Metal-ceramic Crowns Research Articles

Changes in the levels of cytokines IL-1β, IL-4, IL-8, and IL-10 in dental orthopedic fixed prosthetics

Despite significant advances in materials science, introduction of new methods and principles of prosthetic treatment into the practice of dentists, complications after prosthetics with fixed structures are encountered. The result of dental prosthetics of patients with defects of hard tissues of teeth depends not only on the chosen construction and materials from which they are made, but is closely connected with the functional activity of the immune system. Cytokines are an important factor of mucosal immunity. The cytokine system represents one of the key components of mucosal immunity. It regulates normal physiological functions, restoration of haemostasis in the interaction of physical, chemical and biological factors on the body and participates in the pathogenesis of allergic, autoimmune, and autoinflammatory processes. The aim of the study is to compare the content of IL-1â, IL-8, IL-10, and IL-4 in unstimulated saliva and gingival fluid in patients during adaptation to metal-ceramic and oxide ceramic tooth-supported constructions. In the period from 2021-2024, we examined 3 groups of patients aged 46±2 years: group 1 – comparison group, patients without dental constructions in the oral cavity (25 people); group 2 – patients treated with tooth-supported metal-ceramic (MC) crowns (25 people); and group 3 – patients treated with tooth-supported zirconium dioxide (ZrO2) crowns (25 people). On the basis of IL-1â, IL-8, IL-10, and IL-4 we concluded that the mucosal immunity of oral mucous membranes is less affected by the structures made of oxide ceramics compared to the crowns made of metal-ceramics. Similar patterns of changes in the levels of IL-1â, IL-8, and IL-4 in saliva and gingival fluid in patients who underwent dental rehabilitation were found, which allows us to use only saliva in order to eliminate the complexity and specificity of gingival fluid sampling. Also, changes in cytokine indices in saliva and gingival fluid at different stages of prosthodontics reflect the level of reaction of oral mucosal immunity, which can serve as a criterion of the quality of the performed dental treatment.

Influence of various fabrication techniques and porcelain firing on the accuracy of metal-ceramic crowns

BackgroundThe fit of a metal-ceramic restoration is essential to its long-term durability. Regarding marginal and internal fit, there is not enough information about the technologies used in the production of metal-ceramic restorations. The aim of this in vitro study is to compare, both before and after porcelain firing, the marginal, axial, axio-occlusal, and occlusal fit of metal-ceramic restorations manufactured using casting, additive or subtractive computer-aided design, and computer-aided manufacturing techniques (CAD/CAM).MethodsCAD/CAM were used to create 50 prepared maxillary first molar-shaped Co-Cr die models, which were randomly divided into 5 groups (n = 10). Cobalt-chrome copings were produced by casting (C), hard metal milling (HM), soft metal milling (SM), selective laser melting (SLM), and selective laser sintering (SLS) techniques. Before and after porcelain firing, discrepancies of the copings were measured using the silicone replica technique. The data obtained by measurements with a stereomicroscope at x80 magnification were analyzed statistically in the SPSS program. The ROBUST three-way analysis of variance (ANOVA) method was used to compare the discrepancy values.ResultsThere were statistically significant differences among fabrication methods (P < .001). The HM method showed the highest discrepancy (90.1 μm), and the C (63 μm) method showed the lowest discrepancy in terms of the die model- crown fit. The C, SLS, and SM methods (63 μm; 61.6 μm; 67.7 μm) were statistically similar (P > .001). The highest discrepancy was observed on the occlusal area (87.1 μm), and the lowest discrepancy was observed on the axial area (47.7 μm) of the coping. Porcelain firing had a decrease in the discrepancy values (P = .001).ConclusionAll CAD/CAM techniques are appropriate for clinical use; selective laser sintering and soft milling can be the more recommended methods for the compatibility of metal-porcelain restorations, as they have lower discrepancy values than the SLM and HM methods.

