PURPOSE:Monolithic zirconia fixed dental prostheses (FDPs) are widely used because of their favorable esthetic and mechanical properties. Hydrothermal aging and cyclic fatigue may interact to affect monolithic zirconia FDPs, but evidence from anatomically shaped multi-unit restorations remains limited. This study evaluated fracture resistance, phase transformation, and failure characteristics of three zirconia restorative systems after simulated service exposure. MATERIALS AND METHODS:Ninety-six three-unit FDPs were fabricated from self-glazed zirconia (SG), De Corematrix zirconia (DZ), and Lava zirconia (LZ). For each system, the FDPs were divided into four exposure conditions (n = 8): control, cyclic fatigue, low-temperature degradation (LTD), and LTD followed by cyclic fatigue. All specimens were subsequently subjected to load-to-failure testing. Raman spectroscopy and scanning electron microscopy characterized phase transformation and microstructural features. RESULTS:All cyclically loaded FDPs survived 5 × 106 cycles without macroscopic failure. SG showed the highest control fracture resistance. Cyclic fatigue alone produced little change in SG, whereas LTD and combined exposure markedly reduced its fracture resistance. No exposure-related differences were detected for DZ or LZ, although equivalence was not established. Monoclinic-phase formation was not detected after cyclic fatigue alone but was observed after LTD in all systems and was greater after combined exposure. CONCLUSIONS:Simulated service exposure affected the zirconia restorative systems differently. SG exhibited the highest initial fracture resistance but was more susceptible to hydrothermal aging. For DZ and LZ, no differences were detected under the present sample size, but stability was not established. All tested FDPs tolerated clinical-level loads, even after long-term service simulations.
PURPOSE:The aim of this in vivo study was to evaluate and compare the accuracy (trueness and precision) of three portable facial scanning methods: a professional handheld structured-light scanner (P-HS), a low-cost handheld structured-light scanner (LC-HS), and a smartphone with a depth-sensing camera (SP). MATERIALS AND METHODS:Twelve adult volunteers were recruited. Seventeen facial soft-tissue landmarks were marked with adhesive fiducials, and 12 inter-landmark distances were measured. Ten repeated facial scans were acquired from each participant with each method, plus reference scans from an industrial reference scanner. The relative error (RE) was calculated, and trueness and precision were expressed as the mean (Mean-RE) and standard deviation (SD-RE) of REs per participant, distance, and method. The methods were compared using linear mixed-effects models, with pairwise comparisons adjusted by the Holm method (α = 0.05). RESULTS:Statistically significant differences were found in the trueness and precision. The P-HS was the most accurate. The P-HS and SP showed comparable precision, about twice that of the LC-HS, which was the least precise and tended to overestimate. Despite a near-zero net trueness, the SP produced the largest deviations at individual distances. Differences between the trueness and precision of P-HS and SP were not statistically significant. CONCLUSIONS:The facial scanning method significantly affected accuracy. The P-HS best suits high-fidelity workflows; the LC-HS remained within clinically acceptable limits in other studies for less demanding tasks; and the SP was least accurate where point-to-point fidelity is required. Method selection should follow the accuracy each workflow requires.
PURPOSE:This in vitro study examined the initial and long-term retention behavior of individually milled bar (IMB) systems combined with customized patrices (CPs), contrasting electroplated patrices (EP), and friction pin patrices (FPP) concepts. Retention values were related to a previously reported laboratory reference threshold of 5 N. Given the exploratory nature of the design, the study aimed to describe material-dependent trends rather than to establish clinical sufficiency. MATERIALS AND METHODS:Seven IMB-CP combinations were fabricated-four with EP (gold, non-precious alloy, titanium, and zirconia) and three with FPP (non-precious alloy, titanium, and zirconia) (n = 5 per group). Each bar was mounted on two implants embedded in epoxy resin casts and subjected to 5000 insertion-removal cycles in artificial saliva (23°C) using a universal testing machine. Retention forces were continuously recorded, and surface alterations were assessed by profilometry, light microscopy, and environmental scanning electron microscopy. Material wear was determined gravimetrically. Data were analyzed after assessment of normality (Shapiro-Wilk); initial and final retention forces were compared within groups using paired t-tests or Wilcoxon signed-rank tests (α = 0.05). No inferential comparisons between materials or retention concepts were performed; differences between groups are reported descriptively. RESULTS:Initial retention ranged from 5.4 N (titanium-titanium FPP) to 21.7 N (non-precious EP), all exceeding the 5 N laboratory reference threshold. After cyclic loading, final retention ranged from 2.4 N (TF) to 18.5 N (NG). The change in retention (ΔF = F_final - F_initial) varied from -10.1 to +2.1 N across groups. Surface roughness decreased for most EP systems, whereas FPP systems showed greater wear and predictable retention loss. Material change ranged from 8 to 34 µg (IMB) and 36 to 180 µg (CP). CONCLUSIONS:Under the tested laboratory conditions, all IMB-CP systems showed initial retention forces above the 5 N reference threshold. After 5000 insertion-removal cycles, the titanium-titanium FPP combination exhibited the lowest retention and fell below this threshold, whereas the remaining systems maintained retention values above it. EP showed stable or slightly increased retention with minimal measured wear, whereas FPP showed greater, predictable wear-related retention loss. These exploratory observations demonstrate that material pairing plays an important role in retention behavior under in vitro conditions, whereas clinical performance, maintenance requirements, and long-term success should be evaluated in future clinical studies.
