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Abstract #26 — Periradicular wound healing following the use of IRM as a root end filling material
Vol. 18, No. 4, April 1992
AAE Abstracts of Papers
(Abstract #23, continued) into flare-up or no-flare-up groups. The model had a sensitivity of 86%, specificity of 71%, positive predictive value of 75%, and negative predictive value of 83%. The psychosocial factors most successful in predicting flare-ups were 1) the highest level of distress in the six hours prior to the appointment, and 2) desire for control over the anticipated unpleasantness associated with treatment. A B S T R A C T #24 - Effectiveness of apical clearing: histologic and morphologic evaluation. J.L. Parris*, L. Wilcox, R.E. Walton University of Iowa, Iowa City, Iowa Preparation of the apical 1/3 in curved canals is difficult both in debridementand maintaining canal shape. A technique of final apical preparation, "apical clearing," attempts to debride and increase the apical size without transportation. Our study evaluated histologically and radiographically the quality of apical prep with or without apical clearing. Examined were: 1) extent of transportation, and 2) debris accumulation in the apical third. 40 extracted teeth with vital pulps and curved canals were divided into 2 groups. All canals were step-back prepared. 20 had apical clearing. Pre and post-preparation double exposed radiographs evaluated canal deviation (Sepic JOE 15:240). Apical 1/3 of roots were examined histologically and ranked, based on the amount of remaining tissue, predentin, dentin shavings, other debris, and percentage of walls planed. Both groups showed slight deviation of the canal during preparation with no difference between the apical cleared and the non-apical cleared. Histologically, canals in the apically cleared group had less remaining tissue, predentin and debris, as well as more of canal walls planed. In conclusion, this experiment showed the apical clearing technique to result in better debridement in the apical canal with no increase in apical transportation. A B S T R A C T #25 - A comparison of the effectiveness of the conventional step-back technique with that of the passive step-back technique. J.A. Eberhardt*, M. Torabinejad, P. McMillian, D.L. Peters Loma Linda University, Loma Linda, California Cleaning and shaping the root canal system is an important phase of endodontic therapy, and must be performed thoroughly and completely if successful root canal therapy is to be expected. A number of investigators have compared different methods of cleaning and shaping of the root canal system. The purpose of this study was to compare the effectiveness of the conventional step-back technique with that of the passive step-back technique. The passive step-back technique is a modification of the conventional step-back technique using an ultrasonic instrument alternately with hand instrumentation. Utilizing 40 canals from extracted human mandibutar molar teeth with a curvature of approximately 30 degrees, the effectiveness of the conventional step-back techniquewas compared to that of the passive step-back technique. Canal transportation was determined utilizing radiography and computer subtracted images. Canalcleanlinesswas evaluated microscopically at the 1, 3, and 5 mm levels. Statistical evaluationof the results showed that the passive step-back technique produced cleanercanals with less transportation as measured atthe 1, 3, and 5 mm levels compared to those obtained by the conventional step-backtechnique.