The influence of implant depth, abutment height and mucosal phenotype on peri‑implant bone levels: A 2-year clinical trial

ObjectivesTo evaluate the bone changes around equicrestal and subcrestal implants, analyzing the effect of abutment height [short abutments (SA < 2 mm) and long abutments (LA > 2 mm)] and the three components of the peri‑implant soft-tissue phenotype. MethodsTwenty-six patients received 71 implants that were placed according to supracrestal tissue height (STH) in an equicrestal (n = 17), shallow subcrestal ≈1 mm (n = 33), or deep subcrestal ≈2 mm (n = 21) position. After 3 months of healing, rehabilitation was completed using metal-ceramic crowns on multi-unit abutments of 1.5 mm, 2.5 mm, or 3.5 mm in height, depending on the prosthetic space and STH. Longitudinal clinical parameters (STH, mucosal thickness, and keratinized mucosa width) and radiographic data [bone remodelling and marginal bone loss (MBL)] were collected at 3, 6, 12, and 24 months postsurgery. ResultsThe gain in STH was significantly greater around the implants placed in a subcrestal ≈2 mm position. After 2 years, the mean change in bone remodelling in the SA group was significantly greater than in the LA group. According to the multiple linear regression, bone remodelling depends primarily on abutment height (β = -0.43), followed by crestal position (β = 0.34), and keratinized mucosa width (β = -0.22), while MBL depends on abutment height (β = -0.37), and the patient's age (β = -0.36). ConclusionsImplants placed in an equicrestal or subcrestal ≈1 mm position with LA undergo less bone remodelling, while the lowest level of MBL occurs in subcrestal ≈2 mm implants with LA. Differing soft-tissue thicknesses combined with the use of either SA or LA produced significant intergroup differences in bone remodelling and MBL. Clinical significanceAbutment height is the most powerful predictor variable affecting bone remodelling and MBL. Depending on the dimensions of the peri‑implant soft-tissue phenotype, placing the implants subcrestally may also be a viable option to decrease bone remodelling and, consequently, reduce MBL. Clinical trial registrationidentification number: NCT05670340.

Removable prosthesis with precision attachments for the lower jaw in lateral edentation

Background. In certain cases of lateral edentation, some treatment options are limited due to the patient’s desire or maybe due to the fact that biology could not permit otherwise. Hence, in these scenarios the options to use the implant therapy are limited. Case report. 50-year-old female patient was referred to clinic for a full mandibula rehabilitation. In this case the patient was diagnosed with Kennedy Class I. In this situation, the treatment option was fixed metal-ceramic crowns with precision attachments (keyway attachments) for a removable prothesis. Aim. To emphasize the fact that, from a socio-economic point of view, the patient tends to choose the more accessible treatment option, but also the time component has a major impact on the choice they make, the development time of a treatment plan being very important to the patient. Material and methods. 10 cases of partial edentation were analyzed for the possibility of realizing two treatment plans, namely the version with implants or with removable prosthesis. The clinical implications of various aspects of this area were monitored and displayed as results. Results. Patients were much more receptive to the removable prosthesis with precision attachments treatment compared to the insertion of implants. The former has a similar result to the latter, but in a much shorter time span and with lower costs. Conclusions. From the analyzed it was confirmed that edentulous patients can be successfully treated with fixed prosthodontics associated with a removable partial prosthesis with precision attachments with the same benefits that the implant works might have brought them, the patient being satisfied with the quality of life gained as a result of benefitting from removable prosthesis in a relatively convenient period of time.

A Comparative Evaluation of Prosthetic and Biological Outcome as Influenced by Two Different Implant Restorative Materials (Porcelain Fused to Metal and Monolith Zirconia): A Prospective, Cross-arch Study.