PURPOSE:This systematic review aimed to evaluate the long-term effects of misfit on the clinical outcomes of multiunit implant-supported fixed dental prostheses (ISFDPs). METHODS:An electronic literature search was conducted up to December 2025 across five databases: MEDLINE (via Ovid), Embase (via Ovid), Web of Science, the Cochrane Library, and Scopus. Eligible articles were selected based on predefined inclusion and exclusion criteria, and relevant data were extracted. The Newcastle-Ottawa Scale was used to evaluate the methodological quality of the included studies. RESULTS:After screening and applying the eligibility criteria, four articles were identified from the initial 2179 records. Two additional articles were identified through a manual search, bringing the total to six. Although quality assessment indicated that all six studies were at low risk of bias, the comparability domain was weak in most due to limited control of confounding factors. Clinical outcomes in the included studies were reported across four domains: implant cumulative survival rate, screw loosening or fracture, prosthesis-related complications, and peri-implant bone loss. Only one study reported a significantly higher incidence of screw complications in ISFDPs with greater misfit (p = 0.005), whereas most studies did not find a consistent association between misfit and clinical outcomes. CONCLUSIONS:Evidence regarding the clinical implications of misfit in multiunit ISFDPs is limited, with few long-term studies and insufficient control for confounding factors. Limited evidence suggests that greater misfit may be associated with screw complications, whereas no clear association was observed between misfit and peri-implant bone loss.
PURPOSE:To evaluate aesthetic preferences for artificial intelligence (AI)-assisted smile designs produced using four digital smile design software platforms, and to explore associations between these preferences and demographic factors, among dental specialists and laypeople. MATERIALS AND METHODS:A cross-sectional study was conducted to assess aesthetic preferences for AI-assisted smile designs among dental specialists and laypeople. Photographs of 10 standardized models were processed through four digital smile design software platforms: Smilefy, Smilecloud, DTS PRO, and Trios Smile Design. A single prosthodontist reviewed each automated output and adjusted tooth shape, color, midline, gingival contour, and occlusal plane where needed to conform to clinical norms; outputs are therefore best described as AI-assisted rather than fully automated. Each output was labeled A-D to blind participants to the software used; this letter assignment was shuffled independently for each of the 10 model sets rather than following a single fixed layout, though the specific mapping used per set was not formally logged. Participants ranked the four outputs per model from 1 (most aesthetic) to 4 (least aesthetic) using a blinded, pretested questionnaire. Of the participants recruited, at least partial ranking data were available for an analytic sample of 78 dental specialists and 86 laypeople (164 total; demographic data were available for 76 and 85, respectively). Because rankings were ordinal, clustered within participants, and forced-choice, aesthetic preference was analyzed using the Friedman test with Kendall's coefficient of concordance (W) as an effect size, followed by Wilcoxon signed-rank pairwise comparisons with Holm correction. Associations between preference and professional group, age, and gender were examined using Mann-Whitney U and Kruskal-Wallis tests (Holm-corrected), applied to each software's mean rank. RESULTS:Rankings differed significantly across the four software platforms (Friedman χ2 = 349.8, df = 3, p < 0.001; Kendall's W = 0.71, indicating strong agreement). Smilefy and Smilecloud were the most preferred designs overall (mean ranks 1.78 and 1.90, respectively, out of 4), while Trios was the least preferred (mean rank 3.55). Specialists showed significantly stronger relative preference for Smilecloud than laypeople did (rank-biserial r = 0.37, Holm-adjusted p < 0.001), while laypeople were relatively more tolerant of Trios than specialists were (r = -0.44, Holm-adjusted p < 0.001). Within specialists, preference against Trios strengthened significantly with age (Kruskal-Wallis H = 26.2, p < 0.001, ε2 = 0.32); no other age or gender association survived correction for multiple comparisons in either group. CONCLUSIONS:Aesthetic preferences for AI-assisted smile designs differed meaningfully between software platforms and, to a lesser extent, between dental specialists and laypeople, with specialists showing a distinctly stronger relative preference for Smilecloud. Age-related differences were most evident among specialists' preferences for Trios. Given the cross-sectional, non-randomized design and the operator-adjusted nature of the outputs evaluated, these findings should be read as associations rather than causal drivers of preference.
