Biomedical subjects

Luiz Narciso Baratieri

Publications and source records attributed to Luiz Narciso Baratieri.

At least 19 recordsLinked to original sources

PubMed2006

Dentin bond strengths of simplified adhesives: effect of dentin depth.

The objective of this study was to compare the shear bond strength of 3 simplified adhesive systems applied on shallow vs deep dentin. For superficial dentin, 30 human molars were sectioned with a diamond saw to expose dentin immediately below the dentoenamel junction. For deep dentin, 30 molars were sectioned 3 mm below the dentoenamel junction. The teeth were mounted, polished to 600-grit, and randomly assigned to 3 groups (n=10): Single Bonda and OptiBond Solo, total-etch adhesives, and Clearfil Liner Bond 2V, a self-etching primer adhesive. Adhesives were applied, the restorative material Filtek Z250 inserted in a No. 5 gelatin capsule, and light-cured. After 24 hours in water at 37 degrees C, shear bond strength was measured with an Instron at 5 mm/min. The data were analyzed with 2-way ANOVA and Duncan's post-hoc test. The results showed the following shear bond strengths (mean +/- SD in MPa): Single Bond/superficial dentin = 22.1 +/- 2.8; Single Bond/deep dentin = 14.2 +/- 7.0; OptiBond Solo/superficial dentin = 18.9 +/- 4.1; OptiBond Solo/deep dentin = 18.4 +/- 4.8; Clearfil Liner Bond 2V/superficial dentin = 21.0 +/- 7.4; Clearfil Liner Bond 2V/deep dentin = 17.6 +/- 5.9. There were no significant differences between mean shear bond strength for the factor "adhesive system" (P>.822). The Duncan's test showed that Single Bond resulted in higher shear bond strength on superficial dentin than on deep dentin. The mean shear bond strength for Clearfil Liner Bond 2V and OptiBond Solo were not influenced by dentin depth. When data were pooled for dentin depth, deep dentin resulted in statistically lower bond strengths than superficial dentin (P<.01). The influence of dentin depth on shear bond strength depends on the specific composition of the dentin adhesive.

Analysis of Variance↗

PubMed2006

Effect of led light curing on the marginal sealing of composite resin restorations.

Light-emitting diode (LED) curing units are becoming increasingly popular; however, questions remain about their ability to adequately polymerize composite resins. This study was conducted to evaluate the marginal seal of restorations placed with a tungsten halogen curing unit compared to three LED curing units through a microleakage test. The results did not indicate statistical differences between the groups tested for both enamel and dentin margins. Variation of the light-curing unit (quartz tungsten halogen or LED) did not result in discernible differences in the marginal sealing of composite restorations.

Bisphenol A-Glycidyl Methacrylate↗

PubMed2005

Effect of placement techniques on the marginal adaptation of Class V composite restorations.

STATEMENT OF THE PROBLEM: Several techniques are proposed for the restoration of Class V cavities but there is no agreement in the literature as to which technique is more effective. PURPOSE: To evaluate the effect of different techniques of composite increment placement on the marginal adaptation of Class V restorations. METHODS AND MATERIALS: Twenty-four human molars were selected and prepared with standardized saucer-shaped cavity dimensions of 3.0 mm (occlusal-gingival), 2.0 mm (mesial-distal), and 2.0 mm (depth). The margins are in reference to the cemento-enamel junction with 1.5 mm being located on enamel and 1.5 mm on dentin. The cavities were randomly assigned into three groups (n=8) and restored with composites as follows: Group 1, the occlusal increment was placed and cured first followed by the gingival increment; Group 2, the gingival increment was placed and cured first followed by the occlusal increment; and Group 3, the cavities were restored with one bulk increment. Restorations were immediately finished and stored for 24 h in tap water. Specimens were subjected to thermocycling (1000 cycles, 5 degrees C to 55 degrees C, 30 s dwell time) and immersed in 0.5% basic fuchsin solution for 24 h in room temperature. After rinsing with running water, the restorations were sectioned longitudinally and enamel and dentin margins were evaluated and scored according to the microleakage on a 0-3 scale. Data were subjected to Kruskal-Wallis test at p<0.05. RESULTS: Median of microleakage scores for all evaluated groups was zero. No statistical difference was observed among the three groups both in enamel (p = 0.5929) and dentin (p = 0.3679) margins CONCLUSION: The placement technique did not influence the marginal adaptation of moderate Class V restorations. CLINICAL SIGNIFICANCE: No differences on marginal adaptation were observed when restoring conservative Class V cavities using incremental or bulk placement techniques.

