Abstract Purpose This study evaluated and compared the marginal fit of CAD–CAM zirconia crown copings with and without a 3D‐printed control model. Materials and Methods This prospective in vitro trial involved 30 zirconia crown copings made from the same STL file. These were divided into two groups. Half of them had their own 3D‐printed control model made from the same STL file (With‐Printed‐Model group), whereas the other half lacked any control model (No‐Printed‐Model group). Both groups underwent manual adjustments in a systematic way. Their marginal gaps were evaluated using a digital optical microscope from eight zones: buccal, mesiobuccal, mesial, mesiopalatal, palatal, distopalatal, distal, and distobuccal. Results The mean values with standard deviations for the With‐Printed‐Model and No‐Printed‐Model groups were 15.18 ± 14.49 and 12.46 ± 14.09 µm, respectively. All crown copings from both groups were below 75 µm. Statistical analysis showed a significant difference between the two groups. Conclusion The No‐Printed‐Model group demonstrated superior marginal fit compared to the With‐Printed‐Model group. However, the largest marginal gaps from each group were still within the clinically acceptable range below 75 µm. Although the 3D‐printed control model did not improve marginal fit, its primary function is to effectively identify major manufacturing errors.
Factors Influencing Nasoalveolar Molding Treatment Completion and Noncompletion in Infants with Cleft Lip and Palate
Objective Identify sociodemographic factors and comorbidities predictive of nasoalveolar molding (NAM) treatment completion and noncompletion in infants with cleft lip with or without (+/–) cleft palate in a rural-suburban population. Design Retrospective cohort study. Setting Tertiary medical center. Patients, Participants Infants diagnosed with cleft lip +/- cleft palate who initiated NAM treatment between 2013 and 2023. Forty-seven patients met inclusion criteria. Main Outcome Measure(s) Prevalence of NAM treatment completion, defined as continued attendance of NAM appointments until initial lip repair surgery. Results NAM treatment noncompletion rate of 23.4%. Noncomplete NAM treatment was associated with greater additional unscheduled NAM visits ( P < .001); increased days inpatient after birth ( P < .001); NICU admission ( P < .001); public insurance ( P = .007); preterm birth ( P = .008); history of social work visits ( P = .024); increased comorbidities ( P = .028); non-Caucasian race ( P = .034); and presence of siblings ( P = .036). Associated comorbidities included use of feeding tube ( P < .001); and conditions related with renal ( P < .001); cardiac ( P = .004); failure to thrive ( P = .009); syndromes ( P = .009); orthopedic ( P = .011); pulmonary ( P = .022); and ophthalmologic systems ( P = .041). Conclusions Increased overall health complexity, public insurance status, and need for social work support were identified as factors associated with NAM noncompletion. These variables can help identify patients at risk of noncompletion and empower providers to supply individualized support and resources.
The Effect of Patient Specific Factors on Occlusal Forces Generated: Best Evidence Consensus Statement
AbstractPurposeThe purpose of this Best Evidence Consensus Statement was to search the literature to determine if there is a relationship between patient specific factors and occlusal force.Materials and MethodsA literature review was conducted in the following databases: Evidence‐Based Medicine Reviews (EBMR), Cochrane Database of Systematic Reviews, Embase, and Ovid MEDLINE(R) and Epub Ahead of Print. Articles on patient factors and occlusal force were compiled by using a combination of the key words: “bite force,” “occlusal force,” “partial and complete edentulism,” “bruxism,” and “orthognathic class.” Inclusion criteria included meta‐analyses, systematic reviews, randomized controlled trials, case series, and journal articles. Exclusion criteria were case reports, studies in children, animals, and bench studies.ResultsOf the 1502 articles that met the initial search criteria, 97 related to patient‐specific factors affecting occlusal forces. These articles were evaluated, rated, and organized into appropriate categories addressing questions of foci.ConclusionsThe range of occlusal force is highly variable among subjects correlated to patient specific factors such as age, gender, partial and complete edentulism, the presence of a maxillofacial defect, location of edentulous area, orthognathic profile, and magnitude of occlusal vertical dimension. Tooth replacement therapies targeted at increasing occlusal contact seem to have a positive effect on increasing occlusal force. Bruxism does not necessarily demonstrate higher occlusal powering but may have greater tooth contact time. Occlusal force is not clearly affected by the type of dental restoration or restorative material used. The clinical significance of the changes in occlusal forces is yet to be determined.
