Journal of Prosthodontics-Implant Esthetic and Reconstructive Dentistry最新文献

Purpose: This study aimed to determine the perceptibility and acceptability thresholds for the relative translucency parameter (RTP) of ceramic materials, using observer-based assessments under simulated clinical conditions. The null hypothesis was that no difference existed in RTP values for perceptibility and acceptability thresholds.

Materials and methods: Specimens of lithium disilicate in five translucency levels were fabricated into discs and anterior crowns. RTP was calculated using the CIEDE2000 color difference formula with black and white backings. Digital photographs of paired crowns on typodont models were presented to 30 dental clinicians in a controlled visual environment using a randomized Qualtrics survey. Observers judged translucency differences (perceptibility) and clinical appropriateness (acceptability). A repeated-measures logistic regression model was used to analyze observer responses.

Results: A significant relationship was found between Delta RTP (△RTP) and both perceptibility and acceptability judgments (p < 0.0001). Perceptibility thresholds were identified at -17.5, while acceptability thresholds were defined at 12.6. △RTP values exceeding 27 were consistently perceived as different, while values below 12 were often judged acceptable. The null hypothesis was rejected, confirming a statistical difference between perceptibility and acceptability judgments and their relationship to RTP.

Conclusion: Clinically relevant RTP thresholds for translucency perception and acceptability were established. These findings validate RTP as a meaningful and quantifiable tool for assessing esthetic differences in translucency among restorative materials. The results have implications for material selection and clinical decision-making in prosthodontics.

This case report highlights the experience of one maxillofacial surgical patient who delayed prosthodontic treatment for 7 years as they saved to self-fund access to a subsidized prosthodontic service. Without the benefit of a restored opposing dentition for a prolonged period of time, maxillary occlusal plane disruption occurred as a downstream clinical consequence. To manage the complexities arising from delayed presentation, the prosthodontic team developed a highly tailored treatment plan to meet the patient's unique clinical needs, which included fabrication of customized healing abutments, an implant indexing device, and a definitive removable implant-tooth-supported occlusal overlay prosthesis, which incorporated an atypical increase in the vertical dimension of occlusion (VDO) of 12 mm. Following 68 months of follow-up, the patient tolerated the increase in VDO well. Two minor technical complications occurred (denture tooth debond events) and one minor biological complication (localized peri-implant mucositis) within the follow-up period. This report underscores the role of timely prosthodontic involvement in interdisciplinary maxillofacial treatment pathways and advocates for the prioritization of equitable access to specialist prosthodontic services to mitigate preventable challenges in this vulnerable patient cohort.

Purpose: This study validated the alignment accuracy of a novel implant-retained fiducial marker system for aligning digital scans in edentulous mandibles MATERIALS AND METHODS: A mandibular master cast with four implant analogs was fabricated. A reference scan of scan bodies (attached to analogs via spherical fiducial markers) was captured using a calibrated desktop scanner with a fixed-position jig. Without moving the cast, scan bodies were replaced with a milled interim prosthesis (using the same fiducial markers) and rescanned to ensure perfect spatial correspondence. The scan body assembly was rescanned 10 times using the desktop scanner (negative control dataset), then 10 times with an intraoral scanner (IOS). All IOS scans were aligned to the reference prosthesis scan in dental computer-aided design (CAD) software using fiducial marker-based reference alignment. Both negative control and aligned IOS scans were compared to the reference scan using metrology software to compute 3D deviation metrics. Statistical analysis used Mann-Whitney U test and Hodges-Lehmann estimator (α = 0.05).

Results: Mann-Whitney U test revealed a statistically significant difference between groups (p < 0.001). Median RMS error for fiducial alignment was 85.8 µm, compared to 8.4 µm for the negative control. Hodges-Lehmann estimator median difference of -77.7 µm (95% CI: -82.4, -75.1 µm).

Conclusions: Despite statistical differences, the novel fiducial marker system achieved a mean alignment accuracy of approximately 85 µm, which is clinically acceptable. This in vitro study demonstrates technical feasibility. Clinical validation is warranted.

Purpose: To evaluate the impact of palatal alveolar bone thickness at the implant platform level on bone resorption and failure rates in the maxillary aesthetic zone.

Materials and methods: From 2018 to 2023, 81 patients with 118 implants were included. This retrospective study used cone-beam computed tomography to measure labial/palatal bone thickness at three stages (T0: postoperative; T1: 3 months; T2: 6 months). The data are presented as the means ± SDs, with significance set at p < 0.05. Relationships between palatal alveolar bone thickness and implant outcomes were evaluated using Pearson correlations, Chi-square tests, and ANOVA with eta-squared statistics. ROC curve analysis was used to determine the cutoff value for failure-related bone thickness.

