Full Crown Research Articles

Multidisciplinary conservative management of dental fracture in young patient: case report

Introduction: The management of fractured permanent teeth due to dental trauma in young patients is a challenge that requires an efficient approach. Objective: Describe a conservative and multidisciplinary treatment of a case of dental trauma in a 13 years-old boy. Case report: At clinical examination was verified enamel and dentin fracture in the left upper central incisor and a fracture with pulp exposure in the right upper lateral incisor, with subgingival extension of its margin at lingual surface, and no swelling or tooth displacement was observed. At radiographic evaluation, no pulp or periradicular disturbances were verified. It was proposed the surgical lengthening of the clinical crown of the right upper lateral incisor for later performing endodontic treatment. It was decided to make direct composite resin restorations in both fractured teeth, instead of doing a prosthetic treatment in the affected lateral incisor, such as the placement of a full ceramic crown, in an attempt to perform a less invasive treatment, mainly due to the age of the patient. At a two years follow-up visit was observed the maintenance of the health of periapical tissues and the absence of clinical alterations. Conclusion: The restorations were kept in good conditions and aesthetics was considered satisfactory by professionals, patient and parents.

Discrepancy in alloy composition of imported and non-imported porcelain-fused-to-metal (PFM) crowns produced by Norwegian dental laboratories

Purpose Even though the use of full ceramic crowns have become a well-established practice in dental clinics compare to the last decade, the use of imported casted porcelain-fused-to-metal (PFMs) crowns is still prevalent. The use of imported PFMs is often economically driven; however, when dentists order PFMs, they do not have capabilities to examine its true alloy content. Therefore, we raise the questions whether cheaper imported PFMs have more discrepancies in alloy content compared to domestically produced PFMs? Materials and Methods This study included 62 porcelain-fused-to-metal crowns: 41 produced in Norway and 21 imported. Their alloy-composition was determined non-destructively by EDX and SEM. Results and Conclusions Imported PFMs demonstrated larger deviations compared with non-imported PFMs. Significant deviation was found in key metallic elements in the different alloys (W, In, Pd, Ag). The detected deviations in key element such as Wolfram and Indium could influence the PFMs service time. These finding may be of international concern

Marginal gap and fracture resistance of CAD/CAM ceramill COMP and cerasmart endocrowns for restoring endodontically treated molars bonded with two adhesive protocols: an in vitro study

Endocrowns represent a conservative and esthetic restorative alternative to full coverage crowns. They can be constructed using various CAD/CAM materials that can provide a modulus of elasticity similar to that of teeth. The ability to use of such materials in composite blocks that can be easily repaired is also an advantage, provided appropriate bonding performance is ensured. This study, therefore, evaluated the marginal gap and fracture resistance of two CAD/CAM endocrown materials using two bonding protocols. Thirty-two mandibular molars were evaluated in two groups based on the material type: a Cerasmart group (GC America Inc; n = 16) acting as the control and a Ceramill COMP group (Amann Girrbach, Germany; n = 16). These groups were then classified according to the bonding protocol used: a total-etch bonding protocol (n = 8) and a self-etch bonding protocol (n = 8) implemented using RelyX ultimate adhesive resin cement (3M ESPE). The samples were then subjected to aging by simulating a 1-year thermo-mechanical process. The marginal gap results were statistically insignificant across the material and bonding protocol groups before thermo-mechanical aging. Thermo-mechanical aging significantly reduced the marginal gap distance for Ceramill COMP endocrowns cemented using the total-etch protocol (p = 0.002). No statistically significant difference was recorded for the fracture resistance in either the material or bonding protocol groups (p ≥ 0.05). Both materials and bonding protocols can, therefore, be used in the posterior region providing conservative treatment, adequate marginal gap and fracture resistance.

Comparison of Digital and Conventional Impression Methods by Preclinical Students: Efficiency and Future Expectations.

