removing residual water in the hybrid layer, improving the penetration of adhesive monomer, and inhibiting the collagenolytic activities. Clinical significance: The lifespan of adhesive restorations would be increased by utilization of acetone wet-bonding technique.

The Effect of Different Dentin Desensitizers and Self- Adhesive Resin Cement on Shear Bond Strength: In Vitro Study

Objectives: The aim of this study is to evaluate and compare the bond strength of different dentin desensitizers and self-adhesive resin cements to dentin surfaces. Methods: The flat dentin surfaces of 72 wisdom molar teeth were randomly divided into six groups for bond strength analysis (n=12): Group CP: No desensitizer + Primer II A&amp;B+ Panavia F 2.0, Group CM: No desensitizer+ Primer A&amp;B+ Multilink N, Group TP: Tokuyama Shield Force+ Primer II A&amp;B + Panavia F 2.0, Group TM: Tokuyama Shield Force + Primer A&amp;B+ Multilink N, Group UP: Universal dentin sealant + Primer II A&amp;B+ Panavia F 2.0 and Group UM: Universal dentin sealent + Primer A&amp;B+ Multilink N. The shear bond strength test was performed using a universal testing machine (0.5 mm/min). ANOVA test was used to detect significant differences at a p &lt; 0.05. Results: The results indicated that bond strength values varied according to the desensitizing and resin cement materials (p &lt; 0.05). The Tokuyama Shield Force desensitizer did not affect the bond strength of the resin cements to dentin (p &gt; 0.05). Conclusion: The different types of dentin desensitizer applications affected on the shear bond strength results of the self-adhesive resin cements.

Undertaking the biological sex assessment of human remains: The applicability of minimally-invasive methods for proteomic sex estimation from enamel peptides

Being a part of the cultural heritage, skeletal human remains and grave objects are often the only evidence of people who lived many years, or even centuries or millennia, ago, and their preservation for future generations is thus of the utmost importance. The first task in analyzing skeletal remains is to build a biological profile of the individual, including in particular a sex estimation. Recently developed proteomic sex analysis, based on the detection of two sex-dependent forms of the amelogenin protein in tooth enamel, could offer a minimally-invasive and reliable approach applicable to both recent and past populations.The aims of the present study are: 1) to validate the proteomic sex estimation approach with a delicate, minimally-destructive protocol using protein etching in recent and sub-recent identified samples of adult individuals; 2) for the first time, to evaluate the invasiveness of the extraction of amelogenin protein from teeth for proteomic analysis via scanning electron microscope (SEM) and microcomputed tomography (micro-CT); 3) to apply the method to an archaeological sample of unknown adult and juvenile individuals.An assemblage of 60 teeth (32 males and 28 females) of recent and sub-recent origin was used to validate the approach. A sub-sample of 20 teeth (10 males and 10 females) was used to assess the invasiveness of the amelogenin extraction procedure. For the application of the method, samples of 15 adult and 32 juvenile teeth, both originating from medieval populations, were used.Proteomic sex estimation achieved 100% accuracy in this sample. An SEM and micro-CT comparison of the dental surfaces before and after chemical treatment showed an approximately 10% loss of enamel and only 2% loss of dentine. The suitability and minimally-invasive character of the protocol for proteomic analysis in biological sex estimation was demonstrated, as was its applicability to archaeological samples.

Bond Strength of a Novel Universal Resin Cement to Dentin with or without an Adhesive Bonding Agent: An In Vitro Study.

