Ultraconservative dentistry represents a great step forward for the dentist, the profession, and especially the patient. It involves the early detection and complete elimination of all accessible and non-accessible carious material from the tooth. Untreated caries can be extremely and rapidly destructive. The earliest interception of decay maintains total dental health and increases the likelihood of the restored teeth lasting a lifetime. (+info)
Effect of cavosurface angle on dentin cavity adaptation of resin composites.
The effect of the cavosurface angle of dentin cavities prepared in extracted human molars on the cavity adaptation of a resin composite was evaluated by measuring the gap width between the resin composite and the dentin cavity wall. Cavities with cavosurface angles of 90 degrees, 120 degrees, 135 degrees, or 150 degrees were pretreated with one of two commercial dentin bonding systems or an experimental dentin bonding system. The contraction gap width was measured at both the cavity margin and the section cavity using a light microscope. Complete cavity adaptation was obtained with pretreatment of the experimental groups regardless of the cavosurface angle. The contraction gap observed at the cavity margin was prevented with the two commercial dentin bonding systems when the cavosurface angle was increased to 150 degrees. A high correlation was observed between the contraction gap width and the proportion of the free surface to the adhesive surface of the resin composite restoration. (+info)
The influence of configuration factors on cavity adaptation in compomer restorations.
The effect of configuration factor (C-factor) on cavity adaptation was investigated in three compomer and one resin composite restorations. Eighty-four cylindrical dentin cavities (C-factor: approximately 2.5, 3.0 or 4.0) prepared on flat coronal dentin surfaces were filled with the materials in combination with their proprietary adhesive systems. Cavity adaptation was microscopically examined after 15 minutes storage in water at the top surface and at other four sites along the cavity walls. Additionally, indentation testing was performed for each material at 20 minutes and 24 hours after irradiation. Regression analysis revealed no relationship between C-factor and gap dimension in compomer restorations at any of the measuring sites, while a logarithmic relation was found only at the cavity floor of the composite fillings. All materials showed maturation of mechanical properties. The elastic component of the indentation was smaller in compomers than in the composite. It was concluded that C-factor had no influence on the cavity adaptation for compomer restorations. This might be due to reduced stress generation at the bonding interface caused by relatively low mechanical properties immediately after curing, less elasticity, and water absorption in compomers. (+info)
Setting shrinkage and hygroscopic expansion of resin-modified glass-ionomer in experimental cylindrical cavities.
The effects of the C-value (bonded surface area/unbonded surface area) and the volume of the cavity on the volumetric dimensional changes [volumetric setting shrinkage (VSS) and volumetric hygroscopic expansion (VHE)] of a resin-modified glass-ionomer (RMGI) filled in experimental cylindrical cavities were evaluated. The VSS and the VHE rate decreased with increasing C-value. There was a high inverse regression between the cavity C-value and volumetric dimensional changes, but a low regression between cavity volume and volumetric dimensional changes. Therefore, it was thought that greater contraction stress would remain in high C-value cavities than low C-value cavities during the setting process. It was also confirmed that the volumetric dimensional changes of RMGI in cavity were influenced primarily by the cavity C-value. (+info)
Caries-detector dyes--how accurate and useful are they?
Commercially available caries-detector dyes are purported to aid the dentist in differentiation of infected dentin, yet research has established that these dyes are not specific for infected dentin. They are non-specific protein dyes that stain the organic matrix of less mineralized dentin, including normal circumpulpal dentin and sound dentin in the area of the amelo-dentinal junction. A considerable body of evidence indicates that conventional tactile and optical criteria provide satisfactory assessment of caries status during cavity preparation. There is reason for concern that subsequent use of a caries-detector dye would result in unnecessary removal of sound tooth structure. The use of caries-detector dyes has also been suggested as a diagnostic aid for occlusal caries. Although diagnosis of carious dentin beneath apparently sound enamel can be challenging, there is a lack of substantive evidence supporting the use of dyes for this purpose and false positives are a significant concern. Careful visual inspection combined with bitewing radiographic diagnosis has been shown to be the most reliable diagnostic method for the presence of infected dentin requiring operative treatment. (+info)
Rationale and treatment approach in minimally invasive dentistry.
BACKGROUND: Current methods of detecting caries, especially fissure caries, are inaccurate, causing some caries to go undetected until it has reached more advanced stages. Minimally invasive dentistry is a philosophy in which the goal of intervention to conserve healthy tooth structure. The authors review the rationale and role of air abrasion in successful practice in the 21st century that includes the philosophy of minimal intervention. CLINICAL IMPLICATIONS: This objective encompasses a range of clinical procedures that includes assessment of caries risk to reinforce patient self-help, early detection of the disease before lesion cavitation to fortify the oral environment, restoration of fissure caries with maximum retention of sound tooth structure and sealant placement in unaffected areas. This conservative approach minimizes the restoration/re-restoration cycle, thus benefiting the patient over a lifetime. (+info)
Management of extensive carious lesions in permanent molars of a child with nonmetallic bonded restorations--a case report.
The badly decayed molar teeth of a 12-year-old were restored using resin composite and ceramic restorations. The maxillary first left permanent molar, which had an extensive carious lesion that had destroyed most of the coronal hard tissues of the tooth, was restored to shape and function with a heat-treated resin composite onlay restoration. The restoration was followed up for two years. The mandibular right first molar had a failing large amalgam restoration with extensive recurrent caries. After a three-month period of pulp-capping, the tooth was restored with a bonded ceramic onlay restoration. A nine-month follow-up of this restoration is provided. The maxillary right first molar, which also had a failing large amalgam/resin composite restoration, was restored with a direct resin composite restoration. Under traditional treatment regimens, these extensive cavities would have been treated using more invasive procedures such as pin-retained restorations or elective root canal therapy, post placement, core build-up and crowning. Bonded non-metallic restorations avoid the trauma, time and cost that accompany such extensive procedures and offer a more conservative approach. (+info)
Microbial aerosols in general dental practice.
OBJECTIVE: To measure the concentration of microbial aerosols in general dental practices and to use this information to carry out quantitative microbiological risk assessments. METHODOLOGY: Microbial air sampling was carried out continuously during 12 treatment sessions in 6 general dental practices in the South West of England. RESULTS: The microbial aerosol concentration in treatment rooms was generally less than 10(3) colony forming units per cubic metre of air (cfu x m(-3)). However, in 6 out of the 12 visits, at least one peak concentration with much higher numbers of bacteria was detected. The peak concentrations were associated with increased recoveries of presumptive oral streptococci suggesting these aerosols originated from the mouths of patients. These aerosol peaks dissipated within 30 minutes and no dissemination into waiting areas was detected. The peak concentrations were associated with mechanical scaling procedures (47% of procedures giving rise to a peak) and to a lesser extent by cavity preparation (11%). No aerosolised blood was detected. CONCLUSIONS: The data have been used to generate a framework for quantifying risk of exposure of staff to aerosolised microbial pathogens in general dental practice. For example, dentists and their assistants may have a slightly higher risk of exposure to Mycobacterium tuberculosis than the general public. The use of face seal masks that have been shown to protect against aerosolised micro-organisms may reduce this exposure. (+info)