Composite Resin Veneers Research Articles

Fechamento de diastemas com faceta direta de resina composta: relato de caso

The search for an aesthetic standard is increasingly frequent and restoring a harmonious smile represents a real challenge for restorative dentistry. Composite resins are aesthetic and adhesive materials that have received special attention for ensuring predictable and lasting results with minimal tooth sacrifice. The technique of making direct veneers is simple, but requires discretion and attention from its indication to the final stages of its execution. The procedure has high success rates and predictable results with desirable longevity for anterior teeth. The objective of this study was to present a clinical case of diastema closure with direct composite resin veneers on anterior teeth and maxillary first premolars, with the aid of diagnostic wax-up for better accuracy of work on anterior teeth. It is concluded that the application of the direct restorative technique allowed a fast, low, cost and less invasive treatment. Providing a satisfactory result, raising self-esteem and allowing a restoration of the patient's facial aesthetics.

Randomized Clinical Trial on Direct Composite and Indirect Ceramic Laminate Veneers in Multiple Diastema Closure Cases: Two-Year Follow-Up.

In recent years, laminate veneer restorations should be considered as a minimally invasive treatment option for several aesthetic reasons. This study compared direct composite veneers' and indirect ceramic laminate veneers' longevity in multiple diastema closures. A total of 28 patients with a mean age of 26 years received 60 direct resin composite (Estelite Asteria; n = 14) and 60 indirect ceramic veneers (IPS e.max Press; n = 14) on the maxillary anterior teeth with diastema closure. Veneers were evaluated at baseline and thereafter every 6 months for up to 2 years using USPHS criteria. Data were analyzed with Fisher's exact and chi-squared tests, while Kaplan-Meier curve was used to assess time to event. In total, three failures were observed in the form of debonding (n = 1) and fracture (n = 2) in the indirect ceramic veneers. No significant difference was observed between the survival rates of composite and ceramic veneers (Estelite Asteria: 93.4%, IPS e.max Press: 95%; p > 0.05). The overall survival rate was 94.2% (Kaplan-Meier). Staining (n = 11) and roughness (n = 14) were frequently observed for the resin composite veneers up to the final recall. Thereby, the preliminary results from this clinical trial comparing two veneer materials indicated that their survival rates were statistically similar. However, surface quality changes were more frequent in the composite veneer material.

Stress distribution on teeth restored with veneers using various incisal preparation designs: A 3D finite element analysis study

Statement of problemThe type of veneer preparation is often chosen according to the patient’s tooth structure and occlusion. Taking biomechanics into account in this decision-making process provides the clinician with more technical information on how to improve the clinical longevity of restorations. However, biomechanical analyses of veneer preparation designs are sparse. PurposeThe purpose of this 3-dimensional (3D) finite element analysis with microcomputed tomography (µCT) data obtained from realistic models was to assess the influence of different preparations for ceramic and composite resin veneers on restoration and resin layer stress distribution. Material and methodsFour replicas of a central incisor were printed and prepared for laminate veneers with 4 different incisal edge designs: shoulder (SH), palatal chamfer (PC), palatal chamfer and oblique fracture involving the distal angle (OF-PC), and palatal chamfer involving horizontal incisal fracture (IF-PC). After fabrication and cementation of the veneers, the restored replicas were assessed with µCT, and 3D finite element models were built. A 100-N load was applied on the palatal surface at 60 and 125 degrees relative to the longitudinal axis. Maximum principal stress and stress distribution on the veneers, cement layer, and tooth structure were calculated and analyzed. ResultsThe SH preparation exhibited better stress distribution than the PC preparation, and the cement layer and the veneer were subjected to lower stress. The IF-PC preparation had better stress distribution than the OF-PC. The shoulder and IF-PC showed higher stress on laminate veneers, but lower stress on the cement layer. Ceramic veneers exhibited lower stress than composite resin veneers. ConclusionsThe different incisal preparations for laminate veneers influenced stress distribution on restorations and on the resin cement layer. The shoulder type preparation showed better stress distribution and the composite resin veneers showed unfavorable results compared with the ceramic veneers.

