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Journal of the International Academy of... Oct 2019Occlusal adjustment is commonly recommended for patients with periodontitis and traumatic occlusion. The objective of this systematic review was to analyze available...
OBJECTIVE
Occlusal adjustment is commonly recommended for patients with periodontitis and traumatic occlusion. The objective of this systematic review was to analyze available evidence for the association between traumatic occlusal forces and periodontitis.
METHODS
Two focused questions were proposed: What is the effect of traumatic occlusal forces on periodontal parameters in patients with and without periodontitis? And what is the effect of occlusal interventions on periodontal parameters in patients with periodontitis? A systematic review of clinical and observational studies was performed and presented in narrative form.
RESULTS
After title and abstract review a total of 30 articles were retrieved and of these 14 full-text articles were retrieved for analysis. Two RCTs, 1 cohort, 4 retrospective and 7 cross-sectional studies were included. Cross-sectional studies reported a significant association between occlusal discrepancies and probing depth and clinical attachment level. However, the magnitude of the effect is negligible when groups with and without occlusal discrepancies are compared. Intervention studies reported a minimal effect on probing depth and clinical attachment level after occlusal adjustment in patients with periodontitis as compared to teeth without occlusal adjustment.
CONCLUSIONS
Available human studies showed that there is limited evidence that traumatic occlusion is associated with periodontitis and to support the implementation of occlusal adjustment to significantly improve the periodontal condition in patients with periodontitis.
Topics: Bite Force; Cross-Sectional Studies; Humans; Occlusal Adjustment; Periodontitis; Retrospective Studies
PubMed: 31694985
DOI: No ID Found -
The International Journal of... 2021To evaluate and compare the occlusal fit of zirconia crowns designed using a digital articulator method and the traditional method in a self-controlled clinical trial.
PURPOSE
To evaluate and compare the occlusal fit of zirconia crowns designed using a digital articulator method and the traditional method in a self-controlled clinical trial.
MATERIALS AND METHODS
Two zirconia crowns each were prepared for 12 patients with a single posterior tooth defect using two different methods: a digital articulator method and the traditional method. In the traditional method, casts were scanned using a model scanner, and the relative positions of the maxillary and mandibular arches were determined by the intercuspal occlusion of the casts. In the digital articulator method, casts were mounted on a mechanical articulator and scanned, and the relative positions were determined by their respective positions in the articulator. Additional dynamic occlusal adjustments of the digital articulator crowns were performed. Both groups of zirconia crowns were milled in a five-axis milling machine. The time required for occlusal adjustments, the occlusal contacts, the occlusal contact distributions, the number of occlusal contacts, the relative occlusal forces, and patient satisfaction (visual analog scale score) were evaluated. Wilcoxon test, McNemar test, and paired t test were used to compare the parameters between the two methods.
RESULTS
The occlusal adjustment times for the digital articulator and traditional method crowns were 327 ± 226 seconds and 395 ± 338 seconds, respectively (P > .05). There were no significant differences in occlusal contacts, occlusal contact distributions, number of occlusal contacts, relative occlusal forces, or VAS scores between the two methods (P > .05).
CONCLUSION
A digital articulator method for single-crown restoration was applied successfully. Crowns fabricated using a digital articulator or the traditional method can achieve acceptable occlusal fit for single-crown restorations.
Topics: Computer-Aided Design; Crowns; Dental Articulators; Dental Prosthesis Design; Humans; Zirconium
PubMed: 33570515
DOI: 10.11607/ijp.6570 -
BioMed Research International 2021The function of the masticatory apparatus is complete when the dentition is intact with contact between the individual teeth and proper occlusion with the antagonists....
INTRODUCTION
The function of the masticatory apparatus is complete when the dentition is intact with contact between the individual teeth and proper occlusion with the antagonists. For years, occlusal contacts have been studied to determine their exact location and describing various materials and methods for their registration such as paper foil, silk, and Shimstock foil. For years, occlusal contacts have been studied to determine their exact location and describe various materials and methods for their registration such as paper foil, silk, shim stock foil, the T-Scan system, and more recently the OccluSense system. The primary aim of the study was at evaluating which of the occlusal indicators is the most commonly used in practice, and the secondary aim was whether dentists are willing to use digital methods to examine occlusion.
