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Beijing Da Xue Xue Bao. Yi Xue Ban =... Dec 2020To explore the preliminary application of "biocopy function" in digital technology of temporary crown in severe tooth attrition, so as to reduce the difficulty of final...
OBJECTIVE
To explore the preliminary application of "biocopy function" in digital technology of temporary crown in severe tooth attrition, so as to reduce the difficulty of final restoration adjustment in severe tooth wear cases, and save clinical time.
METHODS
Twelve patients aged between 40 and 65 years with severe tooth attrition were recruited in this study. The experimental group (6 cases, 3 females and 3 males) used the method of digital copy of temporary restoration shape when making the final restoration, and the control group (6 cases, 3 females and 3 males) used the traditional method to make the final restoration. The mean time of central occlusal adjustment and protrusive and lateral occlusal adjustment of each crown, the number of follow-up visits of the patients were recorded and statistically analyzed. The occlusal comfort of the first and the third months after wearing the prosthesis was evaluated by the patients, and the difference of the occlusal comfort of the final prosthesis made by the two methods was compared (the full score was 10 points). The occlusal adjustment time and occlusal comfort score were used as measurement data. Single sample test was used. The number of follow-up visits was count data. Rank sum test was used for non-normal continuous variables.
RESULTS
The mean occlusal time of each crown adjustment in the experimental group was significantly lower than that in the control group ( < 0.01), and the median number of follow-up visits in the experimental group was lower than that in the control group ( < 0.01). The average occlusal comfort score of the experimental group was higher than that of the control group at the first time ( < 0.01). After three months of crown wearing, the median occlusal comfort score of the experimental group was higher than that of the control group ( < 0.05).
CONCLUSION
In the case of severe tooth attrition, it is feasible to use the "biocopy function" in the design software to design the final prosthesis, which is conducive to reduce the difficulty of adjustment and achieve predictable functional and aesthetic effects, which is of great significance to save clinical time and improve the accuracy of restoration.
Topics: Adult; Aged; Computer-Aided Design; Crowns; Female; Humans; Male; Middle Aged; Tooth
PubMed: 33550337
DOI: 10.19723/j.issn.1671-167X.2021.01.010 -
Clinical Oral Investigations Jan 2024The aim of this study was to compare failure load and initial damage in monolithic, partially veneered, and completely veneered (translucent) zirconia cantilevered fixed...
OBJECTIVES
The aim of this study was to compare failure load and initial damage in monolithic, partially veneered, and completely veneered (translucent) zirconia cantilevered fixed partial dentures (CFPDs), as well as completely veneered metal-ceramic CFPDs under different support and loading configurations.
MATERIALS AND METHODS
Eight test groups with anatomically congruent CFPDs (n = 8/group) were fabricated, differing in CFPD material/support structure/loading direction (load applied via steel ball (Ø 6 mm) 3 mm from the distal end of the pontic for axial loading with a 2-point contact on the inner cusp ridges of the buccal and oral cusps and 1.3 mm below the oral cusp tip for 30° oblique loading): (1) monolithic zirconia/CoCr abutment teeth/axial, (2) monolithic zirconia/CoCr abutment teeth/oblique, (3) partially veneered zirconia/CoCr abutment teeth/axial, (4) partially veneered zirconia/CoCr abutment teeth/oblique, (5) completely veneered zirconia/CoCr abutment teeth/axial, (6) completely veneered CoCr/CoCr abutment teeth/axial (control group), (7) partially veneered zirconia/implants/axial, and (8) partially veneered zirconia/natural teeth/axial. Restorations were artificially aged before failure testing. Statistical analysis was conducted using one-way ANOVA and Tukey post hoc tests.
RESULTS
Mean failure loads ranged from 392 N (group 8) to 1181 N (group 1). Axially loaded monolithic zirconia CFPDs (group 1) and controls (group 6) showed significantly higher failure loads. Oblique loading significantly reduced failure loads for monolithic zirconia CFPDs (group 2). Initial damage was observed in all groups except monolithic zirconia groups, and fractography revealed design flaws (sharp edges at the occlusal boundary of the veneering window) in partially veneered zirconia CFPDs.
CONCLUSIONS
Monolithic zirconia CFPDs might be a viable alternative to completely veneered CoCr CFPDs in terms of fracture load. However, oblique loading of monolithic zirconia CFPDs should be avoided in clinical scenarios. Design improvements are required for partially veneered zirconia CFPDs to enhance their load-bearing capacity.
