An assessment of Brazilian dentists' knowledge about tooth fragment reattachment: A cross-sectional study.

BACKGROUND/AIM: Crown fractures are common traumatic dental injuries and tooth fragment reattachment is a viable option for restoring a fractured tooth. The aim of this study was to assess the knowledge and experience of dentists in the Federal District regarding the tooth fragment reattachment technique for enamel and dentin fractures. MATERIALS AND METHODS: For the cross-sectional observational study, an electronic form was designed with objective and self-report questions for dentists. The data were analyzed using descriptive statistics, with their absolute and relative frequencies. For the analysis of categorical variables, the nonparametric chi-squared or Fisher exact association tests were used in the statistical software R (version 4.2.1). RESULTS: A total of 416 dentists participated in the study (58.9% female and 41.1% male). Of these, 70% declared they knew about fragment reattachment, but only 42.3% reported previous experience with this procedure. The most common storage medium used for the fractured fragment was milk (78.1%), and the bonding material used for reattachment was light-cured composite resin (86.3%). A majority (66.3%) reported that for a patient with enamel and dentin fracture, with the crown fragment in good condition, they would choose to do the reattachment. CONCLUSION: Dentists demonstrated that they had adequate knowledge about the tooth fragment technique, although many did not have previous experience with this procedure.

Influence of two carbodiimides on the bond strength of universal adhesives to dentin.

The pretreatment of dentin with cross-linking agents during bonding procedures has been proposed to improve the mechanical properties of the collagen in the hybrid layer and reduce the biodegradation of the adhesive interface. The aim of this study was to evaluate the influence of pretreatment with two carbodiimides on the dentin bond strength of universal adhesives, after thermocycling. Three universal adhesives in the self-etching mode were used (Single Bond Universal-SBU, Clearfil Universal-CLU and Ambar Universal-ABU). A self-etching adhesive system (Clearfil SE Bond-CSB) was used as control. Two carbodiimides, 1-ethyl-3-(3'-dimethylaminopropyl)-carbodiimide (EDC) and N,N'-dicyclohexylcarbodiimide (DCC), were applied for 1 min. The excess solution was removed with absorbent paper and the universal adhesives were applied. The specimens were stored for 24 h in distilled water at 37 °C or 10,000 thermal cycles (5-55 °C, 30 s) and then were prepared for microtensile bond strength test (n = 4 teeth, average of 21 sticks per group). Data were analyzed using three-way ANOVA and Tukey's (α = 5%). After 24 h, SBU and CSB had statistically similar bond strength values for the control groups (22.07 ± 9.03 and 19.82 ± 7.28 MPa), with EDC (30.21 ± 11.30 and 19.67 ± 5.36 MPa) and DCC (30.12 ± 13.43 and 19.82 ± 7.28 MPa) pretreatments (p > 0.05). The use of EDC (32.57 ± 9.60 MPa) and DCC (24.71 ± 9.87 MPa) showed statistically higher bond strength for CLU than for the control group (14.62 ± 6.16 MPa; p < 0.05). After thermocycling, the SBU, CLU, and CSB groups showed statistically similar bond strengths with the use of EDC (27.08 ± 8.44; 18.74 ± 5.41; and 24.55 ± 10.43 MPa) and without the use of cross linkers (20.06 ± 7.99; 22.55 ± 9.04; and 26.54 ± 10.13 MPa; p > 0.05). Groups tested after 24 h in distilled water presented higher bond strength than those submitted to thermocycling. It can be concluded that the use of cross linkers influenced the immediate bond strength of the universal adhesives, and this was dependent on the combination of the adhesive system and type of carbodiimide. The use of EDC increased the immediate bond strength of CLU. DCC increased the bond strength of ABU at 24 h, but the values were lower than those of the control group after aging for three out of the four adhesives.

Do anterior and posterior teeth treated with post-and-core restorations have similar failure rates? A systematic review and meta-analysis.

