-
American Journal of Dentistry Apr 2024To compare the fracture resistance and failure mode of porcelain laminate veneers with different preparation depths in endodontically treated teeth.
PURPOSE
To compare the fracture resistance and failure mode of porcelain laminate veneers with different preparation depths in endodontically treated teeth.
METHODS
Root canal treatment was performed for 40 maxillary central incisors, and then the teeth were divided into four groups (n= 10). The preparation depths were as follows: Group A: 0.9 mm, Group B: 0.6 mm, Group C: 0.3 mm, and in all three groups, 2 mm butt joint incisal reductions were performed; Group D was a control group with no preparation. Then 30 lithium disilicate porcelain veneers were milled by CAD- CAM method and cemented. After that, all specimens were subjected to cyclic loading and thermal cycling and finally were tested by a universal testing machine until failure occurred.
RESULTS
The mean failure loads (N) after exposure to continuous load were as follows: Group A: 625.70 (401.45-1037.77), Group B: 780.32 (222.93-1391.82), Group C: 748.81 (239.68-1241.87) and Group D (control) : 509.88 (84.42-1025.85) and P= 0.216. Analysis of failure mode in four groups showed that P= 0.469. There was no significant difference between the control and the other groups. In this study, 0.3, 0.6 and 0.9 mm depths of preparation for porcelain laminate veneers for endodontically treated teeth had no significant difference in fracture resistance and failure mode with non-prepared teeth.
CLINICAL SIGNIFICANCE
Reasonable consideration might be given to porcelain laminate veneer treatment for teeth that have become discolored and resistant to bleaching (such as instances where discoloration is severe following root canal treatment). This approach is considered to be on the conservative side, and has demonstrated that a labial preparation depth reduction of up to 0.9 mm does not have any impact on the failure mode or fracture resistance of endodontically-treated teeth.
Topics: Dental Veneers; Dental Porcelain; Humans; Tooth, Nonvital; Dental Restoration Failure; Dental Stress Analysis; Incisor; Materials Testing
PubMed: 38704854
DOI: No ID Found -
American Journal of Dentistry Apr 2024To evaluate clinical performances of two lithium disilicate systems (Initial LiSi press vs Initial LiSi Block, GC Co.) using modified United States Public Health Service... (Randomized Controlled Trial)
Randomized Controlled Trial Clinical Trial
PURPOSE
To evaluate clinical performances of two lithium disilicate systems (Initial LiSi press vs Initial LiSi Block, GC Co.) using modified United States Public Health Service (USPHS) evaluation criteria and survival rates after 4 years of clinical service.
METHODS
Partial adhesive crowns on natural abutment posterior teeth were made on 60 subjects who were randomly divided into two groups: Group 1: Initial LiSi press and Group 2: Initial LiSi Block. Fabrication of partial crowns was made with full analog and digital procedure in Groups 1 and 2 respectively. The restorations were followed-up for 1 and 4 years, and the modified USPHS evaluation was performed at baseline and each recall together with periodontal evaluation. Contingency tables to assess for significant differences of success over time in each group and time-dependent Cox regression to test for differences between the two groups were used and the level of significance was set at P< 0.05.
RESULTS
Regarding modified USPHS scores, all evaluated parameters showed Alpha or Bravo and no Charlie was recorded. No statistically significant difference emerged between the two groups in any of the assessed variables (P> 0.05). No statistically significant difference between scores recorded at the baseline and each recall. All modified USPHS scores were compatible with the outcome of clinical success and no one restoration was replaced or repaired, and the survival rate was 100% after 4 years of clinical service. No difference was found between traditional and digital procedure to fabricate the crowns. The two lithium disilicate materials showed similar results after 4 years of clinical service.
CLINICAL SIGNIFICANCE
The crowns made with the two tested lithium disilicate materials with analog and digital procedures showed 100% survival after 4 years of clinical service with no statistically significant difference using the modified USPHS scores.
Topics: Humans; Dental Porcelain; Crowns; Male; Female; Adult; Middle Aged; Dental Prosthesis Design; Dental Restoration Failure; Follow-Up Studies
PubMed: 38704851
DOI: No ID Found -
Clinical Oral Investigations May 2024To assess the long-term clinical performance of ceramic in-/onlays (CIOs) and cast gold partial crowns (CGPCs) in posterior teeth in terms of success, survival,...
