Search Results (299)

Three-dimensional printing is commonly used to fabricate provisional dental restorations. Studies have reported that changes in printing orientation affect the physical and mechanical properties of 3D-printed polymeric provisional restorations; however the findings have been inconsistent. Therefore, this systematic review and meta-analysis aims to analyze the articles evaluating the influence of printing orientation on the physical and mechanical properties of 3D-printed polymeric provisional dental restorations. Recommendations provided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed to structure and compose the review. The PICO (Participant, Intervention, Comparison, Outcome) question ordered was: ‘Do 3D-printed provisional dental restorations (P) printed at various orientations (except 0°) (I) exhibit similar physical and mechanical properties (O) when compared to those printed at a 0° orientation (C)?’. An electronic search was conducted on 28 and 29 April 2025, by two independent researchers across four databases (MEDLINE/PubMed, Scopus, Cochrane Library, and Web of Science) to systematically collect relevant articles published up to March 2025. After removing duplicate articles and applying predefined inclusion and exclusion criteria, twenty-one articles were incorporated into this review. Self-designed Performa’s were used to tabulate all relevant information. For the quality analysis, the modified CONSORT scale was utilized. The quantitative analysis was performed on only fifteen out of twenty-one articles. It can be concluded that the printing orientation affects some of the tested properties, which include fracture strength (significantly higher for specimens printed at 0° when compared to 90°), wear resistance (significantly higher for specimens printed at 90° when compared to 0°), microhardness (significantly higher for specimens printed at 90°and 45° when compared to 0°), color stability (high at 0°), and surface roughness (significantly higher for specimens printed at 45° and 90° when compared to 0°). There were varied outcomes in terms of flexural strength and elastic modulus. Full article

Additive manufacturing (AM) has emerged as a transformative technology in dentistry, enabling the production of patient-specific dental applications with reduced costs and fabrication times. Despite the growth of applications, a consolidated understanding of current 3D printing technologies, materials, and performance in dental settings remains fragmented. Here, we perform a Systematic Literature Review (SLR) using the PRISMA protocol, retrieving 19 closely related primary studies. The evidence is synthesized across three axes: application domain, AM technology, and critical quality parameters. Dental restorations, prosthetics, crowns, and implants are the most common applications, while fused deposition modeling, stereolithography, digital light processing, selective laser sintering, and laser-directed energy deposition are the most used technologies. AM materials include polymers, metals, and emerging biomaterials. Key quality determinants include dimensional accuracy, wear and corrosion resistance, and photosensitivity. Notably, biocompatibility and cytotoxicity remain underexplored yet critical factors for ensuring long-term clinical safety. The evidence also suggests a lack of in vivo studies, insufficient tribological and microbiological testing, including limited data degradation pathways of AM materials under oral conditions. Understanding that there are disconnects between the realization of the clinical and the economic benefits of 3D printing in dentistry, future research requires standardized testing frameworks and long-term biocompatibility validation. Full article

This study analyzes 209 dog skeletons from two sites in Wolin (9th–mid-13th century AD) using 100 standard metric variables covering cranial, mandibular, and postcranial elements. Estimated withers height, body mass, age at death, and sex were derived using established methods. The results indicate the presence of at least two to three morphotypes: small spitz-like dogs (40–50 cm, 4–6 kg), medium brachycephalic forms (50–60 cm, 10–15 kg), and larger mesocephalic individuals (up to 65 cm, 20–40 kg). Dogs lived 3–10 years, with both sexes represented. Signs of cranial trauma and dental wear suggest utilitarian roles such as guarding. The size range and morphological diversity point to intentional breeding and trade-based importation. Small dogs likely served as companions or city guards, while medium and large types were used for herding, hunting, or transport. These findings highlight Wolin’s role as a dynamic cultural and trade center, where human–dog relationships were shaped by anthropogenic selection and regional exchange. Full article