Transitioning from injectable resin composite restorations to resin composite CAD/CAM veneers: A clinical report.

To describe a shift from injectable resin composite technique to composite resin computer-aided design and computer-aided manufacturing (CAD/CAM) veneers in addressing esthetic concerns associated with diastemas between anterior lower teeth in a clinical case. Among several techniques proposed for direct resin composite restoration, the "Injectable resin composite technique" has gained popularity for its time-efficiency, reduced technique sensitivity, and diminished reliance on clinician skills. However, challenges such as staining and the need for frequent polishing follow-ups may prompt the consideration of more stable alternatives such as indirect veneer restorations. While ceramic veneers offer superior mechanical and optical properties, resin ceramic veneers, especially those milled from CAD/CAM resin ceramic blocks, offer advantages such as rapid, cost-effective production, simplified intra-oral repairs, less susceptibility to fracture, superior stress absorption, and requires minimal tooth preparation, making them an appealing option for many patients. Moreover, a fully-digital approach not only streamlines the process but also saves time and labor while ensuring the delivery of high-quality restorations to patients. In addressing a patient's dissatisfaction with constant polishing of direct resin composite restorations, a shift to resin composite CAD/CAM veneers was implemented. Utilizing a fully-digital approach with CAD/CAM resin ceramic restorations successfully restored both esthetics and function. While the injectable resin composite technique achieves immediate esthetic results, its low color stability necessitates frequent polishing sessions. The replacement of direct resin composite restorations with CAD/CAM resin composite veneers becomes a viable option for patients seeking more stable restorations that require fewer follow-ups. This transition addresses both esthetic concerns and the need for enduring solutions in restorative dentistry.

Effect of Different Primers on Shear Bond Strength of Base Metal Alloys and Zirconia Frameworks.

Ensuring a secure bond between a framework structure and layering composite resin veneer is essential for a long-lasting dental restoration. A variety of primer systems are available to facilitate the adhesive bonding. Nevertheless, the growing preference for efficiency and simplicity in dentistry has made the one-bottle universal primers a desirable option. This study aims to compare the effectiveness of universal primers on the shear bond strength (SBS) of base metal alloy (BMA) and zirconia to layering composite resin. Each 160 BMA and zirconia 20 × 10 × 5 mm test specimen was fabricated. Eight different primers (SunCera Metal Primer, Metal Primer Z, Reliance Metal Primer, Alloy Primer, MKZ Primer, Monobond Plus, ArtPrime Plus, and Clearfil Ceramic Primer Plus) were applied to 20 specimens in each group. Subsequently, a 5 × 2 mm composite resin build-up was applied. SBS tests were performed after 24 h of water storage and after thermocycling (25,000 cycles, 5-55 °C). On BMA, after water storage for 24 h, the bond strength values ranged from 26.53 ± 3.28 MPa (Metal Primer Z) to 29.72 ± 2.00 MPa (MKZ Primer), while after thermocycling, bond strength values ranged from 25.19 ± 1.73 MPa (MKZ Primer) to 27.69 ± 2.37 MPa (Clearfil Ceramic Primer Plus). On a zirconia base, after 24 h, the bond strengths values ranged from 22.63 ± 2.28 MPa (Reliance Primer) to 29.96 ± 2.37 MPa (MKZ Primer) and from 23.77 ± 3.86 MPa (Metal Primer Z) to 28.88 ± 3.09 MPa (Monobond Plus) after thermocycling. While no significant difference in bond strength was found between the primers on the BMA base, five primer combinations differed significantly from each other on zirconia (p = 0.002-0.043). All primers achieved a bond strength greater than 23 MPa on both framework materials after thermocycling. Thus, all primers tested can be applied to both framework materials with comparable results.

Color Stability, Gloss Retention, and Surface Roughness of 3D-Printed versus Indirect Prefabricated Veneers.