A B S T R A C T #26 - Periradicular wound healing following the use of IRM as a root end filling material. S.A. Johnson*, J.W. Harrison Baylor College of Dentistry, Dallas, Texas IRM is currently advocated as a root-end filling material although in vivo endodontic studies have not been reported. The purpose of this investigation was to compare the periradicular healing response associated with root-end filling using IRM to that associated with rootend filling using amalgam and root-end resection to gutta-percha. Forty mandibular premolar rootswere instrumented and obturated with thermoplasticized gutta-percha and sealer in mongrel dogs. During subsequent periradicular surgery, 20 root-ends were resected and filled with IRM and 10 were filledwith amalgam. The remaining 10 rootends were resected to orthograde gutta-percha. The animals were sacrificed at 10 and 45 days postoperatively and histologic sections prepared. Periradicular healing responses were graded both microscopically and radiographicaliy according to specific criteria and subjected to inferential statistical analysis at a 95% confidence level. At 10 days, IRM root-end fills resulted in periradicular healing that was comparable to amalgam and gutta-percha. The only statistically significant difference demonstrated was a lesser amount of PMN's at the resected root surface in the gutta-percha group. At 45 days, IRM root-end fillings demonstrated the same periradicular healing as amalgam and gutta-percha, both histologically and radiographically. IRM had no detrimental effect on the overall response at this stage and a minimal number of inflammatory cells were present at the filling/ tissue interface. No signs of dissolution or absorption of IRM by the subjacent apical dentoalveolar tissues were seen at 10 or 45 days postoperatively. These results indicate that short term periradicular healing associated with IRM, amalgam and orthograde gutta-percha is essentially the same and that further consideration of IRM as a rootend filling material is warranted. Supported by Baylor College of Dentistry Research Funds and a Graduate Student Award from the Research and Educational Foundation of the American Association of Endodontists. A B S T R A C T #27 - Radicular and periradicular wound healing following root-end filling with cermet glass-ionomer cement. E.N. Miller*, J.W. Harrison Baylor College of Dentistry, Dallas, Texas This study investigated the effect of root-end filling with a cerment glass-ionomer cement on the healing of apical dentoalveolar and osseous tissues following periradicular surgery. Root-end resection to orthograde gutta-percha and sealer was performed on mandibular premolars in dogs. Twelve control root ends received no further treatment, 12 standard treatment root ends were prepared and filled with zinc-free amalgam, and 24 experimentalroot ends were prepared and filled with cermet giass-ionomer cement. Animals were sacrificed 10 or 45 days postoperatively and specimens were prepared for light microscopic evaluation. Histologic specimens and postoperative radiographs underwent evaluation according to ranked criteria and differences were tested for significance to a 95% confidence level with nonparametric statistics. Experimental sPecimens were associated with significantly more rapid replacement of coagulum with granulation tissues emanating from the severed periodontal ligaments than standard specimens. Experimental and control specimens exhibited significantly more rapid resolution of chronic inflammatory infiltrates within these granulation tissues than standard specimens. Those tissues interfaced with the root end filling of control and experimental specimens appeared consistently more mature than their standard counterparts, Experimental filling interfaces appeared to be associated with the most intimate approximation of new apical alveolar bone proper. No significant differences in radiographic appearancewere demonstrated among the three root-end treatments. Supported by Baylor College of Dentistry Research Funds and a Graduate Student Award from the Research and Education Foundation of the American Association of Endodontists.
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AAE Abstracts of Papers
(Abstract #23, continued) into flare-up or no-flare-up groups. The model had a sensitivity of 86%, specificity of 71%, positive predictive value of 75%, and negative predictive value of 83%. The psychosocial factors most successful in predicting flare-ups were 1) the highest level of distress in the six hours prior to the appointment, and 2) desire for control over the anticipated unpleasantness associated with treatment. A B S T R A C T #24 - Effectiveness of apical clearing: histologic and morphologic evaluation. J.L. Parris*, L. Wilcox, R.E. Walton University of Iowa, Iowa City, Iowa Preparation of the apical 1/3 in curved canals is difficult both in debridementand maintaining canal shape. A technique of final apical preparation, "apical clearing," attempts to debride and increase the apical size without transportation. Our study evaluated histologically and radiographically the quality of apical prep with or without apical clearing. Examined were: 1) extent of transportation, and 2) debris accumulation in the apical third. 40 extracted teeth with vital pulps and curved canals were divided into 2 groups. All canals were step-back prepared. 20 had apical clearing. Pre and post-preparation double exposed radiographs evaluated canal deviation (Sepic JOE 15:240). Apical 1/3 of roots were examined histologically and ranked, based on the amount of remaining tissue, predentin, dentin shavings, other debris, and percentage of walls planed. Both groups showed slight deviation of the canal during preparation with no difference between the apical cleared and the non-apical cleared. Histologically, canals in the apically cleared group had less remaining tissue, predentin and debris, as well as more of canal walls planed. In conclusion, this experiment showed the apical clearing technique to result in better debridement in the apical canal with no increase in apical transportation. A B S T R A C T #25 - A comparison of the effectiveness of the conventional step-back technique with that of the passive step-back technique. J.A. Eberhardt*, M. Torabinejad, P. McMillian, D.L. Peters Loma Linda University, Loma Linda, California Cleaning and shaping the root canal system is an important phase of endodontic therapy, and must be performed thoroughly and completely if successful root canal therapy is to be expected. A number of investigators have compared different methods of cleaning and shaping of the root canal system. The purpose of this study was to compare the effectiveness of the conventional step-back technique with that of the passive step-back technique. The passive step-back technique is a modification of the conventional step-back technique using an ultrasonic instrument alternately with hand instrumentation. Utilizing 40 canals from extracted human mandibutar molar teeth with a curvature of approximately 30 degrees, the effectiveness of the conventional step-back techniquewas compared to that of the passive step-back technique. Canal transportation was determined utilizing radiography and computer subtracted images. Canalcleanlinesswas evaluated microscopically at the 1, 3, and 5 mm levels. Statistical evaluationof the results showed that the passive step-back technique produced cleanercanals with less transportation as measured atthe 1, 3, and 5 mm levels compared to those obtained by the conventional step-backtechnique.