ABSTRACTAims and Objectives:The purpose of this study is to compare digital and conventional impression methods by preclinical students in terms of time and ease and to evaluate their preferences and future expectations.Materials and Methods:Twenty volunteered, 2nd year preclinical students (11 females and 9 males) participated in this study. Students took digital and conventional impressions of the left lower first molar which was made full ceramic crown preparation and opposite full arch from a typodont model (Frasaco, Frasaco GmbH, Tettnang, Germany). They used intraoral scanner (CEREC Omnicam, Sirona Dental GmbH, Bensheim, Germany) for digital impression and also used additional type (Express XT Penta H, 3M ESPE, Seefeld, Germany) and condensation type (Zetaplus, Zhermack SpA, Badia Polesine, Italy) silicones for conventional impression. Their taking impression time was measured. Before taking impression and after taking impression, two kinds of questionnaires were conducted to students about their preference, ease of impression methods, and their future expectations. Statistical analysis was performed by IBM SPSS 23 and Excel 2010 version. Differences between conventional and digital impression in terms of time were analyzed by student’s-t paired test and effect of gender was analyzed by students’s-t independent test.Results:There were statistically significant differences between digital and conventional impression methods in terms of taking impression and total impression time (P < 0.001). But there wasn’t any statistically significant difference between two methods in terms of preparation time. About 85% of students preferred the digital impression method and also 85% of students found that the digital impression method was easy. 95% of students expected to find intraoral scanner in the clinic where working first time.Conclusions:As a result of this study, it has been seen that the students preferred the digital impression method to the conventional impression method and found that the digital impression method was easier.

Compressive Strength Evaluation between Metal Ceramic and Zirconia Crowns.An In-Vitro Study

The aim of this study is to evaluate the compressive strength of metal and zirconia cores and also the point of chipping of the veneered porcelain to both the core materials. For the present study, full coverage crowns were fabricated for mandibular molar. The crowns were divided into two groups. First group is five samples of metal ceramic crowns and second group is five samples of zirconia ceramic crowns. These crowns were subjected to static compression loading in a universal testing machine until the fracture of the veneering porcelain. The compressive load was recorded in newton. Data were subjected to student t test analysis. Mean compressive strength for group 1 metal ceramic crowns was 2587.80N and the mean compressive strength for group 2 zirconia ceramic crowns was 1361.00N. The compressive strength of metal when being used as a core material is significantly higher than zirconia. Under static compressive loading, the point of fracture of the veneered porcelains occurred at significantly lower values for the zirconia based restorations when compared to that of metal ceramic restorations.

Use of Restorative Full Crowns Made with Zirconia in Children: A Systematic Review.

Aim and objectiveThe purpose of this systematic review is to analyze the suitability of the zirconia crowns for restoration of damaged primary teeth in children.BackgroundThis systematic review has been conducted in line with the preferred reporting items for systematic reviews (which is also called as PRISMA) guidelines. A search for the relevant articles of zirconia crowns in deciduous teeth has been made in electronic database of PubMed and a study design (meta-analysis), i.e., PICOS framework. The words used in the search are “zirconia crowns” and “primary molars,” “zirconia crowns” and “primary incisors,” “zirconia crowns” and “children,” “zirconia crowns” and “primary teeth.”Review resultsThe database search showed 44 studies of which 20 articles were excluded as they were irrelevant, duplicates, and data were not available. In the present systematic review, the remaining 24 articles were included.ConclusionZirconia crowns have been proved with better results than other crowns in terms of gingival and periodontal health, esthetics, and crown fractures. However, the quantity of tooth preparation and the wear of antagonist tooth are reported to be more in case of zirconia crowns. Future randomized control studies should be carried out in primary teeth due to less number of randomized studies on this topic.Clinical significanceZirconia crowns are now widely used in dentistry and there is an increase in the number of studies, so a systematic review evaluating and comparing results is warranted.How to cite this articleAjayakumar LP, Chowdhary N, Reddy VR, et al. Use of Restorative Full Crowns Made with Zirconia in Children: A Systematic Review. Int J Clin Pediatr Dent 2020;13(5):551–558.

A Comparative Study to Evaluate the Accuracy of Various Spacer Thickness for Polyvinyl Siloxane Putty-wash Impression Techniques: An In Vitro Study.