PURPOSE:This study evaluated the effects of high-speed sintering on the translucency and color of various yttria-stabilized zirconia (YSZ) compositions and identified factors influencing these properties to improve clinical predictability. MATERIALS AND METHODS:A total of 144 disc-shaped specimens fabricated from 3YSZ, 4YSZ, and 5YSZ pucks in shades B1, A3, and C4 were sintered using conventional (∼12 h) or high-speed (∼18 min) protocols. Specimens were polished to a 0.5 µm finish and measured Ø13.75 mm × 1 mm. Porosity, phase content, translucency, color, and elemental composition were quantified (n = 8). Normality was assessed using the Shapiro-Wilk test. Pairwise comparisons were performed using Wilcoxon rank-sum tests where appropriate. The effects of shade, yttria content, sintering protocol, and their interactions were evaluated using factorial ANOVA (α = 0.05). RESULTS:High-speed significantly reduced translucency and diminished the translucency advantage of 5YSZ, particularly in darker shades. The reduced translucency was attributed to increased porosity. High-speed also produced lighter specimens (higher L* values) with lower a* and b* values, indicating a shift toward greener, less yellow color coordinates. Color differences (ΔE00) were greatest in C4-shaded specimens. Additionally, a distinct light-dark subgrouping was observed within the 4YSZ-B1 high-speed condition. Compositional analysis showed that HS reduced Fe2O3 levels while maintaining NiO, suggesting that color changes may be associated with Fe2O3 instability and increased porosity. CONCLUSIONS:High-speed reduced translucency and altered clinically perceptible color in dental zirconia, especially in high-yttria contents and darker shades.
PURPOSE:To evaluate the effects of scanner type and prosthesis design-luting protocol combinations on the passive fit of interim implant-supported complete-arch fixed dental prostheses (ISCFDPs) fabricated using a non-calibrated splinting grammetry system (OptiSplint). The null hypothesis was that scanner type and prosthesis design-luting protocol combinations would not affect the passive fit of interim ISCFDPs. MATERIALS AND METHODS:This in vitro 2 × 3 factorial study utilized a maxillary edentulous FP-3 master cast with 4 multiunit abutment (MUA) analogs. Extraoral scans of the OptiSplint assembly were obtained using either an intraoral scanner (IOS-OptiSplint) or a laboratory scanner (Lab-OptiSplint). Each scanning method was combined with each of the three prosthesis design-luting protocol combinations: (1) Ti-base with freehand cementation, (2) Ti-base cementation on a verification cast, and (3) Direct-to-MUA design, resulting in six experimental groups (n = 10 per group; N = 60). All prostheses were milled from pre-polymerized polymethylmethacrylate (PMMA) pucks using a five-axis milling unit. All PMMA ISCFDPs were evaluated for passive fit on the master cast using the screw-resistance test by two calibrated examiners, with discrepancies resolved by a third. Misfit was determined when incomplete seating or abnormal resistance was detected during sequential screw tightening. Inter-examiner reliability was assessed using Cohen's kappa, and misfit rates were compared via Fisher's exact tests (α = 0.05). RESULTS:Inter-examiner agreement was excellent (98%; κ = 0.95). Laboratory scanning achieved complete passive fit across all three prosthesis design-luting protocol combinations. With the IOS workflow, Ti-base on Cast demonstrated 0% misfit, Ti-base Freehand exhibited 30% misfit, and Direct-to-MUA demonstrated 100% misfit. Group 3 exhibited a significantly higher misfit frequency than all other groups (p < 0.001), whereas no other pairwise comparisons were significant. CONCLUSION:Laboratory scanning of a non-calibrated splinting grammetry system was associated with consistently complete passive fit across all groups. It may provide a predictable approach for achieving passive fit in complete-arch interim prostheses. Extraoral scanning with an intraoral scanner yielded variable results, underscoring the value of verification-cast cementation when using Ti-bases. Within the limitations of this study, the results suggest that Direct-to-MUA workflows may require laboratory-based scanning when using the evaluated systems.