STATEMENT OF PROBLEM: The association between tooth type, location in the dental arch, and selection of a post-and-core system for endodontically treated teeth is unclear. Information on the influence of these parameters on the failure rate of teeth treated with post-and-core restorations is needed. PURPOSE: The purpose of this systematic review and meta-analysis was to assess the available evidence on the failure rates of anterior and posterior teeth treated with post-and-core restorations. MATERIAL AND METHODS: A search was performed in PubMed, Scopus, Web of Science, Latin American and Caribbean Health Sciences Literature database, Brazilian Library in Dentistry, Cochrane Library, and Gray literature for randomized clinical trials comparing the failure rates of anterior and posterior teeth treated with post-and-core restorations. The risk of bias tool from the Cochrane Collaboration was used for quality assessment of the studies. RESULTS: The search strategy identified 2526 articles, and 6 studies were included in the meta-analysis. No difference in the failure rate of post-and-core restorations placed in anterior and posterior teeth was found in most studies. The risk ratio for anterior versus posterior teeth was 1.06 (95% confidence interval [CI], 0.69-1.64; P=.79). The risk ratio for incisors versus canines was 3.08 (95% CI, 0.56-17.04; P=.20) and that for premolars versus molars was 0.45 (95% CI, 0.12-1.74; P=.25). The risk ratio for prefabricated glass fiber posts on anterior versus posterior teeth was 1.13 (95% CI, 0.61-2.09; P=.70) and that for metal posts was 1.10 (95% CI, 0.64-1.91; P=.72). CONCLUSIONS: The failure rates in anterior and posterior teeth treated with post-and-core restorations were similar at short- to medium-term follow-up. More well-designed clinical trials comparing the survival and failure rates of anterior and posterior teeth treated with post-and-core restorations with longer follow-up times are needed.

Lithium silicate endocrown fabricated with a CAD-CAM system: A functional and esthetic protocol.

An endocrown restoration is an alternative approach to complete crowns with intraradicular cores or dowels for the restoration of endodontically treated teeth. Endocrowns conserve tooth structure and require fewer dental visits. This approach has been widely used, and various materials and techniques have been reported. Computer-aided design and computer-aided manufacturing (CAD-CAM) systems can generate and store libraries of teeth with various anatomies in their database, and diagnostic tooth waxing may not be required. However, occlusal adjustments after the cementation of indirect restorations are often frustrating. Thus, a rapid and efficient way of addressing this challenge is necessary. This clinical report presents a protocol for the fabrication and delivery of an endocrown by using the biogeneric design mode with lithium silicate-based ceramic adjusted before its complete sintering.

Planning extensive esthetic restorations for anterior teeth: use of waxed-up study casts and composite resin mock-ups.

The aim of this case report is to highlight the importance of appropriate planning protocols when direct composite resin restorations are used to solve extensive esthetic problems. A 30-year-old patient complained about her small maxillary anterior teeth and short upper lip. All teeth were healthy and light colored, and the patient exhibited good oral hygiene. The anterior teeth were relatively short, resulting in a compromised esthetic relationship between height and width. The maxillary and mandibular right central incisors were in an edge-to-edge relationship. After diagnostic casts and waxed-up study casts were obtained, occlusal adjustment and recontouring of the incisal and labial surfaces of the mandibular right central incisor were performed to increase overjet. To increase the volume of the upper lip, composite resin restorations were planned for the maxillary anterior teeth. To confirm that the contours and color of the new smile were acceptable to the patient, composite resin esthetic mock-ups were made directly in the mouth before the definitive procedure. After definitive restoration of the anterior teeth, additional occlusal adjustments were performed. At the 36-month follow-up, no fracturing or severe wear of the restorations was observed. The restored anterior guidance provided excellent function after 3 years of clinical service.

Fabrication of lithium silicate ceramic veneers with a CAD/CAM approach: a clinical report of cleidocranial dysplasia.

