The objective of the present study was to investigate the association between the anatomical characteristics of different tooth groups and the diffusion and bleaching effect of hydrogen peroxide (H2O2).
Computed tomography (CT) images from five patients were used to assess the hard tissue thickness and pulp volume (PV) of four tooth groups: lower (mandibular) incisors (LI), upper (maxillary) incisors (UI), canines (C), and premolars (PM). Additionally, 80 bovine tooth disks were divided into four groups (n = 20) to match the thickness of each tooth group studied. All the specimens were exposed to a 35% H2O2 bleaching gel, with 50 µL applied for 45 min during the first, second, and third sessions. Diffusion was evaluated using the peroxidase enzyme method. Color change analyses (∆E, ∆E00, and ∆WID) were performed after the three application sessions and 7 days after the bleaching treatment using a spectrophotometer.
The PM group showed greater thickness and PV, followed by the C, UI, and LI groups (P 0.001). The LI group had six times greater H2O2 diffusion compared with the PM group (P 0.001), while the PM group exhibited a PV nine times larger than the LI group. Furthermore, the LI and UI groups achieved color saturation with one fewer session than the C and PM groups.
Specific tooth groups have anatomical characteristics that interfere with bleaching treatment in terms of the diffusion and whitening effect of H2O2. Furthermore, the diffusion capacity of H2O2 was inversely proportional to the thickness of the tooth groups.

OBJECTIVE: The main aim of the present study was to carry out a scoping review on the differences in degree of conversion of monomers regarding several types resin cements, indirect restorative materials, and light-curing procedures used in dentistry.
METHODS: A bibliographic review was performed on PubMed using the following search items: \"degree of conversion\" OR \"filler\" AND \"resin cement\" OR \"inorganic cement\" AND \"organic\" OR \"radiopacity\" OR \"refractive\" OR \"transmittance\" OR \"type\" AND \"resin composite.\" The search involved articles published in English language within the last thirteen years. A research question has been formulated following the PICO approach as follow: \"How different is the degree of conversion of monomers comparing several types of resin-matrix cements?\".
RESULTS: Within the 15 selected studies, 8 studies reported a high degree of conversion (DC) of the organic matrix ranging from 70 up to 90% while 7 studies showed lower DC values. Dual-cured resin-matrix cements revealed the highest mean values of DC, flexural strength, and hardness when compared with light- and self-polymerized ones. DC mean values of resin-matrix cements light-cured through a ceramic veneer with 0.4 mm thickness were higher (~ 83%) than those recorded for resin-matrix cements light-cured through a thicker ceramic layer of 1.5 mm (~ 77%).
CONCLUSIONS: The highest percentage of degree of conversion of monomers was reported for dual-cured resin-matrix cements and therefore both chemical and light-induced pathways promoted an enhanced polymerization of the material. Similar degree of conversion of the same resin-matrix cement were recorded when the prosthetic structure showed a low thickness. On thick prosthetic structures, translucent materials are required to allow the light transmission achieving the resin-matrix cement.
CONCLUSIONS: The chemical composition of resin-matrix cements and the light-curing mode can affect the polymerization of the organic matrix. Thus, physical properties of the materials can vary leading to early clinical failures at restorative interfaces. Thus, the analysis of the polymerization pathways of resin-matrix cements is significantly beneficial for the clinical performance of the restorative interfaces.

Dental composites are gaining great popularity in restorative dentistry because of their aesthetic appeal and capacity to replicate the natural color of teeth. Nevertheless, their lifespan and durability rely on various factors, such as the polishing technique and the environmental conditions they are exposed to. The study aimed to assess the influence of the method of final polishing of dental composite on the surface roughness and microhardness of materials also considering the environment of different pHs. Disc-shaped samples (5 mm diameter and 2 mm thickness) have been prepared for microhardness and roughness tests from two dental composites: A2 Clearfil Majesty ES 2 Classic and A2D Clearfil Majesty Premium. One-third of samples were polished with polishing discs, OptiDisc, another one-third of samples were polished with Eve Diacomp Twist rubbers and polishing brush with diamond particles, and rest of the samples were stored without any polishing (the control group). Tested materials were incubated in distilled water or acidic buffer (pH = 2) for 3 weeks at a temperature of 37 °C. No statistically significant differences were found for roughness for the two materials tested after incubation in liquids. A decrease in Vicker microhardness was found for Clearfil Majesty ES 2 Classic after soaking in a low pH liquid, and no such relationship was found for Clearfil Majesty Premium. The improved resistance of these materials to the negative oral environment may result in the longer survival of composite restorations in patients with poor diet or diseases, causing a decrease in oral pH.

This report describes multidisciplinary care combining orthodontics and restorative dentistry for a patient with Class II occlusion and stained mandibular and maxillary resin composite veneers. The orthodontic treatment improved severe overjet and malocclusion prior to restorative care. Occlusal assessment was provided with a novel digital device (PlaneSystem, Zirkonzahn) that is integrated with digital workflows for the evaluation of the occlusal plane and condylar path inclination. Diagnostic digital impressions and digital wax-up for intraoral mock-ups led to the patient\'s treatment acceptance. Minimally invasive tooth preparation, final digital impressions, and bonding under dental dam isolation fulfilled the patient\'s esthetic and functional demands with all-ceramic restorations.

