Richard W. Ballard

Force decay of elastomeric chains - a mechanical design and product comparison study.

Objectives To evaluate the percentage force decay of elastomeric chain products utilizing three different design mechanisms simulating canine retraction; and to evaluate the percentage force decay of elastomeric chain products from four different companies. Design In vitro, laboratory study. Setting LSUHSC Dental School, New Orleans, LA, USA. Methods Closed (non‐spaced), grey elastomeric chains from four companies were selected for the study. Three acrylic resin jigs were constructed to provide a framework for three simulated space closure mechanisms. The 6‐5‐3, the chain loop, and the 6‐3 were the configuration mechanisms used in the study. Outcome measures An electronic force gauge was used to measure the percentage force decay associated with each elastomeric chain over 28 days at preselected times. Results There was a significant difference in the mean percentage force decay for the three different mechanisms (P<0·001). For all four companies, the 6‐3 mechanical design had the smallest mean percentage force decay. There was a significant difference in the mean percentage force decay for the different companies (P<0·001). For all three mechanisms, Ormco had the smallest percentage force decay while Unitek had the highest percentage force decay. Conclusions The significant difference in the mean percentage force decay for the different mechanisms suggests that the 6‐3 design is a more efficient means of closing extraction spaces utilizing elastomeric chains.

Enamel surface roughness of preferred debonding and polishing protocols

Objective This study investigated the surface roughness of enamel after debonding and instrumentation with commonly used methods. Methods Part I: a survey was sent to active members of the American Association of Orthodontists to determine popular bonding, debonding, and polishing protocols. Part II: brackets were bonded to the buccal surface of 30 extracted human premolar teeth. After debonding, residual adhesive was removed with 12-, 16-, and 20-fluted titanium carbide burs as based upon the survey results. The teeth were scanned with a surface profilometer for surface roughness. Part III: the teeth were further polished using a Reliance Renew polishing point or a prophy cup with pumice and rescanned for surface roughness. Results Part I: the majority of respondents used a generic bracket-removing plier to remove fixed appliances (53%) and a high-speed handpiece for adhesive removal (85%). The most popular bur was a 12-fluted carbide bur without water spray. The majority of respondents used pumice paste and/or Reliance Renew points after adhesive removal. Part II: there was a significant difference in enamel surface roughness when 12-, 16-, and 20-fluted carbide burs were compared via surface profilometry. Part III: further polishing with a Reliance Renew point or a prophy cup and pumice did not provide a significantly smoother surface. Conclusions The results show large variation in debonding and polishing techniques. Creating a smooth enamel surface is equally possible with 12- or 20-fluted carbide burs. Further polishing with pumice and prophy cup or Renew point does not provide an enamel smoother surface.

Interdisciplinary approach to education: preparing general dentists to manage dental trauma

The traditional dental curriculum presents limited opportunities for students to evaluate and treat patients with acute dental trauma. In an effort to increase student experiences, faculty at a dental school initiated and taught an interdisciplinary trauma course from 2014 to 2016. This course was elective, offered in the final year of dental school, and combined student-led and faculty-led case-based discussions of management of traumatic dental injuries with hospital trauma call shadowing. Modifications of the course were made based on student feedback. Preliminary data from student surveys showed a favorable opinion of the course. Attendees were exposed to a higher number of acute traumatic injuries and they expressed greater confidence in their diagnosis and management abilities than their peers.