Material wear significantly impacts the clinical success and longevity of dental ceramic restorations. This in vivo study aimed to assess the wear behavior of IPS Empress^® glass-ceramic inlays and onlays over 14 years, considering the influence of different antagonist materials. Fifty-four indirect restorations of 21 patients were available for comprehensive wear analysis, with complete follow-up data for up to 14 years. Three-dimensional measurements relied on digitized epoxy resin models produced immediately post-insertion (baseline) and subsequently at 2, 4, and 14 years. The occlusal region on the baseline model was delineated for comparative analysis. Three-dimensional superimpositions with models from subsequent time points were executed to assess wear in terms of average linear wear and volumetric loss. Statistical analyses were conducted in R (version 4.4.1), employing Mann–Whitney U tests (material comparisons) and Wilcoxon signed rank tests (time point comparisons), with a significance threshold of p ≤ 0.05. During the entire study period, an increase in wear was observed at each assessment interval, gradually stabilizing over time. Significant differences in substance loss were found between the follow-up time points, both for mean (−0.536 ± 0.249 mm after 14a) and integrated distance (−18,935 ± 11,711 mm³ after 14a). In addition, significantly higher wear was observed after 14 years with gold as antagonist compared to other materials (p ≤ 0.03). The wear behavior of IPS Empress^® ceramics demonstrates clinically acceptable long-term outcomes, with abrasion characteristics exhibiting stabilization over time. Full article

The aim of translucency-enhancing liquids (TEL) is to locally influence the phase composition of zirconia in order to increase its translucency. This study aimed to determine the influence of TEL on 3Y- and 4Y-TZP zirconia concerning roughness, hardness, wear, flexural strength, dynamic stability and fracture force of fixed dental prostheses after thermal cycling and mechanical loading. Two zirconia materials (4Y-TZP; 3Y-TZP-LA, n = 8 per material and test) were investigated with and without prior application of TEL. Two-body wear tests were performed in a pneumatic pin-on-block design (50 N, 120,000 cycles, 1.6 Hz) with steatite balls (r = 1.5 mm) as antagonists. Mean and maximum vertical loss as well as roughness (Ra, Rz) were measured with a 3D laser-scanning microscope (KJ 3D, Keyence, J). Antagonist wear was determined as percent area of the projected antagonist area. Martens hardness (HM; ISO 14577-1) and biaxial flexural strength (BFS; ISO 6872) were investigated. The flexural fatigue limit BFSdyn was determined under cyclic loading in a staircase approach with a piston-on-three-ball-test. Thermal cycling and mechanical loading (TCML: 2 × 3000 × 5 °C/55 °C, 2 min/cycle, H₂O dist., 1.2 × 10⁶ force á 50 N) was performed on four-unit fixed dental prostheses (FDPs) (n = 8 per group) and the fracture force after TCML was determined. Statistics: ANOVA, Bonferroni test, Kaplan–Meier survival, Pearson correlation; α = 0.05. TEL application significantly influences roughness, hardness, biaxial flexural strength, dynamic performance, as well as fracture force after TCML in 3Y-TZP. For 4Y-TZP, a distinct influence of TEL was only identified for BFS. The application of TEL on 3Y- or 4Y-TZP did not affect wear. TEL application has a strong effect on the mechanical properties of 3Y-TZP and minor effects on 4Y-TZP. All effects of the TEL application are of a magnitude that is unlikely to restrict clinical application. Full article

Three-dimensional (3D) printing has emerged as a transformative technology in dental splint fabrication, offering significant advancements in customization, production speed, material efficiency, and patient comfort. This comprehensive review synthesizes the current literature on the clinical use, benefits, limitations, and future directions of 3D-printed dental splints across various disciplines, including prosthodontics, orthodontics, oral surgery, and restorative dentistry. Key 3D printing technologies such as stereolithography (SLA), digital light processing (DLP), and material jetting are discussed, along with the properties of contemporary photopolymer resins used in splint fabrication. Evidence indicates that while 3D-printed splints generally meet ISO standards for flexural strength and wear resistance, their mechanical properties are often 15–30% lower than those of heat-cured PMMA in head-to-head tests (flexural strength range 50–100 MPa vs. PMMA 100–130 MPa), and study-to-study variability is high. Some reports even show significantly reduced hardness and fatigue resistance in certain resins, underscoring material-specific heterogeneity. Clinical applications reviewed include occlusal stabilization for bruxism and temporomandibular disorders, surgical wafers for orthognathic procedures, orthodontic retainers, and endodontic guides. While current limitations include material aging, post-processing complexity, and variability in long-term outcomes, ongoing innovations—such as flexible resins, multi-material printing, and AI-driven design—hold promise for broader adoption. The review concludes with evidence-based clinical recommendations and identifies critical research gaps, particularly regarding long-term durability, pediatric applications, and quality control standards. This review supports the growing role of 3D printing as an efficient and versatile tool for delivering high-quality splint therapy in modern dental practice. Full article

