An in vitro comparison of incisal preparation design on load-to-failure of ceramic veneers

Introduction

This in vitro study aimed to compare the load-to-failure values of two different ceramic veneers (IPS e.max Press [Ivoclar Vivadent] and Vintage lithium disilicate [LD] press [Shofu]) with incisal preparation designs under standardized conditions.

Materials and Methods

Twenty-two intact extracted maxillary incisors were selected and divided randomly into two groups (n = 11). The veneer tooth preparation was standardized in both groups where a butt joint incisal preparation was done along with chamfer margin. Group 1 included veneers made from IPS e.max Press (Ivoclar Vivadent) and Group 2 included veneers fabricated from Vintage LD Press (Shofu). Veneers were luted to their respective abutment teeth using standardized bonding protocols and resin cement for both groups. Later, every specimen was loaded to failure utilizing a universal testing machine, and the outcomes were noted in Newtons (N).

Results

The mean load-to-failure value obtained for Group 1 (IPS e.max Press) was 1386.46 N while that obtained for Group 2 was 1777.07 N. Statistically significant difference was found in this intergroup comparison (P = 0.006).

Conclusion

The load-to-failure value of Vintage LD Press veneers (Shofu) was greater than that of IPS e.max Press veneers (Ivoclar Vivadent).

Total Rehabilitation Using Adhesive Dental Restorations in Patients with Severe Tooth Wear: A 5-Year Retrospective Case Series Study

INTRODUCTION

Currently, there is little clinical evidence to support the medium- and long-term survival and clinical performance of ultraconservative approaches using adhesive restorations in full-mouth restorations. The aim of this case series study was to evaluate the medium-term clinical performance of anterior and posterior adhesive restorations applied with direct and indirect techniques using resin composites and glass-ceramic-based materials.

MATERIALS AND METHODS

The inclusion criteria were an esthetic problem as the main reason for consultation and severe generalized wear of grade 2 to 4 according to the Tooth Wear Evaluation System (TWES 2.0). In addition, at each follow-up appointment, patients were required to submit a clinical-parameter-monitoring record according to the modified United States Public Health Service (USPHS) criteria.

RESULTS

Eight patients with severe tooth wear were treated through full rehabilitation in a private dental clinic in Spain by a single operator (AFC). A total of 212 restorations were performed, which were distributed as follows: 66 occlusal veneers, 26 palatal veneers and 120 vestibular veneers. No signs of marginal microleakage or postoperative sensitivity were observed in any occlusal, vestibular and/or palatal restoration after the follow-up period. The estimated survival rate of the 212 restorations was 90.1% over 60 months of observation, with a survival time of 57.6 months. Only 21 restorations had complications, which were mostly resolved with a direct composite resin. The dichotomous variables of the restoration type (posterior veneer, anterior veneer) and the type of restored tooth (anterior, posterior) were the risk predictors with statistically significant influences (p < 0.005) on the survival of the restorations.

CONCLUSION

According to the results of this study, there is a significantly higher risk of restorative complications in posterior teeth compared to anterior teeth. Also, it can be concluded that the indication of adhesive anterior and posterior restorations is justified in the total oral rehabilitation of patients with severe multifactorial tooth wear, as they are associated with a low risk of failure.

The Influence of a Novel, Crenelated Design of CAD-CAM Ceramic Veneers on the Debonding Strength

(1) Background: Aesthetic dentistry has become one of the most dynamic fields in modern dental medicine. Ceramic veneers represent the most appropriate prosthetic restorations for smile enhancement, due to their minimal invasiveness and highly natural appearance. For long-term clinical success, accurate design of both tooth preparation and ceramic veneers is of paramount importance. The aims of this in vitro study were to assess the stress in anterior teeth restored with Computer-Aided Design (CAD) and Computer-Aided Manufacturing (CAM) ceramic veneers and compare the resistance to detachment and the fracture of ceramic veneers prepared using two different designs. (2) Methods: Sixteen lithium disilicate ceramic veneers were designed and milled using the CAD-CAM technology and divided into two groups according to the preparations (n = 8): Group 1, conventional (CO), with linear marginal contour and Group 2, crenelated (CR), the latter with our novel (patented) sinusoidal marginal design. All samples were bonded to anterior natural teeth. The mechanical resistance to detachment and fracture was investigated by applying bending forces on the incisal margin of the veneers in order to determine which type of preparation leads to better adhesion. An analytic method was employed, as well, and the results of the two approaches were compared. (3) Results: The mean values of the maximum force recorded at the veneer detachment were 78.82 ± 16.55 N for the CO group and 90.20 ± 29.81 N for the CR group. The relative increase, equal to 14.43%, demonstrated that the novel CR tooth preparation provided higher adhesive joints. In order to determine the stress distribution within the adhesive layer, a finite element analysis (FEA) was performed. The statistical t-test showed that the mean value of the maximum normal stresses is higher for the CR-type preparations. (4) Conclusions: The patented CR veneers represent a practical solution to augment the adhesion and mechanical properties of ceramic veneers. The obtained results demonstrated that CR adhesive joints triggered higher mechanical and adhesive forces, which subsequently led to a higher resistance to detachment and fracture.