The long-term color stability and surface properties of anterior laminate veneers are among the crucial factors affecting the clinical longevity of aesthetic restorations. Novel 3D-printed materials are being introduced as definitive restorative treatment. In light of the existing variety of indirect yet minimally invasive composite resin veneers, research on their surface properties is warranted. This in vitro study evaluated the effect of artificial aging by immersion in different staining solutions on the color changes, gloss, and surface roughness (Ra) of 3D-printed veneers compared to the prefabricated resin composite veneer systems (PRCVs) manufactured by Componeer and Edelweiss. Moreover, this study compared the effects of two methods for stain removal: repolishing with Sof-Lex disks and in-office bleaching with 40% hydrogen peroxide. The veneers (n = 24) were randomly divided according to the immersion solutions used, i.e., tea and coffee. Colorimetric measurements, surface roughness, and surface gloss were determined before and after staining and surface treatment with either in-office bleaching or surface polishing. The data were statistically analyzed using two-way ANOVA followed by the Tukey's post hoc test (α = 0.05). Artificial aging with immersion in staining solutions led to significant color changes, increased surface roughness, and gloss reduction in all materials (p < 0.05). The 3D-printed veneers showed higher ΔE values (coffee = 10.112 ± 0.141) and (tea = 10.689 ± 0.771) compared to baseline after 7 days of aging. The 3D-printed veneers had a statistically significant surface roughness Ra (0.574 µm ± 0.073). The gloss was >70% in all groups at baseline; these values dropped in all groups after 7 days of artificial aging. After the stain-removing procedures, the ΔE values decreased in all tested veneers. That being said, they failed to return to the baseline values, and both stain-removing methods were found to have an adverse effect on surface roughness and gloss retention in all tested veneers.

MANUFACTURE OF FACETS IN COMPOSITE RESIN USING THE CHROMATIC RESTORER TEST TECHNIQUE: case report

The concern with aesthetics, seeking a socially beautiful and appropriate smile, makes people increasingly look to dentists for cosmetic procedures. The speed of production, lower cost, minimal wear on dental structures, and immediate results make this procedure routine in clinical practice. In this work, the manufacture of composite resin veneers was reported using the chromatic restorative test technique for anterior teeth and subsequently cemented with thermo-activated resins in a 29-year-old male patient who attended the Lemos Odontologia dental clinic. The patient sought this treatment due to his dissatisfaction with his smile. This work aims to present a clinical case of making composite resin veneers using the chromatic restorative test technique, demonstrating its success and potential. At the end of the treatment, an excellent aesthetic and functional result was obtained, and patient satisfaction was successfully achieved.

ANTERIOR AESTHETIC REHABILITATION WITH GINGIVECTOMY AND COMPOSITE RESIN VENEERS

The advancement of surgical procedures for gingival repair and restorative treatments for anterior teeth, which stand out in the scientific community, has been fundamentally influenced by the pursuit of aesthetics. The purpose of the current study is to describe the clinical behaviour of a patient who has small teeth and a gummy smile. The goal was to use a clinical case to illustrate how anterior cosmetic rehabilitation, which includes gingivectomy and composite resin veneers, can be accomplished. The restoration of anterior teeth involves using better shades, colours, opacities, translucency, and anatomical onformation, while treatments that combine dentistry and periodontics are capable of producing good results, enabling normalisation of the gums, correcting their deformities, and restoring the interdental grooves and papillae. Periodontal surgery called a gingivectomy involves removing extra gum tissue. The purpose of the procedure is to change the tooth’s contour, which generates an increase in the clinical crown, providing a smile with adequate protection and support for the oral environment. Resin veneers or direct restoration on anterior teeth are the dental remodelling treatment that guarantees longevity and satisfactory results, in addition to being minimally invasive. The adhesive systems and composite resins available are of high quality, do not impose aesthetic limits, and allow a natural effect determined by the excellence and technical knowledge of the operator. The plan accomplishment allowed reaching the aesthetic principles and establishing a better contour shape and size, both of the gingival tissue and of the anterior teeth. Thus, the procedure was always performed prioritising the demands and satisfaction of the patient, generating excellent clinical results. This research is duly authorized by Opinion: 6.275.546 CEP/CONEP.

Aging and Fracture Resistance of Implant-Supported Molar Crowns with a CAD/CAM Resin Composite Veneer Structure.

