bluuebunny/crossref_metadata_2025_split huggingface dataset:
Primarily Research
Authors: PAUL STEFAN J. , SCHARER PETER 
Published: July 2007

Dentin bonding has been the object of intensive research for many years. If a substance is expected to bond to a natural tooth surface, the morphologic and physiologic characteristics of the substrate determine both the bonding applications and testing methods used.This two‐part article is a literature review. Part I is a detailed description of the structure of dentin. In Part II the importance of intrapulpal pressure on understanding bonding and testing will be discussed.
Rationalization of Esthetic Restorative Dentistry Based on Biomimetics
Authors: MAGNE PASCAL , DOUGLAS WILLIAM H. 
Published: July 2007

Abstract: The exponential progressivism that characterizes the current decade often comes with substantial financial implications. Dental care is not spared by this phenomenon. However, new generations of concepts emerging from biomimetics provide the operator with the ability to restore the biomechanical, structural, and esthetic integrity of teeth. The development of adhesion and the evolution of porcelain veneers constitute striking examples of this nascent process. Indications for bonding porcelain are extending to more perilous situations (crown‐fractured incisors, nonvital teeth), resulting in considerable improvements, comprising both the medical‐biologic aspect (economy of sound tissues and maintenance of tooth vitality) and the socioeconomical context (decrease of costs compared to traditional and more invasive prosthetic treatments).CLINICAL SIGNIFICANCE: In the bonded porcelain veneer and its extensions, restorative dentistry has found new solutions for the anterior segment that balance the need for functional and esthetic reconstruction. The optimal stiffness of porcelain in thin section, the ideal surface characteristics, and the biomechanical continuum achieved through high performance bonding mean the crown of the tooth as a whole can support incisal or masticatory function. By the same token, the conduction of optical effects from within the tooth combined with the ideal surface features of the porcelain veneer make this restorative approach the ultimate in esthetic satisfaction, for both the practitioner and the patient.
Laboratory Evaluation and Clinical Application of a New One‐Bottle Adhesive
Authors: PERDIGÃO JORGE , BARATIERI LUIZ N. , LOPES MANUELA 
Published: July 2007

Abstract: Purpose: The purposes of this project were to compare the enamel and dentin bond strengths of a new nanofilled one‐coat adhesive system with its predecessor, an unfilled two‐coat adhesive system; to analyze the dentin interfacial ultramorphology, using scanning and transmission electron microscopy (SEM and TEM); and to illustrate the clinical technique associated with the use of the new nanofilled one‐coat adhesive system. Material and Methods: Twenty flat dentin surfaces and 20 flat enamel surfaces were polished on the labial surface of bovine incisors mounted in acrylic resin. The specimens were equally and randomly assigned to four bonding groups: (1) dentin with Prime & Bond 2.1; (2) dentin with Prime & Bond NT; (3) enamel with Prime & Bond 2.1; and (4) enamel with Prime & Bond NT. A composite post was then adapted to the treated area and light‐cured. After thermocycling, shear bond strengths were determined by testing the shear strength of the specimens. The data were analyzed using one‐way analysis of variance (ANOVA) and Student's t‐test. For SEM and TEM, six dentin disks were obtained from middle dentin of human third molars and assigned equally to each adhesive. The adhesives were applied to dentin according to manufacturer's directions. The hybrid layer and resin penetration into dentin tubules were analyzed at an ultramorphologic level, and the observations were compared. Results: Shear bond strengths were as follows: group 1: 17.8 + 4.1 MPa; group 2: 20.5 + 3.5 MPa; group 3: 24.7 + 6.7 MPa; and group 4: 27.0 + 5.4 MPa. Electron microscopy showed that both adhesives penetrated the dentin tubules and formed a fully infiltrated hybrid layer. The nanofiller included in the new one‐application adhesive penetrated the dentin tubules and infiltrated the microspaces between the collagen fibers within the hybrid layer.
Two‐Year Clinical Evaluation of Tooth Whitening Using an At‐Home Bleaching System
Authors: SWIFT EDWARD J. , MAY KENNETH N. , WILDER ALDRIDGE D. , HEYMANN HARALD O. , BAYNE STEPHEN C. 
Published: July 2007