OBJECTIVES
To assess the long-term clinical performance of ceramic in-/onlays (CIOs) and cast gold partial crowns (CGPCs) in posterior teeth in terms of success, survival, complications (biological, technical) and quality.
MATERIAL AND METHODS
In a retrospective study, a total of 325 patients were recorded after up to 24.8 years (mean 13.9 ± 3.8 years) having (pre-)molars restored with CIO (Empress I, Ivoclar Vivadent, n = 161) and CGPC (Degunorm, DeguDent, n = 164) by supervised undergraduate students. A total of 296 restorations were assessed clinically and radiologically in healthy and endodontically treated teeth using modified United States Public Health Service (USPHS) criteria. Cumulative success and survival rates of the restorations were calculated using Kaplan-Meier estimates. Biological and technical complications were recorded. Status of oral health comprising caries risk and localized periodontitis were assessed.
RESULTS
The cumulative success rates of CIOs were 92.1% and of CGPCs 84.2% after mean service times of 14.5 years. The annual failure rates of total service times were 0.5% in teeth restored with CIO (n = 155) and 0.7% in teeth restored with CGPC (n = 163). The cumulative survival rates of CIOs were 93.9% after a mean service time of 15.2 years and decreased to 91.7% after 23.5 years. The cumulative survival rates of CGPCs were 92.6% after a mean service time of 14.9 years and 91.8% after 23.5 years. Complications in CIOs (n = 149) were ceramic fracture (6.7%), secondary caries (4.7%), endodontic complication (2.7%) and tooth fracture (1.3%) compared to CGPCs (n = 147) with endodontic complication (8.8%), secondary caries (4.8%) and decementation (2.0%). Endodontically treated teeth restored with CIO or CGPC revealed significantly less often success compared with corresponding vital teeth (p = .02). CIOs and CGPCs revealed clinically and radiographically good and excellent qualities with 71.8% (107/149) and 68% (100/147) without any significant differences regarding type of restoration.
CONCLUSIONS
Both CIOs and CGPCs achieved high survival rates up to 24.8 years when performed by supervised undergraduate students. The longevity of the restorations may benefit from the intraoral repair of accessible defects and, in case of pulp infection or necrosis, an adequate endodontic management.
CLINICAL RELEVANCE
CIOs and CGPCs made by supervised undergraduate students are proper restoration types in posterior teeth in the long-term. An adequate preparation design, meticulous care in the inserting technique and constant biofilm removal due to proper oral hygiene combined with professional maintenance care are substantial. The clinical long-term performance was mostly limited by ceramic fractures in CIOs and endodontic complications in CGPCs.
Topics: Humans; Retrospective Studies; Crowns; Dental Restoration Failure; Female; Male; Adult; Inlays; Ceramics; Gold Alloys; Dental Caries; Dental Porcelain; Middle Aged; Dental Prosthesis Design; Tooth, Nonvital; Treatment Outcome
PubMed: 38702521
DOI: 10.1007/s00784-024-05682-7 -
BMC Oral Health May 2024This study aims to evaluate the effect of surface treatment and resin cement on the shear bond strength (SBS) and mode of failure of polyetheretherketone (PEEK) to...
BACKGROUND
This study aims to evaluate the effect of surface treatment and resin cement on the shear bond strength (SBS) and mode of failure of polyetheretherketone (PEEK) to lithium disilicate ceramic (LDC). This is suggested to study alternative veneering of PEEK frameworks with a ceramic material.
METHODS
eighty discs were prepared from PEEK blank and from lithium disilicate ceramic. Samples were divided into four groups according to surface treatment: Group (A) air abraded with 110 μm AlO, Group (AP) air abrasion and primer application, Group (S) 98% sulfuric acid etching for 60 s, Group (SP) Sulfuric acid and primer. Each group was subdivided into two subgroups based on resin cement type used for bonding LDC:1) subgroup (L) self- adhesive resin cement and 2) subgroup (B) conventional resin cement (n = 10). Thermocycling was done for all samples. The bond strength was assessed using the shear bond strength test (SBS). Failure mode analysis was done at 50X magnification with a stereomicroscope. Samples were chosen from each group for scanning electron microscope (SEM). The three-way nested ANOVA followed by Tukey's post hoc test were used for statistical analysis of results. Comparisons of effects were done utilizing one way ANOVA and (p < 0.05).