The fabrication of minimally invasive ceramic veneers remains a challenge for dental restorations involving computer-aided design and computer-aided manufacturing (CAD/CAM). The application of an appropriate CAD/CAM protocol and correlation mode not only simplifies the fabrication of ceramic veneers but also improves the resulting esthetics. Ceramic veneers can restore tooth abnormalities caused by disorders such as cleidocranial dysplasia, enamel hypoplasia, or supernumerary teeth. This report illustrates the fabrication of dental veneers with a new lithium silicate ceramic and the CAD/CAM technique in a patient with cleidocranial dysplasia.

Esthetic, occlusal, and periodontal rehabilitation of anterior teeth with minimum thickness porcelain laminate veneers.

Ceramic veneers of minimum thickness provide satisfactory esthetic outcomes while preserving the dental structure. Dental ceramics can both improve the esthetic appearance and reestablish the strength and function of teeth. In worn anterior teeth, functional surfaces, for example, anterior and lateral guidance, can be restored effectively. The characteristics of dental ceramics, such as color stability and mechanical and optical properties, make this material a good choice for indirect restorations, especially when optimum function and esthetics are required. This clinical report presents an occlusal, periodontal, and restorative solution with minimum thickness glass ceramic veneers for worn anterior teeth with multiple diastemas.

Using chemical vapor deposition diamond finishing burs for conservative esthetic procedures.

The article demonstrates how chemical vapor deposition (CVD) diamond burs were used in a simple esthetic and cosmetic procedure to treat discolored anterior teeth. A patient who experienced discoloration after bleaching was treated with direct resin composite veneers. Excess restorative material close to the periodontium was removed with a CVD diamond bur attached to an ultrasonic handpiece. The results indicate that CVD diamond burs are appropriate for removing excess material at the gingival margins of resin composite restorations without damaging the periodontium.

Layering technique with non-Vita shading concepts.

Managing teeth with hypoplasia stains or discoloration using composite resin materials is challenging. When appraising hypoplasia stains, the substrate color and thickness of the material must be considered. The non-Vita shading system has a reduced number of layers, primarily dentin and enamel, which is known as the natural layering concept. The incremental approach of this system allows the masking of substrates with color differences and the reproduction of the optical characteristics of chromaticity, translucency or opacity as well as the value (luminosity). The present study demonstrates and discusses the color sequence for the natural reproduction of tooth structures using an alternative composite resin system from the classical Vita scale.

Macroabrasion and/or Partial Veneers: Techniques for the Removal of Localized White Spots.

Macroabrasion is a technique for the removal of localized white spots using a high-speed, intermittent high speed turbine finishing diamond tip. It is fast, safe, efficient, and an alternative to enamel microabrasion. However, when the stain is deeper, these localized intrinsic stains or defects can be treated with partial direct veneers. A conservative preparation should be done and that allows stratification of the resin to mask the hypoplasia and provide naturalness to the tooth. Thus, the objective of this work is to demonstrate, through a clinical case, macroabrasion and a partial veneer from the preparation, restoration, to the finishing and polishing to remove hypoplastic stains.

Cara smile: Use of planning software to facilitate esthetic dental treatment in a case.

Treatment of the anterior teeth is challenging. Computer resources and software are available to facilitate a digital smile approach, thus allowing the dentist to plan and predict an esthetic result for a patient, particularly when an integrated multidisciplinary approach is necessary. Digital smile design has emerged as a tool in cosmetic dentistry that helps both professionals and the patient to visualize the result, in addition to facilitating a discussion between the two before establishing a final treatment decision. Here, we present a case involving a 27-year-old female who underwent multidisciplinary treatment initiated by digital planning using specific software, namely Cara Smile. The patient presented with complaints of maxillary tooth malalignment, staining, and fractures. To obtain the correct width-to-height ratio, a simulated gingival procedure was performed in the software. Gingivectomy was performed using digital simulation, and 90 days after surgery, cast and wax-up models maintaining the previously planned width-to-height ratio for the maxillary anterior teeth were made. Esthetic crowns and veneers were fabricated using the digital planning protocol. Therefore, Cara Smile is useful to facilitate the diagnosis through digital photos, improve communication between the various professionals involved in treatment, and guide the predictability of treatment and patient acceptance.

