Ultrathin CAD-CAM glass-ceramic and composite resin occlusal veneers for the treatment of severe dental erosion: An up to 3-year randomized clinical trial.

STATEMENT OF PROBLEM: Ultrathin bonded posterior occlusal veneers represent a conservative alternative to traditional onlays and complete coverage crowns for the treatment of erosive dental wear. Data regarding the clinical performance of ceramic and composite resin ultrathin occlusal veneers are lacking. PURPOSE: The purpose of this prospective randomized clinical trial was to evaluate the influence of computer-aided design and computer-aided manufacturing (CAD-CAM) restorative material (ceramic versus composite resin) on the clinical performance of ultrathin occlusal veneers bonded to worn posterior teeth. MATERIAL AND METHODS: Eleven participants (mean age, 30.4 years) had their posterior teeth restored with 24 ceramic (e.max CAD) and 36 composite resin (Lava Ultimate) ultrathin occlusal veneers. The material type was assigned randomly. The tooth preparations were trial restoration driven and included immediate dentin sealing (OptiBond FL). The intaglio surfaces of the ceramic restorations were etched with hydrofluoric acid and silanated, and the composite resins were airborne-particle abraded and silanated. The tooth preparations were airborne-particle abraded and etched with phosphoric acid before restoration insertion. All restorations were adhesively luted with preheated composite resin (Filtek Z100). The participants were evaluated according to the modified United States Public Health Service (USPHS) criteria at baseline and then each year for up to 3 years. Survival rates were estimated with time to failure (primary outcome of interest) as the endpoint (scores 4 or 5). RESULTS: No restorations were lost. Five partial failures, in the form of chipping (all scored 4), were observed in the composite resin group (Lava Ultimate). The Kaplan-Meier survival rates were 100% for ceramic and 84.7% (SE 0.065%) for composite resin. Differences between the 2 groups were not statistically significant (P=.124). In the surviving restorations, significant difference (P=.003) was found for surface roughness as restorations in the composite resin group experienced some surface degradation. CONCLUSIONS: The findings of this medium-term clinical trial suggest that ceramic (e.max CAD) and composite resin (Lava Ultimate) CAD-CAM ultrathin occlusal veneers presented statistically comparable performance regardless of the minor partial failures (restorable chipping) observed in the composite resin group. Higher surface degradation was observed in the composite resin group.

Digital workflow using natural algorithms for cad/cam ceramic anterior and occlusal veneers to restore biocorrosion: a 2-year follow-up case report

Introduction: Biocorrosion is a multifactorial disorder that causes dissolution of hard tissues by extrinsic/ intrinsic factors. Traditionally, restoring biocorrosion wear involves invasive preparations. Objective: This case report aims to describe the rehabilitation of biocorrosion with a minimally invasive approach (thin occlusal and vestibular ceramic laminates) in a fully digital workflow using natural algorithms. Case report: A 23-year-old patient was presented to clinic with generalized tooth wear associated to dentin hypersensitivity. In anamnesis, eating disorders and acid food consumption were reported, supporting the diagnosis of biocorrosion. The restoration of worn tissues involved an additive approach (minimizing additional wear), using a face guided planning protocol and a natural tooth anatomy database to achieve greater naturalness at the final restorations. Rehabilitation of worn tissues was performed using occlusal, anterior ceramic veneers and additive composite restorations. The patient's natural teeth characteristics were preserved, restoring aesthetic and self-esteem, and after 2- year follow-up the patient remains very satisfied. Conclusion: Additive approaches involving the least amount of tissue wear are essential for the biocorrosion restoration. In addition, the integration of natural algorithms to digital workflows brings more aesthetic and precision to definitive restorations, overcoming one of the main challenges of milled aesthetic restorations: the naturalness.