Abstract: Purpose: The purpose of this study was to evaluate the 2‐year effectiveness of a carbamide peroxide at‐home bleaching gel used to provide tooth lightening treatment. Material and Methods: Twenty‐nine patients participated in the original study, during which they treated their maxillary teeth with a 10% carbamide peroxide gel nightly for 2 weeks. Shades were determined before and after treatment by comparison with a Vita shade guide. Twenty‐four patients (a recall rate of 83%) were recalled for evaluation 2 years after the initial bleaching treatment. The shade of the maxillary incisors was evaluated and compared with shades before, immediately after, and at 6 months and 2 years after initial treatment. Data were analyzed using a repeated‐measures analysis of variance. Results: At 2 years after bleaching with a 10% carbamide peroxide gel, the median shade was D2, a six‐increment difference from the baseline median of D3. Twenty of 24 patients (83.3%) had a shade change of two or more units, which is the threshold value for bleaching efficacy using American Dental Association guidelines. The lightening result remained statistically significant (p <.0001) at 2 years.
Effects of Air Abrasion and Acid Etching on the Microleakage of Preventive Class I Resin Restorations: An In Vitro Study
Authors: FU BAIPING , HANNIG MATTHIAS 
Published: July 2007

Abstract: Purpose: To evaluate the effects of air abrasion, acid etching, and the combination of both procedures on the microleakage of preventive Class I resin restorations. Materials and Methods: Eighty‐four extracted human molar teeth were randomly assigned to seven groups with 12 teeth each. Occlusal fissures were opened with a diamond bur and etched with phosphoric acid (groups I and VI); prepared with a diamond bur without etching (group VII); air abraded with the KCP 1000, using SO‐pm aluminum oxide particles without etching (group 11), and with phosphoric acid etching (group 111); or air abraded with 27‐pm aluminum oxide particles without etching (group IV), and with phosphoric acid etching (group V). Preparations were filled with a low‐viscosity resin composite (Liquicoat, groups I to V) or with a low‐viscosity poly acid‐modified resin composite (PrimaFlow, groups VI and VII). Six teeth in each group were thermo‐cycled (5°‐55°C, 2500 cycles). Dye penetration (methylene blue) was evaluated in ordinal scale. Results: The number of non‐thermocycled and thermocycled specimens revealing no microleakage was as follows: group I, 6 and 1; group II, 2 and 2; group III, 4 and 3; group IVY 0 and 0; group V, 1 and 0; group VI, 3 and 2; and group VII, 0 and 0, respectively. No significant differences existed between the thermocycled specimens and non‐thermocycled specimens, except within group I.
Novel Approach to Measure Composite Conversion Kinetics during Exposure with Stepped or Continuous Light‐Curing
Authors: RUEGGEBERG FREDERICK A. , CAUGHMAN W. FRANK , CHAN DANIEL C. N. 
Published: July 2007

Abstract: Purpose: The objective of this research was to evaluate a novel approach to monitor the polymerization reaction during a light‐curing exposure by using infrared (IR) spectroscopy. Materials and Methods: An IR spectrometer was equipped to use an attenuated total reflectance (ATR) element as an IR‐active substrate. The uncured composite (Herculite XRV, Shade A2, Kerr, Orange, California) was placed against the crystal, and the IR spectrum was continuously obtained during various exposure scenarios. The degree of conversion and the maximum rate of reaction were monitored at 0 mm (top surface), 1 mm, 2 mm, and 3 mm beneath the surface. The exposure conditions included continuous 40‐second or 60‐second exposures at 100% intensity (800 mW/cm2) or a stepped output of 10 seconds at 17% maximal output (133 mW/cm2) followed by full output for the remainder of the 40‐second or 60‐second exposure (Elipar Highlight, ESPE, Norristown Pennsylvania). The results were analyzed using MANOVA with appropriate post hoc tests (p < .05). Results: For 40‐second exposures, the peak conversion rates were significantly reduced (p < .05) when using the stepped exposure mode compared to the continuous exposure: 40‐second top surface: stepped = 5.5%/s ± 0.4, continuous = 10.5%/s ± 1.0; 1 mm step = 3.6%/s ± 0.4, continuous mode = 4.8%/s ± 0.2. The same trend was noted when using the 60‐second exposure. Equivalent conversion values (p > .05) beneath the surface between stepped and continuous exposure modes at similar depths 60 seconds after light initiation were only attained at 3 mm 4for the 40‐second exposure. However, using the 60‐second exposure, equivalent conversion values between step and continuous exposure modes at similar depths were obtained. Even with a reduced conversion rate at the surface using the stepped cure mode, polymerization shrinkage forces were sufficient to debond the specimens from the test crystal after only 20 seconds into the exposure. This result indicated that stress development in the curing composite was non‐uniform, and stress values developed at the surface of the restoration were the greatest.
Margin Gap Size of Ceramic Inlays Using Second‐Generation CAD/CAM Equipment
Authors: STURDEVANT JOHN R. , BAYNE STEPHEN C. , HEYMANN HARALD O. 
Published: July 2007