Chipping of implant-supported molar crowns (iSCs) is a frequently reported complication. This study aimed to investigate the in-vitro aging and fracture resistance of iSCs with a CAD/CAM resin composite veneer structure fabricated with the Rapid Layer Technology (RLT) approach. Eight iSCs per group were fabricated by using two different CAD/CAM resin composites (Shofu Block HC: SH; Grandio blocs: GB) for veneer structures, and zirconia (ZrO2), polyetheretherketone (PEEK), and cobalt-chromium (CoCr; control) as framework materials. The surfaces to be bonded were sandblasted, cleaned in an ultrasonic bath, and a coupling agent was applied. A self-adhesive resin luting composite was used to adhesively lute the veneer structures to the frameworks. The crowns were semi-permanently cemented to the abutments. After storage in deionized water, iSCs were loaded in a chewing simulator (TCML, 10,000 thermal cycles 5 °C to 55 °C for 20 s, 1.2 million, loading force 50 N). Four ZrO2 and one CoCr crown did not survive the TCML. The fracture force was determined after 24 h storage in deionized water and yielded values of ≥974 N. Lowest fracture forces were yielded in the PEEK-SH group in comparison to CoCr or ZrO2 groups (p ≤ 0.031). For identical framework materials, no significant influence of the veneering material was observed. All PEEK-GB frameworks fractured, and chipping occurred for ZrO2-SH and all CoCr frameworks. PEEK-SH and ZrO2-GB presented both chipping and framework fractures. Within the limitations of this in-vitro study, the RLT with a CAD/CAM resin composite veneer structure might be a promising approach to veneer iSCs. Yet, the choice of the CAD/CAM resin composite and of the framework material determine the fracture resistance.

Effect of shade and opacity on color differences and translucency of resin composite veneers over lighter and darker substrates.

To evaluate color differences (ΔE00) and translucency parameters (TP) from mono, bi, and trilayer resin composite veneers using different opacities and shades of resin composite over lighter and darker simulated tooth-colored substrates. Mono, bi, and trilayer veneers (1.5mm) (n = 12) were made using two shades (A1 and A2) and three opacities (enamel, body, and dentin) of resin composite over simulated lighter (A1) and darker (C4, and C4+) tooth-colored substrates. CIEDE2000 formula was used to calculate ΔE00 considering simulated tooth-colored substrate versus opacities in distinct mono, bi, and trilayer combinations of resin composite over the simulated tooth-colored substrate. The TP was calculated using color coordinates measured over standard white and black backgrounds. Differences in ΔE00 and TP values were calculated with a Three-way Analysis of Variance followed by Tukey's post-hoc test. A1E and A1B monolayer veneers showed similar TP values. Significantly higher ΔE00 values were observed over darker (C4 and C4+), and lower over lighter (A1) simulated tooth-colored substrate. Bilayer and trilayer veneers using dentin opacity provided similar ΔE00 values over the darker tooth-colored substrate. Distinct shades and opacities of resin composite layer combinations over lighter and darker tooth-colored substrates significantly affected TP and ΔE00 values. A1 shade and dentin opacity of monolayer resin composite veneers yielded higher ΔE00 values over darker tooth-colored substrates.

Injectable Flowable Resin-based Composite Veneers Prior to Ceramic Veneers.

This case report describes the clinical protocols for using injectable flowable resin-based composite veneers without tooth reduction as long-term prototype restorations, followed by conservative feldspathic veneer restorations. The patient's primary concern was to improve her smile. After clinical evaluation, injectable flowable resin composite veneers were recommended as long-term prototypes followed by conservative tooth preparation and ceramic veneers. Flowable composite veneers were created with a transparent silicone index fabricated from a diagnostic wax-up approved by the patient. No tooth reduction was required to place this type of composite veneer. Later, a printed reduction guide was used to provide conservative tooth preparation followed by the cementation of thin feldspathic porcelain veneers under full isolation with a rubber dam. Injectable flowable resin-based composite veneers can successfully act as long-term esthetic prototypes before ceramic veneers. The outcome of these restorations is very predictable because the diagnostic wax-up anatomy is transferred to the mouth through the transparent silicone index, and they can be placed without tooth reduction. Conservative tooth preparation can be performed on the composite veneers so that minimal tooth structure is removed to maximize the bonding performance of ceramic veneers.