MATERIALS AND METHODS
The main primary information of the survey was collected by sending electronically anonymous questionnaires to 2014 dentists, randomly selected from all regions of the country. 228 questionnaires were filled in and returned. To achieve the goal of the study, the self-developed questionnaire was created and tested to survey the opinion about the use of occlusal indicators in dental practice. Each questionnaire contains questions about the sociodemographic and professional status of the people in the group and their opinion about the positives and negatives and the effectiveness of occlusal indicators.
RESULTS
The obtained results confirm the statement that the most frequently used occlusal indicator in dental practice is the articulation paper. Articulation foil and silk are used less frequently than articulation paper. Of the listed quality indicators, Shimstock foil is rarely used in practice. Of the indicated quantitative indicators, the T-Scan system is more used than the OccluSense system. In the era of rapid technology development, the opinion and desire of dentists to increasingly want to introduce in their clinical practice quantitative methods are the digital diagnosis of occlusion.
CONCLUSION
In any dental practice, if technically possible, digital methods would be used, giving more accurate and reliable data on the registered occlusal contacts.
Topics: Adult; Aged; Attitude; Bulgaria; Dental Occlusion; Dentistry; Dentists; Diagnostic Tests, Routine; Female; Humans; Indicators and Reagents; Jaw Relation Record; Male; Malocclusion; Middle Aged; Motivation; Occlusal Adjustment; Surveys and Questionnaires
PubMed: 34778449
DOI: 10.1155/2021/2177385 -
The Journal of Prosthetic Dentistry Nov 2022Monolithic zirconia restorations have become popular because of their excellent mechanical properties and acceptable esthetics. While the biomechanical properties of...
STATEMENT OF PROBLEM
Monolithic zirconia restorations have become popular because of their excellent mechanical properties and acceptable esthetics. While the biomechanical properties of zirconia have been investigated, research into their esthetic properties is sparse. Zirconia can be colored by infiltration before sintering, although how occlusal adjustment can affect restoration color is unclear.
PURPOSE
The purpose of this in vitro study was to analyze the color of differently characterized monolithic white and precolored zirconia specimens after standardized grinding.
MATERIAL AND METHODS
White and precolored monolithic zirconia plates (Cercon ht) (n=36) were stained by infiltration with target colors Vita A2, A3.5, and A4. In a standardized experimental arrangement, all plates were ground in 9 steps, and the color was measured with a spectroradiometer at each step. Color differences (ΔE) were analyzed by using regression analysis, the Kruskal-Wallis test, and the inverse prediction with confidence intervals (α=.05).
RESULTS
Mechanical material removal had a significant effect on the color stability (P<.05) of both white and precolored monolithic zirconia. For each grinding step and each target color, the precolored groups had a significantly lower ΔE mean than the white groups (P<.05), except at the 20-μm step for groups W-A4 and P-A4 (P>.05). For target color A2, the difference was significant with P<.001 at all 9 grinding steps. For target color A3.5, the difference was significant with P=.003 at grinding level 20 μm, and P<.001 for all other grinding steps. For target color A4, the difference was not significant with P=.603 at grinding level 20 μm, whereas the difference was significant with P=.007 at grinding level 50 μm, and with P<.001 for all other grinding steps.
CONCLUSIONS
Precolored zirconia had less color change after grinding than white zirconia. This study established grinding depths for white and precolored zirconia corresponding to color perceptibility and acceptability thresholds.
Topics: Dental Porcelain; Ceramics; Surface Properties; Materials Testing; Zirconium; Color
PubMed: 33896619
DOI: 10.1016/j.prosdent.2021.03.002 -
Journal of Prosthodontic Research Jan 2020To investigate occlusal wear of resin denture teeth in partial removable dental prostheses worn by partially edentulous patients.
PURPOSE
To investigate occlusal wear of resin denture teeth in partial removable dental prostheses worn by partially edentulous patients.
METHODS
Thirty patients with partial removable dental prostheses were included in the study. Thirty-two patients with complete dentures served as a reference group. Occlusal wear after two years was evaluated indirectly using gypsum casts and a three-dimensional laser-scanner device. Overall wear of complete occlusal surfaces and maximum wear of occlusal contact areas were measured. Patient and prosthesis data were analyzed using univariate and multiple linear mixed models.
