High-translucency 4 mol% yttria-partially stabilized zirconia (4Y-PSZ) is widely used for esthetic restorations, but sintering conditions that balance translucency and microstructural control remain unclear. This study evaluated the independent effects of peak temperature, holding time, and heating rate on the microstructure and total luminous transmittance of monolithic 4Y-PSZ. Disks were sintered at peak temperatures of 1470-1560 °C, holding times of 30-180 min, and heating rates of 3-10 °C/min. Grain size and internal defect density (≥0.5 µm) were quantified by scanning electron microscopy, and total luminous transmittance at 0.5 mm thickness was measured using a spectrophotometer. Higher peak temperatures and longer holding times increased grain size (0.481 ± 0.020 to 0.785 ± 0.035 µm, and 0.503 ± 0.037 to 0.730 ± 0.041 µm, respectively) and reduced defect density, whereas heating rate had no significant effect on either. Transmittance remained within a narrow range (approximately 40-43% at 0.5 mm) across all schedules, with 1560 °C yielding the lowest value. These findings indicate that the microstructure of monolithic 4Y-PSZ is governed primarily by peak temperature and holding time, while transmittance is relatively insensitive to the sintering schedule. Practically, a peak temperature of 1500-1530 °C with a 1-2 h hold provides a robust processing window balancing densification, grain coarsening, and optical performance for clinical workflows.

BACKGROUND: In dentistry, interest in computer-aided design and computer-aided manufacturing (CAD/CAM) over traditional denture fabrication systems is increasing. However, few studies have compared the physiochemical and biological properties of different fabrication methods in regards to Candida albicans. C. albicans is the most common oral fungal pathogen, often related to dentures and elderly patients. Although various factors have been reported to influence C. albicans proliferation, conclusive evidence is lacking. Therefore, the aim of this study was to evaluate and compare the physicochemical properties of different denture materials in terms of surface roughness and C. albicans adhesion on the basis of polymerization methods and 3D print orientation. METHODS: Four types of resin disks were prepared: autopolymerization, heat-activated polymerization, milling, and 3D printing. The surface roughness and water contact angle were measured via a confocal laser scanning microscopy (CLSM) and the sessile drop method. After C. albicans inoculation, microbial adhesion was measured by scanning electron microscope (SEM), a crystal violet assay, and an alcian blue assay. To further investigate the relationship between surface roughness and microbial adhesion, 3D-printed resin was fabricated at different build orientations. The resins were printed at 0, 45, and 90-degrees to modulate different surface roughness and simulate commonly used clinical settings. The same experimental set was used. The cell wall thickness of each group was measured via CLSM. For statistical analysis, one-way ANOVA and Tukey’s post hoc tests were performed. RESULTS: The 3D-printed group presented the greatest adhesion with the highest roughness parameters (Ra, Rdq). The milled group presented the lowest adhesion with the lowest surface roughness values. (p < 0.05) Among the 3D-printed samples with different build orientations, the 0-degree presented the lowest surface roughness and the lowest microbial adhesion. (p < 0.05) Microbial adhesion was less related to average roughness and more related to microroughness. The findings were further confirmed with SEM images with prominent grooves and layer lines with speckled patterns on 45 and 90-degree. The cell wall thickness showed no difference between the groups. (p > 0.05). CONCLUSION: Microbial adhesion is significantly affected by fabrication methods and build orientation. Milled and 0-degree 3D printed resins provide improved options with the potential to minimize Candida albicans adhesion with the lowest surface roughness. Due to their high surface roughness and microbial adhesion, 3D-printed resins with different printing orientations require meticulous polishing and regular cleansing. Despite the limitation of in vitro study, this study aims to provide a deeper understanding of surface morphology and microbial adhesion and provide clinical insights that milled and 0-degree printed resin are more favorable in minimizing C. albicans adhesion.