Abstract: Objective: The goal of this study was to determine if the fit of second‐generation computer‐assisted design/computer‐assisted manufacturing (CAD/CAM) (CEREC 2, Sirona Dental Systems, Bensheim, Germany) inlays within Class II cavity preparations were within the range of 50 to 100 um and were equal or better to CEREC 1 inlays. Materials and Methods: Extracted human molars free of surface defects and caries were prepared with standard mesio‐occlusodistal cavity preparations. Ceramic inlays were fabricated with CEREC 2 CAD/CAM equipment and seated into cavity preparations. Digital images were captured at 100 times magnification. Marginal gaps were measured with an image analysis program. For each restoration, gaps were measured at 12 locations along interproximal margins and 10 locations along occlusal margins. Results: No difficulty occurred in seating any of the milled inlays. Average marginal gaps for occlusal (59 ± 35 um) and interproximal (97 ± 66 μm) margins were statistically different (t‐test, p < .01). Average marginal gap for all sites combined was 80 ± 57 μm. Marginal gap widths were smaller than those obtained from a similar study done earlier with the CEREC 1 unit for occlusal (89 ± 65 μm) and interproximal (105 ± 81 μm) margins. Ease of seating with CEREC 2 inlays was much better than with CEREC 1.
In Vitro Penetration of the Pulp Chamber by Three Brands of Carbamide Peroxide
Authors: THITINANTHAPAN WARAPORN , SATAMANONT PIMONMAS , VONGSAVAN NOPPAKUN 
Published: July 2007

Abstract: Purpose: Vital tooth bleaching has become a popular procedure for whitening teeth. Most home bleaching products contain 10% carbamide peroxide. The purpose of this in vitro study was to measure the quantity of hydrogen peroxide that reaches the pulp chamber from three carbamide peroxide products: Opalescence™, Sparkle™, and Rembrandt™. Materials and Methods: Seventy roots of extracted premolars were amputated approximately 3 mm apical to the cementoenamel junction, and the pulp tissues were removed. They were divided into three experimental groups (n = 20) and a control group of 10 teeth. An acetate buffer solution was placed in the pulp chamber before the crown was exposed to the bleaching agent at 37°C for 25 minutes. The buffer solution was removed and reacted with leukocrystal violet and horseradish peroxidase. The optical density of blue color that developed was measured at a wavelength of 596 nm and read from a standard curve for hydrogen peroxide quantity. Results: The measured amounts of hydrogen peroxide were 3.605 ± 1.405,1.282 ± 0.762, and 0.339 ± 0.251 pg for the Opalescence™, Sparkle™, and Rembrandt™ groups, respectively. A statistically significant difference in the hydrogen peroxide levels was observed by analysis of variance (p < .05) among the three groups. It was concluded that the penetration of commercial bleach ing products was different even though the products were labeled as having the same 10% carbamide peroxide.
Comparing the Perception of Dentists and Lay People to Altered Dental Esthetics
Authors: KOKICH VINCENT O. , ASUMAN KIYAK H. , SHAPIRO PETER A. 
Published: July 2007

