Delayed Application Effect on Bond Strength of a Unidose Bonding Adhesive.

Adequate bonding between tooth structure and a composite is among the factors affecting long-term clinical success. Adhesives contain solvents, which are known to evaporate. The researchers sought to determine whether bond strength could be adversely affected when a package of a popular adhesive was left open during a patient visit.

Is Your Dental Adhesive Forgiving? How to Address Challenges.

The quality of the bond at the tooth-restoration interface is crucial to the clinical success of composite restorations. Not only is the adhesive crucial, but equally or even more important is the application. This article addresses pitfalls in the bonding technique, such as over-wetness/over-dryness, over-etching, airthinning, and evaporation. Dental adhesives that are considered forgiving are less technique sensitive, thus potentially yielding more reliable bonding under various clinical conditions.

Introduction to Clinical Practice in Dentistry: Transitioning from Pre-clinical to Clinical Student Doctors at The University of Tennessee Health Science Center College of Dentistry.

Matriculation from the pre-clinical setting to the clinical environment is a tremendous accomplishment and exemplifies the student's perseverance in learning the fundamental concepts necessary for success in the clinical application of dentistry. In an effort to maximize its educational philosophy for the teaching program, the University of Tennessee's College of Dentistry has implemented Introduction to Clinical Practice I and II within the dental curriculum. Introduction to Clinical Practice I and II are designed to help the dental students effectively and smoothly transition to the clinical setting from the classroom and pre-clinical setting. This article describes the university's efforts and continuous improvements within the pre-clinical dental curriculum for advancing students to the clinics. The purpose of this article is to provide helpful information to other dental educational institutions on how to assist their pre-clinical dental students in transitioning to clinical student-doctors.

We May Have Done Something Right: Composite Restorations at the College of Dentistry, University of Tennessee Health Science Center.

The success of composite restorations requires meticulous clinical technique in addition to reliable restorative materials and armamentarium. Early failure of restorations is undesirable and are usually replaced at no cost to patients. A metaanalysis study reported a mean annual failure rate of 1.46% for posterior composite restorations. At the University of Tennessee Health Science Center College of Dentistry (UTHSC CoD) predoctoral clinic the percentage of posterior composite restorations replaced within 12 months, retrieved from 2007-2014 electronic chart 'redo' records, was on average 0.58%. Several factors may have contributed to the quality of composite restorations placed by novice clinicians with modest experience. Student doctors are educated about composite placement in preclinical courses and then work under close supervision during their clinical training. This article describes restorative techniques for composites and the rationales taught at the UTHSC CoD Department of Restorative Dentistry. The objective is to share the information, which can be adopted or modified by general practitioners in daily practice.

Does fluoride gel/foam application time affect enamel demineralization?

The American Dental Association Council on Scientific Affairs recommends a four-minute application of professionally applied topical fluoride, based on clinical evidence for caries reduction. However, some product manufacturers imply that a one-minute application is sufficient. The purpose of this laboratory study was to ascertain if a one-minute application of acidulated phosphate fluoride (APF) is equivalent to a four-minute application for reduction of enamel demineralization. We measured baseline hardness of polished bovine enamel before treatment with APF gel or foam for one or four minutes (N = 10). A control group received no fluoride treatment. The teeth were then immersed in pooled human saliva for 30 minutes, rinsed, and subjected to lactic acid gel to simulate the initial stage of dental caries. After three hours, the hardness was measured and the difference in hardness was determined as an indication of demineralization. We found that enamel hardness was significantly reduced after exposure to lactic acid gel. The reduction was significantly less in all APF-treatment groups compared to the control. However, there was no significant difference between a tooth exposed to APF gel or foam for 1 minute or for 4 minutes (ANOVA/Student-Newman-Keuls, significance level 0.05). In conclusion, APF gel and foam reduced enamel demineralization regardless of a one- or four-minute application time.

Filling cavities or restoring teeth?

Teeth seldom fracture under normal functional loading. This indicates that the natural tooth design is optimized for the distribution of regular masticatory forces by means of its properties and structure. When a tooth is restored with an intracoronal restoration, however, the incidence of tooth fracture increases. Since remaining tissues do not change, the restorative actions apparently alter the original stress distributions. In this study, the effect of different restoration types (unbonded amalgam and bonded composite restorations) were compared with the original stress conditions of the intact tooth, using finite element analysis. It was shown that an unbonded amalgam restoration did not restore the original stress conditions but led to much higher stresses in the buccal and lingual enamel and to higher tensile stresses in the cavity floor. The unbonded amalgam thus filled the cavity but did not restore the tooth. In contrast, a bonded composite restoration restored the original stress pattern in the tooth if there was no polymerization shrinkage. Polymerization shrinkage causes residual tensile stresses in the dentin around the cavity and in the buccal and lingual enamel. Residual tensile stresses in the buccal and lingual enamel are momentary compensated by compressive stress components during occlusal loading. It was concluded that bonding and elimination of residual stresses are prerequisites for restoring the original tooth integrity.