Microleakage and enamel finish.

Cavity preparations that are finished with hand instruments allow significantly less marginal leakage than those which are completed only with rotary instruments. This does not mean that hand-instruments walls are perfectly smooth; it only means that these walls allow less marginal leakage. Cavity preparations restored with composite resin showed more marginal leakage than those restored with amalgam. Also, the degree of marginal leakage was greater in cavity preparations restored with composite resin than in those restored with amalgam. Cavity preparations are more prone to marginal leakage at sharply defined cavosurface acute angles than at the smooth or straight surfaces of the cavity. This pattern of marginal leakage was true for both amalgam restorations and composite restorations, but the degree of marginal leakage was greater when composite resin was used as a restorative material. Since less marginal leakage was found in the finished cavity preparations, it is obvious that all cavity preparations must be finished with hand instruments. This may not completely eliminate the problem of marginal leakage, but it will reduce the potential secondary caries both in degree and frequency. Also, since sharply defined acute angles did exhibit more marginal leakage, this part of the cavity preparation needs special attention. With amalgam and composite restorations at least, these angles should not be sharply defined but should be slightly round, so that better condensation of restorative materials can be obtained. This may reduce the degree of marginal leakage.     

Occupational exposures to human immunodeficiency virus, hepatitis B virus, and hepatitis C virus: risk, prevention, and management

Current data indicate that the risk for transmitting bloodborne pathogens in dental health care settings is low. Pre-exposure hepatitis B vaccination and the use of standard precautions to prevent exposure to blood are the most effective strategies for preventing DHCP from occupational infection with HIV, HBV or HCV. Each dental health care facility should develop a comprehensive written program for preventing and managing occupational exposures to blood that: (1) describes the types of blood exposures that may place DHCP at risk for infection; (2) outlines procedures for promptly reporting and evaluating such exposures; and (3) identifies a health care professional who is qualified to provide counseling and perform all medical evaluations and procedures in accordance with the most current USPHS recommendations. Finally, resources should be available that permit rapid access to clinical care, testing, counseling, and PEP for exposed DHCP and the testing and counseling of source patients.     

Comparison of four methods of assessing root surface debridement

BACKGROUND: While there is great interest in measuring the efficacy of root surface debridement, there is little consensus on how this might be best achieved. The aim of this study was therefore to compare four different methods of assessing root surface debridement in their ability to discriminate between ultrasonically instrumented root surfaces and non-instrumented control surfaces. METHODS: Single-session subgingival root debridement was performed by an experienced operator on 30 teeth prior to their extraction. Following extraction, efficacy of root surface debridement was measured by percentage of remaining calculus, instrument efficiency, modified instrument efficiency, and percentage apical plaque border. In addition, the effect of probing depth landmark (apical plaque border versus connective tissue attachment) on outcomes was assessed. RESULTS: The results indicated that percentage apical plaque border demonstrated highly statistically significant differences between instrumented and control surfaces (P= 0.02). No other assessment method was able to discriminate between instrumented and non-instrumented surfaces, and this may be a function of the low amount of root surface calculus in the experimental sample. In addition, choice of probing depth landmark had a notable effect on the outcomes for instrument efficiency and modified instrument efficiency. Ninety-five percent limits of agreement of interexaminer reproducibility were found to be much higher than intra-examiner measurement for all four methods of assessment. CONCLUSIONS: Percentage apical plaque border appeared to be potentially more useful than other methods for assessing the efficacy of debridement of periodontally involved root surfaces, particularly for measuring instrument penetrability.     

Effect of the adhesive application mode and fiber post translucency on the push-out bond strength to dentin

This study evaluated the effect of the adhesive application mode and fiber post translucency on the push-out bond strength to dentin. Bovine roots were endodontically treated, and 10 roots were used for each adhesive application mode: PB (Prime&Bond 2.1), PB + SC (Self-cure activator), PB + SBM (Scotchbond Multi-purpose adhesive system), BB (Brush&Bond), BB + CAT (chemical catalyst), and BB + SBM. The translucent Light-Post and Aestheti-Post were cemented. The roots/cemented posts were transversally sectioned to originate three thirds (cervical, middle, and apical). The push-out test was performed, and the failure mode of fractured specimens was analyzed. There was no difference between the fiber posts. For PB and BB, the use of hydrophobic adhesive resin SBM increased post bond strength. The use of SC and CAT catalyst did not affect the push-out bond strength values. The apical third presented the lowest bond strengths.     

