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OR 20 Effectiveness of canal finder and hand instrumentation during retreatment
Journal of Endodontics 41, 193
Vol. 22, No. 4, April 1996
OR
A Comparative Analysis of Canal Debridement Using Stainless Steel and NITI Files. R.PILEGGI*, G.N.GLICKMAN & C.A.EDWARDS The University of Michigan, Ann Arbor To date, no study has evaluated the effectiveness of canal debridement with nickel titanium (niti) instruments using densitometry. The purpose of this study was to compare the degree of debridement in simulated canals between stainless steel (ss) and niti files using the balanced force technique. Two groups of 12 resin blocks, each with a 25 ° curved canal, were stained with Rhodamine B fluorescent dye and instrumented with ss Flexofiles or niti Surefiex files. Each canal was instrumented to MAF size #30 and flared to size #45. Unstained blocks served as negative controls; uninstrumented stained blocks served as positive controls. Blocks were sagitally sectioned at 3 levels (apical, outer wall, inner wall) with an Exakt instrument. The density of remaining dye in each section was digitally analyzed using NIH Image. At the apical level. there was no statistically significant difference between ss !mean densitv:119) and niti (mean density:91) (Scheffe. D=.15L On the inner wall. there was a statistically sienificant difference between ss (mean densitv:11-7) and niti (mean densitv:83) (Scheffe. D=.04L On the outer wall. there was no -statisticallv 8ignificant difference between ss (mean density: 94) and niti (mean densitv:74) (Scheffe. D=.5). Within the parameter8 of this studv.niti files removed siQnificantlv more dve than ss files-(unoaired t test, p < .001).
The Lightspeed Canal Preparation Technique Evaluated by Swiss Clinicians. F. Barbakow* & F. Lutz (Dept. PPC, Zurich University, Switzerland). This study evaluated acceptance of the Lightspeed (LS) technique by Swiss practitioners. The LS technique was introduced to Switzerland in June 1994 & 10 other CE courses have been held at the Zurich Dental School. The acceptance was assessed by posting questionnaires to the course attendants, omitting university & institutionally employed dentists. Of the 305 questionnaires posted, 177 (58%) were returned. The data was stored and analyzed in a computer. 80% of the CE participants had used the technique with 60% of them finding it easier & 43% finding the LS preparations quicker. 48% of the clinicians used the technique on all tooth types. 76% of the LS users had fractured a Lightspeed instrument at least once. Amongst others, fractures were caused by too much pressure (25%), incorrect insertion angles (17%) & complicated root morphology (15%). Fractures occurred high up on the instrument shaft (74%) and near the tip (7%). 62% claimed that working lengths were easier maintained by LS than their usual techniques. 52% obturated LS prepared canals easier and quicker compared to their previous preparation techniques. Only 10% of LS users would not recommend the technique, but those who would suggested that proper tuition was unavoidable to minimize the risk of fracture. The LS technique was oositivelv assessed bv clinicians who attended the CE courses in Switzerland where endodontics is not accepted as a specialty.
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Effectiveness of Canal Finder and Hand Instrumentation During Retreatment Noboru Imura *, MArio Luis Zuolo , Maria Olivia Femandes Ferreira, Nell Ferreira Novo - Professores Associados Ensino Odontolrgico - PAEO - S~o Paulo / SP - Brazil The purpose o f this study was to quantify the amount o f remaining gutta-percha/sealer on the canal walls when the Canal Finder system , hand instrumentation and a combination o f both ( hybrid technique ) were used in retreatment cases . The apically extruded debris and the time required for retreatment were also recorded. Sixty extracted maxillary anterior teeth were prepared using a stepback technique and obturated. Reinstrumentation o f all groups was done in conjunction with a solvent. The teeth were split longitudinally and photographed. The total area o f the canal and the area o f the debris were traced and quantified using a computerized image analysis system . The ratio o f remaining obturation material to root canal periphery was derived and statistically analyzed ( Kruskal-Wallis / multiple comparison test, p<0.05 ) .
The hand instrumentation presented less remaining debFis than did the other two g r o u p s . The differences in apicaily extruded debris were not significant among groups . The hybrid technique required significantly less time for retreatment. The canal finder system Was not superior to hand instrumentation.
The Use of Aloe Vera Gel as an Intracanal Medicament H. Maguire*, M. Torabinejad, JD Kettering Loma Linda University, Loma Linda, California
Many beneficial effects have been ascribed to the use of aloe vera on wounds. Surprisingly, despite the widespread use of aloe vera in over the counter gels and creams, few studies have been performed to examine the biological effects of this substance. The purpose of this study was to examine the bactefiocidal effects of aloe vera gel when used as an intracanal medicament. 100 single canal, extracted teeth were instrumented to a master apical file size # 80. The apices were sealed with epoxy resin and the teeth mounted in plaster blocks. The blocks were then sterilized. 90 teeth were inoculated with S. faecalis and 10 teeth (negative controls) were filled with sterile medium. After 24 hours incubation, 40 teeth were filled with calcium hydroxide, 40 with aloe vera gel and 10 were left alone (positive controls). The blocks were then incubated for one week after which time the canals were washed with sterile water and cultures were taken. After 24 hours of incubation the culture tubes were checked for turbidity. 39 of 40 (97.5%) of the teeth medicated with the calcium hydroxide yielded negative cultures whereas only 9 of 40 (22.5%) of the teeth medicated with the aloe vera gel yielded negative cultures. A Chi-squared statistical analysis revealed that the bacteriocidal effects of aloe vera gel were significantly less than that of the calcium hydroxide (p<0.05). It was therefore concluded that aloe vera gel would not be effective as a bacteriocidal intracanal medicament.
