-
The Journal of Prosthetic Dentistry Dec 2023Worn denture teeth are a common reason for replacing complete dentures. However, clinical studies on the amount of denture tooth wear are lacking.
STATEMENT OF PROBLEM
Worn denture teeth are a common reason for replacing complete dentures. However, clinical studies on the amount of denture tooth wear are lacking.
PURPOSE
The purpose of this clinical study was to compare the clinical wear of denture teeth made from double cross-linked (DCL) versus highly cross-linked (HCL) materials after 1 year in service.
MATERIAL AND METHODS
Fourteen participants received maxillary and mandibular removable complete dentures (RCDs). The participants randomly received either DCL or HCL teeth. Each RCD was scanned with an intraoral scanner 1 week after finishing any occlusal adjustment and after 1 year. Occlusal contact marks were recorded using articulating paper, and photographs were made in centric and eccentric movements. The generated 1-week and 1-year standard tessellation language (STL) files of the scans were obtained and trimmed using the Geomagic X software program. After merging the files, the depth of the wear facets was measured using the software program tool that measures the vertical gap distance in micrometers at 100 points distributed on the contact areas. These areas were identified by using the segment tools in the software program. Repeated measures ANOVA was used to analyze the differences between the collected data (α=.05).
RESULTS
The DCL had higher mean ±standard deviation wear (62.7 ±40 µm) than the HCL (37 ±31 µm) after 1 year in service (P<.001).
CONCLUSIONS
Both DCL and HCL denture teeth showed acceptable clinical wear after 1 year of clinical use. HCL denture teeth showed more resistance to occlusal wear than DCL denture teeth.
PubMed: 38160081
DOI: 10.1016/j.prosdent.2023.11.031 -
Scientific Reports Dec 2023How to ensure dental stability in new positions and reduce the likelihood of relapse is a major clinical concern in the orthodontic field. Occlusal contacts between...
How to ensure dental stability in new positions and reduce the likelihood of relapse is a major clinical concern in the orthodontic field. Occlusal contacts between arches may affect the transmission of masticatory forces, thereby influencing the biological response of the periodontal and the oromandibular system. Occlusion factors that may influence the stability after orthodontic tooth movement (OTM) remain largely unknown. Hence, this research was conducted in order to investigate the influence of different occlusal contact patterns on tooth stability and oromandibular system including the masseter muscle and the temporomandibular joint following OTM. By modifying the occlusal surfaces, in vivo animal study models with distinct occlusal patterns corresponding to clinical circumstances were established. The relapse distance of teeth and the level of inflammatory factors in the gingival cervical fluid were analyzed. We also closely observed the histological remodeling of periodontal tissue, masseter tissue, and joint tissue after one week of relapse. Moreover, genes expression in the alveolar bone was analyzed to illustrate the potential biological mechanisms of relapse under the influence of different occlusal contact patterns following OTM. Different occlusal contact patterns after OTM in rats were established. The intercuspation contact between cusp and fossa group exhibited the lowest level of relapse movement, inflammatory factors and osteoclast activity (P < 0.05). On the other hand, groups with interferences or inadequate contacts exhibited more relapse movement, and tend to promote inflammation of periodontal tissue and activate bone resorption (P < 0.05). Adequate occlusal contacts without interference may enhance tooth stability and reduce the likelihood of relapse. After active orthodontic treatment, necessary occlusal adjustment should be made to achieve the desired intercuspation contact relationship and ensure adequate contact between the arches. The elimination of occlusal interferences is crucial to achieving optimal stability and promoting overall healthy condition of the oromandibular system.
Topics: Rats; Animals; Tooth Movement Techniques; Osteoclasts; Bone Resorption; Recurrence
PubMed: 38097596
DOI: 10.1038/s41598-023-46668-x -
Journal of Stomatology, Oral and... Dec 2023Jaw cysts often deeply involve adjacent tooth roots, making it difficult to preserve them. The purpose of this retrospective study was to investigate the effectiveness...
BACKGROUND
Jaw cysts often deeply involve adjacent tooth roots, making it difficult to preserve them. The purpose of this retrospective study was to investigate the effectiveness of an intentional replantation (IR) strategy combined with cyst enucleation in preserving cyst-involved teeth during jaw cyst removal.