Bisphenol A-Glycidyl Methacrylate↗

PubMed2005

Influence of the duration of treatment using a 10% carbamide peroxide bleaching gel on dentin surface microhardness: an in situ study.

This in situ study evaluated the influence of two home-use tooth bleaching regimes (1 hour/day and 7 hours/day) using 10% carbamide peroxide (Nite White Excel 2Z) on the surface microhardness of dentin over a 21-day period. Nine blocks of dentin derived from the teeth of subjects, each with at least two thirds molar in need of extraction, were obtained from the cervical region and submitted to surface-hardness analysis (Shimadsu HMV/2000), fixed to an intraoral palate device fabricated for each subject, and positioned (3 left side, 3 right side, 3 center) according to experimental group. During the bleaching period, casts bearing the whitening agent were applied to the blocks for 7, 1, and 0 hours, respectively (7 left side, 3 right side, 0 center). After the treatment period, the specimens were once again submitted to microhardness analysis, using the same equipment as before, and then analysis of variance and the Scheffé test were applied to the mean differences between the initial and final evaluations. The results demonstrated that the statistical difference between the 1-hour and 7-hour groups was not significant. However, the 7-hour group, when compared with the control group, demonstrated statistically significant differences with a reduction in microhardness. Despite the occurrence of mineral loss in the 1-hour and 7-hour groups, this difference was only 3.1% and 5.4%, respectively, which allows one to conclude that these values probably have no clinical significance.

Adolescent↗

PubMed2005

Porcelain veneers as an alternative for the esthetic treatment of stained anterior teeth: clinical report.

The esthetic treatment of anterior teeth with porcelain veneers is a conservative and lasting treatment option. When the tooth is severely discolored, the clinician must choose a ceramic system very carefully, because translucent materials, such as hot-pressed ceramic, require excessive reduction of the dental structure to mask the discoloration. This article describes a technique in which discolored teeth were masked in a conservative and esthetically pleasing way with feldspathic porcelain veneers.

Adolescent↗

PubMed2004

Flowable composites as "filled adhesives:" a microleakage study.

OBJECTIVE: The purpose of this in vitro study was to investigate the microleakage at dentin margins of a flowable resin composite associated with an adhesive, either light cured separately or co-cured, in Class V cavities. MATERIALS AND METHODS: Twenty four recently extracted human molars were prepared with standardized box-shaped Class V cavities of 3.0 mm (mesial-distal), 2.0 mm (occlusal-gingival), and 2.0 mm depth with margins located on enamel and dentin/cementum on the buccal or lingual surfaces. The cavities were randomly assigned into three groups (n=8): Group I - Single Bond + Filtek Z250 (control); Group II - Single Bond + Filtek Flow (light cured separately) + Filtek Z250; and Group III - Single Bond + Filtek Flow co-cured (light cured simultaneously) + Filtek Z250. After being immersed in tap water for 24 h, the specimens were thermocycled (1000x, 5 degrees -55 degrees C, 30 sec dwell time) and immersed in a 0.5% basic fuchsine solution for 24 h. The restorations were sectioned longitudinally and gingival margins were evaluated for microleakage using a 0-4 scale. Data were subjected to the Kruskal-Wallis test at p<0.05. RESULTS: A statistically significant difference at p = 0.0044 between Groups 1 and 3 and Groups 2 and 3 was observed. Although Group 2 performed slightly better than Group 1, no significant difference was observed. CONCLUSION: The use of a flowable resin composite cured simultaneously with an adhesive yielded the worst results in this study. As no statistical differences were seen between Groups 1 and 2, the use of a flowable composite as a means of minimizing microleakage at dentin margins may be questioned.

Adhesives↗

PubMed2004

Effect of posterior resin composite placement technique on the resin-dentin interface formed in vivo.

