Search Results (944)

We synthesized the current evidence from the literature and conducted a 2 × 3 factorial experiment to quantify the impact of thermocycling on the Vickers microhardness (HV) of dental CAD/CAM materials: VITA ENAMIC (VE, polymer-infiltrated ceramic network) and CERASMART (CS, nanofilled resin-matrix). Sixty polished specimens (n = 10 per Material × Cycles cell; 12 × 2 × 2 mm) were thermocycled at 5–55 °C (0, 10,000, 20,000 cycles; 30 s dwell, ≈10 s transfer) and tested as HV0.3/10 (300 gf, 10 s; five indentations/specimen with standard spacing). Assumptions regarding the model residuals were met (Shapiro–Wilk W ≈ 0.98, p ≈ 0.36; Levene F(5,54) ≈ 1.12, p ≈ 0.36), so a two-way ANOVA (Type II) with Tukey’s HSD post hoc (α = 0.05) was applied. VE maintained consistently higher HV than CS at all cycle levels and showed a smaller drop from baseline: VE (mean ± SD): 200.2 ± 10.8 (0), 192.4 ± 13.9 (10,000), and 196.7 ± 9.3 (20,000); CS: 60.8 ± 6.1 (0), 53.4 ± 4.7 (10,000), and 62.1 ± 3.8 (20,000). ANOVA revealed significant main effects from the material (η²p = 0.972) and cycles (η²p = 0.316), plus a Material × Cycles interaction (η²p = 0.201). Results: Thermocycling produced material-dependent changes in microhardness. Relative to baseline, VE varied by −3.9% (10,000) and −1.7% (20,000), while CS varied by −12.2% (10,000) and +2.1% (20,000); from 10,000→20,000 cycles, microhardness recovered by +2.2% (VE) and +16.3% (CS). Pairwise comparisons were consistent with these trends (CS decreased at 10,000 vs. 0 and recovered at 20,000; VE only showed a modest change). Conclusions: Thermocycling effects were material-dependent, with smaller losses and better retention in VE (PICN) than in CS. These results align with the literature (resin-matrix/hybrids are more sensitive to thermal aging; polished finishes mitigate losses). While HV is only one facet of performance, the superior retention observed in PICN under thermal challenge suggests the improved preservation of superficial integrity; standardized reporting of aging parameters and integration with wear, fatigue, and adhesion outcomes are recommended to inform indications and longevity. Full article

(1) Background: This study aimed to determine the optimum parameters for the treatment of Streptococcus mutans biofilm on clear dental aligners. (2) Methods: A 24-h-old S. mutans biofilm was grown on polyurethane (PU) and poly(ethylene terephthalate glycol) (PETG) aligners. These samples were treated with three chlorhexidine digluconate (CHX)-based antiseptic solutions, manual brushing, and a combination of both, with varying exposure times. The number of adhered bacteria was determined in both untreated and treated samples after sonication. Materials were analyzed with atomic force and scanning electron microscopy, and surface free energy (SFE) values were determined using three different models. (3) Results: Our findings indicated that control strategies do not depend on the type of material. PU and PETG surfaces exhibited similar SFE values (41–45 mJ/m²). Differences in surface roughness were insufficient to cause significant changes in S. mutans behavior. The highest efficacy of all three tested antiseptics was established for the exposure time of 1 min, with efficacy deteriorating just after 3 min. (4) Conclusions: The efficacy of CHX against S. mutans early biofilm is material-independent and time-dependent. The optimal exposure time of 1 min should be combined with brushing, with a general recommendation of the antiseptic-first approach. Full article