PURPOSE:To evaluate the fracture resistance of implant-supported metal-ceramic crowns fabricated using selective laser melting (SLM), according to the metal support height around the screw access hole (SAH) and the substructure design. MATERIALS AND METHODS:Metal-ceramic crowns and rectangular bilayer specimens were fabricated using SLM in two independent experimental series. In the SAH design series, the substructure design was kept constant while the metal support height around the SAH was varied (none, half, and complete metal support; n = 12 per group). In the substructure design series, the SAH configuration was held constant (complete metal support), and the metal substructure design was varied (uniform cut-back, lingual support, and circumferential ring support; n = 12 per group). Crown specimens underwent thermomechanical aging (50 N, 100,000 cycles, 2 Hz, 5°C-55°C), followed by fracture resistance testing, Weibull analysis, failure mode classification, and fractographic analysis. Rectangular bilayer specimens representing each framework design were used for edge-chipping evaluation. Statistical analyses used one-way ANOVA and Tukey HSD tests (α = 0.05). RESULTS:The complete metal support SAH design showed significantly greater fracture resistance than the other SAH configurations (p < 0.05). However, in the corresponding rectangular bilayer specimens, this design showed the lowest edge-chipping resistance among the SAH configurations. Fractographic analysis showed that fractures originated at the occlusal loading site and propagated toward the crown margin. Among substructure designs, the circumferential ring design exhibited significantly greater fracture resistance and superior edge-chipping resistance compared with other designs (p < 0.05). CONCLUSIONS:Complete metal support around the SAH improved fracture resistance. Loading close to the SAH may increase susceptibility to veneering ceramic chipping under the tested conditions. A circumferential ring design providing uniform ceramic support enhanced overall mechanical performance.
PURPOSE:This study aimed to evaluate the effect of different zygomatic implant configurations on the biomechanical behavior of implant-supported prosthetic systems under varying bone conditions using finite element analysis. MATERIALS AND METHODS:Four three-dimensional (3D) finite element models were developed based on two different anatomical conditions representing Zygoma Anatomy Guided Approach (ZAGA) Type 1 and Type 3. In each ZAGA type, two implant configurations were created by positioning zygomatic implants in different regions: lateral incisor-first molar and first premolar-first molar. All models were subjected to vertical and oblique loading conditions. Stress distribution in the peri-implant bone, implants, abutments, and metal framework, as well as implant displacement, was analyzed. RESULTS:Under vertical loading conditions, Models 2 and 4 demonstrated lower stress values and more balanced load distribution, whereas Models 1 and 3 exhibited higher stress concentrations. In contrast, under oblique loading conditions, Models 1 and 3 showed more favorable stress values compared to Models 2 and 4. Implant displacement values were generally higher in Models 2 and 4. Within the limitations of the present finite element analysis, overall biomechanical response patterns were broadly comparable between the ZAGA Type 1 and Type 3 conditions. CONCLUSION:Implant configuration appeared to influence the biomechanical behavior of quad zygomatic implant systems under the tested loading conditions. Models 1 and 3 generally showed a more favorable response under oblique loading, whereas the corresponding models in ZAGA Type 1 and Type 3 exhibited broadly comparable biomechanical patterns.