Results: The palatal alveolar bone at the level of the implant platform was unrelated to the bone resorption or failure rate. ROC analysis (AUC = 0.651) identified < 5.76 mm palatal bone thickness at T0 (root tip level) as a significant failure risk predictor (p < 0.05). Horizontal palatal and labial bone thickness decreased by 21.79% ± 41.18% (p < 0.05) from T0 to T2, with greater labial bone loss.

Conclusions: Palatal alveolar bone thickness at the implant platform level does not influence bone resorption outcomes or survival rates in the maxillary aesthetic zone. However, excessive reduction of palatal bone at the root tip (< 5.76 mm) increases failure risk. Preoperative planning should preserve adequate palatal bone mass while avoiding unnecessary bone removal for long-term stability.

Purpose: Evidence-based dentistry relies on valid statistics, yet misuse remains common. Despite increased emphasis on statistical rigor, recent prosthodontic publications remain underexplored. We hypothesized that statistical misapplications and reporting deficiencies persist in prosthodontic research. This study evaluated the appropriateness, application, and reporting of statistical tests in high-impact prosthodontic journals.

Methods: Original clinical studies published between January 2019 and December 2024 in the Journal of Prosthodontics (JOP), International Journal of Prosthodontics (IJOP), and Journal of Prosthetic Dentistry (JPD) were screened. Eligible articles used quantitative methods with inferential statistics. A 20% stratified random sample ensured representation by journal and year. Articles were assessed using a specialty-adapted checklist covering five domains: test selection, sample size justification, assumption testing, examiner calibration, and result interpretation. A weighted scoring system categorized studies as having no major, minor, or major error. Descriptive statistics and Pearson's Chi-square test, with Monte Carlo simulation as needed, assessed associations. Twenty percent of articles (n = 24) were double-scored; consensus yielded inter-rater reliability κ = 0.94.

Results: A total of 119 clinical studies were reviewed (JPD 57, IJOP 37, JOP 25). Appropriate statistical tests were used in 88% of studies; notably, all 19 studies that involved a statistician demonstrated correct test selection. However, only 32% reported sample-size calculations. Assumption testing was completed in 47% of studies, and examiner calibration was described in 40%. Confidence intervals were absent in 83% of reports, with only 8% both reporting and interpreting them. Overall, 45% of studies had no major statistical error, 35% contained major errors, and 21% showed minor deficiencies. Having no major error was strongly associated with proper test selection and assumption verification (p < 0.001).

Conclusions: Statistical reporting deficiencies persist in prosthodontic research, particularly in sample-size justification, assumption testing, and confidence interval reporting, highlighting the need for specialty-specific checklists, enhanced training, and stronger editorial/reviewer standards.

Purpose: To evaluate the effect of different self-etching primer (Monobond Etch & Prime-MEP) application protocols and aging on micro shear bond strength (µSBS) and surface etching patterns of zirconia-reinforced lithium silicate (ZLS) and lithium disilicate (LD) ceramics.

Materials and methods: Twenty-eight blocks of Vita Suprinity (VS), Celtra Duo (CD), and IPS e.max CAD (EM) were cut into two sections each (n = 56 specimens per ceramic) and divided into groups: 5% hydrofluoric acid with silane (HF + S, control), and MEP scrubbing for 20, 40, and 60 s, with a 40-s reaction time (n = 14 per condition; n = 10 for µSBS and n = 4 for scanning electron microscopy [SEM]). For µSBS, resin cement was applied and light-cured; half of the resin cylinders were stored for 24 h, while the other half underwent thermocycling (TC) (10,000 cycles; dwell time of 30 s between 5°C and 55°C) before testing. Data were analyzed using three-way repeated measures analysis of variance (ANOVA) and Bonferroni post hoc tests (α = 0.05).

Results: The HF + S group showed higher µSBS for EM than VS and CD (p < 0.001). MEP100 achieved comparable µSBS with HF + S for CD (p < 0.001) and improved µSBS for VS and EM (p = 0.128). TC decreased the µSBS values in most groups. The only exception was observed when the VS and CD surfaces were treated with MEP100, and when the CD surface was treated with MEP80. Adhesive fractures were predominantly seen. SEM revealed MEP100 produced etching patterns like HF, with lithium metasilicate and orthophosphate crystals present.

Conclusions: Prolonged MEP application (MEP100) produced etching patterns and µSBS values comparable to HF + S, making it a viable surface treatment alternative for ZLS and LD ceramics.

Purpose: This study examined the survival rate of implants and maxillary implant-supported overdentures (MIS-ODs) and identified the frequency of maintenance needs as well as technical and biological complications associated with MIS-ODs.

