OBJECTIVE:The accuracy of intraoral scanners is commonly described by trueness and precision; however, the extent to which single-tooth crown preparation geometry influences these outcomes across different scanner systems remains unclear. This in vitro study aimed to evaluate trueness and to descriptively assess precision across different preparation designs and scanner systems. METHODS:A maxillary phantom model with nine single-tooth crown preparation designs and one unprepared control was scanned with Trios 5 and Primescan. For trueness, each preparation-scanner combination was scanned five times and compared with a high-accuracy industrial reference scan (ATOS Q) using RMS deviation after best-fit alignment. Trueness was analyzed with two-way ANOVA. Precision was evaluated descriptively using the interquartile range (IQR) of repeated scan RMS values. RESULTS:Trueness RMS values ranged from 0.0247 to 0.0623 mm. The lowest value was observed for occlusal veneer (VE3; partial occlusal) scanned with Trios 5, and the highest value was observed for anterior veneer (VE2; buccal + palatal) scanned with Primescan. Preparation design significantly affected trueness (F(9, 80) = 9.26, p < 0.001), while scanner type showed no statistically significant difference (p = 0.056); the preparation design × scanner interaction was significant (F(9, 80) = 4.84, p < 0.001). Precision varied across preparation designs and scanner types, as reflected by differences in IQR values. CONCLUSIONS:Cavity preparation geometry significantly affected IOS trueness, and this effect was scanner-dependent. Simpler and more optically accessible geometries generally showed lower RMS deviations, although this pattern varied according to specific preparation features. Precision, assessed descriptively using IQR values, varied across preparation designs and scanner systems and should be interpreted cautiously.
OBJECTIVE:To describe the clinical workflow for obtaining intraoral scans, fabricating occlusal devices using different artificial intelligence (AI)-based programs, and delivering the devices. CLINICAL CONSIDERATIONS:Maxillary and mandibular scans of a completely dentate patient receiving a maxillary occlusal device were obtained using an intraoral scanner (Trios 5). The maxillomandibular relationship was obtained at two different positions: maximum intercuspal position (MIP) and 2-mm interocclusal opening achieved with a leaf gauge. The articulated scans were imported into four AI-based programs (Automate, Medit Night Guards, Relu Mouth Guards, and Sprintray Cloud Design) for automatic occlusal device design. One occlusal device was milled and additively manufactured from each design and subsequently delivered using a standardized protocol. CONCLUSIONS:Substantial differences in occlusal device design, fit, and occlusal adjustments were observed among the AI-based programs evaluated. Standardization of intraoral data acquisition and design principles and parameters may be necessary to improve the reliability of AI-based occlusal device design. Further studies are needed to evaluate the accuracy, efficiency, and performance of AI-based programs for occlusal device fabrication.
OBJECTIVE:To evaluate the effect of airborne-particle abrasion (APA) with aluminum oxide on superficial dentin sclerosis, surface topography, and bonding performance of a universal adhesive in natural non-carious cervical lesions (NCCLs), using dentin classification by the North Carolina Index (NCI) and Optical Coherence Tomography Index (OCT). METHODS:Forty-eight premolars with natural NCCLs were distributed according to dentin sclerosis classification (non-sclerotic or sclerotic) by NCI and OCT, with concordant and discordant (dentin types) classifications into four APA treatment groups (n = 8), and two untreated groups (control, n = 8, non-sclerotic and sclerotic, for adhesive testing). Pre- and post-treatment analyses included stereomicroscopy, OCT, microcomputed tomography (volume and thickness loss), and 3D optical profilometry (surface roughness). Adhesive performance of a universal adhesive was assessed by microtensile bond strength (μTBS), nanoleakage (scanning electron microscopy), and chemical mapping (micro-Raman spectroscopy). Data were analyzed with parametric and non-parametric tests (α = 0.05). RESULTS:APA did not significantly change dentin classification by NCI or OCT (p > 0.05) but removed a superficial layer (volume loss: 0.33 mm3; thickness loss: 34 μm) and significantly increased surface roughness (p < 0.001), without dentin-type differences (p = 0.38). Adhesive performance was substrate-dependent: APA improved μTBS in sclerotic dentin (per OCT) and reduced it in non-sclerotic dentin (per OCT). Nanoleakage did not differ among groups (p > 0.05). CONCLUSION:APA modified dentin surface topography without removing superficial dentin sclerosis, while the effect on bonding was substrate-dependent. CLINICAL SIGNIFICANCE:APA-induced surface modification, including volume loss and increased surface roughness, improved bonding performance in sclerotic NCCL dentin without completely removing the sclerotic layer.