PURPOSE:Titanium implants are widely used in prosthodontics, but their bioinert surfaces can limit early osseointegration. This study examined whether electrolyte-tuned anodization can tailor TiO2 nanotube (TNT) coatings to improve in vitro osteogenesis, angiogenesis, and inflammation-related responses. MATERIALS AND METHODS:Titanium was anodized in three electrolytes to produce TNT, TNT-H, and TNT-B coatings. Morphology and roughness were assessed by scanning electron microscope, phase/chemistry by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), and wettability by contact angle. Cytocompatibility and functional responses were evaluated using bone marrow-derived mesenchymal stem cells, human umbilical vein endothelial cells, and RAW264.7 cells, including viability/adhesion assays, macrophage polarization and cytokine expression, and osteogenic/angiogenic assays. RESULTS:TNT-B (mean pore diameter ∼188 nm) showed the most consistent improvements across endpoints, enhancing cell adhesion/proliferation, osteogenesis-associated markers, and angiogenesis-associated signals in vitro, while reducing pro-inflammatory cytokine expression and promoting M2-skewed polarization. TNT-H showed measurable responses versus TNT but did not outperform TNT-B in angiogenic assays under the tested conditions. XRD/XPS indicated minor Ti6O- and defect-related signatures in TNT-B that are relevant to these responses. After annealing, corrosion resistance ranked TNT-H > TNT-B > TNT. CONCLUSIONS:Electrolyte modulation enables the controllable fabrication of TNT architectures and surface chemistry. TNT-B demonstrates promising in vitro performance but exhibits reduced electrochemical stability relative to TNT-H, highlighting a bioactivity-stability trade-off and the need for further optimization and validation before clinical use.
PURPOSE:The purpose of this trial was to assess linear dimensional and volumetric changes of buccal peri-implant soft tissues of mandibular single first molar implants after 3 months of healing using a prefabricated scannable healing abutment (HA) with a convex emergence profile (EP) in comparison with a customized non-scannable HA with a concave EP. MATERIALS AND METHODS:Twenty-four subjects were included in the trial. Single implants were placed in mandibular first molars. Two groups of participants were assigned at random to either a control group that received a custom HA with a concave EP (n = 12) or a test group that received a prefabricated scannable HA with a convex EP (n = 12) on the day of implant placement. Pre- and 3-month intraoral scans were made to measure linear dimensional and volumetric changes of buccal peri-implant soft tissues using a three-dimensional metrology software program. Statistical analysis was performed using Mann-Whitney U test and independent sample t-test for linear dimensional and volumetric changes, respectively (α = 0.05). RESULTS:A statistically significant difference was found regarding the linear dimensional changes between test and control groups at 0 and 1 mm from soft tissue margin around the HA (p = 0.001 and 0.005, respectively), with slightly higher values for the control group. No statistically significant difference was shown between the tested groups at 2, 3, and 4 mm from the soft tissue margin (p = 0.419, 0.073, and 0.908, respectively). Moreover, there was not a statistically significant difference in the digital analysis of volumetric changes between the two groups (p = 0.062). CONCLUSIONS:Scannable HAs with convex EP design showed comparable results to customized HAs with concave EP design regarding the buccal soft tissue volume in mandibular first molar implant sites. Although statistically significant differences were found, this was likely of very limited clinical significance.
PURPOSE:To evaluate the aging-related masking performance of structural-color composites used as luting agents for ultrathin, high-translucency (HT) zirconia-reinforced lithium silicate (ZLS) veneers, comparing a dedicated blocker against its universal counterpart, conventional light-cure veneer cements, and preheated composites. MATERIALS AND METHODS:ZLS discs (VITA Suprinity 0M1-HT; 10 × 0.50 mm2; n = 35; n = 5 per group) were luted to standardized zirconia substrates. Luting media included RelyX Veneer (Translucent, A3, WO), Omnichroma Universal, Omnichroma Blocker, Filtek Z250 XT B1, and Vittra APS E-Bleach. Specimens were aged by thermocycling (10,000 cycles, 5-55°C) followed by coffee immersion (7 days, 37°C). Color was measured over white and black backgrounds at baseline and post-aging using a spectrophotometer. Outcomes included CIEDE2000 color difference (ΔE00), whiteness index change (ΔWID), and translucency parameter change (ΔTP00). Data were analyzed using one-way ANOVA with Holm-adjusted pairwise comparisons (α = 0.05). Results were interpreted against established perceptibility and acceptability thresholds (PT00 = 0.8, AT00 = 1.8; whiteness perceptibility threshold = 0.72, whiteness acceptability threshold = 2.62; TPT00 = 0.62, TAT00 = 2.62). RESULTS:Luting medium significantly affected all optical outcomes (p < 0.001). For the primary endpoint (ΔE00 over black background), Omnichroma Universal showed the smallest change (0.27 ± 0.10), whereas Vittra APS E-Bleach showed the largest (4.38 ± 0.34), exceeding the acceptability threshold in all specimens. Omnichroma Blocker (0.57 ± 0.15) did not differ significantly from Omnichroma Universal after Holm adjustment for the primary endpoint. Filtek Z250 XT B1 (1.30 ± 0.22) exceeded the perceptibility threshold in all specimens. For whiteness change, Vittra APS E-Bleach exceeded the acceptability threshold in all specimens (ΔWID = 6.51 ± 1.29), whereas Omnichroma groups showed negative ΔWID values (-0.80 ± 0.36 and -0.73 ± 0.52). Translucency changes remained below clinically detectable thresholds across all groups. CONCLUSIONS:For ultrathin, HT ZLS veneers, aging-related optical stability was highly luting material-specific. Omnichroma Blocker did not provide superior aging-related masking stability compared with Omnichroma Universal for the primary dark-background endpoint. Vittra APS E-Bleach showed color and whiteness changes that exceeded acceptability thresholds under the tested aging conditions, whereas translucency changes remained limited across all luting media.