RESULTS
The highest mean of shear bond strength values was demonstrated in Group of air abrasion with primer application using conventional resin cement (APB) (12.21 ± 2.14 MPa). Sulfuric acid groups showed lower shear bond strength values and the majority failed in thermocycling especially when no primer was applied. The failure mode analysis showed that the predominant failure type was adhesive failure between cement and PEEK, while the remaining was mixed failure between cement and PEEK.
CONCLUSION
The air abrasion followed by primer application and conventional resin cement used for bonding Lithium Disilicate to PEEK achieved the best bond strength. Primer application did not have an effect when self-adhesive resin cement was used in air-abraded groups. Priming step is mandatory whenever sulfuric acid etching surface treatment is utilized for PEEK.
Topics: Benzophenones; Ketones; Dental Porcelain; Polyethylene Glycols; Resin Cements; Polymers; Dental Bonding; Surface Properties; Shear Strength; Materials Testing; Dental Stress Analysis; Acid Etching, Dental; Sulfuric Acids; Ceramics; Air Abrasion, Dental; Aluminum Oxide; Dental Veneers; Dental Etching; Humans
PubMed: 38698366
DOI: 10.1186/s12903-024-04269-8 -
Clinical Implant Dentistry and Related... May 2024This study aimed to compare implant stabilities between the immediate and early loaded, immediately placed bone-level tapered dental implants in the maxilla and to...
Immediate versus early loading of immediately placed bone-level tapered dental implants with hydrophilic surface in full arch maxillary rehabilitation: A pilot randomized clinical trial with 2-year follow-up.
This study aimed to compare implant stabilities between the immediate and early loaded, immediately placed bone-level tapered dental implants in the maxilla and to evaluate marginal bone loss (MBL), oral health-related quality of life (OHRQoL), and patient satisfaction at a 2-year follow-up. A pilot, prospective, randomized, controlled clinical trial was conducted on 24 maxillary failing dentition patients. The bone-level tapered implants of 12 patients were immediately loaded with temporary restorations, while the other 12 patients did not receive any kind of temporization. Implant-supported screw-retained complete porcelain-fused-to-metal prostheses were delivered to all patients in the seventh postoperative week. The insertion torque values of implants assigned to the immediate and early loading groups were 33.0 ± 4.87 and 29.26 ± 8.31 Ncm, respectively. The dynamics of implant stability changes from implant placement up to a 2-year follow-up were similar for both groups (Penguin®, p = 0.268; Ostell®, p = 0.552), while the MBL was at submillimeter level. The cumulative implant survival rate was 91.80% for immediately loaded implants and 97.22% for early loaded implants, without significant difference (p = 0.162). The total score on the Oral Health Impact Profile questionnaire significantly decreased over time in both groups, indicating improvement in OHRQoL (p < 0.001), and the high level of patient satisfaction remained after 2 years of function regardless of a loading protocol. Both loading protocols, immediate and early, of six immediately placed bone-level tapered dental implants are an adequate treatment choice for fixed rehabilitation of the maxillary failing dentition.
PubMed: 38693759
DOI: 10.1111/cid.13334 -
Journal of Esthetic and Restorative... Jul 2024To validate the reproducibility and inter/intra-observer variability of the Pink Esthetic Score/White Esthetic Score (PES/WES) of single tooth-supported prostheses in... (Randomized Controlled Trial)
Randomized Controlled Trial
OBJECTIVES
To validate the reproducibility and inter/intra-observer variability of the Pink Esthetic Score/White Esthetic Score (PES/WES) of single tooth-supported prostheses in the maxillary esthetic zone (13-23).