To investigate the prosthetic parameters, clinical indices, crestal bone levels, and inflammatory biomarkers in peri-implant crevicular fluid as influenced by two different implant restorative materials i.e., metal ceramic and monolithic zirconia at baseline, 1 Year and 2 Years. Twenty patients with bilateral implants placed in the same arch were selected. Monolithic zirconia (4Y-PSZ) crown was placed on one side whereas a metal ceramic (M C) crown was inserted on the contralateral side after randomization. Interproximal marginal bone level (MBL), clinical parameters, MMP-8 levels in PICF, and prosthetic characteristics (as determined by modified USPHS criteria) were evaluated at baseline, 1-year, and 2-year follow-ups. Data were descriptively examined. The results were evaluated using the Chi-Square Test, ANOVA, and student t-test. At p < .05., statistical significance was determined. Twenty MC crowns and twenty Mono-ZrO2 crowns were delivered. A 100% survival of the implants and the prosthetic crowns was achieved across all patients with no instances of failure noted throughout the two-year follow-up period. The periodontal changes observed in the participants were analysed and demonstrated statistically insignificant alterations. Prosthetic alterations were assessed according to USPHS criteria, revealing minor ceramic chippings and instances of screw loosening within the MC group during both the 1- and 2-year follow-up periods. These incidents were collectively categorized as technical issues. Regarding anatomical form and color match to the surrounding dentition, the Mono- ZrO2 crowns obtained much lower evaluations when compared to the M-C crowns. However, when evaluating the loss of marginal bone and level of inflammatory markers there were no discernible variations between the groups. The null hypothesis that there is no similarity in the survival rates and interactions at the peri-implant interface between the two types of restorations was rejected. Both monolithic zirconia and metal ceramic crowns demonstrated no statistical differences across all parameters examined in the present prospective investigation.

УРОВЕНЬ КОМФОРТА И МОТИВАЦИИ К ОРТОПЕДИЧЕСКОМУ ЛЕЧЕНИЮ ПРИ ДЕФЕКТАХ ТВЕРДЫХ ТКАНЕЙ ЗУБОВ

It is impossible to overestimate the role of dentistry in the life of a modern person. What an ordinary, but at the same time – an important procedure was a visit to the dentist's office. Modern dentistry is the result of a long, painstaking, invaluable work of a large number of people who have been passing on their accumulated experience for many centuries, searching for answers to emerging questions. Even today, dentists and scientific researchers continue to conquer the peaks of dental science, but each of these achievements opens up space for new discoveries[9]. For example, the problem of modern dentistry, the relevance of which cannot be underestimated, is the insufficient identification of patterns of influence of orthopedic treatment on the comfort and quality of life of patients. Restoration of defects in the crown of a tooth with the help of an artificial metal-ceramic or ceramic crown has long been commonplace both in the work of an orthopedic dentist and in the lives of patients. Dental prosthetics solves not only the main problem – the restoration of chewing efficiency and aesthetics, but also increases the comfort and quality of life of patients, encouraging them to continue dental treatment, as evidenced by the results of this work. This study is devoted to the study of the effect of prosthetics with metal-ceramic and ceramic artificial crowns on the level of comfort of life and motivation of patients for orthopedic treatment of hard dental tissues. The paper presents the results of the analysis of medical records of dental patients and a survey of patients who applied for dental prosthetics. The purpose of the study was to assess the quality of life of patients before and after orthopedic treatment of defects in hard dental tissues with artificial crowns and, analyzing the data obtained, determine the correlation of various factors with the level of motivation for prosthetics. Material and methods. The study took place on the basis of the Department and Clinic of General Dentistry of the Military Medical Academy n. a. S.M. Kirov. For the study, 90 medical records of dental patients were taken, the age structure of patients, types, quantity and quality of orthopedic structures in the oral cavity were analyzed. Methods such as statistical, questionnaire, analysis and synthesis, and comparison were used to form conclusions. In the future, the subjects were asked to complete the OHIP-14 RU questionnaire. The results and their discussion. The most extensive age group seeking orthopedic dental care is the category between the ages of 18 and 44 (young age) – 48.5%, most of the subjects (36.4%) have one metal-ceramic crown. As a result of the analysis of data obtained from the OHIP-14 RU questionnaire, a pattern was revealed between orthopedic treatment in persons with defects in hard dental tissues and the level of their quality of life, which had a direct relationship. Thus, prosthetics with artificial crowns, if there are indications for this type of dental treatment, increases the comfort and quality of life of the patient, and also helps to increase motivation for dental treatment.

Influence of ceramic crown design (translucent monolithic zirconia vs. bilayered) of implant-supported single crowns after mechanical cycling.