RESULTS
Overall wear of denture teeth in partial removable dental prostheses was 91 (SD 85) μm, and maximum wear of occlusal contact areas was 329 (SD 204) μm (means and standard deviations). Average and maximum wear values for teeth in complete dentures were both lower than those for teeth in partial removable dental prostheses. However, differences between wear of different types of denture did not reach statistical significance after adjustment for gender, type of tooth, dental status of the opposing jaw, and antagonist material. Statistical analysis revealed that wear was greater for denture teeth occluding with ceramic crowns and/or fixed partial dentures as antagonists.
CONCLUSIONS
Resin denture teeth in partial removable and complete dental prostheses are subjected to clinically important occlusal wear that might destabilize occlusion and cause further problems. Patient-related factors and dental status affect wear behavior and should be taken into consideration when treating patients with removable dentures.
Topics: Denture, Complete; Denture, Partial; Denture, Partial, Fixed; Denture, Partial, Removable; Humans
PubMed: 31085073
DOI: 10.1016/j.jpor.2019.04.004 -
The Journal of Prosthetic Dentistry Mar 2020With the development of computer-aided design and computer-aided manufacturing (CAD-CAM) technology, dentists may determine internal spacing by using the CAD-CAM...
STATEMENT OF PROBLEM
With the development of computer-aided design and computer-aided manufacturing (CAD-CAM) technology, dentists may determine internal spacing by using the CAD-CAM software program and make internal adjustments during the clinical evaluation appointment. How these factors affect marginal adaptation is unclear.
PURPOSE
The purpose of this in vitro study was to evaluate the marginal and internal adaptation of CAD-CAM ceramic and composite resin crowns with different internal spacings before and after internal adjustment by using microcomputed tomography.
MATERIAL AND METHODS
Eight third molars were prepared for a complete crown, and 32 crowns were milled at chairside from composite resin and ceramic materials with different internal spacing (30 μm and 80 μm). After an initial microcomputed tomography scan, the same crowns were adjusted and scanned again. Axial space, occlusal space (OS), marginal discrepancy, and absolute marginal discrepancy were evaluated in both analyses. The need for internal adjustment was determined by an experienced clinician by using a silicone film. The number of internal adjustments was also recorded. The data were analyzed by using a 3-way ANOVA (material, internal spacing, and internal adjustment) and the Bonferroni correction (α=.05).
RESULTS
For axial space, only the material factor was significantly different (P<.001), with the ceramic having the lowest value. For OS, both internal spacing and adjustments presented a statistical difference among groups with the lowest OS values obtained for 80-μm spacing after adjustment. For marginal discrepancy and absolute marginal discrepancy, the adjustment factor also had a significant effect, and the adjustment resulted in smaller measures for both variables. The 30-μm spacing required more adjustments than the 80-μm spacing (P<.05).
CONCLUSIONS
Both the internal adaptation and marginal adaptation were influenced by the internal adjustment, resulting in improved values for both. Although no differences were observed between the 30-μm and 80-μm spacings after internal adjustment for marginal adaptation, the 30-μm spacing required twice as many adjustments, resulting in longer clinical sessions.
Topics: Ceramics; Composite Resins; Computer-Aided Design; Crowns; Dental Marginal Adaptation; Dental Porcelain; Dental Prosthesis Design; X-Ray Microtomography
PubMed: 31307805
DOI: 10.1016/j.prosdent.2019.01.010 -
The Journal of Prosthetic Dentistry Aug 2023The volume of occlusal adjustment of digital occlusal devices designed with different digital occlusal articulators is unknown.
Comparative evaluation of the volume of occlusal adjustment of repositioning occlusal devices designed by using an average value digital articulator and the jaw movement analyzer.
STATEMENT OF PROBLEM
The volume of occlusal adjustment of digital occlusal devices designed with different digital occlusal articulators is unknown.
PURPOSE
The purpose of this clinical study was to evaluate and compare the clinical efficacy and volume of occlusal adjustment of digital occlusal devices designed by using an average value digital articulator and the jaw movement analyzer (JMA).