Background: Dental erosion is the irreversible loss of tooth structure from acid exposure. Its prevalence is rising globally, making it an important oral health concern. However, longitudinal data from Eastern Europe are scarce, especially in Romania. This pilot study aimed to assess the 10-year incidence of dental erosion in Romanian young adults and to compare clinical index scoring with digital scanning. Methods: A 10-year prospective study followed 540 Romanian adults (aged 18–30) selected with no erosive lesions at baseline (Basic Erosive Wear Examination BEWE = 0). Erosive wear was assessed at the 10-year follow-up using BEWE, with 40 participants also undergoing digital intraoral scanning to measure enamel loss (μm). Gender differences were analyzed. Chi-square tests, relative risk, and correlation analyses were performed. Results: After 10 years, 23.2% of participants developed dental erosion. Males exhibited a higher incidence than females (29.9% vs. 17.2%; RR = 1.74, p < 0.001). Among the scanned subset (n = 40), the mean enamel loss was 137 ± 79 µm, with greater wear on palatal vs. buccal surfaces (p = 0.002). BEWE scores were moderately correlated with digital enamel loss (r = 0.58, p < 0.001). Conclusions: Erosion progressed over time in this cohort, with males at higher risk. Digital scanning detected subtle enamel loss not captured by BEWE, indicating greater sensitivity to early changes. BEWE and digital methods provided complementary information; their combined use offers a more comprehensive assessment. Full article

Background and Objectives: Conventional methods for removing cemented fixed prosthetic restorations (FPRs) are unreliable and lead to unsatisfactory outcomes. At their best, they allow the tooth to be saved at the expense of a laborious process that also wears down rotating tools and handpieces and occasionally results in abutment fractures. Restorations are nearly never reusable in any of these situations. Erbium-doped yttrium-aluminum-garnet (Er:YAG) and erbium-chromium yttrium-scandium-gallium-garnet (Er,Cr:YSGG) lasers casafely and effectively remove FPRs, according to scientific studiesre. This study sets out to examine the impact of Er:YAG laser radiation on the debonding of different ceramic restorations, comparing the behavior of various ceramic prosthetic restoration types under laser radiation action and evaluating the integrity of prosthetic restorations and dental surfaces exposed to laser radiation. Materials and Methods: The study included a total of 16 removed teeth, each prepared on opposite surfaces as abutments.y. Based on the previously defined groups, four types of ceramic restorations were included in the study: feldspathic (F), lithium disilicates (LD), layered zirconia (LZ), and monolithic zirconia (MZ). The thickness of the prosthetic restorations was measured at three points, and two different materials were used for cementation. The Er:YAG Fotona StarWalker MaQX laser was used to debond the ceramic FPR at a distance of 10 mm using an R14 sapphire tip with 275 mJ, 20 Hz, 5.5 W, with air cooling (setting 1 of 9) and water. After debonding, the debonded surface was visualized under electron microscopy. Results: A total of 23 ceramic FPRs were debonded, of which 12 were intact and the others fractured into two or three pieces. The electron microscopy images showed that debonding took place without causing any harm to the tooth structure. The various restoration types had the following success rates: 100% for the LZ and F groups, 87% for the LD group, and 0% for the MZ group. In terms of cement type, debonding ceramic FPRs cemented with RELYX was successful 75% of the time, compared to Variolink DC’s 69% success rate. Conclusions: In summary, the majority of ceramic prosthetic restorations can be successfully and conservatively debonded with Er:YAG radiation. Full article