This study aimed to assess the influence of translucent monolithic versus bilayered crowns and whether the use of a CoCr base abutments affects the fatigue and fracture resistance of screwed implant-supported single crowns with external connections under mechanical cycling. Fifty specimens were divided into groups: (1) metal-ceramic (MC) crown, (2) veneered zirconia crown (Zr), (3) veneered zirconia crown with a CoCr base abutment (ZrB), (4) monolithic translucent zirconia crown (MZr), and (5) monolithic translucent zirconia crown with a CoCr base abutment (MZrB). Specimens underwent mechanical cycling (5 × 106 cycles; 150 N) evaluating fatigue resistance (number of failures) and those that failed were subsequently subjected to fractographic analyses (stereomicroscope and scanning electron microscope) to evaluate failure location and area, and maximum fracture load was also measured. The failure-related survival rate (100%) and maximum fracture resistance of the MZrB were significantly higher than those of MC and Zr (50%; p < 0.05). There were no significant differences in the failure rate and fracture resistance when a CoCr base abutment was used or not in the translucent monolithic Zr groups (p > 0.05;MZrB vs. MZr). Failure location, with MC crowns' fractures, noted at the screw area (p = 0.043), while all-ceramic crowns were mostly in the cuspid and to failure area, the Zr group had the largest mean (15.55 ± 9.17 mm2) among the groups, significant difference only when compared with MC (1.62 ± 0.81 mm2) (p = 0.025). Translucent monolithic zirconia crowns exhibited significantly higher fatigue and fracture resistance compared with conventional MC and bilayered crowns. The appropriate choice of material and manufacturing technique is crucial for predicting the higher clinical performance of single crowns. Enhanced mechanical resistance in terms of fatigue and fracture resistance can be achieved by replacing MC and bilayered restorations with computer-aided design and computer-aided manufacturing monolithic zirconia.

Marginal fit of 3-unit implant-supported fixed partial dentures: Influence of pattern fabrication method and repeated porcelain firings.

Marginal fit significantly impacts the long-term success of dental restorations. Different pattern fabrication methods, including hand-waxing, milling, or 3D printing, may affect restorations accuracy. The effect of porcelain firing cycles on the marginal fit of metal-ceramic restorations remains controversial, with conflicting findings across studies. The aim was to evaluate the potential effects of multiple porcelain firings (3, 5, 7 cycles) as well as pattern fabrication method (conventional hand-waxing, milling, and 3D printing) on the marginal adaptation of 3-unit implant-supported metal-ceramic fixed partial dentures. It was hypothesized that neither the wax pattern fabrication method nor repeated ceramic firings would significantly affect the marginal adaptation of metal-ceramic crowns. In this in-vitro study, 30 Cobalt-Chromium alloy frameworks were fabricated based on pattern made through three techniques: conventional hand-waxing, CAD-CAM milling, and CAD-CAM 3D printing (n = 10 per group). Sixteen locations were marked on each abutment to measure the vertical marginal gap at four stages: before porcelain veneering and after 3, 5, and 7 firing cycles. The vertical marginal gap was measured using direct microscopic technique at ×80 magnification. Mean vertical marginal gap values were calculated and two-way ANOVA and Tukey's post hoc tests were used for inter-group comparisons (α = 0.05). The 3D printing group showed significantly lower (P<0.001) mean vertical marginal gaps (60-76 μm) compared to the milling (77-115 μm) and conventional hand-waxing (102-110 μm) groups. The milling group exhibited a significant vertical gap increase after 3 firing cycles (P<0.001); while the conventional (P = 0.429) and 3D printing groups (P = 0.501) showed no significant changes after 7 firing cycles. Notably, the vertical marginal gap in all groups remained below the clinically acceptable threshold of 120 μm. CAD-CAM 3D printing provided superior marginal fit compared to CAD-CAM milling and conventional hand-wax pattern fabrication methods. The impact of porcelain firing on the mean marginal gap was significant only in the milling group. All three fabrication techniques yielded clinically acceptable vertical marginal adaptation after repeated firings. Additive manufacturing holds promise to produce precise implant-supported prostheses.

Restoration of Bilateral Premolars Using Custom Made Cast Post and Core: A Case Report

When grossly carious teeth need to be restored after endodontic treatment, long term success depends on the choice of the post and core systems. A custom-cast post and core is recommended when the remaining tooth structure is compromised and an insufficient ferrule is present. The following case report depicts the restoration of bilateral grossly carious premolar teeth by using custom-cast posts followed by PFM crowns. The patient presented with bilateral severely carious premolars with pulpal necrosis. The treatment plan included endodontic treatment followed by custom-cast posts and cores with PFM crowns. In this way, aesthetics and function for the patient can be achieved by using cast metal posts and metal ceramic crowns for the restoration of premolars.