Artificial intelligence (AI) is increasingly prevalent in biomedical and industrial development, capturing the interest of dental professionals and patients. Its potential to improve the accuracy and speed of dental procedures is set to revolutionize dental care. The use of AI in computer-aided design/computer-aided manufacturing (CAD/CAM) within the restorative dental and material science fields offers numerous benefits, providing a new dimension to these practices. This study aims to provide a concise overview of the implementation of AI-powered technologies in CAD/CAM restorative dental procedures and materials. A comprehensive literature search was conducted using keywords from 2000 to 2023 to obtain pertinent information. This method was implemented to guarantee a thorough investigation of the subject matter. Keywords included; \"Artificial Intelligence\", \"Machine Learning\", \"Neural Networks\", \"Virtual Reality\", \"Digital Dentistry\", \"CAD/CAM\", and \"Restorative Dentistry\". Artificial intelligence in digital restorative dentistry has proven to be highly beneficial in various dental CAD/CAM applications. It helps in automating and incorporating esthetic factors, occlusal schemes, and previous practitioners\' CAD choices in fabricating dental restorations. AI can also predict the debonding risk of CAD/CAM restorations and the compositional effects on the mechanical properties of its materials. Continuous enhancements are being made to overcome its limitations and open new possibilities for future developments in this field.

Background Glass ionomer cement (GIC) serves as a crucial biomaterial in dental restoration, offering applications in filling, lining, and adhesive procedures. Nevertheless, its mechanical properties often fall short, particularly in regions subjected to considerable stress. To address this issue, zirconia nanoparticles are incorporated at specific levels. Aim To assess the antimicrobial efficacy and compressive resilience of GIC modified with zirconia nanoparticles synthesized through green synthesis methods. Material and methods Zirconia nanoparticles were synthesized via a green method utilizing aloe vera extract in solvent form. These nanoparticles were then mixed into GIC at different concentration levels. Group I incorporated zirconia nanoparticles at a concentration of 3%, Group II at 5%, and Group III at 10%, while Group IV was the control, consisting of traditional GIC. Following that, samples were prepared and underwent characterization through various analytical techniques. The ability to inhibit microbial growth and the compressive resilience of the groups were examined. Microbial inhibition against the bacterial strains was assessed through minimum inhibitory concentration (MIC), and the ability to withstand compression was gauged by measuring the maximum force the specimen could endure before fracturing. Data underwent analysis with Statistical Package for the Social Sciences (IBM SPSS Statistics for Windows, IBM Corp., Version 24.0, Armonk, NY). Repeated measures of analysis of variance (ANOVA) were utilized to gauge average MIC values and compressive strength. Following this, Tukey\'s post hoc test was employed for pairwise comparisons. Results The findings indicated, incorporating zirconia nanoparticles into GIC led to an improvement in its antimicrobial effectiveness, with a noticeable enhancement observed as the weight percent (% wt) of the additive increased. This improvement was notably noticeable in its effectiveness against Streptococcus mutans and Lactobacillus, exceeding that of the control with a noteworthy distinction. Furthermore, there were significant enhancements in compressive strength, in Group I (180.48 ± 1.02), Group II (191.25 ± 0.52), and Group III (197.52 ± 0.75), compared to Group IV (167.22 ± 1.235), with significant disparities (p < 0.05). Conclusion The research illustrates that introducing green-synthesized zirconia nanoparticles into GIC leads to heightened bactericidal potency and compressive resilience when contrasted with the control group (Group IV). Notably, the highest concentration of 10% demonstrated the most favourable antimicrobial attributes alongside enhanced strength. Consequently, integrating green-synthesized zirconia nanoparticles into GIC holds potential as a proficient material. In future studies, there should be an exploration of molecular chemistry and bonding mechanisms to enhance our comprehension of its capabilities.

UNASSIGNED: This study aimed to evaluate dental esthetic screening index (DESI) Intraoral component scores among patients attending Qassim University dental clinics and the factors affecting these scores.
UNASSIGNED: This was a retrospective study that included 150 participants aged 18 years or older with full upper and lower anterior dentitions. Standardized intraoral frontal photographs of the patients\' upper and lower dentitions were acquired from their dental records, and the mean rank DESI intraoral scores were evaluated and compared across the demographic and dental characteristics of the study patients.The mean age of the patients sampled was 33.56; 57 % were female and 43 % were male. The mean DESI Intraoral score was 15.33. DESI scores were significantly higher in patients older than 35 years compared with subjects 35 years old or younger (p = 0.015). DESI scores were increased in patients who had anterior restorations compared with those who did not (p = 0.016).
UNASSIGNED: This was the first study of its kind to use the DESI in a large clinical setting. According to the DESI, most patients attending Qassim University dental clinics had good dentofacial aesthetics. Age and the presence of anterior restorations negatively impacted patients\' dentofacial aesthetics. Sex, the nature of the chief complaint, a history of orthodontic treatments, and teeth bleaching did not affect the DESI scores.