Polymers are essential materials in the fabrication of partial and complete dentures, where their mechanical properties directly impact durability, comfort, and clinical performance. This study examines the influence of different manufacturing temperatures on the surface hardness of polymeric materials used in dental applications. A total of 60 experimental samples with a rectangular shape of Vertex ThermoSens polymer (Vertex Dental, 3D Systems, Soesterberg, The Netherlands) were fabricated through injection molding at 280 °C and 300 °C and analyzed over time to assess changes in their properties. Hardness measurements, conducted using the EQUOTIP Shore D hardness tester (Proceq SA, Schwerzenbach, Canton of Zürich, Switzerland), indicated increased hardness over time, with higher values observed in samples fabricated at 300 °C. A two-way ANOVA was performed to evaluate the statistical significance of temperature and time on hardness, revealing a significant effect (F = 14.73, p = 0.0185). These findings suggest that processing polymers at elevated temperatures improves surface hardness, significant for denture longevity and patient comfort. Increased hardness contributes to greater wear resistance. Optimizing polymer manufacturing conditions can thus lead to improved clinical outcomes, ensuring more durable and biocompatible dental prostheses. Full article

Background: In recent years, thanks to the improvement of adhesive techniques, patients affected by tooth wear, related to erosion and/or parafunctional habits, can undergo restoration by adding only what has been lost of their dentition (additive approach). However, since not all clinicians are convinced that dental rehabilitation should be proposed in the early stages of exposed dentin, several treatments are often postponed. It is important to emphasize that, in the early stages, the clinical approach should remain conservative, focusing on dietary counseling, the modification of harmful habits, fluoride application, and risk factor management. Only when these preventive and non-invasive strategies prove insufficient, and the condition continues to progress, should invasive restorative treatments be considered. Unfortunately, epidemiological studies are reporting an increase in the number of young patients affected by erosive tooth wear, and not intercepting these cases earlier could lead to a severe degradation of the affected dentition. In addition, parafunctional habits are also becoming more frequent among patients. The combination of erosion and attrition can be very destructive, and may progress rapidly once dentin is exposed and the risk factors remain unaddressed. The aim of this report was to present a conservative full-mouth rehabilitation approach for severe erosive lesions and to provide a 10-year follow-up assessing the biological, functional, and esthetic outcomes. Methods: In this article, the postponed restorative treatment of a patient, suffering from severe tooth wear, is illustrated. The patient had sought dental treatment in the past; however, due to the already very compromised dentition, a conventional but very aggressive treatment was proposed and refused. Four years later, when the patient finally accepted an alternative conservative therapy, the tooth degradation was very severe, especially at the level of the maxillary anterior teeth. The combination of three different approaches, Speed-Up Therapy, BOPT (Biologically-Oriented Preparation Technique), and the 3 Step Technique, however, improved the capacity to successfully complete the difficult therapeutic task. Results: The biological goals (maintenance of the pulp vitality of all of the teeth and the minimal removal of healthy tooth structure) were accomplished, relying only on adhesive techniques. Conclusions: The overall treatment was very comfortable for the patient and less complicated for the clinician. At 10-year follow-up, biological, functional, and esthetic success was still confirmed. Full article

The aim of this study was to evaluate the effect of different bleaching protocols, including laser-assisted techniques, on the microhardness, surface roughness, and tribological resistance of selected light-cured composites. Three Estelite Universal Flow composites with different flow properties and G-aenial Universal Flo composites were tested. Each group underwent bleaching procedures using Opalescence agents at 10%, 16%, and 40% concentrations, with and without laser activation. Surface microhardness was assessed using the Vickers method, roughness was measured with 3D confocal laser microscopy, and friction coefficients and wear patterns were evaluated using tribological testing. All bleaching protocols resulted in reduced microhardness and increased surface roughness. The most significant changes were observed after treatment with 40% hydrogen peroxide. Laser application, particularly at 16% concentration of carbamide peroxide, helped to partially mitigate these effects in some materials. Bleaching procedures, especially those involving high peroxide concentrations, significantly deteriorated the surface properties of dental composites, which may have clinical implications for the patients. Full article