Comparison of clinical outcomes between single metal-ceramic and zirconia crowns

Statement of problemEvidence comparing the survival of zirconia crowns with metal-ceramic crowns is sparse. Knowledge of their survival and a comparison of their clinical outcomes would improve clinical decision making. PurposeThe purpose of this university-based study was to compare the survival, failures, biological and technical complications encountered with zirconia and metal-ceramic crowns restored and followed up over a similar period. Material and methodsThis retrospective chart review consisted of 403 patients treated at the University of Toronto, Faculty of Dentistry, predoctoral dental clinic in whom zirconia (n=209) and metal-ceramic (n=306) crowns were inserted between September 2015 and July 2016 and followed for up to 7 years. Outcome measures included failure, causes for failure, and complications associated with survival. Inferential statistical analysis included the chi-squared test, t test, Mann-Whitney test, Bonferroni-adjusted z-test, Kaplan-Meier survival test, and logistic regression to examine differences between crown types and explore crown failures (α=.05). ResultsThe mean follow-up period was 3.00 years (median 2.58 years). Forty-one (8.0%) crowns had no follow-up, with no difference in follow-up between crown type: metal-ceramic n=23(7.5%), zirconia n=18(8.6%), χ²(1)=0.20, P=.652). Excluding those with no follow-up, the follow-up time between metal-ceramic (mean=3.07, median=2.58) and zirconia (mean=3.54, median=3.32) crowns was statistically similar (P=.052). There were 62 anterior crowns (12.0%) and 453 posterior crowns (88.0%), χ²(1)=22.40, P<.001, with no difference between groups. Overall, 44 crowns (8.5%) failed, 30 (9.8%) metal-ceramic and 14 (6.7%) zirconia, with no statistical difference in proportion of failed crowns between groups (χ²(1)=1.53, P=.216). There were 35 crowns with biological failures (6.8%), 26 (8.5%) in the metal-ceramic and 9 (4.4%) in the zirconia group, with no statistical difference between groups (χ²(1)=3.33, P=.068). Nine crowns had technical failures (1.7%), 4 (1.4%) in the metal-ceramic group and 5 (2.5%) in the zirconia group, with no statistical difference between groups (χ²(1)=0.73, P=.394). Biological (79.5%) rather than technical complications were found to be the most frequent cause of failure, goodness-of-fit χ²(1)=15.36, P<.001. Tooth fracture (50.0%) specifically was found to be the most frequent cause of failure, χ²(3)=21.27, P<.001. The total number of crowns that survived was 471 (91.5%); 276 (90.1%) were metal-ceramic and 195(93.3%) zirconia. The survival time (years) for metal-ceramic was mean=6.26, 95% CI [6.01–6.51] and for zirconia crowns mean=6.54, 95% CI [6.31–6.77]. Of the crowns that survived, 370 (78.6%) had no clinical complications, and 101 (21.4%) crowns demonstrated similar clinical complications, with no statistical differences between groups. ConclusionsWithin the study follow-up time, the survival of monolithic zirconia and metal-ceramic crowns was 91.5%, with similar clinical complications between groups. Biological complications, especially tooth fracture, were a significantly more frequent complication with both types of crowns.

ASSESSMENT OF DENTAL STUDENTS’ AND DENTISTS’ KNOWLEDGE OF POST AND CORE TECHNIQUE USE IN ENDODONTICALLY TREATED TEETH

Restoring the morpho-functionality of a dental crown that shows extensive surface and depth lesions can be achieved by means of prosthetic therapy represented by different post and core techniques. Purpose The present study aims to assess dental students’ and dentists’ knowledge of post and core techniques using a questionnaire. Material and methods. For this survey-based study a questionnaire was designed consisting of 15 questions related to the category of participants, questions related to the sources of information and questions related to the topic discussed. Results. This study included 55 participants including 39 students in years IV, V and VI, and 16 dentists. Of the 55 participants, 44 were in the 20-29 age group, 10 in the 29-39 age group, and 1 participant was over 40 years old. In terms of gender, 43 were females and 12 males. 74.5% of the participants (n=41) thought that prefabricated fiberglass posts are most often used, followed by cast metal posts, mentioned by 58.2% (n=32) of the respondents. 81.8%(n=45) of the respondents specified intra-radicular aggregated metal-ceramic crowns as the most used substitution method. Conclusion. Based on the results of the study, it can be concluded the main types of prefabricated posts used in post and core techniques were: fiberglass posts and screwed metal posts.