CLINICAL RELEVANCE
Monolithic zirconia may represent a viable all-ceramic alternative to the established metal-ceramic option for CFPD fabrication. However, in daily clinical practice, careful occlusal adjustment and regular monitoring should ensure that oblique loading of the cantilever is avoided.
Topics: Dental Restoration Failure; Ceramics; Zirconium; Denture, Partial, Fixed; Dental Porcelain; Materials Testing; Dental Stress Analysis; Crowns
PubMed: 38221600
DOI: 10.1007/s00784-024-05501-z -
Journal of Personalized Medicine Aug 2022A virtual occlusal adjustment in orthognathic surgery has many advantages; however, the haptic information offered by plaster casts is missing when using intraoral...
A virtual occlusal adjustment in orthognathic surgery has many advantages; however, the haptic information offered by plaster casts is missing when using intraoral scans. Feeling the interferences may be helpful in defining the best possible occlusion. Whether the use of a virtual occlusal adjustment instead of the conventional approach has a significant effect on the postsurgical position of the jaws is a question that remains unanswered. This study compares a virtual method to the conventional method of defining the final occlusion. Twenty-five orthognathic patients were included. Bimaxillary and single-jaw orthognathic surgery (mandible only) was simulated. The two methods were compared regarding discrepancies in the simulated postsurgical position of the mandible, measured three-dimensionally using MeshLab (MeshLab 2020.12 3D). An analysis using SPSS revealed no significant differences between the tested methods (-values: 0.580 to 0.713). The mean absolute discrepancies ranged from 0.14 mm to 0.72 mm, laying within the scope of the clinically acceptable inaccuracies of an osteosynthesis in orthognathic surgery. The lack of haptic information in virtual planning had no relevant influence on the definition of the final occlusion and the simulated postsurgical outcome. However, in individual cases, plaster models might still be helpful in finding the adequate occlusion, especially in the sagittal dimension and in cases of patients with an anterior open bite, but this remains to be tested.
PubMed: 36013237
DOI: 10.3390/jpm12081288 -
Journal of Prosthodontic Research Jan 2024Purpose Temporomandibular disorders (TMDs) are frequent stomatological disorders. However, their treatment is controversial. Therefore, we compared the efficacy of... (Meta-Analysis)
Meta-Analysis
Purpose Temporomandibular disorders (TMDs) are frequent stomatological disorders. However, their treatment is controversial. Therefore, we compared the efficacy of combination therapy (splint therapy along with physiotherapy, manual therapy, and counseling) with physiotherapy, manual therapy, and counseling alone. The extent of mouth opening and pain perception were the outcomes.Study selection Systematic searches for English publications were performed using four major literature databases (Cochrane Library, EMBASE, PubMed, and Web of Science). We included randomized controlled trials. We calculated mean differences with 95% confidence interval (CI) for pain perception and maximum mouth opening (MMO) for the two groups. The Hartung-Knapp adjustment was used for cases comprising at least five studies.Results Six articles were included in the pain perception category, and four were reviewed for MMO at baseline. Four articles assessed pain perception, and two assessed MMO at 1 month. Five articles were analyzed upon comparing pain perception at baseline and 1-month follow-up. The mean difference was -2.54 [95% CI: -3.38; to -1.70] in the intervention group and -2.33 [95% CI: -4.06; to -0.61] in the control group. Two articles were analyzed upon comparing MMO at baseline and 1-month follow-up. The mean difference in the intervention group was 3.69 [95% CI: -0.34; 7.72], whereas that in the control group was 3.62 [95% CI: -3.43; 10.67].Conclusions Both therapies can be used in the management of myogenic TMD. Due to the marginal differences between the baseline and 1-month values, our results could not confirm the efficacy of combination therapy.
Topics: Humans; Splints; Treatment Outcome; Randomized Controlled Trials as Topic; Temporomandibular Joint Disorders; Pain
PubMed: 37286515
DOI: 10.2186/jpr.JPR_D_22_00264 -
The Bulletin of Tokyo Dental College Dec 2021The purpose of this study was to investigate the survival of removable partial dentures with a mandibular bilateral free end saddle (BFES) and abutment teeth in a...