Management of hemangiomas and pediatric vascular malformations

Pediatric vascular anomalies can be difficult to diagnose and complex to treat. One must be able to distinguish hemangiomas from various vascular malformations, as well as appreciate their dynamic course with time. Thorough understandings of the clinical and diagnostic techniques used to evaluate these lesions are paramount for the treating surgeon. In addition, knowledge of current treatments from watchful waiting to radical extirpation is mandatory. This must all be done in the setting of a developing child. We present a current review of the literature regarding the comprehensive care of pediatric vascular lesions.     

Validity of multislice computerized tomography for diagnosis of maxillofacial fractures using an independent workstation

OBJECTIVE: The purpose of this study was to demonstrate the sensitivity and specificity of multislice computerized tomography (CT) for diagnosis of maxillofacial fractures following specific protocols using an independent workstation. STUDY DESIGN: The study population consisted of 56 patients with maxillofacial fractures who were submitted to a multislice CT. The original data were transferred to an independent workstation using volumetric imaging software to generate axial images and simultaneous multiplanar (MPR) and 3-dimensional (3D-CT) volume rendering reconstructed images. The images were then processed and interpreted by 2 examiners using the following protocols independently of each other: axial, MPR/axial, 3D-CT images, and the association of axial/MPR/3D images. The clinical/surgical findings were considered the gold standard corroborating the diagnosis of the fractures and their anatomic localization. The statistical analysis was carried out using validity and chi-squared tests. RESULTS: The association of axial/MPR/3D images indicated a higher sensitivity (range 95.8%) and specificity (range 99%) than the other methods regarding the analysis of all regions. CONCLUSION: CT imaging demonstrated high specificity and sensitivity for maxillofacial fractures. The association of axial/MPR/3D-CT images added important information in relationship to other CT protocols.     

Effect of mechanical cycling on the flexural strength of densely sintered ceramics.

OBJECTIVES: The aim of this study was to evaluate the effect of mechanical cycling on the biaxial flexural strength of two densely sintered ceramic materials. METHODS: Disc shaped zirconia (In-Ceram Zirconia) and high alumina (Procera AllCeram) ceramic specimens (diameter: 15 mm and thickness: 1.2 mm) were fabricated according to the manufacturers' instructions. The specimens from each ceramic material (N=40, n=10/per group) were tested for flexural strength either with or without being subjected to mechanical cycling (20,000 cycles under 50 N load, immersion in distilled water at 37 degrees C) in a universal testing machine (1 mm/min). Data were statistically analyzed using two-way ANOVA and Tukey's test (alpha=0.05). RESULTS: High alumina ceramic specimens revealed significantly higher flexural strength values without and with mechanical cycling (647+/-48 and 630+/-43 MPa, respectively) than those of zirconia ceramic (497+/-35 and 458+/-53 MPa, respectively) (p<0.05). Mechanical cycling for 20,000 times under 50 N decreased the flexural strength values for both high alumina and zirconia ceramic but it was not statistically significant (p>0.05). SIGNIFICANCE: High alumina ceramic revealed significantly higher mean flexural strength values than that of zirconia ceramic tested in this study either with or without mechanical cycling conditions.     

Pain experienced by patients during periodontal maintenance

BACKGROUND: The aims of this study were to determine: 1) the degree of pain experienced by patients during probing and debridement; 2) whether the treating hygienists could estimate the degree of pain experienced by the patients; and 3) whether the patients' pain responses could be predicted by factors such as the patients' age, gender, number of residual periodontal lesions, and answers to a questionnaire on dental anxiety. METHODS: Prior to periodontal maintenance procedures, two groups of 20 adult patients to be treated by two hygienists completed an anxiety questionnaire. Subsequently, measurements of probing depths were performed, followed by pain ratings by each patient using a visual analog scale (VAS). The hygienists also completed a VAS, estimating the pain level they perceived their patient to have experienced. The same protocol was repeated for instrumentation (debridement). RESULTS: Most patients showed low pain responses to both probing and instrumentation. However, using an arbitrary threshold of VAS > or = 40 mm, 20% to 33% of the patients had a significant pain experience. The hygienists were quite accurate in their relative estimates of their patients' pain experiences. Regression analyses disclosed that significant portions of the pain responses could be predicted by the patients' answers to one of the dental anxiety questions. CONCLUSIONS: Recognition of patients who are likely to experience significant pain during periodontal treatment may be facilitated by the use of one question on dental anxiety. During treatment, the ability to gauge and respond to patients' pain experiences would seem to be an important component of a therapist's clinical skills.