MATERIALS AND METHODS
Forty-five patients were randomly assigned to one of the three treatment options (15 patients per group) receiving each one a different crown type: Porcelain fused to metal (PFM), monolithic zirconia, and lithium disilicate. Eight observers from each of four different specialties (Prosthodontists, Orthodontists, Periodontists, and Oral Surgeons) were recruited and assessed twice and four weeks apart (i.e., T1 and T2) 45 photographs of the single tooth-supported prosthesis using PES/WES and compared them with contralateral teeth.
RESULTS
According to the ANOVA and post hoc tests, the zirconia crown type obtained the highest mean score by all observers, with a mean value of 16.70 ± 2.94. The prosthodontists and oral surgeons assigned the lowest mean score to PFM crowns, 13.03 ± 3.47 and 13.80 ± 3.17, respectively. Notably, the prosthodontists awarded the highest scores, specifically 17.50 ± 2.81 for the zirconia crowns. Intraobserver agreement was calculated utilizing the paired t-test. Pairwise comparisons between observers of different specialties revealed significant intraobserver agreement. Interclass correlation coefficient (ICC) scores were statistically significant among four specialties. No difference was detected concerning the interobserver agreement.
CONCLUSIONS
The PES/WES index remains consistent across various observers from different specializations, yielding uniform results in the overall esthetic evaluation. Consequently, in light of the presented preliminary positive results, its use might also be considered for the esthetic assessment of single-tooth-supported prostheses.
CLINICAL SIGNIFICANCE
The PES/WES index may be employed clinically to evaluate single tooth-supported prostheses as it emerged as a reproducible esthetic scoring system.
Topics: Adult; Female; Humans; Male; Middle Aged; Crowns; Esthetics, Dental; Observer Variation; Reproducibility of Results; Zirconium
PubMed: 38689391
DOI: 10.1111/jerd.13243 -
Heliyon Apr 2024Environmental consciousness motivates scientists to devise an alternative method for producing natural fiber composite materials in order to decrease the demand for...
Environmental consciousness motivates scientists to devise an alternative method for producing natural fiber composite materials in order to decrease the demand for synthetic fibers. This study explores the potential of a novel composite material derived from madar fiber-reinforced epoxy with porcelain filler particulates, designed specifically for biomedical instrumentation applications. The primary focus is to assess the material's structural, mechanical, and antibacterial properties. X-ray Diffraction analysis was employed to discern the crystalline nature of the composite, revealing enhanced crystallinity due to the inclusion of porcelain particulates. Fourier-Transform Infrared Spectroscopy confirmed the chemical interactions and bonding mechanisms between madar fiber, epoxy matrix, and porcelain filler. Mechanically, the composite exhibited superior properties when addition of porcelain fillers, maximum results obtain in tensile strength of 51.28 MPa, flexural strength of 54.21 MPa, and impact strength of 0.0155 kJ/m2, making it ideal for robust biomedical applications. Scanning Electron Microscopy provided detailed insights into the morphology and distribution of the reinforcing agents within the epoxy matrix, emphasizing the fibrillated structure of madar fiber and the uniform dispersion of porcelain particulates. Importantly, antibacterial assays demonstrated the composite's potential resistance against common pathogenic bacteria, which is crucial for biomedical instrumentation. Collectively, this research underscores the promising attributes of the madar fiber reinforced epoxy composite with porcelain particulates, suggesting its suitability for advanced biomedical applications.
PubMed: 38681603
DOI: 10.1016/j.heliyon.2024.e29818 -
European Journal of Oral Sciences Jun 2024This study aimed at examining the bond strength between zirconia and ceramic veneer, following the ISO 9693 guidelines. A total of fifty specimens of...
This study aimed at examining the bond strength between zirconia and ceramic veneer, following the ISO 9693 guidelines. A total of fifty specimens of zirconia/ceramic-veneer system were produced using two commercial zirconias (VITA YZ-HT and Zolid HT+ White, referred to as Group A and Group B, respectively) and a ceramic-veneering material (Zirkonia 750). The microstructure (via x-ray diffraction analysis, XRD and Secondary Electron mode, SEM) and the mechanical properties (via 3-point bending tests) of the two groups were assessed. Then, experiments were conducted according to the ISO 9693 and conventional protocols applied for producing zirconia/ceramic-veneer restorations. Bond strength values, measured by 3-point bending tests, were 34.42 ± 7.60 MPa for Group A and 31.92 ± 6.95 MPa for Group B. SEM observations of the cohesively fractured surfaces (on the porcelain side) and the examination for normality using the Shapiro-Wilk test suggested the use of Weibull statistical analysis. Median strength (σ) for Group A and Group B was 34.76 and 32.22 MPa, while the characteristic strength (σ) was 35.78 and 33.14 MPa, respectively. The Weibull modulus disparity between groups (12.69 and 13.07) was not significant. Bond strength exceeded the ISO 9693 minimum of 20 MPa, suggesting satisfactory strength for clinical use.