Association Between Early Implant Failure and Prosthodontic Characteristics
AbstractPurposeTo identify associations between early implant failure and prosthodontic characteristics that could be used to guide subsequent continuous quality improvement efforts of patient care.Materials and MethodsAn implant‐level analysis was performed in which data were abstracted from a prospective clinical database of all adult patients treated with implants and followed up from January 2000 through December 2014 at the Department of Dental Specialties at Mayo Clinic in Rochester, Minnesota. These data were used to determine time to implant failure. Associations between prosthodontic characteristics and early implant failure were evaluated with Cox proportional hazards regression models and summarized with hazard ratios (HRs) and 95% confidence intervals (CIs).ResultsAmong 8762 implants in 2787 patients, 395 (4.5%) failed within the first year of placement at a mean (SD) of 127 (97) days (range, 2‐364 days). Univariable analysis showed no associations between early implant failure and use of a cover screw, prosthesis, or definitive or provisional prosthesis at implant placement. Three of 25 single crowns failed, and use of a single crown was significantly associated with early implant failure (HR, 3.94; 95% CI, 1.08‐14.35; P = 0.04). This study identified no significant associations between prosthodontic characteristics identified after implant placement and early implant failure.ConclusionsUse of a prosthesis at implant placement, use of a definitive or provisional prosthesis, and early mechanical complications were not associated with increased risk of early implant failure. Quality improvement efforts should focus on aspects of decision making that aim to decrease surgical complications.
Early Implant Failure Associated With Patient Factors, Surgical Manipulations, and Systemic Conditions
Abstract Purpose Systematic monitoring of important clinical outcomes is increasingly important for health‐care decision making, especially in the context of continuous quality improvement. Dental implant failure within the first year (early failure) has been previously shown to be more common than subsequent failure. The purpose of this study was to identify associations between early implant failure and patient factors, surgical manipulations, and systemic conditions. Materials and Methods The authors retrospectively identified the records of consecutive adult patients with dental implants seen between 2000 and 2014 in the Department of Dental Specialties, at the Mayo Clinic. Demographic, surgical, and medical data were extracted from the database and individual medical records to determine time to first implant failure. Cox proportional hazards regression models were used to assess associations of demographic, surgical, and systemic conditions with implant failure during the first year post‐implantation, summarized as hazard ratio (HR) (95% confidence interval [CI]). Results Among 8540 implants identified during the study period, 362 (4.2%) failed within the first year of placement at a mean (SD) of 129 (96) days after placement. On univariate analysis, most candidate predictors were not shown to influence first‐year failure. Preplacement surgical manipulations associated with increased early implant failure were bone augmentation only (HR, 1.45; 95% CI, 1.02‐2.05; p = 0.04), socket preservation (HR, 2.67; 95% CI, 1.33‐5.38; p = 0.006), and xenogenic material (HR, 2.12; 95% CI, 1.11‐4.04; p = 0.02). Alveoloplasty only at placement was associated with decreased early implant failure (HR, 0.33; 95% CI, 0.17‐0.65; p = 0.001). Overall, 318 implants (3.7%) had surgical complications within the first year of placement at a mean (SD) of 110 (114) days after placement; any surgical complication was significantly associated with early implant failure (hazard ratio, 15.84; 95% CI, 11.10‐22.61; p < 0.001). After adjustment for age, sex, and implant era, no single or multiple medical condition(s) and no single or multiple medication(s) increased patient risk of implant failure in the first year after placement. Conclusions These findings support a targeted effort to reduce the incidence of surgical complications to reduce early failure of dental implants.
Evaluation of Fracture Resistance in Aqueous Environment under Dynamic Loading of Lithium Disilicate Restorative Systems for Posterior Applications. Part 2
AbstractPurposeThe goals of part 2 of the study presented here were 1) to assess whether there is a difference in failure mode of different thicknesses (2.0, 1.5, 1.0, and 0.5 mm) of anatomically standardized full contour monolithic lithium disilicate restorations for posterior teeth, and 2) to assess if there is a difference among various crown thicknesses when these restorations are subjected to dynamic load forces common for posterior teeth.Materials and MethodsFour groups (n = 10), each with a different thickness of anatomically appropriate all‐ceramic crowns, were to be tested as established from the statistical analysis of the preliminary phase. Group 1: 2.0 mm; group 2: 1.5 mm; group 3: 1.0 mm; group 4: 0.5 mm. The specimens were adhesively luted to the corresponding die, and underwent dynamic cyclic loading (380 to 390 N) completely submerged in an aqueous environment until a failure was noted by graphic recording and continuous monitoring.ResultsThere was a statistically significant difference of the fatigue cycles to failure among four groups (p < 0.001; Kruskal‐Wallis test). The mean number of cycles to fail for 2.0 mm specimens was 17 times more than the mean number of cycles to fail for 1.0 mm specimens and 1.5 times more than the mean number of cycles to fail for 1.5 mm specimens. The 0.5 mm specimens failed with one cycle of loading. A qualitative characteristic noted among the 2.0 mm specimens was wear of the area of indenter contact followed by shearing of the material and/or crack propagation.ConclusionBased on the findings of this study, it may be reasonable to consider a crown thickness of 1.5 mm or greater for clinical applications of milled monolithic lithium disilicate crowns for posterior single teeth.
