By Dr. Eshwar Arasu
The Journal of Endodontics is an invaluable resource for contemporary and historical research in endodontics. In this issue of The Paper Point, I have provided synopses of selected articles from each of the past three months.
1. June 2019: Karishma Patil, Navid Khalighinejad, Nivine El-Refai, Kristin Williams, Andre Mickel. “The Effect of Crown Lengthening on the Outcome of Endodontically Treated Posterior Teeth: 10-year Survival Analysis”
This retrospective study assessed the effect of crown lengthening procedures on the survival of root canal treated teeth over a five- and 10-year span in the endodontic department at the Case Western Reserve University School of Dental Medicine. After endodontic treatment, 97 teeth determined to have at least a 2-mm ferrule received full coverage crowns in the dental school. The other 79 root canal treated teeth comprising the study sample underwent crown lengthening (CL) procedures in the periodontology department prior to delivery of full coverage crowns. Among the 106 endodontically treated teeth, no significant difference was noted in the five-year survival rate between the CL (82.2%) and the control (88.6%) groups. However, the 10-year survival analysis yielded a rate of 51% among teeth in the CL group—significantly lower than the 74.5% rate of the control group. The authors conclude that teeth with a crown-root ratio of <1:1 demonstrated a high survival rate of 93% relative to teeth with 1:1 ratios where the survival rate dropped to 40%. These findings imply that crown-root ratio, rather than osseous CL, may be an important determinant in the long-term survival of endodontically treated teeth.
2. July 2019: Matthew Davis, Suhaila Shariff. “Success and Survival of Endodontically Treated Cracked Teeth with Radicular Extensions: A two- to four-year Prospective Cohort”
In this prospective cohort study, the authors completed a success analysis on 53 posterior cracked teeth from 52 patients who returned for two- and four-year recall appointments. The teeth comprising the study sample were included if they were in function with an opposing tooth and the internal radicular extent of the crack was observed to extent to the level of the canal orifice or up to 5 mm beyond it. Split teeth, cracks confined to coronal dentin, and teeth with fractures across the length of the pulpal floor were excluded. These teeth were root canal treated or non-surgically retreated by a single private practice endodontist, who removed 2-3 mm of the final obturation material apical to the deepest extent of the crack before applying a bonding agent and fluoride-releasing resin as an extended orifice barrier in the canal space and along the chamber floor. The authors report a 100% 2-year survival rate and 96.6% 4-year survival rate for these 53 treated teeth. Data analysis also indicated no significant difference in success when considering pretreatment variables of periodontal pocketing up to 7mm, marginal ridge involvement, crack depth, or pulpal/periapical diagnoses. The authors conclude that outcomes among treated teeth with cracks extending to the root may be improved with the placement of extended intraorifice barriers, occlusal reduction, and expedient delivery of a full-coverage restoration.
3. August 2019: Sarah Bukhari, Bekir Karabucak. “The Antimicrobial Effect of Bioceramic Sealer on an 8-week Matured Enterococus faecalis Biofilm Attached to Root Canal Dentinal Surface”
This in vitro study relied on a dentin infection model of sectioned roots from single-rooted caries-free extracted teeth, which were first treated for smear layer removal before being sterilized. These roots were incubated with E. faecalis for eight weeks with resultant formation of biofilms. The infected dentin models were divided into groups for comparison of Endosequence BC Sealer against AH Plus across either 24-hour or two-week additional incubations. Negative control groups without sealer were also devised for the two additional incubation time points. Confocal laser scanning microscopic analysis allowed for calculation of live/dead bacterial cell ratios in the attached biofilms of each sample. The authors report a statistically significant antibacterial effect of the bioceramic sealer over the AH Plus sealer and negative control groups regardless of surveyed time points (24 hours vs. two weeks) in this 8-week-old E. faecalis biofilm model on radicular dentin.
Eshwar Arasu, D.M.D., M.S.D., is a member of the AAE’s Resident and New Practitioner Committee.