The purpose of this study was to investigate the survival of removable partial dentures with a mandibular bilateral free end saddle (BFES) and abutment teeth in a clinical setting. Only mandibular dentures with a BFES were included (10 or fewer present teeth, and fewer than 4 occlusal units). The endpoints were replacement of denture and loss of abutment teeth. A total of 128 dentures and 595 abutment teeth were analyzed. Nineteen dentures had to be replaced during the observation period (mean duration: 11.4±6.9 years; range: 3 to 36 years). According to Kaplan-Meier analysis, the survival rate was 93.2% at 10 years and 68.6% at 20 years. The estimated mean survival period was 27.8 years. Single-factor analysis using the log-rank test showed that no factor investigated had a significant influence. The main reason for denture replacement was loss of abutment teeth (47.4%). The survival rate of the abutment teeth was 91.3% at 10 years and 77.3% at 20 years. The analysis revealed 4 significant risk factors: male sex (hazard ratio [HR]: 1.78); premolars (HR: 1.67); a lower number of abutment teeth (HR: 3.24); and history of endodontic treatment (HR: 2.79). The removable partial dentures with a mandibular BFES in this study lasted over 20 years, and their survival was influenced by loss of abutment teeth. Dentures are used continuously over long periods of time and should therefore be designed to allow easy adjustment when abutment teeth are lost.
Topics: Dental Abutments; Denture, Partial, Removable; Humans; Male; Mandible; Retrospective Studies; Survival Rate
PubMed: 34776474
DOI: 10.2209/tdcpublication.2020-0061 -
Hua Xi Kou Qiang Yi Xue Za Zhi = Huaxi... Apr 2024The aim of this study was to demonstrate a novel jaw position adjustment technique derived from digital twins and evaluate the application effect of digital...
OBJECTIVES
The aim of this study was to demonstrate a novel jaw position adjustment technique derived from digital twins and evaluate the application effect of digital technology-assisted optimization in the process of adjusting jaw position on patients with temporomandibular disorders (TMD).
METHODS
A total of 74 patients with TMD who attended the Department of Temporomandibular Joint, West China Hospital of Stomatology, Si-chuan University, between June 2022 and May 2023 were selected. The patient's initial computed tomography (CT) and bilateral temporomandibular joint data obtained by magnetic resonance imaging (MRI) were collected. The 148 joints were divided into the normal disc-condyle relationship (N) group, disc displacement with reduction (DDWR) group, and disc displacement without reduction (DDWoR) group. Assisted by digital technology, the patient's CT data were reconstructed, and a personalized reference plane was established to adjust the jaw position. A three-point bite guiding splint was designed by the adjusted occlusal space and then fabricated by 3D printing technology. It was worn by the patients and then reviewed by MRI. Before and after the adjustment of jaw position, the amount and direction of condyle and disc displacement and the angle between condyle and disc were measured as the evaluation indexes of the effect of the adjustment. The correlation with condylar displacement was evaluated.
RESULTS
In the N group, the disc moved backward and downward along the X and Z axes by (-0.60±0.62) and (0.51±0.71) mm, respectively. In the DDWR group, the disc moved backward and upward along the X and Z axes by (-1.33±1.38) and (-0.09±1.31) mm, respectively. In the DDWoR group, the disc moved forward and downward along the X and Z axes by (0.49±1.76) and (1.35±1.76) mm, respectively. The angle between the condyle and the disc decreased after adjustment of the jaw position in all three groups. All patients showed improvement in symptoms after adjustment.
CONCLUSIONS
Digital technology-assisted jaw position adjustment can simplify the process, reduce the sensitivity of the technique, and improve patients' disc-condyle structure and symptoms. Therefore, its application in the treatment of patients with TMD is of great clinical significance.
Topics: Humans; Temporomandibular Joint Disc; Mandibular Condyle; Digital Technology; Joint Dislocations; Temporomandibular Joint; Temporomandibular Joint Disorders; Magnetic Resonance Imaging
PubMed: 38597088
DOI: 10.7518/hxkq.2024.2023327 -
Case Reports in Surgery 2019Because of the anterior disposition on the face and the fragility of the anatomy, the mandible is commonly affected in facial fractures, and the angle region represents...