OBJECTIVE:Accurate transfer of implant positions is critical for achieving passive fit in complete-arch implant-supported prostheses. This clinical case report describes the comparison of eight implant-position acquisition workflows and their influence on the clinical seating of mandibular complete-arch frameworks. The Clinical Seating Score (CSS) was used to assess clinical seating and was compared with three-dimensional deviations. METHODS:A patient receiving mandibular All-on-4 rehabilitation was treated with four implants placed using dynamic navigation. After a 3-month healing period, implant positions were recorded using eight workflows: conventional open-tray impression, intraoral scanning with conventional PEEK, reduced-height titanium, horizontal-arm, centrally oriented, and reverse scan bodies, intraoral photogrammetry, and extraoral photogrammetry. Eight titanium frameworks were fabricated using standardized CAD/CAM procedures and evaluated intraorally by a single experienced clinician using the CSS (0-6), which assessed framework rocking, screw-tightening tension, and a modified Sheffield test. A Clinical Acceptability Bonus (+1) was assigned when predefined clinical deliverability criteria were met. The framework with the highest CSS was used as the reference for three-dimensional deviation analysis. RESULTS:Intraoral photogrammetry produced the highest CSS (6 + 1) and was used as the reference framework. Centrally oriented scan regions and extraoral photogrammetry also produced clinically acceptable seating. Conventional impressions and workflows using conventional PEEK, horizontal-arm, or reverse scan bodies showed greater variability in clinical seating. Deviations of approximately 50-60 μm were generally associated with clinically acceptable seating, whereas discrepancies exceeding approximately 70-80 μm were associated with lower CSS values. These observations suggest that the clinical effect of implant-position discrepancies may vary according to their spatial direction. CONCLUSIONS:Within the limitations of this single clinical case, the CSS provided a structured approach for assessing the clinical seating of complete-arch implant frameworks. Intraoral photogrammetry demonstrated the most favorable clinical seating, while other workflows showed variable outcomes. The proposed CSS and observed deviation ranges should be considered exploratory and require validation in larger clinical studies. CLINICAL SIGNIFICANCE:The CSS may potentially provide a simple and standardized chairside method for evaluating the passive seating of complete-arch implant frameworks. This approach may help clinicians identify clinically relevant misfits before delivery of the definitive prosthesis and support more predictable decision-making during framework verification.
OBJECTIVE:Chitosan is a naturally derived polysaccharide with antibacterial and bioactive properties. This study evaluated the effect of incorporating chitosan nanoparticles into a resin infiltrant on the color change, microhardness, wettability, and penetration depth of the treated white spot lesions. MATERIALS AND METHODS:Twenty-four bovine central incisors were prepared and baseline color and microhardness were measured. Artificial white spot lesions were created and specimens were randomly received either a resin infiltrant or a resin infiltrant containing 0.25 wt% chitosan nanoparticles. Color and microhardness were reassessed after infiltration, after 7 days of coffee immersion, and following secondary demineralization. Resin penetration depth was evaluated using scanning electron microscopy, and surface wettability was assessed by contact angle measurement. Data were analyzed using repeated-measures analysis of variance and independent t-tests (α = 0.05). RESULTS:Chitosan incorporation significantly improved initial color of white spot lesions (p = 0.022); however, after coffee immersion, it caused greater color change (p = 0.003). Stepwise color changes did not differ significantly between the groups (p > 0.05). Although initial surface microhardness values were lower in the chitosan group, this group demonstrated a more stable hardness change after secondary demineralization (p < 0.001). Resin penetration depth and surface wettability were not significantly affected by chitosan addition (p > 0.05). CONCLUSIONS:Incorporation of chitosan nanoparticles improved initial masking ability and resistance to acid-induced hardness loss without compromising penetration depth or hydrophilicity of resin infiltrant over treated enamel. However, increased susceptibility to extrinsic staining highlights the need for further optimization to balance mechanical stability and long-term optical performance.