IntroductionAn accurate impression is one of the prime factors for success of any restoration, more so in field of fixed prosthodontics. The critical aspect is to reproduce fine surface details along with ease of use. Knowledge of impression materials and the techniques to which each is best suited is essential in achieving consistent results.Objective of the studyThe purpose of this study is to evaluate the accuracy of various putty-wash techniques in a laboratory model that simulated the clinical practice.Materials and methodsA metal master model, containing three full crowns fixed partial denture (FPD) abutment preparations, was fabricated. A perforated custom tray was fabricated that can be placed in the same position on the master model for each impression. For each technique, 10 impressions of the master model were made and poured using a die stone. The measurements were made of the models using a measuroscope and the accuracy of the impressions was recorded.ResultsThe statistical comparison between groups I, II, III, and IV casts measurements by using the Mann–Whitney test showed highly significant statistical difference between the various groups from each other (p < 0.001)ConclusionThe accuracy of the working casts obtained from group III impression (two-step using 1 mm coping) was the best, whereas it was least with group II impression (two-step using polyethylene spacer).How to cite this articleGautam N, Ahmed R, Sharma S, et al. A Comparative Study to Evaluate the Accuracy of Various Spacer Thickness for Polyvinyl Siloxane Putty-wash Impression Techniques: An In Vitro Study. Int J Clin Pediatr Dent 2020;13(5):536–542.

RESTORATION OF ENDODONTICALLY TREATED TEETH WITH DIFFERENT CROWNS: A COMPARATIVE STUDY

The optimal way to restore teeth after endodontic treatment continues to remain a controversial topic of heated debate to this day. Endodontically treated teeth (ETT) present with significantly different mechanical properties compared to vital teeth. The modifications in the biomechanical properties and structural integrity of the teeth are most-likely attributed to the volumetric loss of the hard tissues, extent of carious lesion, fracture propagation, final cavity preparation in addition to the access cavity prior to endodontic therapy.&#x0D; Hence based on above findings the present study was planned for comparative evaluation of Restoration of Endodontically Treated Teeth with Different Crowns.&#x0D; The study was planned in Department of Dentistry, Anugrah Narayan Magadh Medical College and Hospital, Gaya, Bihar. The 60 cases of the Endodontically treated teeth (ETT) were enrolled in the present study. The patients were divided in the 4 groups as per different material and restorations given.&#x0D; The survival of ETT is contingent on the residual sound tooth structure that remains after the endodontic access and caries removal are performed consequently the most important factors upon restoring ETT become the maximum preservation and conservation of enamel, dentin and the dentinoenamel junction. Hence, bonded partial restorations are always preferred over full coverage cementable crowns. More clinical studies comparing adhesive crowns bonded to postless build-ups or post and -core build-ups are needed for a better understanding of postless approaches in biomimetic restorative dentistry.&#x0D; Keywords: Endodontically treated teeth, Crown, cores, post, etc.

Influence of Computer-aided Design/Computer-aided Manufacturing Diamond Bur Wear on Marginal Misfit of Two Lithium Disilicate Ceramic Systems.

Marginal misfit of monolithic lithium disilicate ceramic crowns obtained from a chairside computer-aided design/computer-aided manufacturing system is affected after successive millings using a single diamond bur set. This fact can be critical for the longevity of indirect restorations.

Evaluation of marginal and internal adaptation of zirconia crowns constructed from traditional and digital impressions

Background and objective: Recent advancement in restorative dentistry from impression to fabrication is toward digital workflow. There are very few studies, evaluating the internal and marginal fitness of full anatomic zirconia crowns fabricated with different impression techniques. The aim of this study was to determine whether improved technology of digital workflow results in better fitting crowns. Methodology: The mandibular right first molar of a dentoform model was prepared for a full ceramic crown with deep shoulder finish line. Two impression techniques were used,for group one, ten traditional impressions with addition silicone were obtained, while in group two, ten digital intraoral impressions were captured.Twenty full anatomic zirconia crowns were designed and milled using dental CAD/CAM system . The internal and marginal gaps were measured for each crown on the master die with the aid of a stereomicroscope. Results: The average (±SD) for the internal and marginal adaptation was: 145 μm (±39) and 85 μm (±17) for the digital impression group, 188 μm (±141) and 178 μm (±41) for the traditional impression group, respectively. The Kruskal -Wallis test showed no statistically significant difference between the two groups regarding marginal and internal adaptation. Conclusion: Full anatomic zirconia crowns fabricated from intraoral digital impressions demonstrated comparable or even better marginal and internal fit than crowns fabricated with traditional silicone impressions.