Introdução: A biocorrosão é uma desordem multifatorial que causa a dissolução dos tecidos duros por fatores extrínsecos/intrínsecos. Tradicionalmente, a restauração do desgaste por biocorrosão envolve preparações invasivas. Objetivo: Este relato de caso tem como objetivo descrever a reabilitação da biocorrosão com uma abordagem minimamente invasiva (laminados cerâmicos oclusais e vestibulares finos) em um fluxo de trabalho totalmente digital usando algoritmos naturais. Relato de caso: Paciente de 23 anos foi atendido na clínica com desgaste dentário generalizado associado à hipersensibilidade dentinária. Na anamnese, foram relatados transtornos alimentares e consumo de alimentos ácidos, corroborando o diagnóstico de biocorrosão. A restauração de tecidos desgastados envolveu uma abordagem aditiva (minimizando o desgaste adicional), usando um protocolo de planejamento guiado pela face e um banco de dados de anatomia natural do dente para obter maior naturalidade nas restaurações finais. A reabilitação dos tecidos desgastados foi realizada usando facetas oclusais, anteriores de cerâmica e restaurações de resina composta aditiva. As características dos dentes naturais do paciente foram preservadas, restabelecendo a estética e a autoestima, e após 2 anos de acompanhamento o paciente continua muito satisfeito. Conclusão: As abordagens aditivas que envolvem o menor desgaste tecidual são essenciais para a restauração da biocorrosão. Além disso, a integração de algoritmos naturais aos fluxos de trabalho digitais traz mais estética e precisão às restaurações definitivas, superando um dos principais desafios das restaurações estéticas fresadas: a naturalidade.

Double-milled CAD-CAM composite resin restorations: A proof-of-concept approach to producing histoanatomic bilaminar restorations.

Bilaminar semi-indirect composite resin computer-aided design and computer-aided manufacturing (CAD-CAM) restorations may represent a noninvasive and straightforward alternative to direct composite resin or indirect porcelain veneers. They involve partial reduction (incisoproximal cutback) of a CAD-CAM composite resin restoration, creating a histoanatomic dentin base, which can then be freehand-layered with an enamel-like composite resin. However, advanced knowledge of dental anatomy is required as well as additional skills to shape the enamel layer to the original shape that was milled. This article describes a possible answer to this dilemma. The restoration was kept attached to the block while doing the histoanatomic cutback. After the bonding of a thicker bulk of enamel to the cutback base, the block was machined again by using the same design. The method relies on the optimal combination of the freehand additive approach and the subtractive automated process.

Lip Lifting: Unveiling Dental Beauty.

The focus for the achievement of complete success in the esthetic zone has traditionally been on addressing deficiencies of intraoral hard and soft tissue. Often, these deficiencies are accompanied by esthetic concerns regarding the lips that are routinely neglected by the dental team. A predictable plastic surgery technique - the lip lift - has been used for decades to enhance lip esthetics by shortening the senile upper lip to achieve a more youthful appearance. Over the years, this technique has been refined and used in many different ways, allowing its routine incorporation into full facial esthetic planning. Through restoration of the upper lip to its optimal position, the artistry of the dentist and dental technician can truly be appreciated in the rejuvenated smile. By the introduction of this minimally invasive surgical technique to the dental community, patients stand to benefit from a comprehensive orofacial approach to anterior dental esthetic planning.

Biomimetic CAD/CAM restoration made of human enamel and dentin: case report at 4th year of clinical service.

Currently, no dental material can exactly match the unique properties of dentin and enamel. Recently, a revolutionary approach was introduced in which a real tooth was utilized in combination with computer-aided design/computer-aided manufacturing (CAD/CAM) technology to obtain a natural CAD/CAM restoration. After 4 years of clinical service, the case was reevaluated and revealed an optimal condition of the biomimetic restoration.

Simplified treatment of severe dental erosion with ultrathin CAD-CAM composite occlusal veneers and anterior bilaminar veneers.