MATERIAL AND METHODS
Thirty participants were randomly divided into 2 groups, an Average value group and a JMA group, with 15 participants in each group. The centric relation position of the participants was determined by an experienced investigator with the aid of a leaf gauge. An intraoral scanner (TRIOS 3) was used to obtain digital scans of the maxillary and mandibular dentition and the maxillomandibular relationship record in the centric relation position. Personalized articulator parameters of participants in the JMA group were obtained by using a JMA (JMAnalyser). Different articulator parameters were used to fabricate an occlusal device in a denture design software program (exocad DentalCAD). The surface of the occlusal device was coated with a dental optical spray and then scanned by using a laboratory scanner (Kavo LS3). The process was repeated after the occlusal device was adjusted. The files of the 2 scans were imported into a reverse engineering software program, and the root mean square (RMS) values were obtained by best-fit alignment and 3-dimensional comparison. The Shapiro-Wilk normality test and homogeneity of variance test were performed, and t tests were used to evaluate differences in the RMS values between the groups (α=.05).
RESULTS
The experimental data were generally normally distributed (P>.05). No statistically significant difference was found between the RMS values of the Average and the JMA groups (P>.05).
CONCLUSIONS
No significant difference in the volume of occlusal adjustment was found when using occlusal devices made by using the digital average articulator or the JMA, suggesting that either method can be used to program articulators for the fabrication of occlusal devices.
PubMed: 37537106
DOI: 10.1016/j.prosdent.2023.06.018 -
Clinical Oral Investigations May 2022This study aims to analyze the 5-year occlusal change in posterior implant-supported single crowns and the association between the relative occlusal force (ROF) and... (Clinical Trial)
Clinical Trial
OBJECTIVES
This study aims to analyze the 5-year occlusal change in posterior implant-supported single crowns and the association between the relative occlusal force (ROF) and peri-implant bone level.
MATERIALS AND METHODS
Partially edentulous patients who had received implant-supported single crowns in the posterior region were included. Occlusal examinations with a computerized occlusion analysis system were conducted at 0.5, 3, 6, 12, 24, 36, 48, and 60 months after delivery of the implant-supported single crown. The ROFs of implant-supported single crowns, mesial adjacent teeth, and control natural teeth were recorded. Intraoral periapical radiographs were taken at each follow-up time to evaluate marginal bone level (MBL). Ordinary least square regression was used to analyze the association between ROF and MBL.
RESULTS
Thirty-seven posterior implant-supported single crowns in 33 participants (23.9 to 70.0 years) were followed up for 0.5 to 60 months [(42.4 ± 26.0) months]. The ROF of implant-supported single crowns increased from 2 weeks to 3 months (P < 0.01) and increased continuously between all two sequential time points from 6 to 36 months, with significant differences (P < 0.05). Then ROFs of implant-supported single crowns were significantly higher than those of control teeth at 48 and 60 months (P < 0.05). Regression analysis showed that ROF was significantly associated with MBL with a coefficient of 0.008 (P < 0.05).
CONCLUSION
The ROFs of posterior implant-supported single crown have significant change during 5 years' follow-up. The association between ROF and MBL has limited clinical significance.
TRIAL REGISTRATION
Chinese Clinical Trial Registry: ChiCTR-ROC-17012240.
CLINICAL RELEVANCE
The occlusion of implant-supported single crowns should be carefully monitored during follow-up examinations, and occlusal adjustment should be considered to prevent overloading.
Topics: Alveolar Bone Loss; Crowns; Dental Implants; Dental Implants, Single-Tooth; Dental Prosthesis Design; Dental Prosthesis, Implant-Supported; Follow-Up Studies; Humans; Mouth, Edentulous; Prospective Studies
PubMed: 35129663
DOI: 10.1007/s00784-022-04394-0 -
The Journal of Advanced Prosthodontics Dec 2020Recently introduced hybrid and reinforced glass ceramic computer-aided design/computer-aided manufacturing (CAD/CAM) materials have been used for full-coverage...
PURPOSE
Recently introduced hybrid and reinforced glass ceramic computer-aided design/computer-aided manufacturing (CAD/CAM) materials have been used for full-coverage restorations. However; the effect of adjustment and type of materials on internal and marginal adaptation are unknown. This study aimed to evaluate and compare the marginal and internal adaptations of crowns made of three different CAD/CAM materials before and after adjustment.