Biomedical devices often feature a microgap: confined, minuscule spaces that foster bacterial infiltration and biofilm formation. For instance, peri-implantitis with prevalence rates of 4.7-45% at the patient level is a major complication driven by biofilm infections, characterized by chronic inflammation and implant failure. Anaerobic biofilm residing within the microgap serves as a major source of the peri-implantitis, but tools that remove the biofilm are lacking. Therefore, this study presents a novel preventive strategy employing self-powered microbubbler (SM) for targeted decontamination of micrographs in dental implants. SMs are assembled by doping diatoms with MnO2 nanosheets. These particles are activated to generate O2 microbubbles in H2O2 solution via catalase-mimetic activity and can penetrate the biofilm structures. The resulting oxygen bubbles induce effective mechanical disruption and oxygenation within biofilm-mimicking gelatin hydrogels and Porphyromonas gingivalis biofilms found in the peri-implantitis-affected implants. Such biofilm removal from the microgap restored mechanical stability at implant abutment-fixture connections and reduced bacterial leakage. Multispecies biofilms from patient-derived implants were similarly decontaminated with the mixture of SM-H2O2 outperforming conventional antiseptics like 0.2% chlorhexidine and 3% H2O2 alone. This innovative approach extends beyond dental implants to address biofilm-associated challenges in various biomedical devices with microgap vulnerabilities. Overall, SM-based treatments will offer an efficient and nondamaging solution to enhance the sterility and longevity of various bioimplants with intricated and confined structure.

PURPOSE:To evaluate the laboratory accuracy of three intraoral scanners (IOSs) across three types of tooth preparations, using a laboratory scanner as the reference. METHODS:Models of three types of tooth preparations (inlay, onlay, and three-unit fixed partial denture) were designed with CAD software and fabricated using a 3D printer. Reference data were obtained by scanning these models with a desktop laser scanner (Identica Hybrid, Medit Co). Each model was scanned five times using three IOSs: TRIOS4 (3Shape), I500 (Medit Co), and COMFORT+ (DDS), resulting in 45 scans across nine groups. Scan files were exported in STL format and analyzed with Geomagic 3D inspection software. Accuracy was assessed using best-fit alignment and 3D comparison functions. RESULTS:Trueness did not significantly differ among the IOSs within each tooth preparation group (P> 0.05). However, all three IOSs showed significantly lower trueness for the three-unit fixed partial denture compared to the inlay and onlay groups (P< 0.05). Precision significantly varied among the IOSs within the tooth preparation groups (P< 0.05). Specifically, the I500 demonstrated higher precision for inlays, while TRIOS4 and I500 exhibited better precision for onlays and three-unit fixed partial dentures. CLINICAL SIGNIFICANCE:All three tested intraoral scanners (TRIOS, I500, and COMFORT+) demonstrated clinically acceptable accuracy for prostheses fabrication, confirming their suitability for applications ranging from inlays to crowns and bridges.

PURPOSE:The biomechanical advantage of selective pressure impressions over mucocompressive techniques remains unclear. This study aimed to determine whether selective pressure techniques offer substantial biomechanical advantage over mucocompressive impressions using clinical computer simulation. MATERIALS AND METHODS:Two models were analyzed: Model C, with mucocompressive impression tray, and Model S, with selective pressure impression tray with 10-mm diameter circular relief in the midline. Each model included the tray, polyvinyl siloxane (PVS), mucosa, cortical, and cancellous bone. Seven locations were designated, from which the results were analyzed. With a vertical load of 49 N on the palatal area, pressure, von Mises stress, and displacement were evaluated. Statistical analysis was performed using paired-samples t-test and effect size estimation (Cohen's d). RESULTS:Both models generated mucosal displacement and stress transmission to the underlying structures upon load application. In Location 3, where the relief was placed, Model S exhibited lower pressure, stress, and displacement than Model C, indicating localized force reduction. Conversely, other locations exhibited higher values in Model S than in Model C. Low stress in bone for both trays suggested that tray design had minimal effect on bone. All variations demonstrated small effect sizes (d ≤ 0.2), despite statistical significance (P < .007). CONCLUSION:Selective pressure trays modified tissue loading locally at the relief site; however, these did not seem to provide a substantial biomechanical advantage, particularly on bone. Their clinical relevance remains limited and needs further supporting evidence.