The purpose of this study was to evaluate the bond strength and fracture mode of universal resin cement to dentin compared to self-adhesive and adhesive resin cement with and without an adhesive bonding agent. Seventy-two molar teeth were sectioned to expose coronal dentin, divided into three groups, and assigned to RelyX Universal (universal), RelyX Ultimate (adhesive), or RelyX Unicem 2 (self-adhesive) cements from 3M. The 3 groups were further subdivided into 2 subgroups of 12 specimens each, with or without the use of an adhesive bonding agent. Lithium-disilicate discs were bonded to the dentin surface using the cements, stored for 24 hours in distilled water, and subjected to 2,000 thermocycles before shear bond strength testing and fracture mode analysis. Significant differences in bond strength and fracture mode were found between groups based on cement or the use of a bonding agent. Both the universal and adhesive cements had significantly greater bond strengths to dentin with the use of a bonding agent versus no bonding agent. With the self-adhesive cement, there was no significant increase in bond strength to dentin with the use of a bonding agent. The novel universal resin cement had similar bond strengths to dentin as the adhesive cement with the use of a bonding agent, and similar bond strengths as the self-adhesive cement without the use of a bonding agent. The adhesively bonded universal cement had the greatest percentage of mixed and cohesive fractures. When greater adhesion is needed clinically, the novel universal resin cement may be used with an adhesive bonding agent. However, when less adhesion is needed, it could be used without a bonding agent in self-adhesive mode.

Aesthetic rehabilitation on fractured and altered passive eruption anterior teeth: A case report

Objective: This case report aims to present the management of crown fractures with pulpal exposure caused by traumatic injury and a condition called gummy smile or altered passive eruption (APE), through a multidisciplinary approach.&#x0D; Case Report: A 24-year-old male patient came to the Dental Conservation Clinic RSGM Prof Soedomo FKG UGM, complained of broken teeth and pain in the upper front tooth due to an accident. #12 and #21 experienced horizontal discontinuity to the dentine surface and some lines on the labial surface and #11 underwent a fracture with exposure of the pulpal tissue. The patient wants to take care of broken teeth and improve his smiles.&#x0D; Results: A treatment plan was formulated, which consisted of a stepwise treatment including endodontic treatment, crown lengthening, prefabricated glass-fiber post followed by a core build-up, and finally, direct composite to achieve patient satisfaction.&#x0D; Conclusion: The careful planning of a multidisciplinary approach such as endodontics, periodontics, and direct restorations can treat patients with complex aesthetic complaints relating to problems with the tooth and its soft tissues, and immediate restoration for providing a fast, predictable, economical, yet satisfactory result to improves patient self-confidence.

Polyvinylpyrrolidone as a primer for resin-dentin bonding

ObjectiveThis study aimed to investigate the effects of polyvinylpyrrolidone (PVP)-containing primer (PCP) on dentin bonding. MethodsPVP and anhydrous ethanol were used to prepare the PCPs, which were prepared at concentrations of 0.5%, 1%, and 2% (w/v). These PCPs were subsequently applied to the dentin surface, denoted as E1, E2, and E3, respectively. In the control group, no primer was applied. Following the treatment, the dentin surfaces were subjected to analysis using Fourier-transform infrared spectroscopy (FTIR), and the micro-tensile bond strength (MTBS) was evaluated. The failure mode, nanoleakage, and bonding longitudinal section were observed utilizing scanning electron microscopy (SEM). Additionally, the effect of PCPs on matrix metalloproteinases (MMPs) activity was analyzed through an in situ zymography test. Data were subjected to statistical analysis using ANOVA tests (α = 0.05). ResultsSignificant alterations in the infrared resonances associated with collagen cross-linking within the collagen matrix were observed across all PCP groups. The application of PCP demonstrated a noteworthy enhancement in micro-tensile bond strength (MTBS) compared to group C (p < 0.05). Notably, group C exhibited the lowest MTBS (41 ± 7.7 MPa), whereas group E2 demonstrated the highest MTBS (66 ± 11.9 MPa). Even after undergoing aging, the MTBS of the PCP groups remained superior to that of group C (p < 0.05). The resin tag length in the PCP groups was found to be greater than that of group C, and the occurrence of nanoleakage was comparatively lower in the PCP groups, both before and after aging. Additionally, PCP exhibited a dose-dependent inhibition of matrix metalloproteinases (MMPs) activity, which was statistically significant (p < 0.05). ConclusionsThe utilization of PCP Primer exhibits notable enhancements in bond strength, mitigates nano-leakage, and suppresses enzyme activity within the hybrid layer.