Esthetic Rehabilitation with Direct Composite Resin in a Patient with Amelogenesis Imperfecta: A 2-Year Follow-Up.

Amelogenesis imperfecta is a group of conditions caused by over 15 different genes that affects the development of dental enamel and poses some challenges to dentists. An adult patient with amelogenesis imperfecta with severe changes in tooth color and reduction of occlusal vertical dimension sought dental treatment. Diagnostic wax-up was carried out to guide the stratification of a nanoparticulate resin for the restorative treatment. Direct composite resin restorations were applied on all teeth for modification of both esthetics and occlusion. After a 2-year follow-up, the findings appear to suggest that composite resin is a low-cost alternative when compared with indirect ceramic restorations, provides a good esthetic outcome, and offers considerable longevity for cases like the one reported herein.

Cutting efficiency of different diamond burs after repeated cuts and sterilization cycles in autoclave.

CONTEXT: The aim was to evaluate the cutting efficiency of different diamond burs after successive cuts and repeated sterilization in an autoclave. The morphology and grit sizes were analyzed and correlated to cutting efficiency. MATERIALS AND METHODS: Ten medium-grit diamond burs of five different manufacturers were investigated (KG, KG Sorensen; TH, Tri-Hawk; KM, Komet; HC, Heico; and FD, Frank Dental). Changes in the cutting efficiency of diamond burs on composite resin blocks were measured after five repeated cuts and after five sterilization cycles. Grit sizes were analyzed by scanning electron microscopy (SEM) and correlated to cutting efficiency. The data were statistically analyzed using 3-way ANOVA and Tukey's test (α = 0.05). RESULTS: Significant differences were observed for diamond burs (P < 0.0001) and condition (P < 0.0001). FD presented the lowest mean cut time (21.88s), followed by KM (36.08s). TH (40.18s), HC (41.65s), and KG (42.23s) had the highest cut times. The number of cuts was not statistically significant. New burs had a significantly shorter cutting time (33.38s) when compared with the ones after sterilization cycles (39.55s). A moderate to strong positive correlation was found between diamond size and cutting time (Pearson's coefficient of 0.77). CONCLUSION: All diamond burs demonstrated lower cutting efficiency after repeated autoclaving. Cutting efficiency did not decrease as the number of cuts increased.

Clinical Steps for Restoration of Fractured Anterior Teeth: Color Protocol with Non-VITA Scale.

Direct composite resin restorations are commonly provided because of their satisfactory esthetics and minimal wear of opposing tooth structure. Recent restorative systems may not follow the nomenclature of the classical VITA shade guide, using instead a simplified resin color system. A better understanding of these systems and their behavior regarding the incidence of light is an excellent approach to anterior restorations, especially for fractured anterior teeth. This paper demonstrates the color selection and clinical sequence for the natural reproduction of tooth structure using a resin system that does not follow the VITA classical scale.

Color stability of ceramic veneers as a function of resin cement curing mode and shade: 3-year follow-up.