Topics: Zirconium; Dental Veneers; Dental Porcelain; Materials Testing; Dental Bonding; Dental Stress Analysis; X-Ray Diffraction; Microscopy, Electron, Scanning; Surface Properties; Ceramics; Dental Materials; Humans
PubMed: 38679835
DOI: 10.1111/eos.12989 -
British Dental Journal Apr 2024
Topics: Humans; Aluminum Silicates; Potassium Compounds; Dental Porcelain; Ceramics; Incisor; Female
PubMed: 38671127
DOI: 10.1038/s41415-024-7370-3 -
Journal of Dentistry Jun 2024Multilayer monolithic zirconia (M-Zr) crowns can be engineered to achieve gradational translucency and color intensity. However, this modification may compromise the...
OBJECTIVES
Multilayer monolithic zirconia (M-Zr) crowns can be engineered to achieve gradational translucency and color intensity. However, this modification may compromise the mechanical strength, raising concerns regarding the ability of M-Zr crowns to withstand occlusal stresses. The effects of M-Zr crown thickness on translucency and ability to endure occlusal forces were investigated at different tooth positions (incisors, premolars, and molars). The objective was to determine the minimal thickness of M-Zr crowns used in tooth preparation to meet aesthetic and functional demands.
METHODS
M-Zr samples (Vita A1) with four thicknesses (0.5, 1.0, 1.5, and 2.0 mm) were prepared and subjected to translucency testing using a digital colorimeter by 3-third and 9-square division methods. Crown-shaped M-Zr samples with three thicknesses (1.0, 1.5, and 2.0 mm) and three tooth positions (incisor, premolar, and molar) were digitally designed, and 2.0 mm metal abutments were fabricated. The samples were bonded to the abutments; their fracture characteristics were evaluated using a universal testing machine, and their fracture surfaces examined using an optical microscope. Statistical analyses included the Shapiro-Wilk test, Pearson correlation, and one-way and two-way ANOVA with a post hoc Tukey HSD test (α = 0.05).
RESULTS
Color analysis results revealed a significant negative correlation between thickness and translucency (r < -0.96, P < 0.01), with the highest values in the incisal region. Cross-sectional profiles confirmed the uniform thickness and morphology of the digitally designed M-Zr crowns. The results of fracture strength analysis showed position-dependent variability, a strong positive correlation with thickness (r > 0.96, P < 0.01), and fracture strengths consistently exceeding 1200 N across all tooth positions. Fracture patterns indicated that thinner crowns at the incisors and molars were more prone to cracking, whereas those at the premolars demonstrated significantly higher strength (4872.51 N, P < 0.05), only with crack or even no fracture occurring at 2.0 mm.
CONCLUSIONS
Thickness significantly influenced both the translucency and fracture strength of M-Zr, with the tooth position playing an additional role, albeit to a lesser extent. Although thinner crowns exhibited lower strength at each tooth position, even at a thickness of 1.0 mm, fracture strength exceeding 1200 N was maintained, surpassing the typical occlusal forces. Thus, it can be asserted that M-Zr crowns with a minimum thickness of 1.0 mm can meet both aesthetic and functional requirements.
Topics: Zirconium; Crowns; Materials Testing; Dental Prosthesis Design; Humans; Bicuspid; Dental Materials; Surface Properties; Molar; Dental Stress Analysis; Dental Restoration Failure; Color; Dental Abutments; Bite Force; Incisor; Dental Porcelain; Stress, Mechanical
PubMed: 38670331
DOI: 10.1016/j.jdent.2024.105023