OBJECTIVES:To characterize clinical and demographic features of adults presenting with occlusal dysesthesia (OD) and to estimate whether demographic characteristics are associated with the likelihood of OD presentation. METHODS:This retrospective cross-sectional study reviewed charts of 1323 consecutive new adult patients (≥18 years) at a university prosthodontics department from September 2020 to August 2024. OD was defined by occlusion-focused chief complaint without explanatory dental pathology, excluding structural confounders like degenerative joint disease. Controls included all other patients. Variables abstracted included age, sex, medical history, symptom duration, perceived precipitants, and verbatim symptom language categorized into patterns. Comparisons used t-tests and chi-squared tests; associations were assessed via logistic regression adjusted for age, sex, and comorbidities (diabetes, hypertension, hyperlipidemia, cancer). RESULTS:Of 1323 patients, 47 (3.6 %) met OD criteria (mean age 53.6 ± 14.3 years; 83 % female) and 1276 were controls (mean age 55.7 ± 18.7 years; 55 % female). Midlife (40-59 years) was overrepresented (48.9 % vs 27.0 % in controls; p=.004). Symptom duration averaged 25.1 ± 24.4 months; 70.2 % attributed onset to prosthodontic treatment. Common symptoms included pressure/pain (19.1 %) and premature contact (17.0 %). Fully adjusted odds ratios showed higher OD odds for females (OR 4.136; 95 % CI 1.907-8.970; p<.001) and midlife adults (OR 2.315; 95 % CI 1.045-5.141) versus young adults; no association for ≥60 years (OR 0.821; 95 % CI 0.331-2.038). CONCLUSIONS:In this consecutive cohort, female sex and midlife age are independently associated with OD presentation. Although causality cannot be inferred, these findings may support the use of conservative, communication-focused management at the first presentation. CLINICAL SIGNIFICANCE:This study's findings provide a descriptive demographic and clinical profile of patients with OD. Clinicians may consider the observed predominance of female and midlife patients in OD and, when no structural abnormalities are present, may opt for conservative measures such as patient education rather than irreversible adjustments.

ABSTRACT Objectives This study evaluated the feasibility and trueness of superimposing titanium customized abutment library data onto scans of abutments with incomplete areas along margins or proximal surfaces, comparing this approach to the CAD program's hole‐filling function. Material and Methods A dental model with one implant was used. A titanium customized abutment was scanned to create abutment library data. Reference data were generated using a laboratory scanner (Medit T500) and the abutment and neighboring teeth were scanned 10 times with Medit I500, an intraoral scanner (IOS group). Superimposition with abutment library data was performed for fully scanned (F), margin‐deleted (M1 and M2), and proximal‐deleted scans (P). The “Close holes” function of exocad DentalCAD was applied to create the PF group. Trueness was assessed by comparing root mean square (RMS) and point‐based deviations against reference data using Geomagic control X. Statistical analysis was conducted using one‐way ANOVA and Tukey HSD tests. Results Superimposition improved trueness compared to the IOS group, reducing RMS from 42.11 ± 1.11 to 36.37–36.61 μm in the F, M1, M2, and P groups ( p < 0.001). No significant differences were observed among superimposition groups. The PF group exhibited greater deviations than all superimposition groups ( p < 0.001). Point‐based analysis showed significant improvement in superimposed groups ( p < 0.05), except at marginal ridges ( p > 0.05). The hole‐filling function did not enhance trueness ( p > 0.05). Conclusions Superimposing abutment library data improve the trueness of intraoral scans, even when areas along margins and proximal surfaces are incomplete.