Effect of different finishing and polishing procedures on surface roughness and microbial adhesion on highly-filled composites for injectable mold technique.

To evaluate the effect of different finishing and polishing procedures on surface roughness and microbial adhesion and viability of Streptococcus mutans on novel highly-filled composites for injectable mold technique. One hundred sixty specimens were divided into four material groups: FSF (Filtek Supreme Flowable Restorative), TE (Tetric EvoFlow), GUI (G-aenial Universal Injectable) and GUF (G-aenial Universal Flo). Within each group, specimens were split regarding finishing and polishing (F/P) procedures into: SLD (Sof-Lex Discs), SLS (Sof-Lex Spirals), OG (OneGloss) and PG (PoGo). Surface roughness was analyzed using profilometer (Ra and Rz) and scanning electron microscopy (SEM) and Strep. mutans biofilm formation was analyzed using colony forming unit (CFU) and cell viability assay. Two-way analysis of variance (ANOVA) followed by Tukey's post hoc test were used for comparison among groups, Pearson's coefficient was applied for the correlation between Ra and CFU/ml and all data were presented as mean ± SD. Both materials and F/P procedures affect Ra, Rz and Strep. mutans CFU/ml values (p ≤ 0.05). Considering the Ra and Rz, GUI and GUF revealed lower values, compared to FSF and TE and SLD and SLS revealed lower values, compared to OG and PG. Considering the Strep. mutans CFU/ml and viability, GUI and TE presented lower values, compared to GUF and FSF and SLD and SLS presented lower values, compared to OG and PG. Moderate positive correlation was found between Ra and CFU/ml (r = 0.552). The smoothest surfaces possess GUI and GUF, among materials and SLD and SLS, among F/P procedures. GUI adhered the lowest amount of Strep. mutans, due to the smoothest surfaces. FSF and GUF revealed the highest amount of Strep. mutans, due to bis-GMA, bis-MEPP and TEGDMA in their composition. The findings of the present study may be beneficial for the proper selection of highly-filled composites and an adequate finishing and polishing procedure when performing the injectable mold composite resin veneer technique.

Main approaches of biofilm formation in composite resins: a concise systematic review

Introduction: Composite resins are widely used in clinical dental practice to restore the structure lost by caries and dental defects, achieving aesthetic and functional results. Failures in the photoactivation process can cause problems in the mechanical resistance to wear in regions of direct occlusal contact on the restorative material. This occurs due to the reduction in the degree of conversion of monomers into polymers, compromising the clinical performance of the composite resin. Polymerization shrinkage leads to microleakage of the restoration, leading to staining and the development of bacterial biofilms. Objective: It was to carry out a systematic review of the main scientific evidence of biofilm formation on composite resin veneers, identifying potential predictors, as well as proposals to mitigate this problem. Methods: The systematic review rules of the PRISMA Platform were followed. The search was carried out from December 2022 to March 2023 in the Scopus, PubMed, Science Direct, Scielo, and Google Scholar databases, using articles from 2015 to 2022. The quality of the studies was based on the GRADE instrument and the risk of bias was analyzed accordingly, according to the Cochrane instrument. Results and Conclusion: A total of 125 articles were found, 25 articles were evaluated and 20 were included and developed in this systematic review study. Considering the Cochrane tool for risk of bias, the overall assessment resulted in 10 studies with a high risk of bias and 70 studies that did not meet GRADE. It was concluded that the surface properties of resin-based composite materials, as well as surface treatments, can strongly affect bacterial adhesion and biofilm formation. In addition, scientific evidence highlights that cariogenic biofilm formation can alter the surface properties of materials, thus stimulating bacterial adhesion and biofilm formation. Photoactivation allows the curing and crosslinking of polymer chains, essential for the clinical longevity of the composite resin. Insufficient photoactivation culminates in marginal microleakage in restorations and biofilm accumulation on surfaces exposed to the oral environment.