Background: Early preventive dental visits are critical to reducing oral diseases in children and establishing lifelong oral hygiene behaviors. The American Academy of Pediatric Dentistry (AAPD) recommends that a child’s first dental visit occur by age one. However, in Saudi Arabia, limited evidence exists on parental awareness, attitudes, and barriers toward this recommendation. Objective: This study aimed to evaluate the timing of the first dental visit among Saudi children and to identify parental knowledge, barriers, and sociodemographic factors associated with compliance with AAPD guidelines. Materials and Methods: A cross-sectional survey was conducted between April and July 2025 at the Pediatric Dental Clinic, King Saud University, Riyadh. A validated, self-administered Arabic questionnaire was distributed both online and in-clinic to Saudi parents of children under 12 years. A total of 465 completed responses were analyzed using descriptive statistics, chi-square tests, logistic regression, and Spearman correlation to assess associations between parental awareness, socioeconomic variables, and compliance. Results: Of the 465 respondents, 39.6% were aware of AAPD guidelines, yet only 30.5% reported compliance with the recommendation of a dental visit by age one. The most cited barriers were lack of time (42%), difficulty accessing clinics (22%), shortage of pediatric dentists (20%), and lack of awareness (16%). Higher parental education (p = 0.003) and income (p < 0.001) were significantly associated with compliance. A moderate positive correlation was observed between early dental visits and regular annual check-ups (ρ = 0.319). Conclusions: Compliance with AAPD guidelines among Saudi parents remains low, largely due to limited awareness and access barriers. Strengthening parental education, community-based programs, and affordable pediatric dental services is essential to promote preventive care and improve oral health outcomes in children. Full article

The biocompatibility of orthodontic materials is crucial for patient safety, especially concerning their possible mutagenic effects. This study aimed to assess the mutagenic potential of three commercially available orthodontic resins using the Ames test. We tested Resin A, Resin B, and Resin C, which consist of a base and an accelerator component. We used Salmonella typhimurium strains TA98, TA100, TA1535, and TA1537, along with TA1538, both with and without metabolic activation (S9 mix), following standardized protocols. After 48 h, we counted the number of revertant colonies and analyzed the data using two-way ANOVA. The Ames test revealed that Resins A and B induced significant mutagenic activity in strains TA100 and TA1535, with increases in revertant colonies up to about +145% compared with controls, while no effects were observed in TA98, TA1537, or TA1538. Resin C (both the complete mix and the base component) also showed mutagenicity in TA100 and TA1535, whereas the accelerator alone was consistently non-mutagenic. Positive controls confirmed the test system’s sensitivity. In conclusion, some orthodontic resins and their components showed mutagenic activity under the tested conditions. This highlights the need for mutagenicity testing as part of the biological safety assessment of dental materials. Full article

Background/Objectives: Fluoride ion plays a crucial role in protecting teeth against caries by re-mineralizing the caries lesion. The objective of this study was to quantify and compare the fluoride release and recharge of restorative dental materials and their correlation with mass stability. Methods: For this study, 5 × 5 × 2 mm blocks were prepared from GIC, RMGI L, GIOMER, Resin Composite, and RMGI R using a customized silicone index. The amount of fluoride released from each material was quantified using a fluoride electrode at 0 h, 1 day, 3 days, 1-week, and 2-week periods. The fluoride recharge of each material was calculated by quantifying the amount of fluoride uptake from high concentration fluoride solution over a period of 1-week. The mass stability of the materials was measured be quantifying the weight loss/weight gain during fluoride release and recharge phase. The correlation of fluoride release/recharge with weight loss/gain were analyzed using Pearson correlation. Results: One-way ANOVA showed a statistically significant difference in the amount of fluoride released from each group (p < 0.05). The maximum amount of fluoride release was observed on the 3rd day in all the groups except the GIC group, which showed an ascending concentration of fluoride release till 2 weeks. One-way ANOVA showed statistically significant differences in weight loss/gain among the rested group (p < 0.05). GIC showed the highest amount of weight loss and weight gain among the tested materials. Conclusions: The GIC material has the highest fluoride release and RMGI L has the highest fluoride recharge capability. The conventional GIC showed the least mass stability during fluoride release/recharge. Full article