OBJECTIVE:To compare the marginal and internal adaptation and to evaluate the clinical performance and patient satisfaction of CAD/CAM-fabricated all-ceramic crowns produced from lithium disilicate (LDS) and lithium disilicate-reinforced lithium aluminosilicate (LAS) over a 24-month follow-up period. MATERIALS AND METHODS:This randomized controlled, single-blinded clinical trial included 59 posterior single crowns placed in 37 patients. Twenty-nine crowns were fabricated from LDS (IPS e.max CAD; Ivoclar Vivadent), and 30 crowns were fabricated from LAS (n!ce Blocks; Institut Straumann AG). Marginal and internal adaptation were assessed before cementation using an in vivo silicone replica technique. Clinical performance was evaluated at baseline and after 6, 12, and 24 months using the modified United States Public Health Service (USPHS) criteria together with the Gingival Index (GI), Plaque Index (PI), and patient satisfaction assessed using a visual analogue scale (VAS). Statistical analyses were performed at a significance level of p < 0.05. RESULTS:No statistically significant differences were observed between the LDS and LAS groups regarding marginal, rounded shoulder, or occlusal gap measurements (p > 0.05). A statistically significant difference was observed at the axial measurement site (p = 0.014), with the LDS group exhibiting significantly greater axial internal gap values than the LAS group. During the 24-month follow-up period, six restorations failed because of fracture or debonding, including three LDS and three LAS crowns, resulting in survival rates of 89.7% for LDS, 90.0% for LAS, and 89.8% overall. Gingival and plaque index scores remained low and stable throughout the observation period, and patient satisfaction remained high in both groups, with no statistically significant differences between materials (p > 0.05). All clinically surviving restorations received Alpha or Bravo scores according to the modified USPHS criteria. CONCLUSIONS:Within the limitations of this study, CAD/CAM-fabricated LDS and LAS crowns demonstrated comparable marginal adaptation, favorable clinical performance, and high patient satisfaction after 24 months of clinical service. The fully crystallized LAS ceramic appears to be a clinically acceptable and time-efficient alternative for posterior single-crown restorations. Nevertheless, long-term randomized clinical studies with larger sample sizes are required to confirm these findings.
PURPOSE:Current denture liner materials suffer from low tear strength, poor abrasion resistance, weak bond strength to denture material, and increasing risk of denture stomatitis due to adherence of Candida albicans. The aim of this study was to evaluate the effects of the addition of cellulose nanofibers (CNFs) to commercial soft denture liner material on the adherence of Candida albicans and physical and mechanical properties. MATERIALS AND METHODS:CNFs at concentrations of 0.0, 0.5, and 1.0 wt.% were incorporated into a soft liner material. Antifungal effects were assessed by quantifying the adherence of Candida albicans. The Shore A hardness, tensile strength, peel bond strength, and surface roughness tests were employed to assess the properties of the denture liner materials. Chemical interactions between the fibers and liner material were confirmed by Fourier Transform Infrared (FTIR) spectroscopy, and a Scanning Electron Microscope (SEM) was used to assess the CNFs particles and fractured surface morphology. RESULTS:There was a statistically significant decrease in the adherence of Candida albicans in both experimental CNFs groups. FTIR spectroscopic analysis confirmed the existence of strong hydrogen bonding between the CNFs and the liner polymer matrix. The hardness, surface roughness, peel bond strength and tensile strength increased significantly due to the addition of CNFs, most notably at 0.5 wt.%. CONCLUSION:The addition of CNFs to the denture liner material improved mechanical properties and reduced Candida albicans adherence even with increased surface roughness above the established threshold of Ra ≥ 0.2 μm. The 0.5 wt.% CNFs concentration provided the most favorable balance of enhanced antifungal activity and mechanical properties, which suggests that CNFs may have altered surface interactions or adhesion sites and have the potential for clinical use in the mitigation of denture stomatitis.