MATERIALS AND METHODS
Fifteen patients with jaw cysts and deeply involved teeth were treated with IR and cyst enucleation. All patients received root canal therapy prior to surgery, except for one patient who received it during surgery. The involved teeth were extracted, and the root surface was carefully cleaned before IR and cyst enucleation. Patients were followed up for 12-14 months, with indicators including clinical complaints, replanted tooth stability, and root resorption.
RESULTS
No cyst recurrence was observed, and all replanted teeth survived with good local gingival condition and no marked swelling or recession. Radiographic findings showed clear periodontal space surrounding the replanted teeth. One replanted tooth exhibited slight root resorption due to occlusal trauma, but the resorption ceased after occlusal adjustment.
CONCLUSIONS
IR combined with cyst enucleation is an effective strategy for thoroughly cleaning jaw cysts and preserving teeth involved in the cyst.
PubMed: 38097014
DOI: 10.1016/j.jormas.2023.101731 -
Dental Research Journal 2023Horizontal condylar guidance (HCG) is registered by protrusive interocclusal records but in nonarcon articulators, these records can affect the accuracy. The present...
BACKGROUND
Horizontal condylar guidance (HCG) is registered by protrusive interocclusal records but in nonarcon articulators, these records can affect the accuracy. The present study aimed to evaluate the effect of a novel rotation coordinating device (RCD) on condylar guidance setting with protrusive interocclusal records.
MATERIALS AND METHODS
The study was designed as a comparative investigation. Stone maxillary and mandibular casts were mounted on a fully adjustable instrument as the patient. Duplicate casts were mounted on an arcon and a nonarcon articulator with corresponding face bow records and in maximum intercuspation relation. Five different condylar guidance inclinations for both sides (20°, 30°, 40°, 50°, and 60°) were set on the fully adjustable instrument and 16 protrusive interocclusal records were established at each setting. HCG was set for arcon, nonarcon articulators, and nonarcon articulators with RCD. Data were analyzed using one-sample -test to compare with actual HCG and one-way analysis of variance ( =0.05).
RESULTS
Mean HCG for studied articulators was 35.40 for arcon, 30.31 for nonarcon without RCD, and 35.61 for nonarcon with RCD which were significantly different from actual HCG ( < 0.05). HCG of the nonarcon with RCD showed no significant difference with arcon articulator ( = 0.71) while both were significantly different from nonarcon without RCD ( < 0.001).
CONCLUSION
"The RCD" compensates the condylar guidance inclination difference between arcon and nonarcon articulators. The device precisely transfers the hinge movement of the upper member of the articulator to the condylar track.
PubMed: 38020259
DOI: No ID Found -
The Journal of Clinical Pediatric... Nov 2023Low-angle skeletal class II malocclusions are often observed with sagittal and vertical developmental abnormalities of the mandible. Two-phase orthodontic treatment of...
Low-angle skeletal class II malocclusions are often observed with sagittal and vertical developmental abnormalities of the mandible. Two-phase orthodontic treatment of functional orthopedic therapy combined with fixed correction is one of the most common methods to treat of skeletal class II malocclusions. This case report describes the two-phase orthodontic treatment of a patient with severe low-angle skeletal class II malocclusion. A Twin Block orthodontic appliance was used to improve mandibular growth, and the adjustment of the occlusal relationship using a fixed appliance after functional therapy. After treatment, a significant improvement was observed in the patient's facial appearance and occlusal relationship. Additionally, a 7-year follow-up confirmed the stability of the treatment results. Although a vertical facial growth direction is difficult to control, the Twin Block orthodontic appliance in adolescents might effectively improve the difference in the sagittal growth of the mandible. Whilst the growth pattern could not be fully controlled, the treatment significantly improved the patient's facial profile and occlusion.
Topics: Adolescent; Humans; Follow-Up Studies; Malocclusion, Angle Class II; Dental Care; Mandible; Treatment Outcome; Orthodontic Appliances, Functional; Cephalometry; Malocclusion; Orthodontic Appliance Design
PubMed: 37997250
DOI: 10.22514/jocpd.2023.092 -
The Bulletin of Tokyo Dental College Dec 2023This report describes a case of Stage III Grade C periodontitis requiring periodontal regenerative therapy. The patient was a 19-year-old woman who presented with the...
