Comparison of rotary and manual instrumentation techniques on cleaning capacity and instrumentation time in deciduous molars

PURPOSE: The aim of this study was to evaluate, in vitro, the cleaning capacity and time needed for instrumentation of root canals of deciduous molars by manual and rotary instrumentation. METHODS: Thirty-three deciduous molar root canals were injected with India ink and divided into 3 groups: group I--the root canal instrumented manually with K files; group II--the root canal instrumented with rotary Profile .04 instruments; group III--control group, (ie, root canals not instrumented). Instrumentation time was recorded. The teeth were cleared and the removal of India ink was measured in the cervical, middle, and apical thirds. RESULTS: There was no significant difference for cleaning capacity between manual and rotary techniques in the 3 root thirds (P>.05), but both techniques were different from the control group (P<.001). Significantly less time was needed for instrumentation with the rotary technique (3.46 minutes) than with the manual technique (9.06 minutes). CONCLUSIONS: Although no differences were found for cleaning capacity, the reduction of instrumentation time by the rotary technique was a relevant clinical factor for endodontic treatment.     

Comparison of cold lateral compaction and continuous wave of obturation techniques following manual or rotary instrumentation

AIM: To compare different combinations of root canal preparation and obturation technique. METHODOLOGY: A total of 48 freshly extracted human maxillary central incisors were divided into two identical groups on the basis of root canal length and apical diameter. The root canals were prepared by manual crown-down pressureless technique or with a rotary system (ProFile; Dentsply Maillefer, Ballaigues, Switzerland) in a crown-down technique. The coronal diameter and apical size of the root canals were standardized in both preparation techniques. Each main group was then divided into two subgroups and obturated with either cold lateral compaction or continuous wave of obturation with System B (EIE-Analytic Technology, Orange, CA, USA). The distribution of filling material in each canal was assessed by stereomicroscopic examination of eight cross-sections on each tooth. Areas of sealer, gutta-percha and voids were measured on the digital images of a total of 384 samples. Manipulation time and apical extrusion for each group was also determined. Data were statistically analysed using Kruskal-Wallis, anova (Bonferroni/Dunn) or Student's t-test. RESULTS: The percentage of sealer, gutta-percha and voids area between the obturation techniques was not significantly different (P > 0.05). Continuous wave groups had significantly more apical extrusion of sealer (P < 0.05), while none of the obturation techniques had gutta-percha extrusion. Rotary instrumentation was significantly faster than the manual technique (P < 0.05); continuous wave obturation was significantly faster than lateral compaction (P < 0.05). Total manipulation time in the rotary/continuous wave group was significantly shorter than the other groups (P < 0.0001). CONCLUSION: The distribution of filling materials was similar in all combinations of instrumentation and obturation techniques. The continuous wave technique was faster than lateral compaction and it extruded more sealer.     

HERO Shaper镍钛根管器械在老年人根管清理中的应用

目的：比较镍钛机用根管器械,和不锈钢K锉用于老年根管预备时的清理能力和操作时间,为老年牙根管的临床治疗提供实验依据.方法：将门诊拔除的老年患者单根管患牙40颗随机分为2组,分别用不锈钢K锉、HERO Shaper镍钛机用根管器械做根管预备,分析评价其操作时间和根管清理程度.结果：实验组的根管冠部、根尖部的清理效率明显大于对照组的冠部和根部,根中部差异无统计学意义;实验组的根管预备时间为5.74±0.61min,对照组为6.38±0.75min.结论：HERO Shaper根管预备器械与不锈钢K锉相比有较彻底的清理能力且节省操作时间.     

Effectiveness of manual and rotary instrumentation techniques for cleaning flattened root canals

The cleaning capacity of manual and rotary instrumentation techniques in mesial-distal flattened canals was studied by morphometric analysis. Twenty human mandibular incisors were divided into two groups of 10 teeth each: group 1, crown-down technique with rotary instrumentation using ProFile .04; group 2, crown-down technique with manual instrumentation using K-files. The teeth were evaluated with an optic microscope that was coupled to a computer to determine the percentage of root canal area with debris. The nonparametric Mann-Whitney U test showed a statistically significant difference at the level of 1% between the techniques. The manual technique was more efficient in cleaning mesial-distal flattened root canals than the rotary technique, although neither completely cleaned the root canal.     