PURPOSE:This study aimed to evaluate the virtual intercuspal occlusion constructed by the segmented tooth registration method, considering physiological tooth displacement and the conventional buccal bite registration method. MATERIALS AND METHODS:Twenty-nine participants received 29 full crowns on the first molars. Two weeks after delivering the crowns, the posterior regions (upper and lower jaws, U1 and L1) containing the buccal surface occluding in maximum intercuspal position (MIP) under habitual occlusal force were scanned using an intraoral scanner (IOS). Two bite registration methods were conducted: (1) segmenting U1 and L1 into a single tooth and registering to the buccal surface occluding in MIP, respectively (test group), and automatically registering U1 and L1 by the IOS (control group). For evaluation of two virtual intercuspal occlusions, the mean, minimum, and negative mean of interocclusal distance, and occlusal contact area were calculated and compared. The Wilcoxon test was applied to analyze the statistical differences (α = 0.050). RESULTS:In the test group, the interocclusal distance for the second premolars, crowns on first molar, and second molars were as follows: the minimum interocclusal distance ranged from -51.2 to 1.1 µm, the mean from 39.9 to 57.8 µm, and the negative mean from -23.4 to -10.0 µm. These interocclusal distances were significantly larger than those in the control group, which ranged from -136.2 to -79.1 µm; 14.3 to 27.9 µm; and -48.1 to -30.7 µm for the same three indicators, respectively (p < 0.010). The occlusal contact areas for the crowns and adjacent teeth of the test group were significantly smaller than those of the control group, respectively (p < 0.010). Moreover, the mean and negative mean of interocclusal distance had no significant differences between the crowns and second premolars. CONCLUSIONS:By considering physiological tooth displacement, the segmented tooth bite registration method can significantly increase the mean interocclusal distance and reduce occlusal contact areas, thereby correcting the virtual occlusal collisions.
PURPOSE:This study compared the trueness of four digital impression methods in capturing complete-arch implant positions. MATERIALS AND METHODS:An edentulous mandibular model with four angled multi-unit abutment analogs was fabricated and digitized using a desktop scanner (Vinyl HR; Smart Optics) to create a reference dataset. An intraoral scanner (IOS) (Aoralscan Elite; Shining three-dimensional [3D]) equipped with intraoral photogrammetry (IPG) was used for the experimental scans. Four methods were evaluated: direct scanning without splinting (scan body [SB]), splinting scan bodies with light-polymerized acrylic resin (SP), scanning with custom 3D-printed scan aids (SAs), and IPG. A power analysis determined the need for 21 scans per group. Standard tessellation language files were imported into CAD software, converted into implant abutment replicas, and analyzed using 3D inspection software (Geomagic Control X; 3D Systems) to assess 3D, linear, and angular discrepancies. Trueness was analyzed with Kruskal-Wallis and one-way analysis of variance tests (α = 0.05), followed by post hoc analysis. RESULTS:The SB group showed the highest 3D distortion, and the SP group exhibited the highest angular deviation. The IPG and SA groups had comparable linear and 3D deviation values without significant differences. IPG demonstrated the lowest angular distortion of all methods. The right posterior implant recorded the highest 3D distortion, whereas the right anterior implant exhibited the greatest angular deviation. CONCLUSIONS:IPG and SA approaches yielded comparable results, except for angular distortion. These findings provide evidence for selecting optimal digital workflows in full-arch implant rehabilitation. Scan aids can enhance the performance of IOSs in acquiring complete-arch digital impressions, with trueness values approaching IPG systems.