Narrow-diameter implants (NDI) serve as a solution for treating limited bone volume in the anterior mandible. This study aimed to evaluate the one-year clinical outcomes of various NDIs in the mandibular incisor area after immediate loading in partially edentulous patients. This single-center, prospective, single-blinded, randomized controlled trial study included 21 patients, with 7 patients in each of the following groups: control (BLT NC SLActive®; Straumann), experimental group 1 (CMI IS-III Active® S-Narrow; Neobiotech), and experimental group 2 (CMI IS-III Active® Narrow; Neobiotech). Using full digital flow, two fixtures were placed in each patient and immediately provisionalized on the day of surgery. Evaluations encompassed periapical radiographs, implant stability quotient (ISQ), implant stability test (IST) readings, per-implant soft tissue health, patient satisfaction surveys, and esthetic score assessments. Definitive prostheses were delivered twelve weeks post-surgery (CRiS, number: KCT0007300). Following exclusions due to low stability values (n = 2), fixture failure (n = 5), and voluntary withdrawal (n = 1), the implant success rate for patients completing all clinical protocols stood at 100%. The resulting patient failure rates in the control, experimental group 1, and experimental group 2 were 50.0%, 42.9%, and 14.3%, respectively. There were no significant differences between the groups in terms of marginal bone loss, soft tissue health, patient satisfaction, and esthetic scores. Narrow implants showed superior clinical outcomes, followed by S-Narrow and Straumann implants. Calculated one-year survival rates at the implant level were 66.7% for the control group, 85.7% for experimental group 1, and 100% for experimental group 2. All three types of NDIs showed acceptable clinical and radiographic results during the year-long observation period.

Statement of problem Duplicating mandibular movement with a semi-adjustable articulator has been reported to lack accuracy. However, although previous studies have analyzed articulator movement, few have compared excursive tooth contact on the articulator with tooth contact during actual mandibular movement. Purpose The purpose of this clinical study was to evaluate the concordance of semi-adjustable articulator contacts with intraoral contacts during eccentric movements by using a T-scan occlusal analysis system. Material and methods Forty-two participants with normal occlusion and without signs of temporomandibular disorder were analyzed for the reproducibility of eccentric tooth contact on a semi-adjustable articulator. Maxillary casts made from irreversible hydrocolloid impressions were mounted on a semi-adjustable articulator with the facebow. The condylar inclination of the articulator was set by using interocclusal records. Three recordings of right and left excursive mandibular movement and protrusive mandibular movement were made in the supine position by using the T-scan v9.1. The same procedure was then performed with the articulator. The results of complete mandibular movement from T-scan measurements were divided into 4 time points for analysis: T0, T1, T2, and T3. The concordance of intraoral and articulator occlusal contacts was evaluated at each point, and the occlusal force for each tooth was compared. Overall concordance and concordance of the working and nonworking sides were also calculated. Repeated measures analysis of variance was used to analyze differences between the concordance of intraoral and articulator contacts according to mandibular movement direction, time, and working and nonworking sides (α=.01). Results For all teeth, concordance between the intraoral and articulator occlusal contacts during excursive mandibular movement was greatest at T0, decreasing at T1 and T2, and increasing at T3. No significant differences were found in the concordance among the right lateral, left lateral, and protrusive excursion (P>.01). The concordance of working side occlusal contacts during lateral excursion was significantly lower at T3 than that at T0 (P<.01). Conclusions When comparing intraoral and articulator contacts during lateral eccentric mandibular movement, concordance was affected by time and working or nonworking side. Reproducibility of initial eccentric tooth contact on a semi-adjustable articulator appeared to be reliable. However, occlusal adjustment of the working side might be required after prosthesis delivery.

The purpose of this study was to compare the surface changes and shear bond strength between a resin composite and two zirconia ceramics subjected to sandblasting and forming gas (5% H2 in N2) plasma surface treatment. Two types of zirconia ceramic specimens (3Y-TZP and (Y,Nb)-TZP) were divided into groups based on the following surface treatment methods: polishing (Control), sandblasting (SB), sandblasting and plasma (SB-P), and plasma treatment (P). Subsequently, chemical surface modification was performed using Clearfil SE Bond (Kuraray, Tokyo, Japan), and the Filtek Z-250 (3M, Maplewood, MN, USA) resin composite was applied. Shear bond strengths (SBS) and surface characteristics were determined. Plasma treatment was effective in increasing the wettability. For SBS, there were significant differences among the groups, and the (Y,Nb)-TZP and SB-P groups showed the highest bond strength. Similarly, for the 3Y-TZP specimens, the shear bond strength increased with both plasma and sandblasting treatments, although no statistically significant change was observed. In the P group, both (Y,Nb)-TZP and 3Y-TZP showed a significant decrease in shear bond strength with the resin composite compared to the control group.