Abstract: Purpose: This study was designed to determine the perceptions of lay people and dental professionals with respect to minor variations in anterior tooth size and alignment and their relation to the surrounding soft tissues. Materials and Methods: Smiling photographs were intentionally altered with one of eight common anterior esthetic discrepancies in varying degrees of deviation, including variations in crown length, crown width, incisor crown angulation, midline, open gingival embrasure, gingival margin, incisal plane, and gingiva‐to‐lip distance. Forty images were randomized in a questionnaire and rated according to attractiveness by three groups: orthodontists, general dentists, and lay people; 300 questionnaires were distributed. Results: The response rate was 88.2% for orthodontists, 51.8% for general dentists, and 60.6% for lay people. The results demonstrated threshold levels of noticeable difference between the varying levels of discrepancy. A maxillary midline deviation of 4 mm was necessary before orthodontists rated it significantly less esthetic than the others. However, general dentists and lay people were unable to detect even a 4‐mm midline deviation. All three groups were able to distinguish a 2‐mm discrepancy in incisor crown angulation. An incisal plane cant of 1 mm as well as a 3‐mm narrowing in maxillary lateral incisor crown width were required by orthodontists and general dentists to be rated significantly less esthetic. Lay people were unable to detect an incisal plane asymmetry until it was 3 mm, or a lateral incisor narrowing until it reached 4 mm. Threshold levels for open gingival embrasure and gingiva‐to‐lip distance were both at 2 mm for the orthodontic group. Open gingival embrasure became detectable by the general dentists and lay people at 3 mm, whereas gingiva‐to‐lip distance was classified by these groups as noticeably unattractive at 4 mm.
Clinical Study of Tooth Shade Lightening from Dentist‐Supervised, Patient‐Applied Treatment with Two 10% Carbamide Peroxide Gels
Authors: CIBIRKA ROMAN M. , MYERS MICHAEL , DOWNEY MARY C. , NELSON STEVEN K. , BROWNING WILLIAM D. , HAWKINS ISAAC K. , DICKINSON GENE L. 
Published: July 2007

Abstract: Purpose: Prescribed, patient‐applied tooth lightening agents, or nightguard vital bleaching, typically utilizes a 10% carbamide peroxide agent applied during nocturnal hours. The purpose of this randomized double‐blind study was to compare the amount of tooth color change in two groups of subjects using dentist‐supervised, patient‐applied 10% carbamide peroxide gel. Materials and Methods: One group used Opalescence® (Ultradent Products Inc., South Jordan, Utah) and the other Nite White Excel® (Discus Dental, Inc., Los Angeles, California). Evaluation of tooth color for the six maxillary anterior teeth was done using a Vita shade guide at baseline, 1, 2, and 4 weeks. Subjects were instructed to apply the gel nocturnally using a custom‐made soft tray 8 hours per day for 2 weeks. The 16 tabs of the shade guide were ranked according to value from darkest to lightest. The number (1–16) that correlated to the shade tab selected as the match for each tooth was the outcome variable. A Kruskal‐Wallis one way analysis of variance on ranks was used. Results: The test revealed no statistically significant difference between Opalescence® and NiteWhite® Excel for lightening the teeth (p= .807). The color change was still significant after 2 weeks without further bleaching activity. The baseline evaluation of the maxillary incisors and canines for all subjects, regardless of group, demonstrated a significant shade difference, with the canines being darker. This difference was not seen after 2 weeks of active bleaching or at the 4‐week evaluation.
Restoration of Extensive Erosion Areas Using an Indirect Composite Technique
Authors: KNIGHT JAMES S. , SNEED W. DAN 
Published: July 2007

ABSTRACTCervical erosion defects, particularly those of extensive size that are located in an area where control of the operative field is difficult, can present a significant restorative challenge. This article describes an indirect restorative technique to solve this problem. Following tooth preparation, an indirect restoration is luted to the tooth and the margins are finished and polished. Using an indirect technique minimizes operative field isolation time and the total chairside time required to restore the tooth. Clinical cases are presented to illustrate this technique.CLINICAL SIGNIFICANCEAn indirect composite restoration provides a useful treatment option when restoring extensive erosion defects in areas of difficult access.
Prevalence of Noncarious Cervical Lesions and Their Relation to Occlusal Aspects: A Clinical Study
Authors: TELLES DANIEL , PEGORARO LUIZ FERNANDO , PEREIRA JOSÉ CARLOS 
Published: July 2007