OBJECTIVE:This case report describes the esthetic-functional rehabilitation of a patient with unilateral complete cleft lip and palate who was managed multidisciplinarily from 10 to 18 years of age, and reports the clinical outcome 5 years after definitive prosthetic rehabilitation, which was undertaken after late secondary alveolar bone grafting had yielded insufficient bone volume for implant placement. CLINICAL CONSIDERATIONS:Phased orthodontic treatment from age 10-17 (slow maxillary expansion, fixed appliances, growth-coordinated space management) was followed by late secondary alveolar bone grafting at age 17, with concurrent extraction of the periodontally compromised lateral incisor. Although grafting achieved meaningful structural and soft-tissue reconstruction of the cleft zone, postoperative cone-beam computed tomography confirmed that the residual bone height and width remained insufficient for implant placement; after the patient declined further augmentation, a six-unit canine-to-canine monolithic zirconia fixed dental prosthesis incorporating a pink-ceramic-extended ovate pontic was adhesively cemented at age 18 with a 10-methacryloyloxydecyl dihydrogen phosphate-containing dual-cure resin cement, combined with continued dual orthodontic retention. CONCLUSION:Five years after definitive cementation, the restoration was clinically intact, with non-inflamed abutment periodontal conditions and maintenance of bilateral Class I occlusal relationships, transverse maxillary arch form, and esthetic outcome. Maintenance of the transverse arch form is most plausibly multifactorial and is attributed principally to the sustained orthodontic retention protocol rather than to the anterior restoration. This case illustrates the 5-year performance of cross-arch tooth-supported zirconia rehabilitation combined with prosthetic soft-tissue masking and continued orthodontic retention in a cleft patient in whom implant therapy was not feasible. CLINICAL SIGNIFICANCE:Cross-arch monolithic zirconia rehabilitation with a pink-ceramic-extended ovate pontic can provide an esthetic-functional pathway in cleft lip and palate patients in whom implant therapy is not feasible. In the present case, transverse maxillary arch form was maintained over 5 years under continued orthodontic retention, indicating that anterior-only prosthetic rehabilitation is compatible with preservation of arch form when retention is sustained.
OBJECTIVE:To systematically compare the fracture resistance (N) and marginal gap (μm) of 3D-printed versus CAD/CAM-milled resin-based permanent crowns using meta-analytic methods. MATERIALS AND METHODS:A systematic search of PubMed/MEDLINE, Scopus, and Web of Science was conducted from inception to the search date. Eligible studies were in vitro investigations directly comparing 3D-printed and milled full-coverage resin-based crowns and reporting quantitative outcomes for fracture resistance and/or marginal gap. Risk of bias was assessed using the QUIN tool. Random-effects meta-analyses were performed using standardized mean differences (SMDs). RESULTS:Fourteen studies were included (16 study conditions for fracture resistance; 13 for marginal gap). In the primary molar-only analysis, milled crowns demonstrated significantly higher fracture resistance than 3D-printed crowns (SMD -1.49; 95% CI: -2.25 to -0.73; p < 0.001), with the most consistent effect observed under aged conditions (SMD -1.75; 95% CI: -2.31 to -1.19; I2 = 47%). For marginal gap, the primary pooled analysis was non-significant and exhibited extreme heterogeneity (I2 = 99.8%). However, a sensitivity analysis restricted to tooth-supported, direct-measurement conditions (k = 10) showed significantly smaller marginal gaps for 3D-printed crowns (SMD -2.31; 95% CI: -3.47 to -1.14; p = 0.002). CONCLUSIONS:Milled resin-based crowns demonstrated higher fracture resistance, particularly under simulated aging conditions, whereas 3D-printed crowns showed superior marginal adaptation under methodologically comparable conditions. Given the low to very low certainty of evidence and substantial heterogeneity, these findings should be interpreted cautiously, and their clinical relevance remains to be confirmed by well-designed clinical studies.
OBJECTIVE:To evaluate the antioxidant capacity of the baicalein solution (BA), as well as its effect when applied for different times to the surface of bleached dental enamel, considering immediate color stability and bond strength. MATERIALS AND METHODS:Bovine enamel/dentin specimens (4 × 4 × 3 mm) were randomly divided into five groups (n = 10): Positive Control (PC): non-bleached, restored teeth; Negative Control (NC): bleached, restored teeth; and BA5, BA10, BA15 groups, with BA applied for 5, 10, or 15 min after bleaching with HP35%, followed by immediate restoration with Filtek Z350XT composite resin. The antioxidant activity (AA%) was evaluated using the DPPH test. Immediate color stability was assessed by ΔE00 and ΔWID at T1 (post-bleaching) and T2 (post-BA application), with repeated measurements at 24 h (T3) and 7 days (T4). Micro-shear bond strength (SBS) was evaluated at 24 h and 7 days. Statistical analysis was performed at a 5% significance level. SBS data were analyzed using two-way ANOVA, ΔE00 with generalized linear models, and ΔWID with Kruskal-Wallis followed by Dunn's post hoc test. Antioxidant activity and failure modes were analyzed descriptively. RESULTS:The BA solution demonstrated an AA% of 97%. The final analyses (T4) of ΔE00 revealed that BA10 and BA15 presented statistically similar values to NC (p > 0.5), while BA5 exhibited the lowest ΔE00 among the groups (p < 0.05). For ΔWID (T4), all groups showed values similar to NC (p > 0.05). The application of BA improved SBS values at all time points (p < 0.05), with adhesive failures being predominant, followed by mixed failures. CONCLUSION:Baicalein increased bond strength without compromising bleaching outcomes. CLINICAL RELEVANCE:The use of BA showed promising results, indicating its potential as a novel agent to be further studied.