A Comparison of the Effect of Zirconia Crown on Periodontal Tissues: A Nonrandomized Clinical Trial

Background: Dental crowns are effective on the gingival tissue around the teeth. However, using zirconia as crowns due to the method and type of material can effectively improve this effect. Methods: This is a pre-post clinical trial conducted on 35 teeth with metal-ceramic crowns and 35 teeth with zirconia crowns. Teeth were prepared for fabricating metal-ceramic and zirconia crowns. Plaque index (PI), modified gingival index (MGI), pocket probing depth (PPD), papilla bleeding index (PBI), and gingival level (GL) were measured before and six months after getting the dental crown. The data were analyzed using the Mann–Whitney test. Results: In both groups, the GL remained the same after six months of crown placement (P&gt;0.05). In the metal-ceramic group, the PI decreased significantly (P=0.000), but MGI and PBI significantly increased (P=0.000 and P=0.000, respectively) six months after crown placement. Based on the results, PPD increased significantly only on the midlingual surface (P=0.02). The PI significantly decreased in the zirconia group (P=0.000). Nevertheless, PPD represented no change (P&gt;0.050). The comparison between the two groups six months after crown placement indicated that the PI, MGI, and PBI were significantly higher in the metal-ceramic group (P=0.010, P=0.011, and P=0.044, respectively). The metal-ceramic group showed a significantly greater increase in PPD on the midlingual surface (P=0.043). Conclusion: Both crown types on teeth could significantly increase the incidence of gingivitis, and compared with zirconia crowns, metal-ceramic crowns demonstrated significantly more inflammation.

Evaluation of periodontal parameters on abutment teeth rehabilitated with single-unit crowns: A 12-month follow-up

PurposeThis prospective study evaluated the effects of the metal-free crowns on the periodontal tissues of abutment teeth during a 12-month follow-up. Materials and Methods:A sample of 24 patients (N = 32 abutment teeth) who needed a single-tooth restoration were enrolled to receive either a metal-ceramic (n = 21) or lithium disilicate (n = 11). The single-unit crowns were evaluated at baseline, 3-and 12-month follow-up. The periodontal parameters were evaluated: plaque index (PI), gingival bleeding index (GBI), bleeding on probing (BOP), probing depth (PD), clinical attachment loss (CAL), radiographically and clinical crown fitting, bone resorption, and marginal finish lines. Statistical analyses were performed using the Exact Fisher and Mann-Whitney tests, and the Wilcoxon signed-rank test as a post hoc test for Friedman (95 % confidence interval). Results:The marginal finish line showed a statistical difference with a biomaterial type (p =.004). After a 12-months, a significant increase was observed in PI and mean PD for abutment teeth of metal-ceramic crowns. The metal-free crowns presented higher values for GBI and CAL (p2 < 0.05). Only distal cervical evaluation and dental biofilm formation in the abutment teeth showed a statistical difference between the groups at the 12-month follow-up. The supragingival margin metal-ceramic group revealed higher PI values (p2 = 0.005) between the period and the subgingival margin of both biomaterials showed greater GBI scores (p2 < 0.05). Conclusions:Metal-free crowns showed better periodontal outcomes compared to metal-ceramic crowns. Single-unit crown marginal location affects the periodontal tissue condition of the abutment teeth. The marginal fit was not changed regarding the biomaterial type.

Evaluation of Marginal Adaptation of Metal Ceramic Crown with Different Luting Cement

The study aims to evaluate and compare the microleakage of three different luting materials. The materials compared are Zinc phosphate cement, Variolink II Refill and Glass ionomer resin cement. Eighteen recently extracted caries-free wisdom teeth were used . The teeth were cleaned then stored in distilled water until use. The molars were assigned randomly into three groups of 6 teeth of each . The metal ceramic crowns were constructed by means of an indirect laboratory technique. In group A, the crowns were cemented with a traditional Zinc Phosphate. In group B, the tooth preparations were sealed with Variolink II Refill. In group C, the tooth preparations were sealed with glass ionomer resin cement prior to cementation with the crowns. The results showed higher value of microleakage for Zinc phosphate cement. While the least value was for the Variolink II . The value for Glass ionomer resin cement was low. Statistically analysis revealed difference between the Zinc phosphate cement ,Variolink II and Glass ionomer resin cement in microleakage. There was no significant difference in microleakage between Variolink II and Glass ionomer resin cement. This may indicated that the degree of microleakage may influenced by the type of the luting system used.