A B S T R A C T #26 - Periradicular wound healing following the use of IRM as a root end filling material. S.A. Johnson*, J.W. Harrison Baylor College of Dentistry, Dallas, Texas IRM is currently advocated as a root-end filling material although in vivo endodontic studies have not been reported. The purpose of this investigation was to compare the periradicular healing response associated with root-end filling using IRM to that associated with rootend filling using amalgam and root-end resection to gutta-percha. Forty mandibular premolar rootswere instrumented and obturated with thermoplasticized gutta-percha and sealer in mongrel dogs. During subsequent periradicular surgery, 20 root-ends were resected and filled with IRM and 10 were filledwith amalgam. The remaining 10 rootends were resected to orthograde gutta-percha. The animals were sacrificed at 10 and 45 days postoperatively and histologic sections prepared. Periradicular healing responses were graded both microscopically and radiographicaliy according to specific criteria and subjected to inferential statistical analysis at a 95% confidence level. At 10 days, IRM root-end fills resulted in periradicular healing that was comparable to amalgam and gutta-percha. The only statistically significant difference demonstrated was a lesser amount of PMN's at the resected root surface in the gutta-percha group. At 45 days, IRM root-end fillings demonstrated the same periradicular healing as amalgam and gutta-percha, both histologically and radiographically. IRM had no detrimental effect on the overall response at this stage and a minimal number of inflammatory cells were present at the filling/ tissue interface. No signs of dissolution or absorption of IRM by the subjacent apical dentoalveolar tissues were seen at 10 or 45 days postoperatively. These results indicate that short term periradicular healing associated with IRM, amalgam and orthograde gutta-percha is essentially the same and that further consideration of IRM as a rootend filling material is warranted. Supported by Baylor College of Dentistry Research Funds and a Graduate Student Award from the Research and Educational Foundation of the American Association of Endodontists. A B S T R A C T #27 - Radicular and periradicular wound healing following root-end filling with cermet glass-ionomer cement. E.N. Miller*, J.W. Harrison Baylor College of Dentistry, Dallas, Texas This study investigated the effect of root-end filling with a cerment glass-ionomer cement on the healing of apical dentoalveolar and osseous tissues following periradicular surgery. Root-end resection to orthograde gutta-percha and sealer was performed on mandibular premolars in dogs. Twelve control root ends received no further treatment, 12 standard treatment root ends were prepared and filled with zinc-free amalgam, and 24 experimentalroot ends were prepared and filled with cermet giass-ionomer cement. Animals were sacrificed 10 or 45 days postoperatively and specimens were prepared for light microscopic evaluation. Histologic specimens and postoperative radiographs underwent evaluation according to ranked criteria and differences were tested for significance to a 95% confidence level with nonparametric statistics. Experimental sPecimens were associated with significantly more rapid replacement of coagulum with granulation tissues emanating from the severed periodontal ligaments than standard specimens. Experimental and control specimens exhibited significantly more rapid resolution of chronic inflammatory infiltrates within these granulation tissues than standard specimens. Those tissues interfaced with the root end filling of control and experimental specimens appeared consistently more mature than their standard counterparts, Experimental filling interfaces appeared to be associated with the most intimate approximation of new apical alveolar bone proper. No significant differences in radiographic appearancewere demonstrated among the three root-end treatments. Supported by Baylor College of Dentistry Research Funds and a Graduate Student Award from the Research and Education Foundation of the American Association of Endodontists.
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