Because of the anterior disposition on the face and the fragility of the anatomy, the mandible is commonly affected in facial fractures, and the angle region represents 32% of the mandibular fractures; therefore, the objective of the paper was to present a proposal for late correction of the mandibular fracture already consolidated and with occlusal alteration. Patient J.C.P.R., 32, during anamnesis reported loss of sensibility in the mentalis region as well as unilateral posterior open bite for having been a victim of an automobile accident about 1 year and 3 months ago. Physical examination showed elevation in the right mandibular angle region due to the poor positioning of fractured stumps. It has been found that the patient suffered a simple fracture at the mandibular angle, but that had not been treated previously, and it was necessary to treat the fracture sequel. Refraction was performed with a new reduction and fixation through titanium plates and screws, showing that, even being late, the procedure to reduce the fracture sequela was effective, even with the correct functional occlusal adjustment.
PubMed: 31355041
DOI: 10.1155/2019/4627301 -
Journal of Oral Science Mar 2020Studies suggest that analysis of gingival crevicular fluid (GCF) is useful for evaluating periodontal status. In this study, clinical variables related to tooth...
Studies suggest that analysis of gingival crevicular fluid (GCF) is useful for evaluating periodontal status. In this study, clinical variables related to tooth mobility, and multiple cytokine levels in proximate GCF, were measured at four time points during initial periodontal treatment: before treatment (baseline), after supragingival scaling, after occlusal adjustment, and after scaling and root planing (SRP); 20 teeth from 13 patients with periodontitis were included. Baseline interleukin (IL)-10 level in GCF was significantly higher around teeth that showed substantial improvement in periodontal epithelial surface area (PESA) after SRP than around teeth without PESA improvement. IL-3 and IL-16 levels in GCF at baseline were significantly higher around teeth with a periodontal inflamed surface area (PISA) of 0 mm after SRP than around teeth without PISA improvement. In addition, baseline IL-7, IL-11, and IL-12p40 levels in GCF were significantly lower around teeth with decreased mobility after occlusal adjustment than around teeth without decreased mobility. These results suggest that pre-treatment cytokine levels in GCF are useful in predicting the effects of initial periodontal treatment.
Topics: Dental Scaling; Gingival Crevicular Fluid; Humans; Periodontitis; Root Planing
PubMed: 32132326
DOI: 10.2334/josnusd.19-0056 -
The Journal of Prosthetic Dentistry Jul 2023In the digital workflow of complete denture fabrication, one solution for producing computer-aided design and computer-aided manufacturing dentures has been to mill the...
In the digital workflow of complete denture fabrication, one solution for producing computer-aided design and computer-aided manufacturing dentures has been to mill the denture teeth and base separately and then bond them together. The correct bonding of the denture teeth and base is important to reproduce the designed occlusion in the definitive prosthesis. A novel technique is described to assist in the accurate positioning of denture teeth on the denture base by constructing auxiliary positioning slots on the denture base and auxiliary positioning posts on the denture teeth. The technique can assist in accurately assembling CAD-CAM milled complete dentures and may shorten chairside time by reducing clinical occlusal adjustment.
PubMed: 37414596
DOI: 10.1016/j.prosdent.2023.05.017 -
Clinical and Experimental Dental... Dec 2021to determine the presence of marginal bacterial microfiltration in the IAI in different implant/abutment systems, in vitro.
OBJECTIVE
to determine the presence of marginal bacterial microfiltration in the IAI in different implant/abutment systems, in vitro.
MATERIAL AND METHODS
Fifty-six implants from seven different brand names, 4 with cone and 3 with straight connections were used, implant and abutment were connected using the Ncm tightening as indicated by each of the manufacturers and then were sealed. The samples were subjected occlusal load and thermal cycling, a first sample of each group was observed by micro CT and in a second sample (both samples randomly selected) length of connection was measured, while the rest of the samples were mounted on devices according to the bacterial microfiltration model with Porphyromonas gingivalis.
RESULTS
Two of the conical connection system groups did not present bacterial microfiltration, one of the three straight connection groups only microfiltered in one sample, while the other two conical as well as the two straight connection samples showed different and important levels of bacterial microfiltration, all groups presented a direct relationship between the implant-abutment adjustment determined by micro-CT and bacterial microfiltration levels, not related to the connection length.
CONCLUSION
Only two conical connection systems presented no bacterial microfiltration.
Topics: Bacteria; Dental Abutments; Dental Implant-Abutment Design; Dental Implants; X-Ray Microtomography
PubMed: 34151544
DOI: 10.1002/cre2.439