OBJECTIVE:This randomized, single-blind clinical trial evaluated the effect of whitening dentifrices on short-term color stability and tooth sensitivity after in-office bleaching. MATERIALS AND METHODS:A total of 120 participants treated with 40% hydrogen peroxide were randomly assigned to six dentifrice groups (n = 20): one conventional dentifrice (control) and five whitening dentifrices with different mechanisms (abrasive, optical, and chemical). One whitening formulation also contained potassium nitrate as a desensitizing agent. Tooth color was measured spectrophotometrically at baseline, immediately after bleaching, and at 1 week, 1 month, and 3 months using the CIELAB system (ΔE*ab). Tooth sensitivity was recorded using a numeric rating scale at 24 h, 48 h, and 7 days. Color change data were analyzed using repeated-measures ANOVA with Greenhouse-Geisser correction, whereas tooth sensitivity data were analyzed using Friedman, Wilcoxon signed-rank, and Kruskal-Wallis tests with Bonferroni adjustment (α = 0.05). RESULTS:No significant differences in color change were observed among groups at any evaluation time point (p > 0.05). A significant time × group interaction was detected (p < 0.05), mainly due to a reduction in ΔE*ab values in the control group at 3 months, whereas whitening dentifrices did not show significant intragroup changes over time. No significant differences were found among whitening dentifrices. Tooth sensitivity peaked within the first 48 h and decreased over time, approaching zero by Day 7. The dentifrice containing desensitizing agents exhibited significantly lower sensitivity scores during the early postbleaching period (p < 0.05). CONCLUSIONS:No statistically significant differences in color change were observed among dentifrice groups at individual time points; however, differences in color change patterns over time were identified. These findings reflect differences in intragroup trends rather than direct intergroup superiority. Tooth sensitivity was transient and resolved within 1 week in all groups, with lower early sensitivity scores observed in the formulation containing desensitizing agents.
OBJECTIVE:To evaluate the microshear bond strength (μSBS) to lithium disilicate achieved with universal adhesives (with and without silane) compared with one-step and two-step silanes, immediately (IM) and after thermocycling (TC). Chemical interaction (CI) was also assessed. MATERIAL AND METHODS:Lithium disilicate blocks were randomly assigned to nine groups (n = 10) according to surface treatment (silane-free [ALB; AllBond Universal] and silane-containing [AMU; Ambar Universal APS Plus, SBU; Scotchbond Universal Plus] universal adhesives, one-step [PPR; Porcelain Primer, PRO; Prosil, CPR; Ceramic Primer], or two-step silanes [BIS; Bis-Silane, EXP; experimental silane, SIL; Silano Mais]). After hydrofluoric acid etching, treatments were applied and resin cement cylinders bonded. μSBS was measured after 24 h or 10,000 thermocycles. CI was analyzed by micro-Raman spectroscopy. Data were evaluated using two-way ANOVA and Bonferroni tests (α = 0.05). RESULTS:Surface treatment, evaluation time, and their interaction significantly influenced μSBS (p < 0.001). IM, two-step silanes, PPR, and AMU showed higher μSBS, whereas the silane-free universal adhesive demonstrated lower values. After TC, SIL, BIS, PPR, and AMU maintained higher μSBS. Raman analysis demonstrated comparable CI for AMU and SBU compared with one- and two-step silanes. CONCLUSIONS:Bond strength was influenced by pretreatment strategy and aging. Two-step silanes were more consistent, although selected simplified systems achieved comparable performance. CLINICAL SIGNIFICANCE:Two-step silanes remain the most predictable option; however, certain silane-containing universal adhesives and specific one-step silanes may offer simplified alternatives when durability limitations are considered.