A Case Report of Periodontal Regenerative Therapy Using Recombinant Human Fibroblast Growth Factor 2 and Deproteinized Bovine Bone Mineral with Non-incised Papillae Surgical Approach (NIPSA) for Angular Bone Defect in Patient with Stage III Grade C Periodontitis.
This report describes a case of Stage III Grade C periodontitis requiring periodontal regenerative therapy. The patient was a 19-year-old woman who presented with the chief complaint of gingival recession in the incisor region. An initial examination revealed that 45.3% of sites had a probing depth of ≥4 mm and 45.8% bleeding on probing. Radiographic examination showed angular bone resorption in #25, 26, 31, 36, and 46 and horizontal resorption in other regions. Initial periodontal therapy was implemented based on a clinical diagnosis of Stage III Grade C periodontitis (generalized aggressive periodontitis). Occlusal adjustment was also performed at sites showing premature contact (#26 and 36) after suppression of inflammation. Periodontal regenerative therapy using recombinant human fibroblast growth factor (rhFGF) -2 was performed on #25, 26, and 46. Combination therapy with rhFGF-2 and deproteinized bovine bone mineral (DBBM) was performed on #31 and 36. A non-incised papillae surgical approach (NIPSA) was used on #31. Periodontal conditions were then re-evaluated and the patient placed on supportive periodontal therapy. Regenerative therapy using rhFGF-2 and DBBM with NIPSA yielded an improvement in clinical parameters and bone resorption. This improvement has been adequately maintained over a 12-month period. Continued care is needed to maintain stable periodontal conditions.
Topics: Animals; Cattle; Female; Humans; Young Adult; Aggressive Periodontitis; Alveolar Bone Loss; Fibroblast Growth Factor 2; Follow-Up Studies; Gingival Diseases; Guided Tissue Regeneration, Periodontal; Minerals; Periodontal Attachment Loss; Treatment Outcome
PubMed: 37967939
DOI: 10.2209/tdcpublication.2023-0011 -
Journal of Oral Rehabilitation Mar 2024Occlusal interferences lead to changes in mandibular kinematics to compensate and improve function. However, the effects of different types of eccentric disturbance on... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
Occlusal interferences lead to changes in mandibular kinematics to compensate and improve function. However, the effects of different types of eccentric disturbance on the comminution capacity are not known.
OBJECTIVE
To determine the immediate effect of eccentric occlusal interferences on masticatory performance.
METHODS
This crossover clinical trial included 12 healthy dentate subjects aged 25.2 ± 3.3 years who were randomly submitted to seven types of occlusal interference: unilateral and bilateral laterotrusive and mediotrusive, protrusive, dummy and control (no interference). The interference forms were planned in a semi-adjustable articulator, fabricated with composite resin and adhered to the mandibular first molars such that subjects' maximum intercuspation was maintained. Masticatory performance and the chewing rate during 20 cycles were evaluated during subjects' comminution of silicone test food under one interference condition per test day; the multiple sieve method was applied to the comminuted particles. The interference was removed upon test completion, and a 1-week washout period was applied between tests.
RESULTS
Comminuted median particle sizes were larger under unilateral (4.94 ± 0.41 mm) and bilateral (4.81 ± 0.49 mm) laterotrusive, bilateral mediotrusive (4.65 ± 0.50 mm) and protrusive (4.83 ± 0.54 mm) interferences (p < .05) than under the control (4.01 ± 0.52 mm) and dummy (4.18 ± 0.58 mm) conditions (p < .05). Only unilateral and bilateral laterotrusive interferences narrowed the comminuted particle size dispersion (p < .05). The chewing rate did not differ among conditions (p = .1944).
CONCLUSION
Artificial eccentric interferences had an immediate adverse effect on masticatory performance by resulting in larger comminuted particles.
CLINICAL TRIAL REGISTRATION
Brazilian Registry of Clinical Trials (RBR-8g5zfg8).