Objective: This study aimed to evaluate the effect of incorporating bioactive particles (montmorillonite loaded with chlorhexidine, MMT/CHX) and different concentrations of silica nanoparticles (0%, 3%, 5%, 7%, 10%, and 15 wt%) into a universal dental adhesive on its degree of conversion, bond strength, water sorption, solubility, and antimicrobial activity. Materials and Methods: A universal adhesive was modified with 1 wt% MMT/CHX and varying amounts of silica nanoparticles. Degree of conversion was analyzed by Fourier transform infrared spectroscopy (FTIR), and microtensile bond strength was evaluated at 24 h, 6 months, and 12 months after water storage. Water sorption and solubility were measured according to ISO 4049, and antibacterial activity was tested against Streptococcus mutans using the agar diffusion method. Results: All experimental adhesives containing ≥7% silica showed significantly reduced water sorption and solubility. The presence of MMT/CHX imparted consistent antimicrobial activity across all experimental groups. Degree of conversion remained stable across all groups and storage periods. Notably, after 12 months, only the experimental groups maintained or improved bond strength, while the control group showed a significant reduction. Failure mode analysis indicated increased mechanical integrity with higher filler content. Conclusions: Incorporating 1 wt% MMT/CHX and ≥7 wt% silica into a universal adhesive improved long-term bond strength, reduced degradation, and introduced antibacterial properties without compromising polymer conversion. These findings support the potential of developing durable, bioactive adhesive systems for restorative dentistry. Clinical Significance: The incorporation of bioactive and reinforcing nanoparticles into universal adhesives enhances bond durability and introduces antibacterial properties without compromising polymerization. This innovation may lead to longer-lasting restorations and reduced risk of secondary caries in clinical practice. Full article

The aim of this laboratory study was to evaluate the fitting accuracy of complete-arch implant-supported fixed dental prostheses (ISFDPs) and the occurrence of possible constraint forces after ISFDP fixation using the All-on-four treatment concept. A titanium model was fabricated with support posts for implants in positions 15, 12, 22, and 25. The forces acting on these posts were assessed using strain gauge half bridges. Implants (BEGO Semados^® SCX Implantat 4.1 mm × 10 mm, BEGO Implant Systems, Bremen, Germany) were fixated on top of the support posts. Based on conventional impressions and intraoral scans, two 12-unit monolithic ISFDPs made from cobalt–chromium alloy (CoCr) and zirconia (ZrO₂) were fabricated, jointed with titanium adhesive abutments (PS TiB NH, BEGO), and successively attached to the model. Constraint forces caused by ISFDP fixation were measured for each implant without external force. After testing four ISFDPs with different materials and impression techniques, four new implants were fixated (n = 10 model situations). A standard linear mixed model was used to assess horizontal and vertical constraint forces. The horizontal constraint forces acting on the implants were oriented in the oral direction, indicating that the ISFDPs were too small. The highest constraint forces were measured on implant 22 in the horizontal and vertical directions. Within the limitations of the present laboratory study, the fitting accuracy of complete-arch CoCr and ZrO₂ ISFDPs based on the All-on-four concept was sufficient for clinical use. Restorations made using conventional impressions had better fitting accuracy and reliability than those made using intraoral scans. Full article

