Direct restorative materials use in Australia in 2002

Placement of Posterior Composite Restorations: A Cross-Sectional Study of Dental Practitioners in Al-Kharj, Saudi Arabia

Dental practitioner-related factors can affect the quality of composite restorations. This study aimed to investigate the clinical techniques used by dental practitioners (DPs) while placing direct posterior composite restorations. Methods: A questionnaire survey that sought information related to the placement of posterior composite restorations was delivered to 161 DPs working in the Al-Kharj area, Saudi Arabia. The collected data were statistically analyzed using Pearson’s Chi-square test and Fisher’s exact test considering the DP’s working sector and the answered questions. Results: A total of 123 DPs completed the survey (76.4% response rate). There was a statistically significant difference between DPs working in the private sector and those working in the governmental sector in 7 out of 17 questionnaire items namely: preparing a minimum depth of 2 mm, (p = 0.001); mechanical means of retention, (p = 0.003); operative field isolation, (p = 0.004); adhesive strategy, (p < 0.001); light-curing unit used, (p = 0.013); the use of radiometer, (p = 0.023), and dental matrix selection, (p < 0.001). Conclusion: The clinical techniques applied by DPs working in the private sector in Al-Kharj, Saudi Arabia when placing posterior composite restorations, including the specifications of cavity preparation, operative field isolation, and selection of the dental matrix system, may be substandard compared to those applied by DPs working in the governmental sector.

Direct Restorations, Endodontics, and Bleaching: Materials and Techniques Used by General Dentists of New Zealand

Background

To investigate the selection and use of direct restorative materials, endodontic techniques adopted, and approaches to bleaching by general dentists in New Zealand.

Methods

A questionnaire comprising 19 sections and 125 questions was distributed via mail to 351 general dentists in New Zealand who were selected, at random, from the Dental Council of New Zealand's 2016 register.

Results

A total of 204 questionnaires were returned, of which 188 were usable. Direct resin composite was the most commonly used material for occlusoproximal cavity restorations in premolars (93.7%) and permanent molars (85.2%). Resin-modified glass ionomer cements (34%) and resin composite materials (31.4%) were more commonly used in the restoration of deciduous molars. Home-based vital bleaching was provided by a significant number of dentists (86%), while only 18% provided practice-based bleaching. Cold lateral condensation was the most commonly used obturation technique (55.8%), and 83% of respondents reported using rubber dam for treatments.

Conclusions

The findings from this study indicate that dentists in New Zealand are adapting to new materials and technologies to provide high quality care to their patients. Aesthetic treatments such as bleaching have become an integral part of general dental practice.

Clinical Decision Making on Extensive Molar Restorations

Extensive loss of posterior tooth substance, which traditionally was restored with amalgam or indirect restorations, is more commonly being restored with resin-based composite restorations. Using a questionnaire, we aimed to survey dentists' clinical decision making when restoring extensive defects in posterior molar teeth. The questionnaire, which included questions on background information from the dentists, clinical cases with treatment options, and general questions about restoring extensive posterior defects, was sent to 476 dentists. The response rate was 59%. Multiple logistic regressions were used to investigate the different associations. Most of the respondents preferred a direct composite restoration when one cusp was missing, while indirect restorations were most preferred when replacing three or four cusps. Younger dentists and dentists working in the private sector had a greater tendency to choose an indirect technique compared with older colleagues. Generally, the most important influencing factor in clinical decision making was the amount of remaining tooth substance. Factors that appeared to be less important were dental advertisements, use of fluoride, and dietary habits. Female dentists perceived factors such as oral hygiene, patient requests, and economy to be more important than did their male colleagues.

Class II composite restorations: importance of cervical enamel in vitro

OBJECTIVE

This study evaluated the importance of enamel at the cervical margin for support and retention of a class II composite restoration in relation to fracture strength, fracture mode, and leakage.

