Peeso Reamers Research Articles

Effect of eugenol-containing and resin endodontic sealers on retention of prefabricated metal posts cemented with zinc phosphate and resin cements

PurposeThe aim of this study was to compare the effects of two endodontic sealers on the retention of posts cemented with zinc phosphate or resin cement. Materials and methodsCrowns of 72 mandibular premolars were removed at the cementoenamel junction. Root canals were prepared and specimens were randomly divided into two groups of 36. In each group, 12 specimens were obturated with gutta percha only; 12 specimens with gutta percha/ZOE sealer and 12 specimens with gutta percha/AH26. In the first group, 10mm Post spaces were prepared with Peeso reamers size 4 and, size 5 stainless steel Paraposts were cemented in with zinc phosphate. In the second group, 10mm Post spaces were prepared with Fiber Lux size 5.5 drills and size 5 Paraposts were cemented with Panavia F2.0. After mounting in resin blocks, posts were pulled out by universal testing machine at 1mm/min and results were analyzed by two-way ANOVA and Dunnett test. ResultsMean forces (in Newtons) required to remove posts cemented with zinc phosphate in canals obturated without sealer, with ZOE, and with AH26 sealers were 270±83, 281±128 and 266±67, respectively; and for posts cemented with Panavia F2.0 were 520±290, 464±212 and 229±108, respectively. Statistical analysis showed that AH26 significantly reduced retention of posts cemented with Panavia F2.0 (p<0.05). ConclusionDifferent sealers had no significant effect on retention of posts cemented with zinc phosphate. However posts cemented with Panavia F2.0 showed reduced retention in canals obturated with AH26.

Residual dentin thickness of bifurcated maxillary premolars following two post space preparation methods.

The aim of this in vitro study was to compare the effect of Gates-Glidden and Peeso reamer drills on residual dentin thickness during post space preparation in order to discover which method has minimum root structure damage. Thirty extracted human maxillary premolars with bifurcations at root middle were horizontally cut 15 mm coronal to the apical end after root canal treatment. The samples were scannedby Cone Beam Computed Tomography (CBCT) before and after preparing the post space. Residual dentin thicknesses were measured at 4-, 6-, and 8-mm levels from the apex. Data were analyzed using repeated measured ANOVA. Endodontic therapy and post space preparations removed more dentin within the bifurcation of both roots compared to outer dentin. The difference in residual dentin thickness was highly significant regarding stage (before and after post space preparation) in all levels and stage × device in coronal and middle levels (P<.05). This in vitro study emphasizes the minimal dentin width in the buccal root of maxillary premolars, especially near the bifurcation. Lack of adequate residual dentin thickness after post space preparation implies that the use of posts in maxillary first premolars should be limited. When mandatory, it is recommended that post space be prepared with Gates-Glidden drill in the palatal root of maxillary first premolars and use of Peeso reamer be avoided.

Investigation of the effect of different prefabricated intracanal posts on fracture resistance of simulated immature teeth

The aim of this study was to assess fracture resistances of simulated immature single-rooted teeth whose roots have been backfilled using 3 different post systems after a 4mm apical mineral trioxide aggregate (MTA) placement. Forty-eight maxillary anterior teeth were assigned into four groups. The lengths of each root were standardized by cutting off the coronal and apical portions to obtain 13±1mm samples and root canals were enlarged. The #6 Peeso reamers were allowed to protrude 1mm beyond apex to simulate immature teeth. Apical 4mm of each tooth was filled using MTA. The remaining portions were treated as follows: Group 1 (Control): AH Plus+Gutta-percha cold lateral compaction. Group 2: Glass fiber posts (FRC Postec Plus post) cemented using self-adhesive resin cement. Group 3: Quartz fiber posts (D.T. Light post) cemented using self-adhesive resin cement. Group 4: Zirconia posts (Cosmopost) were placed using self-adhesive resin cement. Specimens were embedded in self-curing acrylic. A compressive load was applied lingually at a crosshead speed of 1mm/min at an angle of 45º until fracture in a universal testing machine. The mean fracture resistances were 823.17±188.80, 1155.50±190.37, 1208.00±254.32, and 1153.25±195.71 Newtons for Groups 1, 2, 3, and 4, respectively. All experimental groups had significantly higher fracture resistance compared with the control group (P<0.01). No statistically significant difference was noted between the experimental groups (P>0.05). All post systems exerted a similar reinforcing effect to a simulated immature tooth and may be preferred specifically in situations which require additional reinforcement.

Effect of Different Techniques of Immediate and Delayed Post Space Preparation on Apical Seal

The purpose of this study was to investigate the effect of different post space preparation techniques and times on the apical seal of two types of gutta-percha obturation techniques. Materials and methods: Two hundred extracted human lower premolars were selected for this study. All teeth were decoronated to adjust the working length at 14 mm. The canals were instrumented with ProTaper rotary instruments to size F3. The (200) root canals were randomly divided into two groups (100) of each according to the obturating method. Then each group was sub divided into (10) sub groups (10) of each (2 control groups and 8 experimental groups). Nine mm segment of gutta-percha was removed from the roots in each of the experimental groups either immediately after obturation or 7 days later using either heated pluggers, or Gates-Glidden drills or ProTaper rotary instruments or peeso reamers. The roots in the control groups were left without any post space preparation. The canal orifice of the roots in the experimental groups was sealed with amalgam. The extend of linear dye leakage was measured in mm with a stereomicroscope at (X 20). One-way ANOVA and sheffe statistical analysis were performed to the data collected. Results: The groups with ProTaper rotary instrument prepared the post space immediately after obturation( gps 3,11), showed the lowest mean leakage, but the difference was not statistically significant than the other experimental groups. T-test represented no significant differences existed at either two time interval studied and the type of obturation techniques. Sheffe-test for the post space preparation techniques revealed that there were a significant differences occurred with the use of ProTaper rotary instruments regardless the time interval and the obturation techniques. Conclusions: ProTaper rotary instrument provided less microleakage comparing to the other instruments used to prepare the post space. The post space preparation did not affect the apical seal in comparison with that of the intact filling.