Objectives: Rapid maxillary expansion (RME) is widely used in orthodontics to correct transverse maxillary deficiencies. Beyond its skeletal and dental effects, RME may influence upper airway dimensions and respiratory function, particularly in growing individuals. This study aimed to evaluate the impact of RME on pulmonary function in adolescents using spirometric measurements. Materials and Methods: Fifteen adolescent patients (8 females, 7 males; mean age: 13.93 ± 2.89 years) diagnosed with maxillary transverse constriction underwent orthodontic treatment with acrylic-bonded RME appliances over a mean duration of 3.56 ± 0.67 months. Respiratory function was assessed via spirometry at baseline (T0) and one day after appliance removal (T1). Parameters recorded included peripheral oxygen saturation (SpO₂), forced expiratory volume in one second (FEV₁), forced vital capacity (FVC), FEV₁/FVC ratio, and vital capacity (VC). Data were analyzed using the paired-samples t-test (for normally distributed variables) or the Wilcoxon signed-rank test (for non-normal distributions), with statistical significance set at p < 0.05. Results: Following RME treatment, all respiratory parameters showed a consistent upward trend but did not reach statistical significance. SpO₂ increased from 96.98 ± 0.96% to 97.01 ± 0.98% (p = 0.925). VC rose from 2.86 ± 1.07 L to 3.03 ± 0.80 L (p = 0.626). The FEV₁/FVC ratio improved from 90.88 ± 12.17% to 92.34 ± 7.37% (p = 0.742). Mean FEV₁ increased from 2.61 ± 0.72 L to 2.72 ± 0.68 L (p = 0.518), while FVC rose from 2.87 ± 0.75 L to 2.96 ± 0.69 L (p = 0.547). No adverse effects were reported during the treatment period. Conclusions: This study identified a non-significant but consistent trend toward improved pulmonary function following RME in adolescents. These preliminary findings should be considered hypothesis-generating rather than confirmatory evidence, as none of the outcomes reached statistical significance. While the observed upward trends in oxygen saturation, lung volumes, and expiratory performance suggest potential respiratory benefits, larger-scale, controlled, and long-term studies incorporating both spirometric and anatomical airway assessments are needed to validate these observations. Full article

Adhesion of different microorganisms to the surface of dental materials has generated significant interest since one of the most important requirements of biomaterials to be considered successful is their ability to withstand the damage caused by microorganisms that may lead to failure and the onset of different pathologies, such as caries. In vitro testing has demonstrated that surface modification is an alternative approach to reduce the adhesion of microorganisms to surfaces. The objective of this work was to assess the adhesion of Streptococcus mitis, Streptococcus mutans, and Candida albicans to a dental composite surface modified following a biomimetic approach and coated with salivary proteins. Soft lithography was used to copy the topography from the Crocosmia aurea leaf and then transfer it to the surface of dental composite discs that were coated with saliva proteins. Surfaces were characterized by contact angle and atomic force microscopy. S. mitis, S. mutans, and C. albicans were used to assess bacterial and fungal adhesion in monoculture and co-culture. The topographic modification of the surface of a dental composite reduced the adhesion of assessed microorganisms and the adhesion of these species in monoculture and co-culture on saliva-coated surfaces was higher than on topographically modified surfaces. Full article

Purpose: The study aimed to assess and compare the fracture toughness of resin-bonded fixed dental prosthesis (RBFDP) of different ceramic materials and connector parameters. Methods: Twenty extracted human incisal teeth were utilized as abutments for the RBFDP. Zirconia (Zir) and lithium disilicate (LD) were manufactured in the form of anterior cantilever RBFDPs (n = 10 per group). Each material was tested using two connector designs, with the following dimensions for height (h), base (b), and width (w): 5 (h) × 4 (b) × 1 (w) mm (n = 5), and 4 (h) × 2 (b) × 1 (w) mm (n = 5). Prostheses were computer-aided design and computer-aided manufacturing (CAD/CAM) fabricated from Zir (IPS e.max ZIRCAD prime) and LD (IPS e.max CAD). Surface pretreatment of the prosthesis was completed prior to cementation with a dual-cured resin cement (Rely-X Ultimate). The combined teeth and prostheses were subjected to thermocycling before load-to-fracture testing at 45-degrees in the center of the pontic using a universal testing machine (Shimadzu Universal Testing Machine). The types of fracture failures were observed and classified as either favorable (non-catastrophic/repairable) or unfavorable (catastrophic/non-repairable) when viewed under an electron microscope. Results: The highest fracture toughness was observed in 5 (h) × 4 (b) × 1 (w) mm for Zir, reaching 269 ± 27 N, and LD, reaching 180 ± 83 N. The lowest values were found in 4 (h) × 2 (b) × 1 (w) mm for Zir at 237 ± 52 N and LD at 116 ± 25 N. Two-way ANOVA showed the fracture strength for dimension 5 (h) × 4 (b) × 1 (w) mm was significantly higher compared to dimension 4 (h) × 2 (b) × 1 (w) mm after adjusting for the type of material (p = 0.02). One Zir sample, measuring 5 (h) × 4 (b) × 1 (w) mm, exhibited tooth fracture under applied load. Meanwhile, two LD samples of the same dimensions became decemented under load. Conclusions: RBFDPs made from Zir exhibited a pattern of higher load-to-fracture values compared to LD for all dimensions; however, this was not statistically significant. The connector parameter has a more significant influence compared to the material used to fabricate an RBFDP in the anterior region. Full article