Vol. 22, No. 4, April 1996
OR
A Comparative Analysis of Canal Debridement Using Stainless Steel and NITI Files. R.PILEGGI*, G.N.GLICKMAN & C.A.EDWARDS The University of Michigan, Ann Arbor To date, no study has evaluated the effectiveness of canal debridement with nickel titanium (niti) instruments using densitometry. The purpose of this study was to compare the degree of debridement in simulated canals between stainless steel (ss) and niti files using the balanced force technique. Two groups of 12 resin blocks, each with a 25 ° curved canal, were stained with Rhodamine B fluorescent dye and instrumented with ss Flexofiles or niti Surefiex files. Each canal was instrumented to MAF size #30 and flared to size #45. Unstained blocks served as negative controls; uninstrumented stained blocks served as positive controls. Blocks were sagitally sectioned at 3 levels (apical, outer wall, inner wall) with an Exakt instrument. The density of remaining dye in each section was digitally analyzed using NIH Image. At the apical level. there was no statistically significant difference between ss !mean densitv:119) and niti (mean density:91) (Scheffe. D=.15L On the inner wall. there was a statistically sienificant difference between ss (mean densitv:11-7) and niti (mean densitv:83) (Scheffe. D=.04L On the outer wall. there was no -statisticallv 8ignificant difference between ss (mean density: 94) and niti (mean densitv:74) (Scheffe. D=.5). Within the parameter8 of this studv.niti files removed siQnificantlv more dve than ss files-(unoaired t test, p < .001).
The Lightspeed Canal Preparation Technique Evaluated by Swiss Clinicians. F. Barbakow* & F. Lutz (Dept. PPC, Zurich University, Switzerland). This study evaluated acceptance of the Lightspeed (LS) technique by Swiss practitioners. The LS technique was introduced to Switzerland in June 1994 & 10 other CE courses have been held at the Zurich Dental School. The acceptance was assessed by posting questionnaires to the course attendants, omitting university & institutionally employed dentists. Of the 305 questionnaires posted, 177 (58%) were returned. The data was stored and analyzed in a computer. 80% of the CE participants had used the technique with 60% of them finding it easier & 43% finding the LS preparations quicker. 48% of the clinicians used the technique on all tooth types. 76% of the LS users had fractured a Lightspeed instrument at least once. Amongst others, fractures were caused by too much pressure (25%), incorrect insertion angles (17%) & complicated root morphology (15%). Fractures occurred high up on the instrument shaft (74%) and near the tip (7%). 62% claimed that working lengths were easier maintained by LS than their usual techniques. 52% obturated LS prepared canals easier and quicker compared to their previous preparation techniques. Only 10% of LS users would not recommend the technique, but those who would suggested that proper tuition was unavoidable to minimize the risk of fracture. The LS technique was oositivelv assessed bv clinicians who attended the CE courses in Switzerland where endodontics is not accepted as a specialty.
%
Effectiveness of Canal Finder and Hand Instrumentation During Retreatment Noboru Imura *, MArio Luis Zuolo , Maria Olivia Femandes Ferreira, Nell Ferreira Novo - Professores Associados Ensino Odontolrgico - PAEO - S~o Paulo / SP - Brazil The purpose o f this study was to quantify the amount o f remaining gutta-percha/sealer on the canal walls when the Canal Finder system , hand instrumentation and a combination o f both ( hybrid technique ) were used in retreatment cases . The apically extruded debris and the time required for retreatment were also recorded. Sixty extracted maxillary anterior teeth were prepared using a stepback technique and obturated. Reinstrumentation o f all groups was done in conjunction with a solvent. The teeth were split longitudinally and photographed. The total area o f the canal and the area o f the debris were traced and quantified using a computerized image analysis system . The ratio o f remaining obturation material to root canal periphery was derived and statistically analyzed ( Kruskal-Wallis / multiple comparison test, p<0.05 ) .
The hand instrumentation presented less remaining debFis than did the other two g r o u p s . The differences in apicaily extruded debris were not significant among groups . The hybrid technique required significantly less time for retreatment. The canal finder system Was not superior to hand instrumentation.
The Use of Aloe Vera Gel as an Intracanal Medicament H. Maguire*, M. Torabinejad, JD Kettering Loma Linda University, Loma Linda, California
Many beneficial effects have been ascribed to the use of aloe vera on wounds. Surprisingly, despite the widespread use of aloe vera in over the counter gels and creams, few studies have been performed to examine the biological effects of this substance. The purpose of this study was to examine the bactefiocidal effects of aloe vera gel when used as an intracanal medicament. 100 single canal, extracted teeth were instrumented to a master apical file size # 80. The apices were sealed with epoxy resin and the teeth mounted in plaster blocks. The blocks were then sterilized. 90 teeth were inoculated with S. faecalis and 10 teeth (negative controls) were filled with sterile medium. After 24 hours incubation, 40 teeth were filled with calcium hydroxide, 40 with aloe vera gel and 10 were left alone (positive controls). The blocks were then incubated for one week after which time the canals were washed with sterile water and cultures were taken. After 24 hours of incubation the culture tubes were checked for turbidity. 39 of 40 (97.5%) of the teeth medicated with the calcium hydroxide yielded negative cultures whereas only 9 of 40 (22.5%) of the teeth medicated with the aloe vera gel yielded negative cultures. A Chi-squared statistical analysis revealed that the bacteriocidal effects of aloe vera gel were significantly less than that of the calcium hydroxide (p<0.05). It was therefore concluded that aloe vera gel would not be effective as a bacteriocidal intracanal medicament.