OBJECTIVE:To evaluate the effect of glass-ceramic spray deposition and artificial aging on the shear bond strength (SBS) of a resin cement to zirconia. MATERIALS AND METHODS:One hundred Y-TZP zirconia specimens were assigned to five groups (n = 20): airborne-particle abrasion (APC, control), lithium disilicate spray coating (LC), glaze paste (GP), and two glaze spray systems (ES and NS). APC specimens were air-abraded, whereas coated groups were etched with 5% hydrofluoric acid. All specimens received a silane/MDP ceramic primer application and were bonded with dual-cure resin cement. Half of the specimens were tested after 24 h and half after thermocycling (10,000 cycles). Data were analyzed using a two-way ANOVA and Tukey's test (α = 0.05). RESULTS:Surface treatment and aging significantly affected SBS (p < 0.001). Thermocycling reduced SBS in all groups. APC showed the highest SBS under both conditions, followed by LC. No differences were observed among glaze groups after thermocycling. CONCLUSIONS:APC showed the highest short- and long-term bond strength among all groups, followed by LC, which demonstrated better bonding performance than glaze-based systems. After thermocycling, SBS decreased in all groups, and LC revealed about half the SBS recorded for APC.
INTRODUCTION:Malocclusion and altered dentofacial esthetics significantly influence adolescents' psychosocial well-being during a sensitive developmental period. Understanding these impacts is important for esthetic and orthodontic treatment planning. METHODS:A total of 254 adolescents from orthodontic clinics in Osijek, Rijeka, and Split completed the Malocclusion Impact Questionnaire (MIQ), the Psychosocial Impact of Dental Esthetics Questionnaire (PIDAQ), the Jaw Functional Limitation Scale (JFLS), along with Likert-type scales assessing satisfaction with dental and facial appearance and perceived need for orthodontic treatment. RESULTS:The Croatian MIQ showed a unidimensional structure with excellent internal consistency (α = 0.92). MIQ correlated strongly with PIDAQ domains (r = -0.58-0.76, p < 0.001) and the esthetic component of the IOTN as rated by both patients and orthodontists (r = 0.27 and 0.32; p < 0.001), but not with JFLS or objective malocclusion indices. Malocclusion impacts were influenced by the increased esthetic component of IOTN (6% of variance; p < 0.001), female gender (13%; p < 0.001), and increased age (3%; p = 0.011). CONCLUSION:Older female adolescents experienced a greater psychosocial impact of malocclusion. The Croatian MIQ is a valid and reliable instrument for assessing the psychosocial impact of malocclusion.
OBJECTIVE:This study aimed to evaluate the effectiveness of periodic repolishing on the surface and mechanical properties of resin-based CAD/CAM materials subjected to combined mechanical cycling and simulated toothbrushing, with or without periodic repolishing. METHODS:Two resin-based CAD/CAM materials were investigated (Tetric CAD [TC] and Shofu HC [SH]). Groups (n = 12) were assigned according to the evaluation period and repolishing (RPL) condition. The aging protocol comprised simulated toothbrushing (ST-200 g load, 250 cycles/min) combined with mechanical cycling (MC-50 N load, 1.67 Hz frequency) performed in aging intervals (AI-2.4 × 105 MC + 10,000 ST), totaling two periods (5 × AI and 10 × AI). Periodic repolishing was performed using a clinical polishing system (OptraGloss, Diamond High-Gloss polisher [HP]). Surface roughness (Ra), Vickers microhardness (VH), flexural strength (FS), and elastic modulus (EM) were quantitatively evaluated, while SEM and AFM analyses were performed qualitatively. Data normality and homogeneity were verified, followed by two-way ANOVA and Tukey's post hoc test (α = 0.05). RESULTS:Aging significantly increased surface roughness and reduced microhardness in both resin-based CAD/CAM materials (p < 0.05). Periodically repolished groups (T1RPL and T2RPL) showed higher VH and lower Ra values (p < 0.05) than their non-repolished counterparts (T1 and T2). No significant differences in FS or EM were observed after aging (p = 0.664 and 0.185, respectively). CONCLUSION:Aging significantly affected the surface roughness and microhardness of both materials. Periodic repolishing proved to be an effective strategy for minimizing the effects of aging, thereby reducing surface roughness and preserving microhardness. CLINICAL SIGNIFICANCE:Intraoral repolishing at yearly recall intervals may help control surface degradation, maintain smoother surfaces, and preserve microhardness over time, particularly for indirect restorations fabricated from resin-based CAD/CAM materials.