Biomechanical effects of a hard insert and air space in mouthguards on the shock absorption and protection against fractures of direct resin composite veneers from trauma.

Mouthguards (MTG) are used to prevent dental trauma. However, their protective effect on esthetic restorations and whether modified MTGs are beneficial is uncertain. The aim of this study was to evaluate the effect of hard inserts and air spaces in MTGs in protecting direct resin composite veneers during impact. Twenty resin composite veneers (1.0 mm) were prepared on upper right central incisors on printed maxilla models using polyether. The effect of the MTGs was evaluated in four groups (n = 5): Con-MTG, conventional custom-fit MTGs made with two layers of ethylene vinyl acetate (EVA); Air-MTG, MTGs with the insertion of 2.0 mm air space between the two layers of EVA and tooth surface; PETG-MTG, MTGs with 1.0 mm of polyethylene terephthalate glycol-modified (PETG) inserted between the EVA layers; and No-MTG, comprising resin composite veneers without MTG. The printed models were fixed in a pendulum device, and the impact was performed at 30°. The strain (μS) and shock absorption (%) of the MTG were recorded using strain gauges. Failure modes and cracks were evaluated using macro photography and transillumination and analyzed using the chi-square test. Strain and shock absorption data were analyzed using the one-way analysis of variance followed by Tukey's test (α = 0.05). Mouthguards reduced strain and enhanced shock absorption, regardless of the MTG type (p < .001). Con-MTG, Air-MTG, and PETG-MTG had shock absorption rates of 76.1%, 72.3%, and 33.4%, respectively (p < .001). The single No-MTG model had a root fracture, while all the others had superficial damage. None of the MTG models had cracks or fractures. Mouthguards protected the resin composite veneers. The Con-MTG and Air-MTG groups had lower strain and greater shock absorption than the PETG-MTG. Resin veneers had no cracks or damage following MTG use. However, 80% of the veneers had surface damage when no MTG was used.

The ability of mouthguards to protect veneered teeth: A 3D finite element analysis.

Professional and amateur athletes might have veneer restorations. The aim of this study was to investigate the protective effect of mouthguards on veneered anterior restorations. A nonlinear dynamic analysis was performed to simulate conditions during an impact with or without a custom-made mouthguard. Using a computer-aided design (CAD) software, a slice of a human maxilla was designed containing an upper right central incisor. The model was composed of mucosa, cortical bone, trabecular bone, periodontal ligament, dentin, enamel, and pulp tissue. The enamel was prepared (feather design), restored with an indirect veneer (1.0 mm thickness), and duplicated to simulate both conditions with or without a mouthguard (4 mm thickness). Both models were subdivided into finite elements using the computer-aided engineering (CAE) software. Frictionless contacts were used, and an impact was simulated in which a rigid sphere hit the model at 1m s-1 . Fixation was defined at the base of the bone. The elastic modulus of the veneer was assessed by using five different restorative materials (resin composite, hybrid ceramic, zirconia-reinforced lithium silicate, lithium disilicate, and zirconia). Von Mises stress, minimal principal stress, and maximum principal stress (in MPa) were obtained and plotted for visual comparison. Von-Mises results showed higher stress concentrations in the veneer's cervical labial region for models without a mouthguard. Observing the quantitative results for each model, the highest compressive (709 MPa) and tensile (58 MPa) stresses occurred in the situation without a mouthguard with a zirconia veneer, while the lowest occurred in resin composite veneer with a mouthguard (8 and 5MPa). The mouthguard was able to reduce the stresses in the tooth structure and it also reduced the risk of fracture in all conditions. Mouthguards were beneficial in reducing the effects of dental trauma regardless of the restorative material used to manufacture the indirect veneer, since they act by dampening the generated stresses during the trauma event. Equal impact stresses on a mouthguard will lead to higher stresses in veneered teeth with more rigid restorative materials leading to a less protective effect.

Wear pattern-associated color stability of prefabricated composite veneers versus ceramic veneers.