The influence of curing mode and shade of resin cements on the color stability of minimum-thickness ceramic veneers after a three-year storage time in distilled water was evaluated in this study. Ninety-six 0.5-mm-thick feldspathic ceramic veneers (Mark II) were luted onto resin composite substrates (Filtek Z350 XT, shade A2E) with two light-cured (NX3 Light-cure and AllCem Veneer) and dual-cured resin cements (NX3 dual-cure and AllCem) in various shades. The specimens were stored in distilled water at 37°C. Color measurements were performed with a spectrophotometer at the following times: 1h and 24h; 7, 30, and 180 days; and 1, 2, and 3 years. Data for color difference (ΔEab) light-cured and dual-cured resin cements were analyzed by two-way ANOVA with repeated measures and Tukey's test (α = 0.05). For the light-cured cements, the ΔEab values were as follows: NX3-Yellow (2.37±1.35) = ACV-A1 (2.40±1.21) = ACV-Trans (2.52±1.46) = ACV-E-Bleach M (2.56±1.42) = NX3-White (2.69±1.49) = NX3-Clear (2.98±1.68). The lowest ΔE values were found for 1 h (0.61±0.36)a, followed by 24 h (1.15±0.55)b and 30 days (2.48±1.11)c. One year, 180 days, and 2 and 3 years presented higher ΔEab values (3.34±0.94, 3.52±1.04, 3.52±0.95 and 3.55±1.14, respectively)d. For the dual-cured cements, the ΔEab values varied as follows: NX3-Clear (2.32±1.24)a = NX3-Yellow (2.37±1.32)a = NX3-White (2.76±1.43)a < AC-Trans (3.77±1.91)b = AC-A3 (4.13±2.11)b < AC-A1 (5.38±2.92)c. Considering time, the lowest ΔEab values were found for 1 h (0.48±0.25)a, followed by 24 h (2.13 ±0.83)b, 30 days (3.54±1.31)c, and 180 days (3,70±1.73)c. The follow-up times of 1 (4.43±2.15)d, 2 (5.02±1.74)e, and 3 years (4.90±2.12)e presented higher ΔEab values. This study demonstrated that light-cured resin cements were less susceptible to color change than dual-cured cements. After 2 years of follow-up, all cements presented ΔEab values above the acceptability threshold.

Micro-CT Analysis of Y-TZP Copings Made by Different CAD/CAM Systems: Marginal and Internal Fit.

PURPOSE: The aim of the study was to measure the marginal and internal adaptation (MIA) of zirconia copings, made of 4 ceramic systems for CAD/CAM, using microcomputed tomography (micro-CT) technology. MATERIAL AND METHODS: Two identical stainless steel models were used, representing a preparation for full ceramic crown on a lower molar. The master models were then scanned for the production of copings from specific yttrium oxide partially stabilized tetragonal zirconia polycrystal ceramic blocks of each system (n=10): Cerec/inCoris Zi, Sirona; Cercon/Cercon base, Dentsply; Ceramill/Ceramill Zi, Amann Girrbach; and Lava/Lava Frame Zirconia, 3M ESPE. MIA was evaluated measuring 4 points as follows: marginal gap (MG), axial wall gap (AW), axio-occlusal angle gap (AO), and central occlusal area gap (CO). The data were statistically analyzed by ANOVA and Tukey's test (α = 0.05). RESULTS: The ceramic system Lava showed greater internal desadaptation (80.75 ± 22.69 µm) while CEREC presented the lowest values (49.92 ± 11.77 µm). There were significant differences between the measurement points evaluated. CO demonstrated the greater values (77.03 ± 22.61 µm). All marginal and internal adaptation values were considered clinically acceptable. CONCLUSION: It was concluded that there was an influence of the type of ceramic system in marginal and internal adaptation of copings in zirconia.

Tooth movement with elastic separators before ceramic veneer treatment: Rearranging asymmetric diastemas by managing the horizontal distance.

The treatment of diastemas should be conservative to preserve tooth structure, and porcelain veneers provide an esthetic solution with minimal tooth preparation. However, asymmetric diastemas can be difficult to treat and may require redistribution of spaces. Additionally, extensive proximal restorations may negatively impact periodontal health. Minor tooth movement with elastic separators can be used to redistribute the interdental spaces and provide space for the interdental papilla. The aim of this paper was to present a clinical treatment involving the movement of peg-shaped maxillary lateral incisors with elastic separators to rearrange the spaces of asymmetric diastemas, thereby managing the horizontal distance during rehabilitation of the smile with minimally invasive ceramic veneers.

Digital smile design and mock-up technique for esthetic treatment planning with porcelain laminate veneers.