OBJECTIVE: The aim of this study was to evaluate the morphology of the resin-dentin interface formed in vivo with two posterior resin composite placement techniques (incremental and bulk). METHOD AND MATERIALS: After approval from the patients, 12 Class II cavities with margins in enamel (2.5 x 2.5 x 4.5 mm) were prepared in caries-free premolars scheduled to be extracted for orthodontic reasons (n = 6). The cavities were restored with Single Bond + Filtek P60 as a bulk condensable technique or Single Bond + Filtek Z250 as an oblique incremental technique. After 1 week, the teeth were extracted with minimal trauma to the restored area. After the teeth were sectioned, a polyvinyl siloxane impression was taken from the resin-dentin interface to control for artifacts created during preparation for scanning electron microscopy. The specimens were subsequently processed for and observed under a scanning electron microscope to assess gap formation. RESULTS: The mean percentage of gap formation was 6.1% for teeth restored with the incremental placement technique and 18.7% for teeth restored with the bulk placement technique. The difference was statistically significant. CONCLUSION: The incremental placement of posterior resin composites may still provide better seal than the new bulk condensable technique.

Bicuspid↗

PubMed2004

Bonding to cervical sclerotic dentin: effect of acid etching time.

PURPOSE: The aim of this in vitro study was to evaluate the microtensile bond strengths (MTBS) of two total-etch one-bottle adhesive systems to natural cervical lesions with 2 different etching times (15 s vs 30 s). MATERIALS AND METHODS: Thirty-two human canines and premolars with saucer-shaped noncarious cervical defects were cleaned and randomly assigned to 4 groups. The adhesive systems - Single Bond (SB; 3M ESPE) or OptiBond Solo Plus (OP; Kerr) - were applied on cervical dentin after acid etching with the proprietary acid gel (35% or 37.5% phosphoric acid) for 15 s (manufacturer's instruction) or for 30 s. The respective hybrid composite was inserted in three increments and light cured. After 24 h water storage, the specimens were cut perpendicularly with a low-speed diamond saw (Isomet) to obtain slices with a cross section of ca 0.8 mm. After that, the slices were trimmed with a diamond bur to obtain a surface area of 0.7 +/- 0.05 mm2 (n = 12). MTBS was measured in a Bencor device with an Instron machine at a crosshead speed of 0.5 mm/min. The data were subjected to two-way ANOVA and Tukey's LSD post-hoc test (p < 0.05). RESULTS: MTBS are given in MPa (mean +/- SD), where means with the same superscript letter are not statistically different at p < 0.05: OP15 = 30.9 +/- 8.8ab, SB15 = 25.6 +/- 9.6bc, OP30 = 19.0 +/- 4.8c, SB30 = 35.9 +/- 11.0a. When data were pooled for "adhesive system", SB resulted in statistically higher bond strengths than OP (p < 0.043). "Acid etching time" had no significant effect (p < 0.766), but the interaction of the two main factors yielded significant differences (p < 0.0001). Extending etching time to 30 s resulted in a more predictable bond to noncarious cervical sclerotic dentin with SB, but resulted in lower MTBS with OP. CONCLUSION: Composite bonding to cervical sclerotic noncarious dentin may depend on acid demineralization capacity and bonding system. Knowing the etching demineralization rates of the commercially available acid etching seems to be an important factor for selecting the best acid-etching time of cervical sclerotic dentin.

Acid Etching, Dental↗

PubMed2004

Direct posterior resin composite restorations: considerations on finishing/polishing. Clinical procedures.

In spite of advances in materials and techniques for direct posterior composite restorations, some problems remain, such as occlusal wear rate, marginal breakdown, and marked operator technique sensitivity. To enhance longevity of these restorations, finishing and polishing procedures are commonly indicated. Although these procedures offer advantages, they also have some drawbacks, such as higher marginal breakdown and increased susceptibility to wear following finishing procedures. Faced with the disadvantages brought by finishing and polishing procedures, it seems reasonable to try and find a technique to omit them. This paper presents clinical cases exhibiting a restorative technique that prevents, or at least reduces, the need for instrumentation of the restoration. In cases when finishing procedures are necessary, the restorations should be sealed with a specific resinous agent to impart new strength to the instrumented surface and improve marginal integrity. In addition, the suggested technique promotes a better occlusal anatomy than that attained with the traditional technique.

Acid Etching, Dental↗

PubMed2004

Contemporary trends and techniques in tooth whitening: a review.

