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Operative Dentistry Sep 2023To assess the accuracy of selective enamel etching (SEE) in a laboratory setup simulating clinical conditions.
OBJECTIVE
To assess the accuracy of selective enamel etching (SEE) in a laboratory setup simulating clinical conditions.
METHODS AND MATERIALS
A model with permanent human teeth was fabricated. It included a first mandibular molar with a mesio-occlusal-distal inlay preparation, a maxillary central incisor, and a canine with a class IV and class V cavity, respectively. Two dentists (with 1 year and 10 years work experience) repeatedly (n=10 per cavity) performed SEE with a custom gel that had identical rheological properties as a commercially available phosphoric acid etchant. An intraoral scanner was used for image acquisition. To assess the accuracy of SEE, special software was used (OraCheck, Cyfex, Zurich, Switzerland). Two independent investigators analyzed baseline scans and scans taken of the cavities while the gel was in place. The statistical analysis comprised t-tests, Pearson correlation, and analysis of variance (α=0.05).
RESULTS
The level of accuracy, whose average values ranged from 61.1% to 87.0%, showed significant differences between teeth, with the highest level observed in the class V cavity, followed by the class II inlay preparation and the class IV cavity (p<0.001). Across the cavities, no significant correlation was observed between the application time and the accuracy of SEE (p=0.07).
CONCLUSION
This laboratory study suggests that inadvertent conditioning of dentin adjacent to enamel may be common during SEE. Investigations involving larger samples of dentists are needed to corroborate this finding.
Topics: Humans; Dental Enamel; Dental Caries; Image Processing, Computer-Assisted; Incisor; Computers
PubMed: 37635464
DOI: 10.2341/22-114-L -
Polymers Aug 2023This study aimed to evaluate the fracture resistance of class II MOD cavities restored using different techniques and materials. Sixty extracted maxillary molars were...
This study aimed to evaluate the fracture resistance of class II MOD cavities restored using different techniques and materials. Sixty extracted maxillary molars were selected and standardized class II MOD cavities were prepared using a custom-made paralleling device. The specimens were divided into four groups based on the restoration technique used: Group 1 (direct resin composite), Group 2 (short-fiber-reinforced composite resin), Group 3 (composite polyethylene fiber reinforcement), and Group 4 (CAD/CAM resin inlays). Fracture resistance was assessed for each group after thermocycling aging for 10,000 cycles. The mode of fracture was assigned to five types using Burke's classification. To compare the fracture force among the tested materials, a paired sample -test was performed. The significance level for each test was set at < 0.05. Significant differences in fracture resistance were observed among the different restoration techniques. CAD/CAM inlays (2166 ± 615 N), short-fiber-reinforced composite resin (2471 ± 761 N), and composite polyethylene fiber reinforcement (1923 ± 492 N) showed superior fracture resistance compared to the group restored with direct resin composite (1242 ± 436 N). The conventional resin composite group exhibited the lowest mean fracture resistance. The choice of restoration material plays a critical role in the clinical survival of large MOD cavities. CAD/CAM inlays and fiber-reinforced composites offer improved fracture resistance, which is essential for long-term success in extensive restorations.
PubMed: 37631470
DOI: 10.3390/polym15163413 -
Journal of Functional Biomaterials Aug 2023Biocompatible polymers such as polymethyl methacrylate (PMMA), despite fulfilling biomedical aspects, lack the mechanical strength needed for hard-tissue implant...
Biocompatible polymers such as polymethyl methacrylate (PMMA), despite fulfilling biomedical aspects, lack the mechanical strength needed for hard-tissue implant applications. This gap can be closed by using composites with metallic reinforcements, as their adaptable mechanical properties can overcome this problem. Keeping this in mind, novel Ti-mesh-reinforced PMMA composites were developed. The influence of the orientation and volume fraction of the mesh on the mechanical properties of the composites was investigated. The composites were prepared by adding Ti meshes between PMMA layers, cured by hot-pressing above the glass transition temperature of PMMA, where the interdiffusion of PMMA through the spaces in the Ti mesh provided sufficient mechanical clamping and adhesion between the layers. The increase in the volume fraction of Ti led to a tremendous improvement in the mechanical properties of the composites. A significant anisotropic behaviour was analysed depending on the direction of the mesh. Furthermore, the shaping possibilities of these composites were investigated via four-point bending tests. High shaping possibility was found for these composites when they were shaped at elevated temperature. These promising results show the potential of these materials to be used for patient-specific implant applications.
PubMed: 37623664
DOI: 10.3390/jfb14080420 -
Stomatologiia 2023Carrying out an objective assessment of the quality of performance of the technique of prosthetics with stump pin tabs of the upper and lower molars.