Materials and methods: This retrospective cohort study included 86 patients who received 86 MIS-ODs between 1982 and 2023 in a university setting. Data analyses were performed to determine the survival rate of implants and MIS-ODs, as well as the frequency of maintenance events and complications (technical and biological). The survival proportion of MIS-ODs was estimated, and prognostic factors were analyzed using Cox regression analyses (p < 0.05).

Results: The median follow-up time for MIS-ODs in this study was 39.0 months (interquartile range [IQR]: 15.0-84.3). Among 86 MIS-ODs, 45.3% had non-splinted attachments and 54.7% had splinted attachments; 9.3% of prostheses were supported by 2 to 3 implants, 59.3% by 4 implants, and 31.4% by more than 4 implants. The most common maintenance intervention was adjustment of the prosthesis intaglio surface. Technical complications occurred in nearly 60% of cases, with inadequate prosthesis retention being the most frequently reported issue. The most prevalent biological complication was peri-implant mucositis. Lastly, 27.9% of prostheses (24 cases) required a new prosthesis after a median survival time of 58.5 months (IQR: 16.0-79.0) due to acrylic tooth wear, implant loss, fabrication errors, and suboptimal retention.

Conclusions: Within the limitations of this study, MIS-OD survival is independent of the prosthesis design characteristics. However, certain technical and biological complications can affect the survival of MIS-ODs.

Purpose: To compare the stainability, translucency, opalescence, whiteness, gloss, and hardness of 4 computer-aided design and computer-aided manufacturing (CAD-CAM) restorative materials after simulated coffee drinking and color correction.

Materials and methods: Four CAD-CAM blocks were investigated (n = 40): resin nanoceramic (Cerasmart, CS), polymer-infiltrated ceramic network (Vita Enamic, VE), lithium disilicate glass ceramic (IPS e.max CAD, EC), and zirconia-reinforced lithium silicate glass ceramic (Vita Suprinity, VS). The color stability (ΔE₀₀), relative translucency (RTP), opalescence (OP), and whiteness stability (ΔWI_D) were measured with a spectrophotometer. Gloss (GU) was recorded with a gloss meter, and hardness (HM) was detected with a Martens hardness testing device. The specimens were observed at baseline (T0), after coffee thermocycling (CTC) (T1), and after color correction (T2). ΔE₀₀ was analyzed by two-way ANOVA, ΔWI_D was analyzed with one-way ANOVA, and RTP, OP, WI_D, GU, and HM were assessed with repeated ANOVA to evaluate the effects of material type, treatment, and their interactions on the tested properties. Post hoc pairwise comparisons were assessed by Tukey HSD and Student t-tests (α = 0.05).

Results: ΔE₀₀, WI_D, OP, GU, and HM outcomes were significantly impacted by material type (p < 0.001) and treatment (p ≤ 0.028), whereas ΔWI_D and RTP were affected by material type (p ≤ 0.03). CS exceeded the ΔE₀₀ perceptibility threshold at T1. VS exhibited the highest stain resistance, RTP, and HM, and the least was in VE and CS. Color correction serums reversed CTC-induced staining among VS and VE (p < 0.001).

Conclusions: Zirconia-reinforced lithium silicate glass-ceramics demonstrated superior color stability and hardness when subjected to coffee thermocycling and color correction serum.

Purpose: This study evaluates the thermodynamic benefits of including an irrigation fluid channel in the design of surgical guides used for dental implant site drilling.

Materials and methods: Two types of guides suitable for hosting artificial bone plates that mimic the mechanical properties of human alveolar bone were designed: a classical guide (CLA-a splint with a guiding cylinder) and a guide with an internal coolant channel (INT). They were fabricated from titanium powder by selective laser melting. Graduated drillings were performed using a pilot bur followed by two larger ones; infrared thermography was used to record the temperature of the drill upon exit and the peak temperature of the specimen right after the bur's retraction.

Results: The rise in bone temperature (mean ± standard deviation) while drilling through the CLA (INT) guide was 13.2 ± 3.6 (9.0 ± 3.4)°C for Drill 1, 4.3 ± 1.0 (2.1 ± 1.0)°C for Drill 2, and 2.1 ± 0.6 (0.4 ± 0.5)°C for Drill 3; the differences were statistically significant (p < 0.0032). To characterize individual differences between pairs of drillings conducted with different guides, Bland-Altman analysis was performed for the most thermogenic step. The mean difference between temperature elevations recorded with CLA and INT was -5.8°C, whereas the limits of agreement were 2.9°C and -14.4°C. In 95% of the cases, INT displayed more efficient cooling than CLA.

Conclusion: Surgical guides with incorporated coolant channels ensure better heat removal than conventional guides. Further research is needed to assess bone overheating within a few hundred micrometers from the osteotomy edge.