Three-dimensional finite element analysis of different endodontic access methods and full crown restoration in the maxillary central incisor

This study evaluates the effects of different endodontic access methods and full-ceramic crown on the stress distribution in the maxillary central incisor by using three-dimensional finite element analysis. Computed tomography scans of the maxillary central incisor were used to construct a three-dimensional finite element model of the maxillary central incisor. According to the different methods of endodontic and the prosthetic treatments, four models were established, namely, group A (traditional access cavity preparation with resin filling), group B (traditional access cavity preparation restored full-ceramic crown), group C (minimally invasive endodontics with resin filling) and group D (minimally invasive endodontics restored full-ceramic crown). A static force of 100 N and a direction of 45° was applied to the long axis of the tooth at the junction of the incisal section one-third and middle section one-third. The maximum principal stress, the von Mises stress and the modified von Mises stress of the tooth tissue were analyzed using the finite-element analysis software. 1) Stress peaks: the stress peaks of the maximum principal stress, the von Mises stress and the modified von Mises in group A were the largest, except that the stress peak of von Mises stress in group D was slightly lower than that in group C. The stress peaks of the maximum principal stress and the modified von Mises in group C were the lowest. The stress peaks of the maximum principal stress and the modi-fied von Mises stress in group D were lower than those in groups A and B. 2) Stress distribution: compared with group A, the stress distribution of cervical dentin and the area of stress concentration in group C was lower and smaller. In the root dentin, the stress distribution in group C was more uniform than that in group A, and the stress was dispersed to several areas of the root apex. After crown restoration, no significant difference was observed in stress distribution between groups B and D in the root region. The stress distribution state of group B was not significantly different from that of group A. No significant difference was observed in the stress distribution state between groups D and C. 1) From the perspective of biomechanics, the minimally invasive access was adopted for the maxillary central incisor. 2) Full crown restoration is recommended after traditional access cavity preparation. No obvious advantage is observed in stress analysis for minimally invasive endodontics-restored full-ceramic crown.

EVALUATION OF DIFFERENT TYPES OF CROWNS USED FOR RESTORATION OF ENDODONTICALLY TREATED TEETH

Endodontically treated teeth (ETT) have been problematic in most cases as a result of dental caries, fractures, previous restorations and endodontic procedures. Several post system techniques and materials are currently used to build up ETT with moderate or severe loss of coronal tooth structure and to retain final restorations. Following root filling, the custom-made cast metallic post and core with metal-ceramic crowns was the traditional restoration of choice, but this has changed. The patients’ primary motivation for seeking superior dental aesthetics, particularly in the anterior aesthetic zone, has prompted the development of non-metallic restorations. Several new types of polymeric and more aesthetic quartz and glass-fibres posts, combined with direct resin composite cores, provide an aesthetic foundation for an all-ceramic crown and have overcome the aesthetic limitations of metallic posts and cores in the anterior teeth. Until recently, there has been controversy in the dental community regarding which material or technique is the most favourable for the restoration of ETT. It seems that the amount and retentive capacity of the remaining tooth structure, the position of the tooth in the dental arch, the functional or para-functional loading on the tooth, and the treatment plan to restore aesthetics and function all influence the selection of the most appropriate post system for each case. Hence the present study was planned for Evaluation of Different Types of Crowns Used For Restoration Of Endodontically Treated Teeth.&#x0D; The present study was planned in Department of Conservative Dentistry and Endodontics, Buddha Institute of Dental Science and Hospital, Patna, Bihar, India. The 40 cases of maxillary anterior endodontically treated teeth (ETT). The roots were restored with reinforced GFPs (Relaxy Fiber Post, 3M ESPE, Germany), and composite resin cores (Tertic-N-Ceramic, Ivoclar Vivadent, Lichenestine).&#x0D; The survival of ETT is contingent on the residual sound tooth structure that remains after the endodontic access and caries removal are performed consequently the most important factors upon restoring ETT become the maximum preservation and conservation of enamel, dentin and the dentinoenamel junction. Hence, bonded partial restorations are always preferred over full coverage cementable crowns. More clinical studies comparing adhesive crowns bonded to postless build-ups or post and -core build-ups are needed for a better understanding of postless approaches in biomimetic restorative dentistry.&#x0D; Keywords: Endodontically treated teeth, Crown, cores, post, etc.