UNLABELLED: The popularity of tooth whitening has increased with the advent of patient-applied, peroxide-based whitening agents, as well as increased media influence. Peroxides are considered effective and safe when used under professional supervision. Whitening methods include those prescribed by a dental professional for the patient's at-home use, those applied by the dental professional in the office, a combination of both, or methods available over the counter (OTC). This article reviews the effect of contemporary whitening agents and illustrates the clinical application of three methods prescribed by dental professionals. LEARNING OBJECTIVES: This article presents the use of three different types of whitening agents for improved aesthetics. Upon reading this article, the reader should be able to: Distinguish the difference between professionally administered in-office and at-home tooth-whitening results. Identify the effects of whitening agents on dental tissues.

Humans↗

PubMed2004

Microtensile bond strength to root canal vs pulp chamber dentin: effect of bonding strategies.

PURPOSE: The aim of this in vitro study was to compare the microtensile bond strength (MTBS) between root canal and pulp chamber dentin with two bonding strategies (self-etching primer and total-etch technique). MATERIALS AND METHODS: The pulp chamber of four human canines was accessed and the pulp chamber and root canal prepared with spiral drills. The teeth were cut into halves parallel to the long axis of the tooth and randomly assigned to two groups: Clearfil SE Bond + AP-X(SE) (Kuraray) and SingleBond + Filtek Z250(SB) (3M ESPE). After 24 h in water storage, the specimens were cut perpendicular to the root into 1.0-mm slices with a low-speed diamond saw. Specimens were trimmed to obtain hourglass shapes with a bond area of 1.0 mm2 (n = 12). Three specimens were obtained from the cervical root canal dentin (R) and from the coronal pulp chamber dentin (C). The MTBS was measured in a Bencor device with an Instron machine at a crosshead speed of 0.5 mm/min. The data was analyzed with two-way ANOVA and Tukey LSD post hoc (p < 0.05). RESULTS: MTBS in MPa (mean +/- SD) were: SB.C = 25.3 (+/-6.5)a; SB.R = 16.9 (+/-6.0)b; SE.C = 16.9 (+/-3.4)b; SE.R = 16.8 (+/-5.3)b. Means with the same letter are not statistically different at p < 0.05. When data were pooled for "dentin region", coronal pulp chamber dentin resulted in statistically higher bond strengths than root canal dentin (p < 0.013). CONCLUSION: Bonding to pulp chamber dentin seems to be more predictable than to root canal dentin. In the former region, the total-etch technique may result in a higher bond strength.

Acid Etching, Dental↗

PubMed2003

Using opaquers under direct composite resin veneers: an illustrated review of the technique.

UNLABELLED: In restorative dentistry direct composite resin materials can be used to conservatively resolve many esthetic problems. Opaque resins are often necessary to mask discolorations and/or dark backgrounds when restoring anterior teeth. This article presents a direct composite resin veneer technique using opaquers. Potential problems with the tone of restorations after the use of opaquers are discussed. Advantages, limitations, and the clinical technique are presented. Training, as well as attention to the technique, contributes to an acceptable result. CLINICAL SIGNIFICANCE: Resinous opaquers can be used as a valid adjunct to the direct composite resin veneer technique when conservatively restoring dark teeth.

Child↗

PubMed2003

Ceramic inlays and onlays: clinical procedures for predictable results.

UNLABELLED: The use of ceramics as restorative materials has increased substantially in the past two decades. This trend can be attributed to the greater interest of patients and dentists in this esthetic and long-lasting material, and to the ability to effectively bond metal-free ceramic restorations to tooth structure using acid-etch techniques and adhesive cements. The purpose of this article is to review the pertinent literature on ceramic systems, direct internal buildup materials, and adhesive cements. Current clinical procedures for the planning, preparation, impression, and bonding of ceramic inlays and onlays are also briefly reviewed. A representative clinical case is presented, illustrating the technique. CLINICAL SIGNIFICANCE: When posterior teeth are weakened owing to the need for wide cavity preparations, the success of direct resin-based composites is compromised. In these clinical situations, ceramic inlays/onlays can be used to achieve esthetic, durable, and biologically compatible posterior restorations.

Biocompatible Materials↗

PubMed2003

Tooth fragment reattachment: fundamentals of the technique and two case reports.

Coronal fractures must be approached in a methodical and clinically indicated way to achieve successful restoration. One option for treatment is reattachment of the dental fragment. Reattachment creates a very positive emotional response in the patient and simplifies the maintenance of the patient's original occlusion. This article discusses dental fragment reattachment techniques and presents clinical cases of coronal fracture involving enamel, dentin, and pulpal exposure.