PURPOSE:To characterize current private practice patterns of prosthodontists in the United States using the 2024 American College of Prosthodontists (ACP) survey and to assess longitudinal trends relative to surveys conducted between 2008 and 2017. MATERIALS AND METHODS:A web-based survey was distributed to 2793 prosthodontists from December 6, 2024, to January 31, 2025, and a total of 284 responses were received (10%). Analyses focused on those in private practice, and survey domains included demographics, practice organization, clinical activity, and financial performance and were compared with prior ACP surveys. RESULTS:The mean age of private practice respondents was approximately 55 years, reflecting continued workforce aging. Female representation increased to about 25%. Practice models shifted away from sole proprietorship toward group and employed arrangements. Most respondents worked 40-49 h per week, with 30-39 h devoted to patient care. Fixed prosthodontics and implant procedures accounted for the largest share of clinical time and revenue, and general dentists remained the primary referral source. Mean gross receipts exceeded $2.1 million, and mean net income was over $500,000, representing substantial improvement compared with earlier survey periods. CONCLUSION:The 2024 survey demonstrates a marked recovery in the economic performance of private practice prosthodontists compared with declines observed between 2008 and 2017. Long-term trends toward an aging workforce and increasing female representation persist. Structural shifts away from solo practice continue, reflecting broader changes within dentistry. Despite these changes, core clinical practice patterns remain stable, with fixed and implant prosthodontics dominating practice activity and revenue.
A 52-year-old male patient presented with chronic posterior maxillary pain, multiple dental wear with mild sensitivity, compromised anterior esthetics, and impaired function correlated with failed posterior restorations and occlusal disharmonies. A comprehensive rehabilitation protocol was implemented using facial and intraoral scanning, digital smile design, and staged prosthetic procedures, including endodontic retreatment, gingivectomy, and restoration delivery at an increased vertical dimension of occlusion (VDO). The final phase involved digital occlusal analysis to assess and refine inter-arch contacts. Within the limitations of a single case report, the outcome demonstrated functional and esthetic improvement, with establishment of a stable, harmonious occlusion at the therapeutic VDO. This case illustrates a digital, interdisciplinary approach that may be useful in managing similar complex rehabilitative scenarios.
PURPOSE:Although peri‑implantitis is known to affect adjacent natural teeth, its site‑specific influence on neighboring implants remains poorly characterized. The purpose of this retrospective study was to evaluate whether peri‑implantitis exerts localized, site‑specific detrimental effects on adjacent dental implants and to determine whether these effects differ between mesial and distal adjacent implants. MATERIALS AND METHODS:A retrospective chart review was conducted on patients with two or more adjacent implants in function for ≥1 year, in which at least one implant was diagnosed with peri-implantitis. Clinical parameters such as probing depth (PD), relative probing depth (RPD), free mucosal margin (FMM), bleeding on probing (BOP) and radiographic bone levels were recorded and analyzed using linear and generalized linear mixed-effects models, accounting for patient-level clustering. RESULTS:Fifty-three patients contributed to 78 peri-implantitis affected main implants and 100 adjacent implants. Overall, RPD was significantly greater at near sites than far sites (p = 0.0237), and FMM was more apical at near sites than far sites (p = 0.007). Distal adjacent implants showed significantly deeper PD (p = 0.037) and greater RPD (p = 0.034) at near sites, whereas mesial adjacent implants exhibited only increased recession (p = 0.012) compared to far sites. Marginal bone loss differences were small and not statistically significant. Notably, 53% of adjacent implants developed peri-implantitis. CONCLUSION:Peri-implantitis exerts localized, site-specific effects on adjacent implants, with more pronounced soft-tissue breakdown at near surfaces, particularly affecting distal neighbors. These findings underscore the need for close monitoring of implants adjacent to peri-implantitis sites.