Advancements in Computer-Aided Design/Computer-Aided Manufacturing (CAD/CAM) have promoted the development of novel dental materials for several types of definitive restorations. The aim of this study was to evaluate the surface characteristics of resin-based CAD/CAM restorative materials, fabricated using both subtractive and additive manufacturing techniques. The materials tested included Filtek Z550 (FZ), Vita Enamic (VE), Shofu HC (SH), and VarseoSmile TriniQ (TQ). For each material, 24 specimens were prepared; half were manually polished following the manufacturer’s recommendations, while the other half underwent standardized metallographic polishing. The surface roughness, wettability, and molecular composition were assessed. A statistical analysis was performed using IBM SPSS 29.0 at a 95% confidence level (α = 0.05). Statistically significant differences in surface properties were observed between direct and indirect restoratives following manual polishing, with SH performing favorably in terms of surface roughness. The polishing method significantly influenced the surface characteristics of each material, except for certain roughness parameters in SH. Both surface roughness and wettability were dependent on the material and the polishing technique, highlighting the need for improved material-specific polishing protocols. Full article

The aim of this study was to determine the possibilities of using cold-plasma technology in counteracting the development of denture stomatitis (DS) in patients using different kinds of prosthetic restorations. The study focused mainly on the effect of cold atmospheric plasma on prosthetic materials, such as acryl (AR), acetal (AT), and a prosthetic metal alloy (MA). The materials were tested in terms of the effect of the plasma exposure time (5, 10, and 20 min) on changes in the chemical composition, morphology, and surface topography (FT-IR, SEM-EDS, optical profilometer) as well as changes in the color and contact angle (spectrophotometer, goniometer) after the plasma process. Furthermore, the ability of reference fungi (C. albicans and C. glabrata) to adhere to non-modified and cold atmospheric plasma (CAP)-modified dental materials was examined to evaluate the susceptibility of dental material surfaces to 12 h fungal contamination. The obtained results demonstrate that CAP appears viable for the surface modification of the acetal resin and the metal alloy, not compromising their structural integrity while variably limiting fungal overgrowth involved in the development of DS, whereas its application to the acrylic resin may be inadvisable due to morphological and optical alterations. Full article

Background: The addition of chlorhexidine in dental restorative materials is a promising strategy to reduce the recurrence of tooth decay lesions. However, the main challenge is to develop materials with antimicrobial activity in the long term. Objective: This study analyses the effect of filler type and concentration of resin composites supplemented with chlorhexidine loaded in carrier montmorillonite particles (MMT/CHX) regarding their chemical, physical, and short- and long-term antimicrobial proprieties. Materials: Experimental composites were synthesized with 0, 30, or 60% filler in two ratios, 70/30 and 80/20, of barium glass/colloidal silica, respectively, and 5 wt% MMT/CHX. Conversion was measured using near Fourier-transform infrared spectrometry. Sorption and solubility were determined by specimen weight before and after drying and immersing in water. Flexural strength (FS) and elastic modulus (E) were determined by three bending tests using a universal test machine. Chlorhexidine release was monitored for 50 days. Streptococcus mutans UA159 was used in all microbiological assays. Inhibition halo assay was performed for 12 months and, also, biofilm growth for the specimens and colony-forming unit (CFU). Remineralization assay was used on restored teeth using measurements of microhardness Knoop and CFUs. Results: Conversion, sorption, and solubility were not affected by filler type and concentration. FS and E increase with the filler concentration, independent from filler type. Chlorhexidine was significantly released for 15 days for all experimental materials, and the increase in filler concentration decreased its release. Halo inhibition was observed for a longer time (12 months) in materials with 60 wt% filler at 70/30 proportion. Also, 60 wt% filler materials, independent from the filler ratio, reduced the CFU in relation to the control group from 8 to 12 months. In the remineralization assay, besides the absence of differences in hardness among the groups, after biofilm growth, the CFU was also significantly lower in materials with 60 wt% filler. Conclusions: Materials with 60% filler, preferentially with 70% barium glass and 30% silica, and 5% MMT/CHX particles demonstrated long-term antimicrobial activity, reaching 12 months of effectiveness. Also, this formulation was associated with higher mechanical properties and similar conversion, sorption, and solubility compared to the other materials. Full article