To evaluate the effect of different surface wear patterns on the discoloration tendency of two different prefabricated composite veneers and lithium disilicate ceramic veneers. Discoloration tendency of two prefabricated composite resin veneers (Visalys Veneer Chairside (VIS) and Componeer (COM)) were compared to lithium disilicate veneers (IPS) in vitro. For each material, n = 60 samples were allocated to different test groups, and therefore each n = 10 specimens per group went through different wear tests. Mechanical abrasion tests were conducted using a toothbrush simulator, while erosive effects were carried out by citric acid (pH 1.57). A combination of abrasion and erosion tests was conducted as well. Four groups of wear tests were implemented: (1) abrasion, (2) abrasion followed by erosion, (3) erosion, and (4) erosion followed by abrasion. Another group was stored in distilled water as the control and one group was stained without a prior wear test. The staining solution was made from a coffee-tobacco brew. Specimens were stored in the coffee-tobacco solution for 21 days. Color measurements were performed with VITA Easyshade. To evaluate intramaterial discoloration, one half of every specimen was protected with foil. After storage in the staining solution, the first measurement was carried out on the 'protected' (untreated) surface, followed by a second measurement on the 'processed' (treated) discolored surface. Euclidean distance (ΔE) of discoloration was calculated according to the CIE-L*C*h* system. Data were analyzed with ANOVA followed by Games-Howell post hoc test and paired t-test (α = 0.05). Highest changes in ΔE were found in COM after 'abrasion' (ΔE -2.55) and 'erosion followed by abrasion' (ΔE -1.41). The discoloration tendency of VIS was affected by all wear tests, but changes were below the perceptive threshold (ΔE -0.19-0.32). Only abrasion followed by erosion affected the discoloration of IPS significantly, but findings were below the perceptive threshold, as well (ΔE -0.09). Prefabricated composite resin veneers revealed a low level of discoloration tendency after different wear tests. Nevertheless, in most cases the lowest discoloration tendency was found in specimens made from lithium disilicate.

12- months color stability of direct resin composite veneers in anterior teeth: Clinical trial

Background: This clinical trial aims to evaluate the color changes of direct resin composite veneer (DCV) restorations based on spectrophotometric analysis of 4 different types of resin composites between the baseline immediately after polishing and after one year of follow-up. Materials and methods: 28 patients were assessed for eligibility for participation, aged between 18 and 38 years old, who indicated for DCV restorations in anterior maxillary teeth were considered for participation in this study. In total, 25 patients who met the inclusion criteria were selected (6 males and 19 females, mean age: 20.9 at the time of restoration placement), and 3 patients were excluded. Participants were divided into four groups based on the type of composite resin used for restorations. Group 1 nanohybrid Ips Empress direct (Ivoclar Vivadent)](IPS) (13 restorations/6 patients), group 2 microfilled [Essentia (GC cooperation Japan)](ES) (14 restorations / 7 patients), group 3 supra-nano filled [ Estelite ∑ Quick (Tokuyama, Tokyo, Japan)](EQ) (17 restorations / 7 patients) and group 4 nanofill [Filtek Ultimate (3M ESPE)](FU) (13 restorations / 5 patients). Baseline Color measurements were performed with a spectrophotometer immediately after finishing and polishing (baseline), and after one year of recall, color change (ΔE) from baseline values and after one year of follow-up of DCVs were calculated according to CIELab color coordinates. For this, a silicone mold was fabricated for each patient and used as a guide for each measurement to standardize the site of the readings. Statistical analysis of the data was applied using the Kruskal-Wallis test with Dunn-Bonferroni posthoc test after controlling the distribution of data in terms of normality with the Shapiro Wilk test. Results: At the end of one year,25 participants(57restorations) were followed up. The mean ΔE of IPS, EQ, and FU composites were higher than the ES composite resin, but there was no statically significant difference between all types of composites (P&gt; 0.05). There was no statistically significant difference in the mean ΔL* between any types of composite resin (p&gt; 0.05). There was a significant change in Δa* and Δb* after a one-year recall for all the types of DCV restorations (p &lt; 0.05). Conclusion: After one year of follow-up, the spectrophotometer measurements of direct resin composite veneer restorations, it was concluded no difference between the mean ΔE of ES, IPS, FU, and EQ resin composite. ES (Microfilled hybrid) showed a lower mean ΔE value compared to the other groups. All groups of resin composite showed color changes within clinically acceptable levels after a one-year follow-up.