Restorative treatment for patients with dental erosion requires an analysis of the degree of structural damage. Patients affected by moderate to severe dental erosion are particularly challenging because complex occlusal reconstruction will be needed. Ultrathin bonded occlusal veneers represent a conservative alternative to traditional onlays and complete coverage crowns for the treatment of severe erosion. This article describes a complete mouth rehabilitation with ultrathin computer-aided design and computer-aided manufacturing (CAD-CAM) composite resin occlusal veneers in a patient with a severely eroded dentition. In the maxillary anterior teeth, the bilaminar approach was chosen with lingual composite resin veneers and labial porcelain veneers. The main benefit of this approach is the possibility of using additive adhesive techniques, allowing only strategic reduction of sound dental structure or no preparation.

The non-vital discolored central incisor dilemma.

The restoration of anterior teeth is frequently a demanding mission. Patients generally have high expectations for the anterior region, which makes the emotional side of treatment especially important. When this involves discolored endodontically treated teeth, consensus can hardly ever be found as to the chosen approach. Bleaching with direct composites is undoubtedly the most conservative choice for these cases. However, this may require more maintenance (touch-up bleaching and repairs) in the long term, which is an important issue for adult patients. On the other hand, bonded porcelain veneers represent a more 'high-end' option, as they recover the original biomechanics of the intact tooth, allow an optimal masking of the substrate, remain stable, and have a reasonable biological cost when compared to full-coverage crowns. This strategy is explained in this article and documented with a clinical case. We describe treatment planning based on the biomimetic concept, taking into consideration what is possible with current materials and techniques when combined with the patient's particular needs, including the introduction of an innovative step during dentin sealing--the microsuction. The laboratory work was totally accomplished by 'teledentistry', with no direct contact between the dental technologist and the patient.

An approach to biomimetics: the natural CAD/CAM restoration: a clinical report.

Those in the dental field have always pursued the perfect dental material for the treatment of compromised teeth. Gold, amalgam, composite resin, glass ionomer, and porcelain have been used. Tooth-like restorative materials (composite resin and porcelain) combined with an effective hard tissue bond have met the growing demand for esthetic or metal-free restorations in the past 15 to 20 years. However, none of those materials can fully mimic the unique properties of dentin (compliance and crack-stopping behavior) and enamel (wear resistance, function). The aim of this article is to report the restoration of an extensively damaged tooth with a natural restoration obtained by milling an extracted third molar tooth with a computer-aided design and computer-aided manufacturing (CAD/CAM) system. The main benefit of this novel technique is the replacement of lost tissues by actual enamel and dentin, with the potential to recover mechanical, esthetic, and biologic properties. The indication for extracting third molars and premolars because of impaction or for orthodontic reasons makes these posterior teeth readily available. The innovation of the method presented here is the optimal use of the extracted tooth substrate thanks to its positioning technique in the CAD/CAM milling chamber.

Modeling of ultrathin occlusal veneers.

OBJECTIVE: The purpose of this investigation was to compare stresses within bonded porcelain and composite resin ultra-thin occlusal veneers to restore advanced erosive lesions. MATERIALS AND METHODS: A sound maxillary molar was digitized with a micro-CT scanner. The 2D image data were converted in a 3D model using an interactive medical image processing software (Mimics). Standard triangle language files (STL files) of enamel and dentin surfaces were then exported to the software 3-matic to execute design and meshing operations. Solid 3-dimensional (3-D) models acquired in a finite element software (Marc/Mentat) were subjected to nonlinear contact analysis to simulate occlusal loading at 200N and 800N. Values of maximum principal stress and ultimate tensile strength were used to calculate the risk of fracture and for validation with existing experimental data. RESULTS: There were marked differences in stress distributions both at 200N (maximum peak values of 21.59, 28.63, 31.04MPa) and 800N (96.16, 115.73, 134.90MPa) for all restorative materials (MZ100, Empress CAD and e.max CAD, respectively). High tensile stresses (measured in the central groove) were found at 800N with the ceramic occlusal veneers showing occlusal stress peaks 17-29% higher than composite resin. The estimated risk of fracture was decreased for ultrathin composite resin occlusal veneers, which correlated with the existing validation data. SIGNIFICANCE: Ultra-thin composite resin (MZ100) and lithium disilicate (e.max CAD) occlusal veneers represent a conservative alternative to traditional onlays and complete coverage crowns for the treatment of severe erosive lesions in the posterior dentition.