Background: The rapidly growing elderly population in Sri Lanka faces multiple challenges, including the ill effects of tooth loss. Tooth loss and denture wear could both affect the amount and variety of food intake of the elders, leading to a state of compromised health. Therefore, it is essential to identify whether both tooth loss and denture wear affect the nutritional status of the elderly. This study evaluated the associations between tooth loss, denture-wearing status, and nutritional levels among a sample of the elderly population attending the Dental Teaching Hospital in Peradeniya, Sri Lanka. Methods: An analytical cross-sectional study was carried out at the Dental Teaching Hospital in Peradeniya, Sri Lanka. Using the G*Power v3.1 statistics software, a sample size of 61 patients aged 60 years and above was determined as the minimum sample size. Data were gathered by means of a self-administered questionnaire, patients’ files, and an examination to identify height and weight for assessing body mass index (BMI). Minitab v18.0 statistical software was used for analysis of data, and a p-value < 0.05 was considered statistically significant. Results: One hundred patients were recruited for this study, and the majority (sixty-seven) were female. The majority (71%) were between the ages of 60 to 69 years. The majority (60%) were denture wearers and 8% had nine or more occluding pairs (of natural teeth), 25% had five to eight, and 67% had four or fewer occluding pairs. Fifty-two percent (52%) were of normal weight, while 40% were over-weight and 8% were underweight, respectively. No statistically significant associations were identified between BMI and the denture status or number of missing teeth (p-values > 0.05). There were no statistically significant associations between the underweight or overweight status and denture wearing or occluding pairs (p-values > 0.05). However, the frequency of grain intake and the number of occluding pairs were significantly associated with each other (p-value = 0.024). Also, the frequency of taking snacks was associated with denture wearing (p-value = 0.006). Conclusions: The nutritional status (BMI) of the elderly does not necessarily correlate with their denture-wearing status or the number of existing occluding pairs/number of missing natural teeth. There is no significant association noted between the denture-wearing status and the food avoidance (soft, hard food, fruits, and grains, except snacks). There is no significant association between the number of occluding pairs available in natural dentition and the avoidance of soft foods or snacks, except for grains. Given the limitations of this study, it can be suggested that nutritional strategies for the elderly population could be designed universally, irrespective of their dentate or denture status. However, further research with a larger cohort is needed to validate these findings. Full article

Multi-principal element alloys (MPEAs) exhibit distinct characteristics compared to conventional single-principal element-based metallic materials, primarily due to their unique design, resulting in intricate microstructural features. Currently, a comprehensive understanding of the fabrication processes, compositional design, and microstructural influence on the tribological and corrosion behavior of multi-component alloys remains limited. While the hardness of MPEAs generally correlates positively with wear resistance, with higher hardness typically associated with improved wear resistance and reduced wear rates, quantitative relationships between these properties are not well established. In this study, the Al₁₀Cr₁₇Fe₂₀NiV₄ alloy was selected as a model system. A homogeneous Al₁₀Cr₁₇Fe₂₀NiV₄ alloy was successfully synthesized via mechanical alloying followed by spark plasma sintering (SPS). To further investigate the correlation between hardness and wear rate, varying concentrations of alumina nanoparticles were incorporated into the alloy matrix as a reinforcing phase. The results revealed that the Al₁₀Cr₁₇Fe₂₀NiV₄ alloy exhibited a single-phase face-centered cubic (FCC) structure, which was maintained with the addition of alumina nanoparticles. The hardness of the Al₁₀Cr₁₇Fe₂₀NiV₄ alloy without nano-alumina was 727 HV, with a corresponding wear rate of 2.9 × 10⁻⁴ mm³·N⁻¹·m⁻¹. The incorporation of nano-alumina increased the hardness to 823 HV, and significantly reduced the wear rate to 1.6 × 10⁻⁴ mm³·N⁻¹·m⁻¹, representing a 45% reduction. The Al₂O₃ nanoparticles effectively mitigated alloy wear through crack passivation and matrix strengthening; however, excessive addition reversed this effect due to the agglomeration-induced brittleness and thermal mismatch. The quantitative relationship between hardness (HV) and wear rate (W) was determined as W = 2348 e^(−0.006HV). Such carefully bounded empirical relationships, as demonstrated in studies of cold-formed materials and dental enamel, remain valuable tools in applied research when accompanied by explicit scope limitations. Full article