OBJECTIVE:This report presents a multidisciplinary approach for timely and effective rehabilitation of a patient with bilateral maxillary defects, incorporating sequential obturator prostheses, orofacial myofunctional therapy, and multi-dimensional functional assessments, with a 10-year follow-up. CLINICAL CONSIDERATION:Rehabilitation following extensive maxillectomy requires coordinated interdisciplinary care. The sequential use of obturator prostheses eliminates the "cavity period", enabling early restoration of oral functions and preservation of facial morphology. Orofacial myofunctional therapy assists in preventing postoperative trismus and improving adaptation to obturator prostheses. Multi-dimensional functional assessments offer a structured framework to monitor and enhance rehabilitation outcomes. CONCLUSION:The proposed multidisciplinary approach in this clinical report demonstrates a comprehensive and effective strategy for the prosthetic rehabilitation of bilateral maxillary defects, highlighting early recovery of oral functions and facial appearance, with sustained outcomes over long-term follow-up. CLINICAL SIGNIFICANCE:This report highlights practical considerations for the rehabilitation of patients with extensive maxillary defects. For similar cases, clinicians may consider a multidisciplinary approach incorporating the sequential use of obturator prostheses to facilitate early restoration and maintenance of function and esthetics, combined with orofacial myofunctional therapy to improve patient adaptation. The integration of multidimensional functional assessments provides a structured and replicable approach for monitoring treatment outcomes.
OBJECTIVE:This study aimed to evaluate the adhesive performance of a new self-cure bulk-fill restorative system compared with conventional and light-cured bulk-fill resin composites after mechanical and thermal cycling. MATERIALS AND METHODS:Sixty molars were prepared for Class I cavities and restored according to the restorative systems from each group. After 24 h of storage, 30 specimens were sectioned to obtain rectangular sticks (0.9 ± 0.1 mm2), which were submitted to microtensile bond strength testing. The remaining specimens were submitted to mechanical cycling; subsequently, beams were thermocycled and tested. Three beams from each group were subjected to nanoleakage testing to obtain illustrative images. Two-way ANOVA and Tukey's post hoc tests were performed, with a significance level of 5%. RESULTS:No difference on bond strength was observed among groups after 24 h (p > 0.05). Although all restorative systems showed adhesion reduction, self-cure bulk-fill resin composite showed higher values compared to other resin composites after cycling (p < 0.05). Nanoleakage images revealed a continuous adhesive interface between the self-cure bulk-fill composite and dentin, which was maintained after cycling. CONCLUSIONS:New self-cure bulk-fill resin composite showed initially similar adhesive performance to other restorative systems; however, it demonstrated superior adhesion after mechanical and thermal aging.
OBJECTIVE:Evidence on zirconia dental implants remains limited. This retrospective study evaluated clinical and radiographic outcomes of contemporary ceramic implant systems placed in private practice with variable follow-up of up to 11 years. MATERIALS AND METHODS:This retrospective cohort evaluation included 174 patients receiving 275 zirconia implants (one-piece systems and a two-piece tissue-level screw-retained system) placed between 2013 and 2025 with a minimum one-year follow-up. Implant survival and success rates were assessed. Standardized periapical radiographs were analyzed using ImageJ to measure marginal bone levels at placement and annually thereafter. Peri-implant soft tissue health was evaluated using the modified Plaque Index and modified Gingival Index. RESULTS:Kaplan-Meier cumulative implant survival was 97.6%, and overall success was 95.3%. Mean first-year marginal bone loss ranged from 0.25 to 0.74 mm, with a pooled mean of 0.49 mm. Mean annual bone loss after year 1 was low at 0.12 mm/year. Soft tissue indices remained low, and no suppuration was observed. Two implant fractures occurred (0.73%); remaining failures were associated with lack of osseointegration or aseptic loosening. CONCLUSIONS:Within the limitations of this retrospective study, contemporary ceramic implant systems demonstrated high survival and success with stable peri-implant bone levels and favorable soft tissue conditions. CLINICAL SIGNIFICANCE:This study provides real-world clinical and radiographic data on contemporary ceramic implant systems, including one-piece ceramic implants and ATZ two-piece ceramic implants with carbon fiber screws. These findings may help clinicians contextualize the observed performance of ceramic implants in daily practice. Ceramic implants may represent a viable metal-free treatment option for appropriately selected patients, particularly in esthetically demanding situations, when careful case selection, system-specific training, and adherence to surgical and restorative protocols are applied.