Novel-design ultra-thin CAD/CAM composite resin and ceramic occlusal veneers for the treatment of severe dental erosion.

STATEMENT OF PROBLEM: Ultra-thin bonded posterior occlusal veneers represent a conservative alternative to traditional inlays and complete coverage crowns for the treatment of severe erosive lesions. There is a lack of data regarding selection of the most appropriate material and its influence on fatigue resistance, which may affect restoration longevity. PURPOSE: The purpose of this study was to assess the influence of CAD/CAM restorative material (ceramic vs. composite resin) on fatigue resistance of ultra-thin occlusal veneers. MATERIAL AND METHODS: A standardized nonretentive tooth preparation (simulating advanced occlusal erosion) was applied to 40 extracted molars including removal of occlusal enamel, and immediate dentin sealing (Optibond FL). All teeth were restored with a 0.6 mm-thick occlusal veneer (Cerec3 chairside CAD/CAM system). Reinforced ceramics (Empress CAD and e.max CAD) and composite resins (Paradigm MZ100 and XR (experimental blocks)) were used to mill the restorations (n=10). The intaglio surfaces were HF-etched and silanated (reinforced ceramics) or airborne-particle abraded and silanated (composite resins). Preparations were airborne-particle abraded and etched before restoration insertion. All restorations were adhesively luted with preheated Filtek Z100. Cyclic isometric loading was applied at 5 Hz, beginning with a load of 200N (x5,000), followed by stages of 400, 600, 800, 1000, 1200 and 1,400N at a maximum of 30,000 cycles each. The number of cycles at initial failure (first cracks) was recorded. Specimens were loaded until catastrophic failure (lost restoration fragment) or to a maximum of 185,000 cycles. Groups were compared using the life table survival analysis (α=.008, Bonferroni-method). RESULTS: Empress CAD and e.max CAD initially failed at an average load of 500N and 800N, respectively with no specimen withstanding all 185,000 load cycles (survival 0%); with MZ100 and XR the survival rate was 60% and 100%, respectively. CONCLUSIONS: Both composite resins (MZ100 and XR) increased the fatigue resistance of ultra-thin occlusal veneers (P<.001) when compared to the ceramics evaluated (Empress CAD and e.max CAD).

In vitro fatigue resistance of CAD/CAM composite resin and ceramic posterior occlusal veneers.

STATEMENT OF PROBLEM: Thin, bonded, posterior occlusal veneers constitute a conservative alternative to traditional complete coverage crowns. Information regarding selection of the appropriate material and its influence on fatigue resistance, which may affect the longevity of the restoration, is missing. PURPOSE: The purpose of this study was to assess and compare the fatigue resistance of composite resin and ceramic posterior occlusal veneers. MATERIAL AND METHODS: Thirty extracted molars received a standardized nonretentive tooth preparation (simulating advanced occlusal erosion), including removal of occlusal enamel, exposure of dentin, and immediate dentin sealing (Optibond FL). All teeth were restored with a 1.2-mm-thick occlusal veneer (Cerec 3 chairside CAD/CAM system). The restorations (n=10) were milled from leucite-reinforced and lithium disilicate ceramics (IPS Empress CAD and IPS e.max CAD, respectively) and a composite resin (Paradigm MZ100). The intaglio surfaces of the ceramic restorations were conditioned by hydrofluoric acid etching and silane. Airborne-particle abrasion and silane were used to condition the composite resin restorations. Preparations were airborne-particle abraded and etched. All restorations were bonded with preheated luting material and submitted to cyclic isometric loading at 5 Hz, starting with a load of 200 N (x5000 cycles), followed by stepwise loading of 400, 600, 800, 1000, 1200, and 1400 N at a maximum of 30,000 cycles each. The number of cycles at initial failure (first cracks) was recorded. Specimens were loaded for a maximum of 185,000 cycles. Groups were compared using the life table survival analysis (alpha=.016, Bonferroni method). RESULTS: IPS Empress CAD failed at an average load of 900 N, with no specimen withstanding all 185,000 load cycles (survival 0%), while IPS e.max CAD and Paradigm MZ100 demonstrated survival rates of 30% and 100%, respectively. None of the specimens exhibited catastrophic failure, but only cracks limited to the restorative material. CONCLUSIONS: Posterior occlusal veneers made of composite resin (Paradigm MZ100) had significantly higher fatigue resistance (P<.002) compared to IPS Empress CAD and IPS e.max CAD.

