Resin Composite Versus Amalgam Restorations Placed in United States Dental Schools.

OBJECTIVES
To investigate the latest teaching policies for posterior resin composite placement versus amalgam and to determine the actual numbers of posterior resin composites versus amalgam restorations placed in American dental schools from 2008 to 2018.


METHODS
Emails were sent to the deans of all 66 dental schools in the United States to collect data in the forms of: 1) Questionnaire on current teaching policies of posterior composite and amalgam restorations; and 2) Data entry form to collect the actual numbers of posterior composite and amalgam restorations placed in their clinics. Descriptive statistics were used to summarize ratios of posterior restorations. Inferential analysis (chi-square test and z-test) was employed to compare posterior restoration proportions over time and within each year. Level of significance was set at 0.05.


RESULTS
For the teaching questionnaire, the response rate was 52% (n=34). Seventy-six per cent of the responding schools reported that they assign 50% or more of their preclinical restorative teaching time towards posterior resin composite placement, while 50% of the responding schools devoted 25% or less towards amalgam teaching. Data entry response rate was 26% (n=17). In 2008, amalgam and resin composite restorations were placed almost equally. However, resin composite restorations were placed significantly more frequently from 2009 onwards in all responding schools. The results revealed a significant ongoing increasing trend in placing posterior resin composites in all responding schools over time (p<0.05).


CONCLUSIONS
Data analysis revealed a clear trend towards an increase in posterior resin composite restoration placement and a decrease in the number of amalgam restorations. However, the time assigned for posterior resin composite teaching is not aligned with quantity of restorations placed. Review and adjustment of the time allocated for teaching and training of each material are suggested.