Introduction: The aim of this study was to investigate the spatial relationship between the incisive canal (IC) and apical region of the maxillary central incisors in the Korean population, using cone-beam computed tomography (CBCT) imaging. The findings are intended to inform and improve the planning and execution of immediate implant placement in the maxillary esthetic zone. Materials and methods: CBCT data were collected from 94 patients (48 men, 46 women) aged 20–79 years at Gangnam Dental Clinic, Seoul, South Korea. The sample was divided according to age into three groups: 20–39 years, 40–59 years, and 60–79 years. Exclusion criteria included missing maxillary anterior teeth, severe crowding, periodontitis, pathology, and image artifacts. Measurements of the distance from the root apex to the incisive canal (RIC-11-P, RIC-21-P) and from the root apex to the buccal bone (RBB-11-B, RBB-21-B) were taken from CBCT images. Statistical analyses were conducted using Welch’s t-test, ANOVA, and Pearson correlation, with significance set at p < 0.05. Results: The mean distances from the root apex to the incisive canal were 3.77 mm (RIC-11-P) and 3.62 mm (RIC-21-P), while the mean distances to the buccal bone were 0.86 mm and 0.94 mm, respectively. Males exhibited significantly greater distances compared to females, both in the NPC-to-root apex and buccal bone measurements. Age-related variations were observed, with younger individuals showing shorter distances from the IC to the root apex. However, ANOVA tests and Pearson correlation analysis indicated no statistically significant correlation in these distances across different age groups. The study highlights significant gender differences in maxillary central incisor anatomy, with males having larger distances from the root apex to both the IC and buccal bone, which has implications for implant placement. While age-related changes were observed, they did not significantly affect the mean distances in a statistically meaningful way. Conclusions: These findings underscore the need for personalized treatment planning in immediate implant placement, particularly in relation to gender and age. Comparisons with other population studies suggest that these anatomical differences may be consistent across various ethnic groups, though individual variance factors should still be considered. Full article

The growing challenge of biofilm-associated infections in dentistry necessitates advanced solutions. This review highlights the potential of smart bioactive and antibacterial materials—bioactive glass ceramics (BGCs), silver nanoparticle (AgNP)-doped polymers, and pH-responsive chitosan coatings—in transforming restorative dentistry. BGCs reduce biofilms by >90% while promoting bone integration. AgNP-polymers effectively combat S. mutans and C. albicans but require controlled dosing (<0.3 wt% in PMMA) to avoid cytotoxicity. Chitosan coatings enable pH-triggered drug release, disrupting acidic biofilms. Emerging innovations like quaternary ammonium compounds, graphene oxide hybrids, and 4D-printed hydrogels offer on-demand antimicrobial and regenerative functions. However, clinical translation depends on addressing cytotoxicity, standardizing antibiofilm testing (≥3-log CFU/mL reduction), and ensuring long-term efficacy. These smart materials pave the way for self-defending restorations, merging infection control with tissue regeneration. Future advancements may integrate AI-driven design for multifunctional, immunomodulatory dental solutions. Full article