Efficacy of five rotary systems versus manual instrumentation during endodontic retreatment

The purpose of this study was to evaluate the efficiency of ProFile, GT, ProTaper, Race and K3 rotary instruments compared with hand K-files for removal of gutta-percha during retreatment. Sixty mandibular premolars were instrumented with GT rotary files and filled by thermomechanical compaction of gutta-percha and AH Plus sealer. The teeth are randomly divided into 6 groups of 10 specimens each. The roots were split longitudinally, digital images were created using a flatbed scanner, and the areas with remaining filling material were demarcated using Image Tool 1.21 software. The results indicate that GT left significantly less (p<0.05) remaining filling material (1.18 ± 1.47) than hand (3.70 ± 3.16) and Hero instruments (2.99 ± 2.58). There was no statistically significant difference (p<0.05) among the others techniques: ProFile (1.99 ± 2.66), ProTaper (2.00 ± 1.99) and K3 (2.71 ± 2.87) when compared with GT. In conclusion, GT, ProFile, ProTaper and K3 were more effective in removing gutta-percha than manual and Hero instruments.     

Comparison of apical transportation in four Ni-Ti rotary instrumentation techniques

A new radiographic technique was used to compare apical transportation in four Ni-Ti rotary instrumentation sequences. Mesiobuccal canals of 60 extracted mandibular molars were randomly divided into four groups. Groups 1 and 3 were instrumented by crown-down and groups 2 and 4 by step-back technique with 0.06 ProFiles series 29 to size 6. In groups 3 and 4 Greater Taper files were first used in a crown-down manner. The central axes of initial and final instruments were radiographically superimposed to measure loss of working length (WL) and transportation at 0, 0.5, 1, 3, and 5 mm from WL. ANOVA test showed no significant differences among groups regarding degree of transportation or loss of WL. Transportation was negatively correlated with radius of curvature at 0.5 and 5 mm from WL. The results indicate that the operational sequence of ProFiles or preinstrumentation with GT files has no effect on degree of transportation and loss of WL.     

Comparison of rotary instrumentation and continuous wave obturation to reciprocating instrumentation and single cone obturation with a hydrophilic sealer

This in vitro study compared the effectiveness between ProFile 29 Series rotary system followed by continuous wave obturation and the Endo-Eze system. Thirty-six human mandibular canine and premolar teeth were randomly separated into 2 groups of 18. Each tooth was embedded in resin and sectioned at 2, 6, and 12 mm from the apex and viewed under the scanning electron microscope at 50-150x magnification. The percentages of canal space occupied by gutta-percha, sealer, debris, and voids were measured and analyzed with Image J software. Results were calculated by using an analysis of variance model with fixed effects for method, distance, and distance interaction. Repeatability of measurements and intraclass correlation coefficients were calculated. These results demonstrated that obturation with the continuous wave technique achieved significantly more gutta-percha occupying the canal space than the Endo-Eze system. Under the conditions of this study, the continuous wave technique was less likely to exhibit voids than the Endo-Eze technique. Furthermore, neither the Profile Series 29 nor the Endo-Eze system cleaned and shaped elliptical canals consistently.     

Use of nickel-titanium rotary files for root canal preparation in primary teeth

This article reviews the use of nickel-titanium rotary files for root canal instrumentation in primary teeth. The pulpectomy technique is described and the advantages and disadvantages of using rotary files are discussed. Specific recommendations for the selection of materials and devices are made.     

Comparison of proximal caries detection in primary teeth between laser fluorescence and bitewing radiography

PURPOSE: The purposes of this in vitro study were to: (1) compare the accuracy of a laser fluorescence system (DIAGNOdent) in proximal caries diagnosis in primary teeth with that of bitewing radiography, using the histological examination as a gold standard; and (2) evaluate the reliability of the DIAGNOdent examination. METHODS: Included were 107 extracted primary molars without obvious cavities on proximal surfaces. The teeth were examined by 2 examiners using DIAGNOdent directly on the lesions (without contact; ie, proximal surfaces were not in contact with other teeth) and indirectly (with contact; ie, proximal surfaces were in contact with adjacent teeth). To simulate contacting teeth, the studied surface was set adjacent to a sound surface in a wax base. The contacting teeth were also diagnosed using bitewing radiography. Results of the diagnoses were compared with a histological gold standard. Sensitivity and specificity were calculated for each diagnostic system. Inter- and intraexaminer reliabilities of DIAGNOdent were calculated using intraclass correlation (ICC). RESULTS: At the dentine caries (D3) level, the sensitivities of bitewing radiography (with contacting teeth) and DIAGNOdent with and without contacting teeth (direct application) were 0.41, 0.85 and 0.93, respectively, and the specificities were 1, 0.89, and 0.87, respectively. Both inter- and intraexaminer reliabilities using DIAGNOdent with and without contacting teeth (direct application) were very high (ICC=0.97 to 0.99). CONCLUSIONS: The reliability of DIAGNOdent is very high and its diagnostic validity (sum of sensitivity and specificity) is higher than that of bitewing radiography for proximal caries detection in primary teeth.     