SURVIVAL RATE OF IMPLANT-SUPPORTED, SINGLE-TOOTH RESTORATIONS BASED ON ZIRCONIA OR METAL ABUTMENT IN PATIENTS WITH TOOTH AGENESIS: A 5-YEARS PROSPECTIVE CLINICAL STUDY

Purpose: The primary aim was to investigate survival rate of zirconia versus metal abutments, and the secondary aim was clinical outcomes of all-ceramic versus metal-ceramic crowns on single-tooth implants. Material and Methods: Patients with tooth-agenesis participated to previously published prospective clinical study with three-year follow-up were recalled after five years. Biological variables included survival and success rate of implants, marginal bone level, modified Plaque and Sulcus Bleeding Index and biological complications. Technical variables included restoration survival rate, marginal adaptation and technical complications. The aesthetic outcome of crowns and peri-implant mucosa in addition to patient-reported outcome were recorded. Descriptive analysis, linear mixed model for quantitative data, or generalized linear mixed model for ordinal categorical data were applied; significance was set to 0.05. Results: Fifty-three patients (mean age: 32.4 years), with 89 implants participated to the 5-years examination. The implants supported 50 zirconia abutments with 50 all-ceramic (AC) crown and 39 metal abutments with 29 metal-ceramic (MC) and 10 AC crowns. Conclusions: Zirconia-based single-tooth restorations are reliable alternative materials to metal-based restorations with favorable biological and aesthetic outcome, and few technical complications.

Replacement of metal-ceramic crown with fully ceramic: Case report

Dental treatments with aesthetic involvement drive the market towards an increase in the quality and diversity of materials, aiming to provide the highest satisfaction for both the patient and the dentist. Faced with limitations in metal-ceramic treatments, fully ceramic systems have evolved, enabling excellent aesthetic and functional results when appropriately indicated. The purpose of this case report is to describe a clinical case of oral rehabilitation in an aesthetic area through the replacement of a metal-ceramic crown with pure lithium disilicate ceramic (E-Max) for tooth 22. For the clinical success of the treatment, it was necessary to perform teeth whitening and dental recontouring with composite resin of the adjacent teeth prior to the fabrication of the definitive crown. Considering the techniques and materials used, the treatment performed was able to provide a result of clinical excellence, especially in this region that demands higher aesthetic requirements, offering satisfaction and restoring the patient's self-esteem.

Single crown vs. composite for glass fiber post-retained restorations: An 8-year randomized clinical trial

ObjectivesThis study aimed to compare the success and survival rates of metal-ceramic crowns and composite resin restorations applied in root filled teeth that received a glass fiber post. MethodsA prospective, randomized controlled trial, with equivalent parallel groups was designed. Eighty-two teeth were randomly allocated to the metal-ceramic or composite resin groups. Multivariate Cox regression analysis with shared frailty for patients and Kaplan-Meier curves were performed using success and survival rates (p<0.05). ResultsSeventy-five post-retained restorations (34 metal-ceramic crowns and 41 composite restorations) in 62 patients were analyzed. The median follow-up was 8.1 years [IQR 4.0–9.9]. Twenty-seven failures were observed. Twenty-two failures (81.5 %) were observed in the composite resin group, of which six (27.3 %) were not repairable. Five failures (18.5 %) were observed in the metal-ceramic crown group, of which three (66.6 %) were non-repairable. The cumulative success rate at 8 years was 85.0 % for crowns (AFR=1.31 %) and 43.2 % for composite resins (AFR=6.58 %), while the survival rate was 93.8 % for crowns (AFR=0.52 %) and 97.6 % for composite resins (AFR=0.20 %). Considering the success rates, adjusted multivariate Cox regression showed that composite resin had a Hazard Ratio of 5.07 (95 %CI, 1.99–12.89) greater than the metal-ceramic crown. No significant difference in the failure risk was observed when the survival rates were considered (HR=0.38, 95 %CI (0.10 – 1.44), p = 0.156). Co-variables did not affect the success and survival rates (p>0.05). ConclusionsMetal-ceramic crowns showed a higher success rate than composite restorations. The survival rates were similar, but composite restorations presented a higher need for repairs. Clinical SignificancePost-retained composite restorations may need more reinterventions during the lifecycle, although more preservation of sound tooth structure is expected with a large restoration of resin post-and-core. These aspects have to be discussed with the patient for decision-making planning.