OBJECTIVE
Carrying out an objective assessment of the quality of performance of the technique of prosthetics with stump pin tabs of the upper and lower molars.
MATERIALS AND METHODS
A retrospective assessment of the quality of dental preparation and modeling of root pin inlays was carried out by analyzing CBCT studies using the RadiAnt program. Measurements were carried out and 80 CBCT studies of patients who had tabs in their molars performed in various clinics of the city of Moscow were studied.
RESULTS
Restoration of defects in the hard tissues of teeth with cast root pin tabs has specific features related to the anatomy of the roots and the distribution of the chewing load. An analysis of the practical implementation of the prosthetics technique and the compliance of the quality of the tabs with the requirements of clinical recommendations showed that they are performed only in 47.5% of cases with respect to modeling the length of the pin part of the tabs (relative to the length of the tooth root), in 40.0% of studies - on the quality of root canal filling; in 36.3% - on the residual thickness of the walls of the tooth root. The requirements for the ratio of the foliar and pin parts of the tabs were not met in any of the cases. In the case of tab modeling, the requirements for maintaining a safe zone in the area of root furcation and tooth tissue thickness of at least 1.0 mm were met only in 36.25 (32.50±3.75)% of cases.
CONCLUSION
Improving the quality of prosthetics using tabs lies not only in the plane of a more responsible approach to determining indications for this type of prosthetics, performing techniques and algorithms, using modern tools, but also in the field of working out the methodology for manufacturing tabs in multi-root teeth taking into account the anatomy of the roots of chewing teeth, the distribution of chewing pressure and the number of pin parts of tabs.
Topics: Humans; X-Rays; Retrospective Studies; Radiography; Algorithms; Mastication
PubMed: 37622300
DOI: 10.17116/stomat202310204143 -
Clinical Oral Investigations Sep 2023The aim of this systematic review and meta-analysis is to assess the comparative clinical success and survival of intracoronal indirect restorations using gold, lithium... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVES
The aim of this systematic review and meta-analysis is to assess the comparative clinical success and survival of intracoronal indirect restorations using gold, lithium disilicate, leucite, and indirect composite materials.
MATERIAL AND METHODS
This systematic review and meta-analysis were conducted following the Cochrane Handbook for Systematic Reviews of Interventions and PRISMA guidelines. The protocol for this study was registered in PROSPERO (registration number: CRD42021233185). A comprehensive literature search was conducted across various databases and sources, including PubMed/Medline, Embase, Cochrane Library, Web of Science, ClinicalTrials.gov, and gray literature. A total of 7826 articles were screened on title and abstract. Articles were not excluded based on the vitality of teeth, the language of the study, or the observation period. The risk difference was utilized for the analyses, and a random-effects model was applied. All analyses were conducted with a 95% confidence interval (95% CI). The calculated risk differences were derived from the combined data on restoration survival and failures obtained from each individual article. The presence of heterogeneity was assessed using the I statistic, and if present, the heterogeneity of the data in the articles was evaluated using the non-parametric chi-squared statistic (p < 0.05).
RESULTS
A total of 12 eligible studies were selected, which included 946 restorations evaluated over a minimum observation period of 1 year and a maximum observation period of 7 years. Results of the meta-analysis indicated that intracoronal indirect resin composite restorations have an 18% higher rate of failure when compared to intracoronal gold restorations over 5-7 years of clinical service (risk difference = - 0.18 [95% CI: - 0.27, - 0.09]; p = .0002; I = 0%). The meta-analysis examining the disparity in survival rates between intracoronal gold and leucite restorations could not be carried out due to methodological differences in the studies.
CONCLUSIONS
According to the currently available evidence, medium-quality data indicates that lithium disilicate and indirect composite materials demonstrate comparable survival rates in short-term follow-up. Furthermore, intracoronal gold restorations showed significantly higher survival rates, making them a preferred option over intracoronal indirect resin-composite restorations. Besides that, the analysis revealed no statistically significant difference in survival rates between leucite and indirect composite restorations. The short observation period, limited number of eligible articles, and low sample size of the included studies were significant limitations.
CLINICAL SIGNIFICANCE
Bearing in mind the limitations of the reviewed literature, this systematic review and meta-analysis help clinicians make evidence-based decisions on how to restore biomechanically compromised posterior teeth.
Topics: Dental Porcelain; Aluminum Silicates; Composite Resins; Gold
PubMed: 37597003
DOI: 10.1007/s00784-023-05050-x -
Journal of Endodontics Dec 2023This study evaluated the resistance to fracture of endodontically treated premolars (ETPs) with mesio-occluso-distal (MOD) cavities filled with nanohybrid composite...