Are Metal-Free Monolithic Crowns the Present of Prosthesis? Study of Mechanical Behaviour.

Purpose: To analyze in vitro the mechanical behavior of five types of complete coverage crowns fabricated from different materials. Materials and methods: Seventy-five full coverage crowns were divided into five groups according to material: Group I, metal core with feldspathic ceramic covering (MC- control group); Group II, zirconia core with feldspathic ceramic covering (CZ); Group III, tetragonal monolithic zirconia (TMZ); Group IV, cubic monolithic zirconia (CMZ); Group V, high molecular weight polymethyl methacrylate (PMMAG) doped with graphene nanoparticles. All crowns underwent in vitro fatiguing by dynamic loading in wet conditions to simulate the masticatory forces to which prosthodontic materials are subject in the oral medium. Lastly, fracture resistance was evaluated by static compression testing. Results: The fracture resistance values obtained were as follows: Group MC, 2443.6 ± 238.6 N; Group CZ, 2095.4 ± 329.2 N; Group TMZ, 2494.6 ± 236.6 N; Group CMZ, 1523.6 ± 325.2 N; and Group PMMAG, 1708.9 ± 386.6 N. Group MC presented higher strength with statistically significant differences in comparison with Groups CZ (P = 0.002), CMZ (P < 0.001), and PMMAG (P < 0.001). Weibull distribution showed less probability of cumulative biomechanical failure in Groups MC and TMZ. Conclusions: Metal-ceramic and tetragonal zirconia showed high fracture resistance, while cubic zirconia and PMMA doped with graphene nanoparticles obtained lower values.

Enhanced Bone Remodeling Effects of Low-Modulus Ti-5Zr-3Sn-5Mo-25Nb Alloy Implanted in the Mandible of Beagle Dogs under Delayed Loading.

Titanium (Ti) and its alloys are widely used in the dental and prosthetic implant fields due to their favorable biocompatibility. In this study, porous surface coatings incorporated with nanoscale hydroxyapatite particles on the surface of Ti and Ti–5Zr–3Sn–5Mo–25Nb (TLM) alloy were fabricated by microarc oxidation followed by hydrothermal treatment; the surface roughness and hydrophilicity were obviously enhanced by the surface modification procedure. In vivo, four adult male beagle dogs were selected for an implantation procedure and restored with full metal crowns after healing for 3 months. The bone responses were evaluated via histomorphological observation. Raman spectral analysis and nanoindentation experiments were used to quantitatively and qualitatively estimate the characteristics of the bone formed around the implants. Compared to the Ti group, the TLM titanium alloy group showed a significant increase in the percentage of bone–implant interface contact, bone inside the thread, mineralization, crystallinity, modulus of elasticity, and hardness of the integrated bone after delayed loading in the TLM group. Therefore, the TLM titanium alloy is considered a candidate implant material with desirable biomechanical compatibility, especially under applied stress.

Bioecological aspects of plantation nut cultivation of Siberian cedar (Pinus sibirica du tour.) in Russia

The conditions for obtaining the maximum gross yield of pine nuts on the grafting plantations have been considered. Nut production plantations are created in the most productive vegetative conditions (not lower than II-III quality class). The selection of areas was carried out on the basis of forest vegetation zoning, bioecological properties and climatic conditions. First of all, plantations are laid in the zone of ecological optimum, outside the natural range (zone of coniferous-deciduous forests of the European part of Russia). Valuable clone genotypes of Siberian cedar for seed and pollen productivity have been selected on graft plantations and in the archives of plus tree clones. Mixing of clones is carried out taking into account the reproductive differentiation of genotypes, providing a biologically possible output of full-grain seeds from the cone. Clones of various reproductive types and seed productivity are placed on the plantation in the absence of natural sources of pollination. Dates of flowering and pollen dispersion must be the same. The distance between the trees should ensure the yield increase with full crowns for at least 50-80 years. Maximum distance between high-yielding grafts and pollinating grafts is not more than 15 m.