Survival of Endodontically Treated Maxillary Anterior Teeth with Aesthetic Post-Restoration: A Prospective Intervention Study

Introduction: There is much debate over the best choice of restorative material and the placement method for the most successful treatment. Many teeth that have undergone endodontic treatment may not have enough structure to support a restoration or crown. To improve retention for the restorative material, ferrule may be used. Adhesive techniques have transformed the way we restore teeth after root canal treatment, starting with the shift from using cast post-and-core to using fibre post. The use of fibre-reinforced posts has been found to prevent irreparable root fractures thereby improving the longevity of the treatment. Aim: To compare two different types of aesthetic fibre posts for 12 months. Materials and Methods: A prospective interventional study was carried out in the Department of Prosthodontics, Manav Rachna Dental College (Faridabad) for a period of 12 months from Nov 2022- Oct 2023. Forty participants with single rooted, endodontically treated, maxillary anterior teeth in the age bracket of 15-55 years, both males and females of the north Indian population were included in the study. Teeth were selected where a post-retained crown was indicated and post space was prepared using a piezo reamer drill at 5000 rpm. At least 4 mm of obturation is left in the canal to maintain the apical seal. Furthermore, Zircon-enriched silicon fibre and glass fibrereinforced posts were cemented into the prepared post space. Metal-ceramic crowns were cemented and baseline periapical radiographs were obtained. At the interval of one month, three months, six months and one year, the patients were evaluated. The Fischer’s exact test was utilised to establish the association between categorical variables and the level of significance (p-value &lt;0.05). Results: One year follow-up revealed no failures in crown movement when evaluated under finger pressure, recurrent caries, or root fractures. One case of glass fibre-reinforced post showed a fracture of the post and another case of glass fibre post showed periapical radiolucency at 6-month intervals on clinical and radiographical examination which was significant when compared to Zircon-enriched silicon fibre post group (p-value=0.02). Conclusion: Both aesthetic fibre-reinforced post systems used in single-rooted upper anterior teeth demonstrated similar success rates in restoring root canal treated teeth.

Evaluation of Marginal and Internal Adaptation of Crowns Fabricated with Three Different Zirconia CAD/CAM Materials.

Marginal and internal adaptation are key factors that determine the clinical success of dental restorations. The aim of this study is to evaluate the marginal and internal fit of crowns fabricated with three different CAD-CAM zirconia materials; two monolithic zirconia materials and one veneered zirconia copings in comparison with conventional metal-ceramic crowns. Ninety-six extracted molars (n = 96) were selected. Teeth were randomly divided into four groups (n = 24), and the following restorations were fabricated: Metal-ceramic crowns (Control group) (Group CG); monolithic zirconia crowns (GC initial) (Group MZ1); monolithic zirconia crowns (InCoris TZI),(Group MZ2); bilayered zirconia crowns, cores (InCoris ZI) veneered with a low-fusing glass-ceramic (IPS Emax Ceram),(Group BZ). Internal and marginal adaptations were evaluated using the silicone replica technique. A total of 20 points were recorded for every tooth under the light microscope at 20x magnifications. Results were compared using one-way analysis of variance (ANOVA) and the posthoc Tukey's test at a significance level of 0.01. Marginal, marginal-internal, axial, and occlusal gaps between CG, MZ1, MZ2, and BZ crowns showed statistically significant differences (P < 0.01). Monolithic zirconia groups showed better marginal adaptation compared with the veneered zirconia crowns.

Analysis of the retention properties of teeth prepared for metalceramic crowns and bridges

Analysis of the retention properties of teeth prepared for metalceramic crowns and bridges