Mechanical Properties of SDR™ and Biodentine™ as Dentin Replacement Materials: An In Vitro Study

The aim of this study is to evaluate the shear bond strength of nanohybrid composite resins (NCR) and microhybrid composite resins (MCR) placed over three different dentin replacement materials: SDR-Smart Dentin Replacement™, Biodentine™, and resin-modified glass ionomer cement (RMGIC). Thirty acrylic blocks (50 mm × 20 mm × 15 mm), each with a central hole, were prepared, which were randomly distributed into three equal groups, each corresponding to one of the three dentin replacement materials-SDR, Biodentine, and RMGIC. The central holes were then filled with these materials. After setting and application of the respective adhesive system, the specimens were further divided into two subgroups each of NCR or MCR. The respective composite material was then applied to the dentin replacement materials using a cylindrical plastic matrix. Shear bond strength was tested on a universal testing machine (Instron 3366), at a crosshead speed of 1.0 mm/minute. SDR attained consistently higher shear bond strength (means: 21.18, 22.19 Mpa) values than RMGIC and Biodentine, with both types of composite resins (MCR and NCR), which were statistically significant (p <0.001). When considering the means of the shear bond strength measurements obtained by the two types of the composite resin, no significant difference (p <0.05) was found between them with all three types of dentin replacement materials. There is no significant difference in the bond strengths achieved between MCR and NCR to the different dentine replacement materials. Hence, either type of composite resin may be expected to achieve similar bond strengths to the underlying substrate. SDR™ is a suitable dentine replacement material for placing below a composite resin veneer as it can achieve immediate higher bond strengths. SDR can be used as an effective bulk fill material in deep dentinal caries which can be capped with composite resins.

Three-year Follow-up of Conservative Direct Composite Veneers on Eroded Teeth.

This clinical case describes an esthetic rehabilitation of a young patient presenting with erosive tooth wear. The etiological factors for the erosion in this clinical case was excessive carbonated beverages and lemon water intake. The patient's main complaint was the yellowish aspect of her smile. The treatment procedure selected was direct resin composite veneers in the six maxillary anterior teeth. A three-year follow-up of the case is presented. The three-year follow-up showed a successful clinical performance of the treatment procedure after a finishing/polishing protocol.

Adhesive Management of Anterior Tooth Wear in Combination with the Dahl Concept—A 27-Month Observational Case Series

Localized anterior maxillary tooth wear caused by erosion and attrition with loss of interocclusal space is difficult to manage. This observational case-series study reports six cases with worn anterior dentition treated with labial ceramic and palatal direct resin composite veneers at an increased vertical dimension of occlusion without restoration of unaffected posterior teeth. Thirty-six palatal direct veneers were made in six patients from a nanohybrid resin composite with the help of a wax-up-based template at an increased vertical dimension. After the complete re-establishment of posterior occlusion, 40 labial lithium-disilicate ceramic veneers were fabricated with a mock-up-guided method. The sandwich veneers were evaluated according to the United States Public Health Service (USPHS) criteria after a mean service time of 22.7 months. Re-establishment of posterior contacts as well as subjective patient satisfaction and function were evaluated. The overall success of the labial ceramic veneers was excellent. The quality of the palatal resin composite restorations was found to be good with predominantly "Alpha" scores. The marginal quality (11.1% and 33.3% of integrity and discoloration, respectively) and surface roughness (16.7%) showed small deteriorations indicated by "Beta" scores. The resin composite showed, in general, signs of wear facets which resulted in "Beta" scores in 44.4% of the cases. Posterior contacts re-established firmly within 4 weeks in all cases. Patient satisfaction with esthetics and function was high. The short-term outcome of this non-invasive treatment option is favorable and promising.