Modelling the effect of storage temperature on respiration rate of Pineapple (Ananas comosus L.) with crown

Maintaining freshness and functional quality of the fruit is a challenge in the food industry since consumers demand of fresh pineapple is high. Thus, it is important to know the effect of various storage temperature on respiration rate to controlling the quality and extends the shelf-life. The respiration rate (RR) was studied over a period of storage time by treating the full crown pineapple in the storage room of 7°C, 15°C and 25°C. A closed system method was used to measure the respiration rate at 2, 4, 12, 24 hours intervals over 7,5-14,5 days of storage. Three temperature variations and three replications were carried out to observe the respiration rate. Respiration rate based on the O2 consumption at 7°C is 2,05 ml.kg−1.h−1, at 15°C is 6,45 ml.kg−1.h−1 and at 25°C is 22,33 ml.kg−1.h−1, while based on CO2 produce at 7°C is 5,90 ml.kg−1.h−1, at 15°C is 20,83 ml.kg−1.h−1 and at 25°C is 67,91 ml.kg−1.h−1. The modelling was conducted using Michaelis-Menten (MM) uncompetitive inhibition. The storage temperature of 7°C resulted MM constant Vmo is 4,28 and Vmc is 29,04; at the 15°C Vmo is 59,18 and Vmc is 200; and at the 25°C Vmo is 140 and Vmc is 805,10 with SSE ranged from 0,000378 to 0,0295. The Vmo-constant activation energy (Ea) is 132,42 kJ/mol and frequency factor (A) is 3E+25, while Vmc-constant Ea is 132,94 kJ/mol and A is 1,7E+26 with R2 ranged from 0,82 to 0,99. The best storage temperature recomendation with distribution time more than 30 days at 12-13°C.

High-Strength Porcelain Veneering of Zirconia Prosthetic Mimetic Restorations (PRIMERO) by Cognitive Design and Manufacturing

Esthetic prosthetic restorations, with natural reflection, color from within and color gradients influenced by the internal dentinal core anatomy can best be accomplished by veneered zirconia, rather than with crowns of color and structure graded monolithic zirconia. Concern about the high incidence of chipping with some of the porcelains for zirconia substructures has led to a massive shift from veneered zirconia to the use of monolithic zirconia for crowns and bridges. Because zirconia has four times the hardness of metal, initial concern about antagonist abrasion could with numerous studies be negated. Clinical long-term effects of lack of abrasion of full zirconia crowns, in comparison with 30-75 μm/year for surrounding and opposing dentition is still poorly documented. Massive crack formation in enamel probes has been reported in specimens after in-vitro fatigue testing with opposing monolithic zirconia. In-vitro and clinical studies have shown that only reinforcement of the structure of veneering material can prevent chipping. This article compares the fatigue behavior of three-unit bridges with a substructure of Primero zirconia veneered with Primero Enamel (PR) with bridges with Cercon Base zirconia inner-structure veneered with Ceramco PFZ and Cercon Ceram S (CR1 and CR2) and assess the possibilities and increase their scope to cognitive design and manufacturing of porcelain veneered zirconia crowns and bridges. Fatigue testing of four times eight 3-unit bridges were produced for each of the three porcelains and a reference. The results show that efficient crack-stopping prevented chipping with the PR bridges, while the bridges with conventional porcelains CR1 and CR2, showed failures. We conclude that chipping is mainly porcelain related. Cognitive design and fabrication of the dentin zirconia core will lead to prosthetic mimetic restorations (PRIMERO) with natural esthetics.

Color matching of full ceramic versus metal-ceramic crowns - a spectrophotometric study.