METHODS

Sixty-five newly extracted teeth were randomly divided into five groups. Within each group, standardized class II preparations were made at the mesial surface of the tooth with four different preparation designs. Group D (n=15) had the cervical margin placed below the cemento-enamel junction (the dentin group), and in the other three groups (the enamel groups: E1, E2, and E3), the cervical margin was within the enamel (n=15 each). Group E3 had restorations with cuspal coverage, while groups E1 and E2 differed in vertical dimension. Intact teeth without preparation or restoration were tested as controls (n=5). The area of the horizontal part of enamel at the cervical margin of the preparation (available cervical enamel) was calculated. The teeth were restored with a nanofilled composite material and an etch-and-rinse adhesive system. The teeth were subjected to artificial aging consisting of thermocycling and mechanical cyclical loading. The restorations were subsequently loaded until fracture. The teeth were examined microscopically to assess fracture mode and leakage at the interface between the restoration and the tooth substance.

RESULTS

The fracture strength in group D (without cervical enamel) and E3 (with cuspal coverage and cervical enamel) was lower (p<0.01) than in the other two groups (with cervical enamel). There was a correlation between the area of available cervical enamel and fracture strength (p<0.01). The median fracture strength for the control teeth was not significantly different from groups E1 and E2. Group D exhibited a predominance of adhesive fractures, while the other groups revealed more cohesive fractures.

CONCLUSION

The results from this study indicate that available cervical enamel has an impact on the performance of class II composite restorations.

Posterior amalgam restorations--usage, regulation, and longevity

The use of dental amalgam has declined, but in most of the world, amalgam is the most widely used and widely taught direct restorative material for load-bearing posterior restorations. There are few national regulations on the use of amalgam; however, there are several nations where few amalgam restorations are placed. Long-term studies have shown that under optimum conditions, posterior restorations of amalgam and resin composite last longer than reported previously and that amalgam restorations outlast composite restorations. In general practice settings, posterior amalgam and composite restorations both have lower longevities.

Attitudes of general dental practitioners in the UK to the use of composite materials in posterior teeth

OBJECTIVE

To determine the opinions and current methods used in placing posterior composite restorations by general dental practitioners.

SETTING

The study was completed by general dental practitioners randomly selected from across the UK.

METHOD

A questionnaire was devised to gain this information. It was sent to 500 UK dentists chosen at random from the general dental register, with an explanatory letter and reply-paid envelope.

RESULTS

Two hundred and sixty-seven replies were received. Sixty-one percent of dentists felt amalgam use had decreased over the last five years, 75% felt posterior composite use had increased. Regarding choice of posterior material, almost all cited clinical indication as the most influential factor while patient's aesthetic demands (89%),wish for a certain material (78%) and the dentist's confidence using a certain restorative material (76%) were contributing factors. Regarding the techniques used, contemporary techniques were employed although there was confusion regarding the need for rubber dam and the most appropriate method of lining the cavity. A case scenario of a pregnant patient who required treatment found that 66% of respondents would place a restoration other than a temporary dressing, with 16% placing an amalgam restoration.

CONCLUSIONS

The majority of dentists surveyed place load bearing posterior composite restorations regularly. Their choice of restorative material is influenced by clinical indications and the patient's aesthetic demands. The techniques used were appropriate, although there was confusion around the need for rubber dam and the most appropriate method to line the cavity. There was also confusion in relation to the most appropriate materials for use in pregnancy.

On material choice and fracture susceptibility of restored teeth: An asymptotic stress analysis approach

OBJECTIVE

The ultimate success or failure of a restored tooth is largely dependent on clinical management. Clinicians may choose from a number of restorative materials, different clinical techniques and cavity preparation procedures. The purpose of this study was to specifically examine aspects of the material choice holding other factors constant.

METHODS

The current paper adopts a fundamental result in the linear theory of elasticity on the singular stress distribution in a bi-materials wedge to analyze the fracture susceptibility of different materials used for the restoration of a tooth.

RESULTS

Comparable results are reported for amalgam, gold alloys and ceramic materials. It is shown that due to a wide variety of mechanical properties the application of resin-based composites could lead to improved or less fracture resistance of the restored tooth.

SIGNIFICANCE

This variety in the mechanical properties for resin-based composites could be partially responsible for the contradictory evidences reported by different clinical studies. The present work contributes evidence from an analytical model to assist the restorative dentist in selection of an appropriate restorative material and guide the manufacturing companies on the preferred physical properties of newer designed materials.