The use of digital tools offers a new perspective to daily clinical activities. The digital information serves as a starting point for a wax-up and intraoral mock-up, which is widely reported in literature as an objective and efficient communication tool among dentist, patient, and technician. This case report of a maxillary anterior rehabilitation demonstrates esthetic planning with the digital smile design (DSD) system and a direct mock-up technique. After preoperative photographs were obtained, digital planning was created using DSD. However, due to differences in virtual simulation, a direct mock-up with composite resin was performed. Porcelain laminate veneers using feldspathic ceramics were used to restore the anterior teeth. Many times, the DSD simulation is not enough for the patient to understand and observe the changes that will be performed on the anterior teeth. This combination of techniques can offer predictability to results as well increasing the patient expectation satisfaction.

Effect of surface treatments on the bond strength of CAD/CAM fiberglass posts.

BACKGROUND: There is no ideal protocol for the surface treatment of fiber posts, especially when using a computer-aided design/computer-aided manufacturing (CAD/CAM) experimental fiberglass block. The purpose of this study was to evaluate the bond strength of a CAD/CAM customized glass fiber post and core after applying different surface treatment techniques. MATERIAL AND METHODS: Forty premolars were prepared to receive a customized CAD/CAM glass-fiber post and core obtained from an experimental block of glass fiber and epoxy resin. The specimens were randomly distributed in 4 groups (n=10) according to the post and core surface treatment: ETH - 70% ethanol; HP - 24% hydrogen peroxide for 1 minute; ETH/S - 70% ethanol + silane; HP/S - 24% hydrogen peroxide + silane. The universal adhesive containing silane was applied on the posts and prepared post spaces in all groups. The posts were cemented using dual cure resin cement. The specimens were stored in distilled water at 37°C for 24 h, cut (two slices of 1 mm for each root third - coronal, middle, and apical) and subjected to push-out test (0.5 mm/min). Data was subjected to two-way ANOVA (surface treatment and root third) and Tukey's test (α=0,05). RESULTS: There was no significant difference of bond strength values among groups, regardless the surface treatment (p >0.05). There was significant difference on bond strength values for the different root thirds (p<0.05) (coronal>middle=apical). CONCLUSIONS: The different surface treatment and application of additional silane in the CAD/CAM customized glass-fiber post and core does not interfere on bond strength values. The root dentin third interfered on the bond strength, with higher values for the coronal third. Key words:Post and core technique, cad/cam, shear strength, hydrogen peroxide.

Effect of different bleaching protocols on whitening efficiency and enamel superficial microhardness.

BACKGROUND: Tooth bleaching is a popular aesthetic treatment to modify the color of teeth. Despite the extensive literature concerning the subject, there is still no consensus regarding the application mode of the different bleaching agents and their effect on enamel. Therefore, this study evaluated the influence of different bleaching protocols on whitening efficiency and enamel superficial hardness. MATERIAL AND METHODS: Bovine enamel fragments were embedded in acrylic resin and wet-sanded to obtain a flat buccal surface. The specimens were then randomly divided into 6 groups (n=10), based on the bleaching material [HP Maxx 35% (35% hydrogen peroxide), HP Blue 35% (35% hydrogen peroxide + Ca) and Whiteness Perfect 10% (10% carbamide peroxide)] and application mode (3 applications of 15 min, 1 application of 45 min, 1 application of 1h30 or 1 application of 3h30). The color and superficial hardness were assessed before and after bleaching. The color was assessed by means of a digital spectrophotometer, using CIELab parameters. Vickers hardness was determined using a load of 200g for 10s. Data were statistically analyzed by one-way ANOVA with repeated measures and Tukey's test (α = 0.05). RESULTS: Concerning the color alteration, the groups were similar to each other, except for at-home bleaching protocols, which were statistically different from each other. Similarly, there was a reduction in hardness values comparing the initial and final periods, with lowest final hardness for the at-home bleaching protocol group applied for 3h30. CONCLUSIONS: It can be concluded that the bleaching protocols influenced the final color and enamel surface hardness, evidencing that lower gel concentrations applied for longer periods promoted greater variation in color and lower final hardness. Key words:Tooth bleaching, roughness, microhardness, in-office, at-home bleaching.