PURPOSE:The purpose of this systematic review was to compare the clinical outcomes and patient-reported outcome measures (PROMs) of digitally and conventionally fabricated removable partial denture (RPD) frameworks. METHODS:This systematic review followed the Preferred Reporting Items for Systematic reviews and Meta-Analyses. An electronic search was performed in PubMed/MEDLINE, Scopus, Embase, and Web of Science. Clinical studies comparing clinical outcomes and/or PROMs of digitally and conventionally fabricated RPD frameworks, with no restrictions on publication year or language, were included. Studies involving other types of oral rehabilitation or those without full-text availability were excluded. RESULTS:From 863 studies identified, 14 were included in this review. Clinical outcomes assessed included adaptation, periodontal health, masticatory efficiency, denture stomatitis, weight, success, and placement rates, adjustment time, stability, number of framework remakes, and components requiring adjustment. PROMs included patient satisfaction, oral health-related quality of life (OHRQoL), and patient preference. No significant difference in rest adaptation was observed between conventional and digital workflows (p = 0.070). Some studies suggested that digitally fabricated RPD frameworks may be associated with reduced bone loss, improved masticatory efficiency, and fewer incidences of denture stomatitis. Regarding PROMs, the digital workflow resulted in higher patient satisfaction, whereas OHRQoL and patient preference were similar between techniques. CONCLUSIONS:Digitally fabricated RPD frameworks showed satisfactory clinical outcomes and PROMs and may represent a viable alternative to conventional methods.
PURPOSE:This randomized controlled clinical trial compared peri-implant soft tissue responses to CAD-CAM-milled versus 3D-printed polymethylmethacrylate (PMMA) custom healing abutments following second-stage implant surgery. MATERIALS AND METHODS:Twenty-two osseointegrated implants were randomly allocated to receive either CAD-CAM-milled (Group I, n = 11) or 3D-printed (Group II, n = 11) PMMA custom healing abutments. Peri-implant crevicular fluid IL-1β was quantified via ELISA at 1, 2, and 4 weeks. Modified gingival index, bleeding on probing, plaque index, and probing depth were recorded concurrently. Abutment surface roughness and degree of monomer conversion were also assessed. Intergroup and intragroup comparisons utilized appropriate parametric and nonparametric tests (α = 0.05). RESULTS:The 3D-printed group showed significantly higher gingival index scores at week 4 (p = 0.001) and greater bleeding on probing at weeks 2 and 4 (p < 0.05). Both groups demonstrated significant increases in probing depth and plaque index over time (p < 0.05), without significant intergroup differences. IL-1β concentrations rose significantly in both groups (p < 0.001), remaining consistently and significantly elevated in the 3D-printed group throughout all time points (p < 0.001). 3D-printed abutments exhibited significantly greater surface roughness values for Ra (p < 0.001), Rp (p = 0.001), and Rz (p = 0.03), alongside a lower degree of monomer conversion (84.8% vs. 94.1%), indicating inferior polymerization efficiency. CONCLUSIONS:Clinical, biochemical, and biomaterial evidence collectively demonstrate that CAD-CAM-milled PMMA healing abutments promote a more favorable peri-implant soft tissue response than 3D-printed alternatives, suggesting that the fabrication method critically influences early biological tissue healing.
PURPOSE:To evaluate strains generated by different denture attachment systems, peri-implant sites, and retention levels under 3-mm posterior upward displacement in 2-implant-retained overdentures and to evaluate dislodgement angles. MATERIALS AND METHODS:Four attachment groups (LOCATOR with standard-range insert (LOC), LOCATOR with extended-range insert (LOE), LOCATOR R-Tx with standard-range insert (LOR), and Novaloc (NOV)), each with three retention levels, were tested. Peri-Implant strains were recorded during simulated posterior upward displacement until complete insert dislodgement. Dislodgement angles were also measured. Strain data were analyzed by three-way mixed ANOVA, and dislodgement angles were analyzed by two-way ANOVA (α = 0.05). RESULTS:A significant interaction between attachment system and peri-implant site was found for strain (p < 0.001). The NOV group exhibited significantly higher strain values than the other groups at each site, whereas no differences were observed among the LOC, LOE, and LOR groups. Across systems, the mesial site exhibited the highest strain values. For dislodgement angle, significant main effects were found for attachment system (p < 0.001) and retention level (p = 0.002). The LOR group exhibited the greatest dislodgement angle, followed by the LOC, LOE, and NOV groups. High retention resulted in significantly lower dislodgement angle than medium (p = 0.002) and low retention (p = 0.021), whereas there was no difference between medium and low retention (p = 1.00). CONCLUSIONS:Attachment system significantly affected peri-implant strain and dislodgement angle under posterior upward displacement. The NOV attachment exhibited the highest peri-implant strain, particularly at the mesial site. Retention insert level did not significantly affect the peri-implant strain but did affect dislodgement angle. The LOR attachment demonstrated the greatest dislodgement angle, whereas the NOV attachment showed the lowest dislodgement angle.