Background and aimsTo verify the color match of metal-ceramic and full ceramic crowns, using instrumental methods.MethodsA number of 153 teeth (anterior and posterior teeth), in 62 patients, were restored with metal ceramic (MC, n=119), pressed-ceramic (PC, n=28), and zirconia-ceramic (ZC, n=6) full coverage crowns. The shade of a reference natural tooth was recorded instrumentally with a dental spectrophotometer (Vitaeasyshade Advance 4.0) in “single tooth measurement”, which provided the base color in Vita Classic (VC) and Vita 3D Master shades (3D).For verifying the outcome of the restoration “verify restoration” mode was used, and ΔE values were recorded for both VC and 3D Master shade guides. Moreover, matching symbols were also recorded (***=good, **=fair, *=poor). Descriptive statistics was performed and data were analyzed (One-sample z-Test, α=0.05) for comparison with visual thresholds in dentistry (Perceptibility Threshold – PT=1.2 and Acceptability Threshold – AT=2.7).ResultsThe data did not follow a normal distribution (Kolmogorov-Smirnov test, p<0.05). Recorded color difference was significantly higher than PT and AT, for all types of restorations, regardless of the coding system (p<0.05). For MC crowns in 2.52% (4.20% for 3D) of the cases the color difference was smaller than PT, in 19.32% (the same for 3D) of cases was between PT and AT, and in 78.15% (76.47% for 3D) of cases was higher than the AT. For PC crowns in 3.57% (0% for 3D) of the cases the color difference was smaller than PT, in 25% (32.14% for 3D) of cases was between PT and AT, and in 71.42% (67.85% for 3D) of cases was higher than the AT. In the case of ZC crowns none of the restorations had color difference smaller than PT, but in 16.66% of cases was between PT and AT, and in 83.33% of cases was higher than the AT, for both VC and 3D.ConclusionWithin the limitations of the study, a better color match was achieved in the case of pressed ceramic crowns, made of lithium disilicate. In most of the situations the color difference between the restoration and the reference tooth exceeded the perceptibility thresholds, but the matching was recorded as “fair” by the spectrophotometer.

Sonrisa mejorada por carillas dentales - Reporte de un caso

Ceramic veneers have evolved in the last few years as an aesthetic restoration in the field of aesthetic dentistry. It is a conservative option as compared to full coverage crowns for improving the patients smile. Ceramic veneers are widely used for smile designing in patients with fluorosis, midline diastema, hypoplastic teeth, and peg shape laterals. Clinical relevance: This article highlights the smile designing of a young patient with fluorosis using ceramic veneers, which not only improves the smile of the patient but has positive psychological benefits.

Fifteen-year outcome of posterior all-ceramic inlay-retained fixed dental prostheses

ObjectivesTo evaluate the long-term clinical outcome of inlay-retained fixed dental prostheses (IRFDPs) made from lithium-disilicate glass-ceramic. Material and methodsForty-five IRFDPs were placed in 42 patients (21 women, mean age 36.1 years and 21 men, mean age 42.0 years). The IRFDPs replaced 4 premolars and 19 first molars in the maxilla and 4 premolars and 18 first molars in the mandible. All teeth were prepared following a standardized protocol for ceramic inlay restorations. Five of the 45 FDPs were hybrid-retained restorations, i.e. one abutment tooth with an inlay retainer and one with a full crown retainer.All restorations were fabricated from heat-pressed lithium-disilicate ceramic (IPS e.max Press, Ivoclar Vivadent AG). The minimal size of the proximal connector was 16 mm2 (4 mm × 4 mm in height and width) with a minimum occlusal ceramic thickness of 1.5 mm. Hydrofluoric acid etching (5%) and silane application was used for conditioning the bonding surfaces. Standard adhesive luting techniques were performed using a dentin adhesive and a resin composite. Standardized follow-up reports were performed annually. The survival rates were performed using the Kaplan-Meier analysis. ResultsThe mean observation period was 100 months (minimum 4, maximum 234 months). Thirty-three FDPs (73%) failed during the observation period and had to be replaced by other restorations. The Kaplan-Meier survival rate for IRFDPs was 57% after 5 years, 38% after 8 years and 22% after 15 years, while for hybrid-retained FDPs it was 100% after 5 years, 60% after 8 years and also 60% after 15 years. ConclusionWith the design used in the current, study lithium-disilicate ceramic IRFDP had a high clinical failure rate and cannot be recommended for regular clinical use.