Rubber Dam Isolation for Bonding Ceramic Veneers: A Five-Year Post-Insertion Clinical Report

It has been well-documented that uncontaminated ground enamel provides the most predictable substrate for the bonding of ceramic veneers, and thus conservative tooth preparation with complete isolation using a rubber dam is key to the long-term success of the restorations presented with five years of follow-up. Rubber dam isolation provides several advantages to the clinician, such as preventing contamination of the working field by saliva, blood, and sulcular fluids, and improving direct visibility. However, it may be a challenge to the younger clinician to properly isolate teeth prior to bonding ceramic veneer. The present case report demonstrated the sequence and some clinical tips for a case in which the rubber dam is placed from a second premolar to the opposite second premolar and held with clamps, the rubber dam is gently invaginated into the sulcus, and clamps are selected and placed on each tooth to create an ideal situation for the adhesion of the ceramic veneer. This step-by-step sequence may help the younger clinician in understanding how to gently manage soft tissue in order to properly provide complete isolation with rubber dam for future bonding of ceramic veneers. Following these methods, the clinician can achieve complete isolation, invaginate the rubber dam in the sulcus without causing tissues to bleed, and reduce the time needed for bonding procedures.

Multidisciplinary clinical approach of an orthodontic treatment and complete digital rehabilitation of laminate veneers for esthetically compromised worn teeth

AIM

The present clinical case reports on the workflow of a multidisciplinary treatment including both orthodontic and esthetic procedures for the rehabilitation of a young patient with severe wear in the anterior area of both the maxillary and mandibular arches due to malocclusion. The described workflow comprises a digital step-by-step process that involves 3D printing, intraoral scanners, and CAD/CAM milling systems.

RESULTS

Accurate diagnostic and treatment planning were paramount when different specialties needed to combine and work together. For that purpose, different digital procedures helped to improve the predictability and the dynamic of the orthodontic and restorative treatments.

CONCLUSION

The present multidisciplinary clinical case was executed with a digital approach that assisted to speed things up and achieve a predictable treatment option.

Essay III: Adhesive restorative options for restorative space management in the anterior zone with or without orthodontic pretreatment: some clinical considerations and case presentations

An unfavorable relationship between the form and dimension of the dental arch and the number, dimension, and shape of the existing teeth can pose several esthetic, biologic, and functional problems. In this article, the various restorative options are discussed based on clinical and scientific evidence: Gap closure and substitution of missing teeth: restorative transformation of substituted teeth into homologous teeth with odontoplasty, direct composite, etched pieces or porcelain veneers. Gap opening and tooth replacement with all-ceramic adhesive bridges, including pontic site development. Gap distribution and restorative compensation with direct composite restorations, etched pieces or porcelain veneers. Gap shifting and restorative compensation with all-ceramic adhesive bridges, composite, etched pieces or veneers. Gap compensation by reconstructive compensation without orthodontics. The reconstructive tools including composite restorations, ceramic veneers, and adhesive bridges are discussed, and numerous cases are presented to illustrate the concepts.

Interventions in management of dental fluorosis, an endemic disease: A systematic review

Objective:

Mottling and pitting of enamel due to excess fluoride consumption may affect one's self-esteem due to unaesthetic appearance and also in turn can affect the quality of life. This present study was conducted to assess various treatment approaches available for patients with dental fluorosis.

Materials and Methods:

Literatures were searched from August 1998 to August 2019 for articles in the management of dental fluorosis. The databases used were National Center for Biotechnology Information (NCBI) and Google Scholar. In NCBI, the filters were modified to randomized controlled trial, clinical trial, human trial, and free full-text articles. The following queries were used in order to search for the article: treatment for dental fluorosis, intervention of dental fluorosis, and management of dental fluorosis.

Results:

All the five studies selected after screening were randomized controlled trials. Total number of patients included in this study were 304 with the mean age of 17.7 years old. They were treated with microabrasion, bleaching, resin infiltration or combination of microabrasion with bleaching, and resin infiltration with bleaching. Microabrasion resulted in less esthetic improvement compared with bleaching. Meanwhile, resin infiltration showed a greater improvement in esthetics in comparison to bleaching. Resin infiltration with additional infiltration time and combination of resin infiltration with bleaching are the best treatment options.