Practice‐Based Evidence from 29‐Year Outcome Analysis of Management of the Edentulous Jaw Using Osseointegrated Dental Implants
AbstractPurposeThe aim of this retrospective study was to summarize practice‐based evidence associated with long‐term outcomes (>20 years) in the management of edentulous patients. The patient population was managed with implant‐supported prostheses, following the original osseointegration protocol, provided over the period from 1983 to 1991 in the group prosthodontics practice at the Mayo Clinic. The data are an example of practice quality assurance monitoring and are used to refine care delivery when needed and to provide information regarding expected outcomes in a shared decision‐making interaction with prospective patients.Materials and MethodsTwo hundred and sixty four patients with at least one edentulous jaw were identified. Of these, 255 completed their care and follow‐up at the Mayo Clinic (209 mandible only, 35 maxilla only, 11 mandible and maxilla). Prosthodontic outcomes categorized as anticipated or unanticipated prosthetic and biologic events and the respective interventions required for each were recorded to assess follow‐up event dynamics for this care modality.ResultsThe mean duration of follow‐up for 190 of the 255 patients (65 died at a mean follow‐up of 12.6 years) was 13.0 years (median 13.6; range 0.3 to 28). At least one prosthetic event was experienced by 148 patients (58%), and 81 (32%) experienced at least one biologic event. Overall, patients experienced 3.8 times more prosthetic events than biologic events. Twenty‐four (9%) patients experienced 35 implant failures. Overall survival rates at 20 years were 86% for prostheses, 15% survived free of any event, and 92% experienced survival free of implant failure (95% confidence interval).ConclusionAnticipated and unanticipated prosthetic events occur throughout the life of the hybrid prosthesis. Prosthetic events significantly surpass (four times more) biologic events and occur significantly later in the follow‐up. For this patient group, 8.6% (22/255) had implant‐supported prostheses remade during follow‐up in this patient population. These findings support the recommendation that prosthodontic care for missing teeth be thought of in a “chronic condition” context, recognizing that long‐term outcome monitoring to provide realistic care expectations is important for demonstrating care value in oral health promotion.
Evaluation of Fracture Resistance in Aqueous Environment of Four Restorative Systems for Posterior Applications. Part 1
AbstractPurposeThe goals of this study were to: (1) establish a range of the performance of four restorative systems for posterior single‐tooth crowns under single load to fracture submerged in an aqueous environment, (2) identify restorative system(s) of interest to be examined in the second study phase under sliding contact step‐stress fatigue as full‐contour anatomically appropriate single posterior tooth restoration(s), (3) establish a range for loading/testing for phase 2.Materials and MethodsForty specimens (n = 10/group) of 2 mm uniform thickness were tested. Group 1: monolithic lithium disilicate IPS e.max Press; group 2: IPS e.max ZirPress, 0.8 mm zirconia core with 1.2 mm pressed veneering porcelain; group 3: IPS e.max ZirPress, 0.4 mm zirconia core with 1.6 mm pressed veneering porcelain; group 4: IPS InLine PoM. Specimens were bonded to a block of polycast acrylic resin on a 30° sloped surface with resin cement. Specimens were axially single loaded to failure while submerged under water.ResultsThere was a statistically significant difference (p < 0.001) in failure load among the four restorative systems. Lithium disilicate showed a mean failure load similar to mean maximum posterior bite forces (743.1 ± 114.3 N). IPS e.max Zirpress with a 0.4 mm zirconia core exhibited the lowest mean failure load (371.4 ± 123.0 N).ConclusionFracture resistance of monolithic lithium disilicate in an aqueous environment is promising and requires second phase testing to evaluate the potential of various thicknesses appropriate for posterior single tooth applications. Doubling the IPS e.max Zirpress zirconia core from 0.4 mm to 0.8 mm increased the fracture resistance of this restorative system threefold.