OBJECTIVE:To evaluate the effect of glazing dwell time and cooling duration on the flexural strength and surface microhardness of high-translucency 3 mol% yttria-stabilized tetragonal zirconia polycrystal (3Y-TZP). MATERIALS AND METHODS:Total of 108 rectangular zirconia specimens (20 × 4 × 2 mm) were fabricated from preshaded monolithic blocks and sintered at 1530°C. Specimens were divided into nine groups (n = 12). The control group (NG) remained unglazed. Experimental groups underwent conventional firing (CF;1-min dwell) or extended firing (EF; 3-min dwell) at 850°C, each combined with four cooling durations (4,7,9, or 12 min) between 850°C and 600°C. Flexural strength was evaluated using a four-point bending test (ISO 6872:2015) with Weibull analysis, while surface microhardness was measured using the Vickers method (50 g, 10 s). Data were analyzed using two-way ANOVA and Tukey's HSD test (α = 0.05). RESULTS:Significant differences were observed in flexural strength and microhardness (p < 0.001). The unglazed group showed the highest strength (698 ± 18 MPa; m = 46). Among glazed groups, EF3 (3-min dwell/9-min cooling) exhibited the highest characteristic strength (σ₀ = 657 MPa). EF1 (3-min dwell/4-min cooling) showed the lowest strength (466 ± 23 MPa), below ISO requirements. Microhardness decreased with longer cooling durations. CONCLUSIONS:Glazing parameters significantly affect 3Y-TZP properties. Extended firing with controlled slow cooling (9 min) optimizes strength and reliability, while rapid cooling compromises performance.
OBJECTIVES:To assess, firstly, the impact of three sintering speeds on translucency and grain size of 3.5Y-TZP zirconia (Katana HT) across clinically relevant thicknesses, and secondly, the effect of thermocycling on translucency. MATERIALS AND METHODS:Disc specimens were fabricated at six thicknesses (0.7-2.0 mm) and sintered using SLOW (7 h), FAST (90 min), or UHSS (18 min) protocols. Translucency (TP00, TPab) was calculated after color measurements with a VITA Easyshade V on white and black background before and after thermocycling (n = 15). Grain size and crystalline composition were assessed was analyzed using SEM images (linear intercept). The effects of thickness, sintering, and thermocycling were quantified using a three-way ANOVA with η2a linear mixed-effects model with specimen as a random factor and partial η2. RESULTS:Thickness was the primary factor determining translucency (pη2 = 0.97, p < 0.001). In addition, the sintering protocol had a statistically significant, but limited effect (pη2 = 0.360.29). FAST produced higher translucency than UHSS (p = 0.01)Sintering protocols resulted in statistically significative translucency differences, yet within the acceptability thresholds (ΔTP00 < 2.627). The effects of thermocycling were negligible (pη2 < 0.001 = 0.003). Grain size decreased with faster sintering (p < 0.05), with no SEM-detected degradation after thermocycling. Crystalline composition was affected by sintering protocol. The effects of thermocycling were negligible for all outcomes. CONCLUSIONS:Considering the 3.5Y-TZP zirconia composition and the furnace specificity, translucency was predominantly influenced by thickness, while sintering speed exhibited minimal clinical impact. UHSS enables major time reduction without compromising optical performance. CLINICAL SIGNIFICANCE:Within the limitations of this in vitro study and within the tested furnace systems, ultra-high-speed sintering protocolUHSS allowed a substantial reduction in 3.5Y-TZP processing time while maintaining translucency within clinically acceptable thresholds. Ultra-high-speed sintering protocols for 3.5Y-TZP restorations, appear to be a promising solution, reducing processing time while maintaining translucency within clinically acceptable thresholds. Restoration thickness remains the primary design parameter for achieving desired translucency.