Topics: Humans; Dental Occlusion; Mandible; Mastication; Molar; Particle Size; Double-Blind Method
PubMed: 37964439
DOI: 10.1111/joor.13620 -
International Journal of Computerized... Nov 2023To evaluate the accuracy and reproducibility of real and virtual occlusal contact points in implant-supported, fixed complete dentures.
AIM
To evaluate the accuracy and reproducibility of real and virtual occlusal contact points in implant-supported, fixed complete dentures.
MATERIALS AND METHODS
The study included 19 participants using mandibular interim complete-arch fixed prosthesis supported by 3 or 4 implants as opposed to conventional removable complete dentures. At installation, an examiner installed the prostheses and verified the occlusal contact points through 2 methods: recording the real contact points with carbon paper (RC) followed by occlusal photography and intraoral scanning (VC) to record the virtual contact points to obtain a screen print of the software. Then, the two images were randomized to determine the order to be inserted into Microsoft PowerPoint for blind and paired evaluation. The independent variables consisted of the distribution of occlusal contacts points (qualification through pre-defined scores based on the position of the contact points on the surfaces of the teeth) and the reproducibility of the methods by verifying the number of occlusal points. For this, a descriptive analysis was used to evaluate the distribution of occlusal contacts points and the Wilcoxon test for the reproducibility of the occlusal contact points between the methods (p<0.05).
RESULTS
The methods had 100% and 73.6% real and virtual occlusal contact points, respectively, which is considered clinically excellent. There was no significant difference regarding the reproducibility of the methods by the number of occlusal contact points (RC: x̅13.32; VC: x̅13.68; p=0.715).
CONCLUSION
The use of the tested intraoral scanner can be an easy and fast tool for studying and mapping the occlusion, and storing data for future treatment, with the conventional method being the preferred method for performing the occlusal adjustment.
PubMed: 37947209
DOI: 10.3290/j.ijcd.b4626921 -
International Journal of Computerized... Oct 2023The adjustment and transfer of a stable occlusion can be a major challenge in prosthetic rehabilitations. The aim of this study was to assess a non-invasive treatment...
AIM
The adjustment and transfer of a stable occlusion can be a major challenge in prosthetic rehabilitations. The aim of this study was to assess a non-invasive treatment option for complex prosthetic rehabilitations and occlusal analyses using 3D-printed restorations clinically.
MATERIALS AND METHODS
Eleven patients received a partial or complete rehabilitation with the aid of 3D-printed restorations (n=171). After 12 months of clinical service, all restorations were analyzed using the United States Public Health Service (USPHS) criteria.
RESULTS
The 12-month clinical data revealed that 3D-printed restorations showed a survival rate of 84.4%. Complications occurred mostly regarding the anatomical form (7%) or marginal integrity (6AC%) and were consequently rated "Charlie" or "Delta." Color stability and color match of 3D-printed restorations were rated "Alpha" in 83% and 73%, respectively, of all restorations. Marginal inflammation was rated "Alpha" in 89% of all restorations. An excellent surface texture and no secondary caries or postoperative sensitivities (100%) were observed.
CONCLUSIONS
3D-printed restorations might be an alternative treatment option for initiating complex prosthetic rehabilitations. Technical complications rarely occurred. Biological complications did not occur at all. The color stability showed promising results after 12 months of clinical service. However, the results should be interpreted with caution. Long-term results with a high number of restorations should be awaited.
PubMed: 37823541
DOI: 10.3290/j.ijcd.b4451424 -
Zhonghua Kou Qiang Yi Xue Za Zhi =... Oct 2023Rehabilitation of complete edentulism is naturally related to temporomandibular joint (TMJ) since the proper functioning of complete denture depends on the normal... (Review)
Review
Rehabilitation of complete edentulism is naturally related to temporomandibular joint (TMJ) since the proper functioning of complete denture depends on the normal movement of TMJ. This review briefly introduced the design of occlusion in complete denture, characteristic of different occlusal patterns, and key points in registration of maxillomandibular relationship and occlusal adjustment. This review emphasized the significance of complete denture restoration to the health of TMJ.
Topics: Humans; Temporomandibular Joint; Temporomandibular Joint Disorders; Dental Occlusion; Occlusal Adjustment; Denture, Complete; Tooth Loss
PubMed: 37818531
DOI: 10.3760/cma.j.cn112144-20230730-00048