MATERIALS AND METHODS
One acrylic resin maxillary first molar was prepared and served as the master die. Thirty-six restorations were fabricated using CAD/CAM system (CEREC Omnicam, MCXL) with three materials including lithium disilicate (IPS e.max CAD), zirconia-reinforced lithium silicate (Suprinity), and hybrid ceramic (Enamic). Internal and marginal adaptations were evaluated with the reference point matching technique before and after adjustment. The data were analyzed using mixed ANOVA considering α=.05 as the significance level.
RESULTS
The effect of adjustment and its interaction with the restoration material were significant for marginal, absolute marginal, and occlusal discrepancies (<.05). Before adjustment, Suprinity had lower marginal discrepancies than IPS e.max CAD (=.18) and Enamic (=.021); though no significant differences existed after adjustment.
CONCLUSION
Within the limitations of this study, crowns fabricated from IPS e.max CAD and Suprinity resulted in slightly better adaptation compared with Enamic crowns before adjustment. However, marginal, axial, and occlusal discrepancies were similar among all materials after the adjustment.
PubMed: 33489018
DOI: 10.4047/jap.2020.12.6.344 -
Zhonghua Kou Qiang Yi Xue Za Zhi =... Jan 2023To investigate the influence of light and heavy bite force on the mandibular movement trajectories, and the influence of bite force on virtual occlusal pre-adjustment...
To investigate the influence of light and heavy bite force on the mandibular movement trajectories, and the influence of bite force on virtual occlusal pre-adjustment of digital full crown. From October 2021 to March 2022, 10 postgraduate volunteers (3 males and 7 females, aged 22-26 years) were recruited from Peking University School and Hospital of Stomatology. Maxillary and mandibular digital models of the participants were obtained by intraoral scanning. Jaw relations were digitally transferred under heavy bite force and mandibular movement trajectories under light and heavy bite force were recorded by jaw motion analyser. Three mandibular markers were chosen, namely the mesial proximal contact point of the central incisor (incisal point) and the mesial buccal cusp tips of the bilateral first molars. The three-dimensional displacements of the markers under two kinds of bite force in the intercuspal position (ICP), the sagittal projection of the three-dimensional displacements in the protrusive edge-to-edge position, and the coronal projection of the three-dimensional displacements in the lateral edge-to-edge position of upper and lower posterior teeth were measured. Single-sample -test was used to compare the three-dimensional displacements and the corresponding sagittal projection and coronal projection with 0, respectively. The left maxillary central incisor and left mandibular first molar were virtually prepared by the reverse engineering software. Then dental design software was used to design digital full crown using the copy method. The mandibular movement trajectories under light and heavy bite force were separately used to guide virtual occlusal pre-adjustment. The three-dimensional deviations (mean deviations and root mean square) between the lingual surface of the left maxillary central incisor or the occlusal surface of the left mandibular first molar and that of the natural tooth before preparation were calculated (light bite force group and heavy bite force group), and the differences between the two groups were compared by the paired -test. Under the two kinds of bite force, the three-dimensional displacements of the markers in the ICP were (0.217±0.135), (0.210±0.133) and (0.237±0.101) mm, respectively; the sagittal projection of the three-dimensional displacements of the markers in the protrusive edge-to-edge position were (0.204±0.133), (0.288±0.148) and (0.292±0.136) mm, respectively; the coronal projection of the three-dimensional displacements of the mesial buccal cusp tips of the bilateral first molars in the lateral edge-to-edge position were (0.254±0.140) and (0.295±0.190) mm, respectively. The differences between the above displacements and 0 were statistically significant (<0.05). The results of occlusal pre-adjustment showed that the mean deviations of the lingual surface of the left maxillary central incisor in the light and heavy bite force groups were (0.215±0.036) and (0.195±0.041) mm (=3.95, =0.004), respectively. The mean deviations of the occlusal surface of the left mandibular first molar were (0.144±0.084) and (0.100±0.096) mm (=0.84, =0.036), respectively. Both the light and heavy bite force have an influence on the mandibular movement trajectories. Virtual occlusal pre-adjustment of prostheses with mandibular movement trajectories under heavy bite force can obtain morphology of lingual or occlusal surfaces closer to the natural teeth before preparation.
Topics: Male; Female; Humans; Bite Force; Tooth; Mandible; Molar; Occlusal Adjustment
PubMed: 36642452
DOI: 10.3760/cma.j.cn112144-20220507-00243