Fracture Resistance of Endodontically Treated Premolars Using Nanohybrid Composite, Fiber-Reinforced Composite, Horizontal Glass Fiber Posts, and Ceramic Inlays: An In Vitro Study.
INTRODUCTION
This study evaluated the resistance to fracture of endodontically treated premolars (ETPs) with mesio-occluso-distal (MOD) cavities filled with nanohybrid composite (NHC), fiber-reinforced composite (FRC), horizontal glass fiber posts (HFP), and ceramic inlays (CI).
METHODS
Eighty-four intact maxillary premolars were taken, and endodontic treatment was performed followed by MOD cavity preparations (except in the control group). They were distributed into 7 groups based on type of restoration: intact teeth (control group), ETP + MOD (not restored), NHC, FRC + NHC, HFP + NHC, FRC + HFP + NHC, and CI groups. Samples were subjected to universal testing machine until the fracture occurred and failure mode was visually inspected.
RESULTS
Mean and standard deviation of fracture resistance of the 7 groups ranged from 265.6 ± 68.0 N to 1023.7 ± 76.5 N. The highest reading was noted for intact teeth followed by FRC + HFP + NHC group and then the CI group, with no significant difference among the 3 groups. The lowest reading was noted for the ETP + MOD group. Maximum unrepairable fractures were seen in the ETP + MOD and CI groups.
CONCLUSION
FRC + HFP + NHC combination and CIs increased the resistance to fracture of ETPs significantly.
Topics: Humans; Inlays; Composite Resins; Bicuspid; Post and Core Technique; Tooth Fractures; Ceramics; Tooth, Nonvital; Dental Stress Analysis
PubMed: 37595683
DOI: 10.1016/j.joen.2023.08.004 -
General Dentistry 2023Patients with a complex problem set involving multiple levels of altered structure challenge the clinician to develop an individualized, appropriate treatment plan....
Patients with a complex problem set involving multiple levels of altered structure challenge the clinician to develop an individualized, appropriate treatment plan. Dentofacial deficiency, occlusal problems, and loss of tooth structure require intervention to establish stability and regain function, speech, esthetics, and masticatory muscle comfort. The comprehensive examination must quantify each problem to specify the diagnosis for realistic treatment planning. The clinical case of a patient with Costello syndrome is presented to illustrate essential concepts in diagnosis and treatment of complex cases, including (1) Global Diagnosis of anterior esthetic relationships, (2) occlusal analysis with diagnostic casts verified in centric relation, (3) comprehensive restoration previewed with a diagnostic wax-up and removable acrylic resin overlay, (4) adhesive monobody composite resin onlays that preserve tooth structure, and (5) programmed occlusion, quantified with digital occlusal analysis, to ensure stability and comfort. Costello syndrome is a neurodevelopmental syndrome causing multisystem effects, including a distinctive craniofacial phenotype, cardiovascular disease, intellectual disability, growth hormone deficiency, and dental abnormalities such as delayed dental development, bruxism, and demineralized enamel lesions. In the present case, quantification of the patient's problem set allowed precise treatment planning that resulted in predictable restoration.
Topics: Humans; Composite Resins; Costello Syndrome; Inlays; Centric Relation; Bruxism; Dental Restoration, Permanent
PubMed: 37595083
DOI: No ID Found -
BMC Oral Health Aug 2023Large cavity designs and access cavities impair endodontically treated tooth fracture resistance. As the tooth's strength is known to reduce significantly after the root...
BACKGROUND
Large cavity designs and access cavities impair endodontically treated tooth fracture resistance. As the tooth's strength is known to reduce significantly after the root canal treatment, occlusal loading as a result of functions such as chewing, biting and certain parafunctional tendencies makes the endodontically treated tooth vulnerable to fracture. Hence, after endodontic treatment, it is vital to give adequate and appropriate restorative material to avoid tooth fractures. Accordingly, the choice of such restorative material should be dictated by the property of fracture resistance.
OBJECTIVE
The goal of this study was to conduct a systematic review and critical analysis of available data from in vitro studies examining the fracture resistance of endodontically treated posterior teeth restored with fiber-reinforced composites.
METHODOLOGY
The Preferred Reporting Items for Systematic Review and Meta-Analysis (PRIS-MA) Statement was used to guide the reporting of this systematic review A comprehensive literature search was performed using MEDLINE (via PubMed), Scopus, ScienceDirect, Google Scholar, and LILACS. A manual search of the reference lists of the articles was also performed. The databases provided a total of 796 studies from the electronic systematic search. The databases provided a total of 796 studies from the electronic systematic search. Two reviewers scrutinized the papers for eligibility based on inclusion/exclusion criteria and extracted data. The studies were assessed for their potential risk of bias. Based on modified JBI & CRIS (checklist for reporting in vitro studies) guidelines, along with the methodology and treatment objective, we have formulated 13 parameters specifically to assess the risk of bias. A total of 18 studies met the inclusion criteria and were included for qualitative analysis. Considering the high heterogeneity of the studies included, a meta-analysis could not be performed.