Adolescent↗

PubMed2003

Direct adhesive restoration of anterior teeth: Part 2. Clinical protocol.

Contemporary adhesive restorations allow clinicians to deliver minimally invasive, functional, and aesthetic treatment for compromised dentition in the anterior and posterior regions. Part 1 of this article discussed the state-of-the-art relating to composite restorations, both in situations deemed to be relatively uncomplicated and those that are more complicated. This second part discusses the clinical protocol for the placement of direct composite materials as well as the tooth preparation considerations that must be addressed when providing minimally invasive treatment options.

Clinical Protocols↗

PubMed2003

Direct adhesive restoration of anterior teeth. Part 1. Fundamentals of excellence.

Contemporary composite resin materials have significantly evolved, facilitating the delivery of aesthetic and functional restorations. The predictability of this treatment modality has been significantly improved by the introduction of adhesive protocols. This three-part series proposes a simplified protocol and the fundamentals for minimally invasive, aesthetic, direct adhesive restorations of anterior teeth. The first part of this series offers an overview of the state-of-the-art relating to composite restorations, both in situations deemed to be relatively uncomplicated and those that are more challenging.

Adhesives↗

PubMed2003

Direct adhesive restoration of anterior teeth: Part 3. Procedural considerations.

Direct composite restorations represent a minimally invasive, aesthetic treatment option. The development of contemporary bonding procedures has allowed for improved aesthetics and restorative success. Incorporation of predictable adhesive protocols will increase the restoration's longevity and durability. This article presents the restorative procedures, adhesive protocol, and insertion considerations that must be addressed when using resin bonded options.

Acid Etching, Dental↗

PubMed2002

Effect of bleaching agents on the hardness and morphology of enamel.

PURPOSE: The goal of the present laboratory study was to analyze the effect of two home bleaching agents (Opalescence 10%, Ultradent, and Hi-Lite II, Shofu) as well as the separate solutions of 10% carbamide peroxide primary components (3% hydrogen peroxide and 7% urea) on enamel microhardness and surface morphology. MATERIALS AND METHODS: Thirty human molars stored in water for no longer than 3 months were selected. Their facial and lingual surfaces were embedded in acrylic resin, and the specimens were polished with up to 600-grit sandpaper. The 30 molar sections were divided into five groups as per treatment modality (n = 6); group 1, 10% carbamide peroxide bleach with carbopol (Opalescence, Ultradent); group 2, oxygen-free gel bleach (Hydroxylite, Hi-Lite II, Shofu); group 3, 3% hydrogen peroxide with carbopol (Dermus Pharmacy, Florianópolis, SC, Brazil); group 4, 7% urea treatment (Dermus Pharmacy); and control, group 5, artificial saliva (Dermus Pharmacy). Prior to treatment, six indentations (Vickers) were made on each of the six surfaces in each group under a load of 100 g for 30 seconds. Bleaching procedure was conducted for 3 hours per day for 2 weeks, the control group excepted. Following each bleaching session, the specimens were washed with deionized water and kept in artificial saliva at 37 degrees C, this solution being changed daily. Pre- and post-treatment microhardness data were analyzed using a two-way analysis of variance. In a similar way, 30 other specimens underwent the same procedures. After the bleaching period, the samples were observed under the scanning electron microscope. RESULTS: Specimens submitted to bleaching treatment with 3% hydrogen peroxide gel as described in this study showed a significant reduction of surface microhardness (p < .0001). The other treatment modalities had no effect on surface microhardness. No morphologic alterations were observed on enamel submitted to bleaching gel of 10% carbamide peroxide (Opalescence), oxygen-free gel (Hi-Lite II, Shofu), or 7% urea solution compared with the control (artificial saliva). However, the specimens bleached for 3 hours per day for 2 weeks with 3% hydrogen peroxide gel presented areas of mild erosion. The effect, nevertheless, was not uniform, occurring with varying intensity on all samples of enamel bleached with 3% hydrogen peroxide. CLINICAL SIGNIFICANCE: Bleaching treatment conducted with two home bleaching agents (Opalescence 10%, Ultradent, and Hi-Lite II, Shofu) had no adverse effects on enamel microhardness or on surface morphology. Bleaching with 3% hydrogen peroxide can have a negative effect on enamel hardness and surface morphology when performed as described in this study.

Acrylic Resins↗