Use of nickel-titanium rotary files for root canal preparation in primary teeth

This article reviews the use of nickel-titanium rotary files for root canal instrumentation in primary teeth. The pulpectomy technique is described and the advantages and disadvantages of using rotary files are discussed. Specific recommendations for the selection of materials and devices are made.     

Fundamental design factors in rotary dental instrumentation

Experimental work has been carried out involving the measurement of the power requirements for low speed conservative procedures. The clinical significance of these results is considered. Handpiece loss has been evaluated and a composite low speed power specification defined. Power requirements over the whole speed spectrum are discussed in relation to rotary tooling.     

Glide-path: comparison between manual instruments,first generation rotary instruments and M-Wire new generation rotary instruments

ObjectivesThe aim of this research is to compare the different glide path instruments in order to assess the work time and the number of use for each instrument.Materials and methodsThere were used 100 endodontic resin blocks with an S curvature for each group of instruments, on each block, first were used the k file # 10 and then the glide path was done using always the Xsmart machine, setting torque 5.2 n/cm², speed 250 g/m, all instruments were used until their separation and then the results were studied.The time was also counted to obtain the complete pre-flaring for each group.The same test was also repeated on extracted teeth, chosen from mb canal of maxillary molars, and mandibular molars, a total of 50 canals for each group; also in this group the pre-flaring was done counting the number of use for each instrument up to their separation and counting the time to obtain it.Result and conclusionsPathfiles group tested on resin blocks: pathfile #13 the result was: 100 out of 100 canals, pathfiles#16: 60 out of 100 canals, pathfile #19: 42 out of 100 canals.Pathfiles group tested on extracted teeth: pathfile #13: 50 out off 50 canals, pathfiles#16: 50 out of 50 canals, pathfile #19: 50 out of 50 canals, no separated instruments.Proglider group on resin block: single proglider 100 out of 100 blocks.Proglider group on extracted teeth: single proglider 50 out of 50 canals.Time to obtain the pre-flaring with pathfile: 10 s.Time to obtain the pre-flaring with proglider: 8 s.Both files give good results for an effective canal pre-flaring and glide path, making easier the following canal shaping independently of the chosen shaping technique.There are no significant differences in the working time, and the strength of the pathfiles is confirmed for the new M-wire file: proglider.     

机用镍钛器械预备清理根管效果的定量分析

目的:比较机用镍钛根管预备器械ProFile与手动器械对弯曲根管的清理效果.方法:3组弯曲根管分别进行ProFile、手动不锈钢RT锉、NiTiflex锉预备.立体显微镜下观察根管纵截面并采用图象分析软件Scion Image 1.62定量分析根管碎屑分布比例与根尖栓塞的形成.结果:ProFile组碎屑指数小于其他两组;碎屑栓发生率各组无显著性差异,但与根管弯曲部位相关.结论:ProFile器械采用冠根向深入法对弯曲根管碎屑的清理优于手动器械,但仍应注意弯曲位于根尖1/3段者易发生根尖阻塞.     

Comparison of hand stainless steel and nickel titanium rotary instrumentation: a clinical study

The aim of this study was to compare the effect of hand instruments and rotary nickel titanium Flex-Master files used by eight experienced dentists in private practice on the extent of straightening of curved root canals. In patients, 110 canals were prepared by FlexMaster instruments, and 84 canals were enlarged using hand instruments. After instrumentation, all canals were obturated. Preoperative and postoperative radiographs were taken of each tooth using customized bite blocks. Straightening of the canal curvatures was determined with a computer image analysis program. Preparation time and size of the master apical file were also recorded. The use of FlexMaster instruments resulted in significantly less straightening and a shorter preparation time (p < 0.0001) compared with hand instrumentation. Master apical file sizes were significantly greater for FlexMaster than for hand instruments (p < 0.01). This clinical study indicates that FlexMaster instruments prepared curved canals rapidly and with only minimal straightening.