Non-invasive objective implant stability measurements are needed to determine the appropriate timing of prosthetic fitting after implant placement. We compared the early implant stability results obtained using resonance frequency analysis (RFA) and damping capacity analysis (DCA) depending on the implant length and bone density. Total 60, 4.0 mm diameter implants of various lengths (7.3 mm, 10 mm, and 13 mm) were used. In Group I, low-density bone was described using 15 PCF (0.24 g/cm3) polyurethane bone blocks, and in Group II, 30 PCF (0.48 g/cm3) polyurethane bone blocks were used to describe medium density bone. RFA was performed using an Osstell® Beacon+; DCA was performed using Anycheck®. Measurements were repeated five times for each implant. Statistical significance was set at P <0.05. In Group I, bone density and primary implant stability were positively correlated, while implant length and primary implant stability were positively correlated. In Group II, the implant stability quotient (ISQ) and implant stability test (IST) values in did not change significantly above a certain length. Primary implant stability was positively correlated with bone density and improved with increasing implant length at low bone densities. Compared with the Osstell® Beacon+, the simplicity of Anycheck® was easy to use and accessible.

OBJECTIVE:To compare fully guided flapless implant surgery using a light-cured surgical guide (FG group) with partially guided open flap surgery (PG group) in the posterior maxilla when performing simultaneous sinus floor elevation in terms of the accuracy, time requirements, and patient/clinician-reported outcomes (PROMs and CROMs). MATERIALS AND METHODS:In this study, 56 tissue-level implants were placed with crestal sinus floor elevation in 56 patients at single-tooth sites, with 28 implants allocated to the PG group and 28 to the FG group. The deviations of the placed implants from the virtually planned positions were measured at the implant platform and apex and for the angular deviation. The presurgical preparation time and the duration of surgery were measured. PROMs and CROMs were made by administering questionnaires at multiple time points. RESULTS:Horizontal deviations at the platform and apex and the angular deviation were significantly smaller in the FG group than the PG group (p < .05). Presurgical preparation and surgery times were significantly shorter in the FG group (p < .001). Patient satisfaction and willingness to receive repeat treatment were significantly better in the FG group than in the PG group (p < .005 and .025, respectively). Clinicians were more satisfied in the FG group than the PG group (p < .05). CONCLUSION:When placing an implant with sinus floor elevation, the flapless approach using a fully guided surgical system can be more accurate, faster, and increase the satisfaction of both the clinician and patient compared to the partially guided surgery.

Correction for ‘Crystallinity-modulated hollow CeO 2− x nanorods as free radical scavengers for long-term photostability in organic photovoltaics’ by Seongwon Yoon et al. , J. Mater. Chem. C , 2023, 11 , 970–979, https://doi.org/10.1039/D2TC04152A.

PURPOSE:The primary stability of a dental implant is critical for successful osseointegration during immediate loading. The cortical bone should be prepared to achieve enough primary stability, but not overcompressed. In this study, we investigated the stress and strain distribution in the bone around the implant induced by the occlusal force applied during immediate loading at various bone densities by the FEA method to compare cortical tapping and widening surgical techniques.MATERIALS AND METHODS:A three-dimensional geometrical model of a dental implant and bone system was created. Five types of bone density combination (D111, D144, D414, D441 and D444) were designed. Two surgical methods-cortical tapping and cortical widening-were simulated in the model of the implant and bone. An axial load of 100 N and an oblique load of 30 N were applied to the crown. The maximal principal stress and strain were measured for comparative analysis of the two surgical methods.RESULTS:Cortical tapping showed lower maximal stress of bone and maximal strain of bone than cortical widening when dense bone was located around the platform, regardless of the direction of the applied load.CONCLUSIONS:Within the limitations of this FEA study, it can be concluded that cortical tapping is biomechanically more advantageous to the implants under occlusal force during immediate loading, especially when the bone density around the platform is high.