In recent years, significant advancements in dental and periodontal diagnostics have paved the way for improved care. Among the available approaches, laser fluorescence (LF) is a promising method. This case report explores the utilization of a 405 nm diode laser as a diagnostic tool in the non-surgical treatment of biofilm-induced gingivitis, as well as its application in routine daily practice for diagnosing restorations and dental caries. A 24-year-old male patient and a 21-year-old female patient were included. A 405 nm diode laser (Smart M, Lasotronix, Poland) was used as a diagnostic tool with a tip diameter of 8 mm. In case one, the utilization of the 405 nm diode laser enhanced the patient\'s ability to perceive the presence and extent of plaque and calculus, aiding in motivation and education regarding supra-gingival dental biofilm control and it assisted the operator in precisely localizing plaque and calculus, thereby enabling more effective mechanical debridement and ultimately improving treatment outcomes. In the second case, the utilization of the laser facilitated the detection of defective composite fillings aiding in both accurate diagnosis for the operator and effective communication with the patient regarding the need for re-treatment. This study illustrates the potential of the relatively new 405 nm diode laser as a promising diagnostic tool in the daily management of periodontal patients and the detection of defective dental fillings in daily practice.

UNASSIGNED: To determine which components in a new restorative material (Renewal MI) improve its ability to form resin tags within demineralized dentine.
UNASSIGNED: Varied components included polylysine (PLS), monocalcium phosphate (MCP), powder to liquid ratio (PLR), 4-methacryloyloxyethyl trimellitate anhydride (4META), and polypropylene glycol dimethacrylate (PPGDMA). Urethane dimethacrylate (UDMA), containing PPGDMA (24 wt%) and 4META (3 wt%), was mixed with glass filler with MCP (8 wt%) and PLS (5 wt%). PLR was 3:1 or 5:1. Reducing MCP and/or PLS to 4 and 2 wt% respectively or fully removing MCP, PLS, 4META or PPGDMA gave 16 formulations in total. Renewal MI, Z250 (with or without Scotchbond Universal adhesive) and Activa were used as commercial comparators. Collagen discs were obtained by totally demineralizing 2 mm thick, human, premolar, coronal dentine discs by immersion in formic acid (4M) for 48 h. The restorative materials were then applied on top (n = 3), before dissolving the collagen in sodium hypochlorite (15%). SEM/EDX was employed to determine resin tags length, composition, and surface coverage.
UNASSIGNED: Tags were >400, 20 and 200 µm and covered 62, 55 and 39% of the adhesion interface for Renewal MI, Scotchbond and Activa, respectively. With experimental formulations, they were 200 and >400 µm long with high vs. low PLR and composed primarily of polymerized monomers. Percentages of the adhesion interface covered varied between 35 and 84%. Reducing PLS or MCP caused a decline in coverage that was linear with their concentrations. Reducing MCP had lesser effect when PLS or PLR were low. Removal of 4META caused a greater reduction in coverage than PPGDMA removal.
UNASSIGNED: PLS, MCP, 4META, PPGDMA and low PLR together enhance Renewal MI tags formation in, and thereby sealing of, demineralized dentine.

BACKGROUND: Occlusal contacts can be stained and thereby visualised employing occlusal indicators. Qualitative and quantitative indicators are differentiated. The hybrid system OccluSense supposedly combines analogue contact marking and digital registration of contacts. The reliability and validity of its contact marking have not yet been validated.
OBJECTIVE: The aim of this controlled randomised in-vitro study was to examine the reliability and validity of analogue contact staining with OccluSense compared to Arti-Fol and the reference standard Gnatho-Film.
METHODS: An experimental apparatus was designed to simulate static occlusion. The occlusal contacts were stained 50 times with Gnatho-Film to determine the average number and location of contacts registered. For comparison, the contacts were pre-stained with Gnatho-Film and then registered with Arti-Fol or OccluSense 50 times each. Every staining was statistically evaluated and compared to Gnatho-Film alone, regarding the number and location of contacts. Based on the observed characteristic staining behaviour of OccluSense, a modified evaluation strategy was developed for its colour markings (OccluSense (mod.)).
RESULTS: Both evaluations of OccluSense determine that the same number of contacts was registered in over 94% of all cases. Neither OccluSense nor Arti-Fol stain the exact same number of contacts as Gnatho-Film, but the modified evaluation OccluSense (mod.) did improve the results for validity.
CONCLUSIONS: When employing the modified evaluation strategy, OccluSense staining achieves similar reliability and validity as the reference standard. Pre-colouring of occlusal contacts with Gnatho-Film and the modified evaluation strategy, might become standard for analysing occlusal contacts stained by OccluSense in the future.