RESULTS
The majority of the included studies had a moderate or high risk of bias. When compared to traditional hybrid composites, fiber-reinforced composites showed increased fracture resistance of endodontically treated teeth in the majority of investigations. On the other hand, limited evidence was found for the bulk fill composites. Moreover, moderate evidence was found for the fracture resistance of inlays and fiber posts with fiber-reinforced composites for core build-up in endodontically treated teeth. No evidence could be found comparing the fracture resistance of endo crowns and fiber-reinforced composites in endodontically treated teeth.
CONCLUSION
According to the research, using fiber-reinforced composites instead of conventional hybrid composites improves the fracture resistance of endodontically treated teeth. However, there was a high risk of bias in the research considered. No judgments could be reached about the superiority of one material over another based-on comparisons between other core restorations.
Topics: Humans; Tooth, Nonvital; Dental Materials; Crowns; Tooth Fractures; Composite Resins; Dental Stress Analysis
PubMed: 37574536
DOI: 10.1186/s12903-023-03217-2 -
The European Journal of Prosthodontics... Feb 2024The aim of this paper is to compare the survival and success rates of endodontically treated posterior teeth restored with full veneer crowns or full cuspal coverage...
INTRODUCTION
The aim of this paper is to compare the survival and success rates of endodontically treated posterior teeth restored with full veneer crowns or full cuspal coverage onlays in vivo.
METHODS
A literature search using PubMed, Medline and Embase via Ovid, and The Cochrane Library retrieved English and non-English language articles from 1946 to April 2022. Electronic searches were supplemented with the use of forward citation chaining via Google Scholar.
RESULTS
A total of eleven studies met all predetermined search criteria. Data were extracted and tabulated. Survival rates for onlays ranged from 95% to 100% at two years and 90.7% to 100% at three years with success rates ranging from 86.6% - 96.6% at two years and 86.6% to 96% at three years. Survival results for full veneer crowns were reported at 87.8% at over two years, 95.1% at three years, and 84% - 97.73% at five to ten years. Success rates have been reported at 91.11% - 92.64% at five years and 60% at six years.
CONCLUSIONS
The data suggest that the use of onlays instead of full veneer crowns in the restoration of endodontically treated posterior teeth is favourable in the short to midterm.
Topics: Humans; Crowns; Tooth, Nonvital; Inlays
PubMed: 37549135
DOI: 10.1922/EJPRD_2547Lane11 -
The European Journal of Prosthodontics... Feb 2024The aim of this study was to investigate the co-influence of indirect mesio- occlusal-distal (MOD) cavity geometry and inlay restoration bonding on quasi-static fracture...
INTRODUCTION
The aim of this study was to investigate the co-influence of indirect mesio- occlusal-distal (MOD) cavity geometry and inlay restoration bonding on quasi-static fracture load of the restored tooth.
METHODS
Forty-eight intact human molar teeth were selected and prepared for standardized edge-shaped or round-shaped MOD cavities. The resin composite (Cerasmart, GC) inlays were bonded with the state-of-the-art inlay bonding protocol or with intentionally deteriorated bonding using n-hexane-wax solution for preconditioning. Restored teeth were loaded along the long axis of the tooth. Ultimate fracture load was recorded, and the type of fracture was visually determined and classified. Statistical analysis of load values was performed by Kruskal-Wallis test.
RESULTS
Round-shaped cavity design with bonded restoration presented the highest fracture load (1658N). Bonding had significant influence on the fracture load of roundshaped cavity design (p=0.0003), whereas cavity design had no influence when the bonding was deteriorated (p=0.8075). In the case of deteriorated bonding, either the inlay or tooth fractured separately whereas in the bonded inlays fractures were commonly found both in the tooth and inlay.
CONCLUSIONS
According to this study, bonded inlay restoration increased fracture resistance, while cavity design had no statistical difference on fracture resistance of the restored tooth.
Topics: Humans; Inlays; Dental Porcelain; Dental Cavity Preparation; Tooth Fractures; Tooth; Composite Resins; Dental Caries; Dental Stress Analysis; Dental Restoration, Permanent; Materials Testing
PubMed: 37549134
DOI: 10.1922/EJPRD_2510Yli-Urpo08