ABSTRACT Purpose: The purpose of this study was to assess noncarious cervical lesions in young patients and to establish a possible relation with occlusal aspects. Materials and Methods: Forty‐eight dental students (28 males; 20 females) between the ages of 16 and 24 years, were investigated to verify the presence of noncarious cervical lesions and their relation to some occlusal aspects. The assessment involved a questionnaire, clinical examinations, and model analysis. Results: The results indicated that the lower first molars (21.3%), the upper first molars (16.0%), the upper first premolars (12.8%), the lower first premolars (11.7%), and the lower second premolars (11.7%) were the teeth most affected by the lesions. Age was a significant factor with respect to the presence of lesions; the students with noncarious cervical lesions were older than the students who showed no lesions. Among the 79 teeth exhibiting lesions, 62 (78.5%) showed wear facets. In the group with lesions, the mean, per subject, was 15.0 teeth with wear facets, whereas in the group without lesions the mean was 10.8 teeth with wear facets per subject, suggesting that occlusal stress has some effect on lesion development.CLINICAL SIGNIFICANCENoncarious cervical lesions are characterized by loss of tooth structure on the cervical area of the tooth and can result in esthetic problems for the patient, as well as discomfort due to the hyper‐sensibility that often occurs at the location of the lesion. The results obtained reinforce the multifactorial theory, shared by several authors, for the etiology of such lesions. However, as the limitations of each etiologic agent begin to be understood, there will be a decrease in the possibility of misleading interpretations of the result of present or future investigations.
Effect of Whitening Agents Containing Carbamide Peroxide on Cariogenic Bacteria
Authors: BENTLEY CAROLYN D. , LEONARD RALPH H. , CRAWFORD JAMES J. 
Published: July 2007

ABSTRACT Purpose: The purpose of this study was to investigate the in vitro antibacterial effects of three different carbamide peroxide products (Nitewhite®, Opalescence®, and Proxigel®) on cariogenic microorganisms (mutans streptococci [MS] and lactobacilli), and to evaluate the effects of a 10% carbamide peroxide solution (Proxigel®) on salivary levels of MS and lactobacilli clinically. Materials and Methods: Growth inhibition studies were performed to determine the concentration and exposure time of carbamide peroxide to give total inhibition of recoverable growth of MS lactobacilli. Paraffin‐stimulated saliva samples were collected from subjects before and after 6 weeks of treatment with 10% carbamide peroxide in bleaching trays, and levels of MS and lactobacilli were determined. Results: The growth inhibition studies showed no visible growth of MS or lactobacilli at 24‐, 48‐, or 72‐hour incubation, after a 2‐hour exposure to 1% carbamide peroxide. Identical results were obtained with all three carbamide peroxide products. In the clinical study, the mean salivary MS levels, expressed as logarithm colony‐forming units per milliliter (CFU/mL), were 5.38 for the pretreatment samples and 5.23 for the post‐treatment samples. The differences were not statistically significant (p > .05). However, there was a reduction in logarithm lactobacilli counts from a mean of 4.12 pretreatment to a mean of 2.74 post‐treatment. This was statistically significant (p < .05).CLINICAL SIGNIFICANCEThis study indicates that carbamide peroxide solution is bacteriostatic for MS and lactobacilli in vitro and could reduce salivary levels of lactobacilli in vivo. Ten percent carbamide peroxide solution, when used in nightguard vital bleaching, is an antimicrobial that may be useful as an anticariogenic agent.
Enamel Microabrasion: A New Approach
Authors: CROLL THEODORE P. , HELPIN MARK L. 
Published: July 2007

ABSTRACTEnamel microabrasion is a proven method of removing superficial intrinsic enamel discoloration defects. The method is safe, easily performed, and causes no discomfort for the patient. A new commercially available microabrasion system has been introduced by Ultradent Products Inc. In addition, a new tooth isolation material is available, along with a visible light‐activated in‐office hydrogen peroxide solution. This article describes these new products and documents tooth‐color correction for two young patients using this new tooth‐color correction approach.CLINICAL SIGNIFICANCEEnamel microabrasion and vital bleaching can be used effectively to treat enamel dysmineralization and associated discoloration in children and adolescents.