Conclusion:

Based on this systematic review, resin infiltration with increased infiltration time is the best treatment approach in treating dental fluorosis.

Combination esthetic treatment of anterior teeth affected by idiopathic enamel hypoplasia: a case report

The esthetic management of enamel dysplasia presents an opportunity for the practitioner to integrate expertise in diagnosis, biomaterials, and technique. In addition to considerations of appearance, careful attention must be paid to occlusal function and restorative material properties. This case report highlights a combined approach of conservative lithium disilicate indirect restorations and composite resin direct veneers to electively restore the anterior teeth of a patient diagnosed with idiopathic enamel hypoplasia.

Minimally invasive veneers: current state of the art

Ceramic veneers are considered a conservative solution for patients requiring improvement of the shape, color, or position of their anterior teeth. Ceramic veneers have been extensively and successfully used to mask intrinsic staining, to give the appearance of straightening, and to correct minor malformations of anterior teeth without the removal of substantial amounts of sound tooth substance. The current literature was reviewed to search for the most important parameters determining the long-term success and correct application of ceramic veneers.

Influence of ceramic thickness and type on micromechanical properties of light-cured adhesive bonding agents

OBJECTIVE

The aim of this study was to evaluate the micromechanical properties of different adhesive bonding agents when polymerized through ceramics.

MATERIALS AND METHODS

Sixty sound extracted human third molars were selected and the crowns were sectioned perpendicular to the long axis in order to obtain dentin slices to be bonded with one of the following adhesives: Syntac/Heliobond (Ivoclar-Vivadent) or Adper-Scotchbond-1XT (3M-ESPE). The adhesives were cured by using a LED-unit (Bluephase®, Ivoclar Vivadent) with three different curing times (10 s, 20 s and 30 s) under two ceramics (IPS-e.max-Press, Ivoclar-Vivadent; IPS-Empress®CAD, Ivoclar-Vivadent) of different thicknesses (0 mm, 0.75 mm, 2 mm). Thirty groups were included, each containing 60 measurements. Micromechanical properties (Hardness, HV; indentation modulus, E; and creep, Cr) of the adhesives were measured with an automatic microhardness indenter (Fisherscope H100C, Germany). Data were statistically analyzed by using one-way ANOVA and Tukey's post-hoc test, as well as a multivariate analysis to test the influence of the study parameters (SPSS 18.0).

RESULTS

Significant differences were observed between the micromechanical properties of the adhesives (p < 0.05). The ceramic type showed the highest effect on HV (Partial-eta squared (η(2)) = 0.109) of the tested adhesives, while E (η(2) = 0.275) and Cr (η(2) = 0.194) were stronger influenced by the adhesive type. Ceramic thickness showed no effect on the E and Cr of the adhesives.

CONCLUSIONS

The adhesive bonding agents used in this study performed well by curing through different thicknesses of ceramics. The micromechanical properties of the adhesives were determined by the adhesive type and were less influenced by ceramic type and curing time.

Dental Erosion in a Partially Edentulous Patient with Gastroesophageal Reflux Disease: A Case Report

Diseases such as gastroesophageal reflux disease (GERD), bulimia, anorexia, and extrinsic alimentary factors may cause dental erosion (DE). The minimally invasive therapeutic attitude preserves the remaining healthy tooth structure. In the earlier stages, the direct restoration of dental lesions is possible, using composite materials. In advanced stages of DE, prosthetic treatments are recommended for stable esthetic and functional results. We present a case of DE in a partially edentulous patient who benefited from a complex therapy. The prosthetic project of the case involves ceramic veneers associated with dental and implant supported fixed prosthesis for the restoration of esthetics, mastication, phonetics and their maintenance.

Esthetic integration between ceramic veneers and composite restorations: a case report

The tooth structure preservation is the best way to postpone more invasive therapies. Especially in young patients more conservative techniques should be applied. Bonded porcelain veneers and even more the direct composite restorations, are the two therapeutic procedures that require the fewer sacrifice of dental tissue, finalized to the optimal recovery of aesthetic and functional outcome.Although the two techniques require different methods and materials, is possible to achieve a correct integration of both the methods by some technical and procedural measures. In the presented case is planned a rehabilitation of the four upper incisors by ceramic veneers and direct composite restorations.Care is taken for the surface treatment of ceramic restorations, with the objective of achieving integration, not only between natural teeth and restorations, but also between the different materials in use.The purpose of this article is to show how a proper design of the treatment plan leads to obtain predictable results with both direct and indirect techniques.