Composite resin reinforced with pre-tensioned glass fibers. Influence of prestressing on flexural properties.

OBJECTIVES: This investigation evaluated the flexural properties of two composite resins, and the influence of unidirectional glass fiber reinforcements, with and without pre-tensioning. METHODS: Two composite resins (Q: Quixfil and A: Adoro) were used to fabricate 2 mm x 2 mm x 25 mm beams (N = 10), reinforced with two fiber bundles along the long axis of the beam and pre-tensioned under a load equivalent to 73.5% of its tensile strength (groups QPF and APF). In two other experimental groups, the bundles were similarly positioned but without pre-tension (groups QF and AF). Two more groups were included without fiber reinforcement (control groups Q and A). After 24h storage, specimens were subjected to a three-point flexural bending test to establish the flexural module, the deflection at initial failure and the flexural strength. Data were analyzed using a two-way analysis of variance (composite resin system and fiber reinforcement type) and the Tukey HSD post hoc tests (alpha = .05). RESULTS: The results showed that prestressing increased the flexural module of Adoro specimens (p<.001) but not Quixfil (p = .17). Prestressed beams reached greater deflection at initial failure than those conventionally reinforced (p<.001), namely .85-1.35 mm for Adoro and .66-.90 mm for Quixfil. Prestressing also significantly increased the flexural strength of beams (p<.001) in both Adoro and Quixfil groups, from 443.46 to 569.15 MPa and from 425.47 to 568.00 MPa, respectively. SIGNIFICANCE: Pre-tensioning of unidirectional glass fibers increased both deflection until initial failure and flexural strength of Quixfil and Adoro composite resins, however, with limited effects on the flexural modulus.

A new proposal to optimize the occlusal margin in direct resin composite restorations of posterior teeth.

Modern operative dentistry provides practitioners of esthetic dentistry the means for performing direct restorations in a virtually imperceptible way. However, this attribute of resin composite can cause difficulties because the absence of contrast between the tooth structure and the restoration can impede visualization of the cavity limits. The purpose of this article is to highlight some operative steps that, when appropriately performed, will facilitate the building of direct resin composite restorations in posterior teeth, significantly reducing the possibility of restorative overextension.

Moldagem com elastômeros não aquosos: visão atual / Nonaqueous elastomeric impression materials: an up-to-date view

A obtenção de excelência estética em restaurações indiretas depende de correta moldagem. Para esse propósito, os elastômeros não aquosos são materiais extremamente eficazes, pois apresentam propriedades químicas, físicas e mecânicas que permitem a reprodução detalhada dos tecidos moles e duros da cavidade oral. O objetivo deste artigo é apresentar um enfoque clínico sobre os materiais elastoméricos não aquosos existentes quanto a seleção, técnicas de aplicação, interações com outros materiais, métodos de desinfecção e falhas mais comuns na moldagem de restaurações indireta.