Background: Gastroesophageal reflux disease (GERD) is a chronic condition that causes an abrupt decrease in salivary pH in the oral cavity, which can lead to demineralization, erosion, hypersensitivity, functional impairment, and possibly fracture of dental elements. The aim of this clinical study is to compare two types of treatment in patients with dental erosion diagnosed with gastroesophageal reflux. Methods: Thirty patients were enrolled in this randomized clinical trial. Each patient underwent clinical evaluation and esophageal pH measurement, in order to diagnose GERD. After an initial examination and assessment by an experienced dentist, the Trial group (15 patients) was assigned to home treatment with a zinc hydroxyapatite-based toothpaste and a hydroxyapatite-based paste, while the Control group (15 patients) was assigned to home treatment with zinc hydroxyapatite-based toothpaste only. The following indices were measured: Basic Erosive Wear Examination Index (BEWE); Schiff Air Index (SAI); Plaque Index (PI); and Bleeding Score (BS). Each index was assessed at T0 during the first visit, one month (T1), three months (T2), six months (T3), nine months (T4), and 12 months (T5). The Kolmogorov–Smirnov test was used to analyze the normality of the data, while Friedman’s test followed by Dunn’s post hoc test were used to compare the two groups (significance threshold: p < 0.05). Results: The results showed no statistically significant change in the BEWE and SAI indexes (p > 0.05). However, an improvement in dentin sensitivity and BS was observed. Plaque control also improved. Conclusions: The results of this study indicate that the additional hydroxyapatite paste did not significantly improve the outcomes of the study in respect to hydroxyapatite toothpaste alone. However, there was an improvement in the oral health of GERD patients using hydroxyapatite-based remineralizing treatment in terms of oral and periodontal indices calculated. Full article

Background and Objectives: Oral appliances (OAs) are commonly used to manage sleep-disordered breathing conditions, including primary snoring, and offer an alternative treatment for individuals with obstructive sleep apnea (OSA) who cannot tolerate continuous positive airway pressure (CPAP) therapy. Our study analyzed the possible factors associated with higher snoring rates compared with those associated with lower snoring rates. Materials and Methods: A customized dental brace with a tongue compressor was the essential part of the Lin OA (LOA). The compressor is available in various lengths, ranging from 0.5 to 3.0 cm across different versions. The participants wore the LOA throughout the night while sleeping. Their snoring rates were recorded using the SnoreClock app on their cell phones. Results: The analysis included 36 participants, comprising 30 males and 6 females. The participants had a mean age of 44.91 ± 9.96 years, a mean BMI of 26.18 ± 3.50 kg/m², and an average recording duration of 398.27 ± 77.56 min per session. In total, 4052 sleep recordings were analyzed. The number of files for females was less than that for males (563 vs. 3489). In this study, individuals belonging to the highest one-third based on the baseline snoring rate (H group) experienced a significant reduction in snoring, approximately 84.8%, when using the LOA-3 cm device equipped with a 3 cm tongue compressor. The individuals who belonged to the lower two-thirds based on the baseline snoring rate were classified as the L group. Among male participants, snoring decreased by approximately 66.4%. Similarly, among female participants in the L group, snoring decreased by approximately 69.3% when using the LOA-3 cm. Conclusions: In this study, we observed a significant reduction in snoring for the two groups of participants wearing the LOA-3 cm, with the rate decrements ranging from 66.4% to 84.8%. This reduction was more pronounced in the H group than in the male participants in the L group. Further studies are needed to explore the reasons for these findings. Full article