Comparison of the fracture resistance of simulated immature permanent teeth using various canal filling materials and fiber posts

The purpose of this study was to compare the fracture resistances of immature teeth treated with MTA along with root canal obturation methods using AH Plus, MetaSEAL, MTA Fillapex sealers + lateral compaction technique, and Unicore quartz fiber posts. Fifty single-rooted maxillary anterior teeth were divided into five groups. The crowns were dissected and root canals were enlarged. #6 Peeso reamers were allowed to protrude 1 mm. beyond the apex to simulate immature teeth. The apical 4-5 mm of each tooth was filled using Angelus white MTA. The remaining portions of canals were obturated as follows: Group 1: No backfilling (control), Group 2: AH Plus + gutta-percha, lateral compaction, Group 3: MetaSEAL + gutta-percha, lateral compaction, Group 4: MTA Fillapex + gutta-percha, lateral compaction, Group 5: UniCore Fiber posts luted using PermaFlo DC. The specimens were embedded into self-curing acrylic poured into identical cylinders which were mounted on a jig providing a 45° angle. A compressive load increasing at 1 mm min(-1) was applied and the maximum load at which fracture occurred was recorded. Statistical analysis was performed using Kruskal-Wallis and Dunn's multiple tests. The highest fracture resistance was obtained with Group 5 (Fiber posts) whereas Group 4 (MTA Fillapex) yielded the lowest values. The mean fracture resistance value of Group 2 (AH Plus) was significantly higher than Group 4 (MTA Fillapex) (P = 0.001). The mean fracture value of Group 5 (Fiber posts) was significantly higher than Group 2 (AH Plus), Group 3 (MetaSEAL), and Group 4 (MTA Fillapex) (P = 0.02, 0.004, and 0.0001, respectively). Within the limitations of this study, UniCore quartz fiber posts provided the highest resistance. This methodology may specifically be advantageous for teeth with arrest of development at early stages, as these teeth are more susceptible to fracture owing to their excessively weak dentinal walls.

Permeability of remaining endodontically obturated material after post-space preparation using different techniques of gutta percha removal - An in vitro study

Background and objective: This study was done to compare the effects on the apical seal when a flame-heated endodontic plugger, a NiTi rotary instrument and peeso reamers were used to prepare post-space in a root canal previously obturated with gutta-percha and sealer. Method: 55 extracted anterior teeth were used. Biomechanical preparation was done using step-back technique. Obturation was done using lateral condensation technique. The samples were divided into following groups of post-space preparation techniques. Amalgam was condensed into all experimental post space preparations. The roots were covered with sticky wax and nail polish leaving only the apical foramen then were placed in containers of India ink, and then washed in tap water. The roots were decalcified, dehydrated and then cleared. The extent of ink penetration was measured with a stereomicroscope. Statistical analysis was performed. Results: There was no statistically significant difference in linear apical dye leakage between the three experimental groups. Interpretation and conclusion: In this study rotary instruments showed lowest mean leakage but the difference was not statistically significant.

Periapical radiographs overestimate root canal wall thickness during post space preparation

To evaluate differences between anatomic and radiographic measurements of root canal wall thickness (RCWT) after each root canal preparation stage during post placement. Twenty mandibular premolars with a single canal were decoronated and the roots embedded in resin using a teflon muffle. Roots were sectioned horizontally at a pre-established level and canals were prepared for post placement. Endodontic hand files were used for root canal preparation, followed by Gates Glidden drills and Peeso reamers. Standardized radiographs and photographs at pre-established measurement levels were taken before preparation, after root canal instrumentation, after Gates Glidden preparation and after Peeso enlargement. All images were digitized and RCWT at the mesial and distal walls measured (IMAGETOOL 3.0). Differences between radiographic and anatomic measurements were analysed with paired t-tests. anova was used to compare the percentages of radiographic distortions. Regardless of the time-point evaluated, RCWT determined by radiographs were greater than the respective anatomic measurements (P < 0.05). The difference detected at each stage was similar and constant (P > 0.05). Throughout preparation for post placement, radiographic images overestimated the RCWT by approximately 25%, regardless of the clinical stage evaluated.

Coronal sealing ability of three sectional obturation techniques – SimpliFill, Thermafil and warm vertical compaction – compared with cold lateral condensation and post space preparation

The purpose of this study was to evaluate the effect post space preparation has on the coronal seal of root canals obturated with cold lateral condensation of gutta-percha compared with the corsonal sealing ability of three sectional obturation techniques not requiring post space preparation. Sixty-eight human maxillary central incisors were divided equally into four groups: cold lateral condensation (Group I), SimpliFill (Group II), Thermafil (Group III) and warm vertical compaction (Group IV). After coronal flaring, all four groups were cleaned and shaped with Lightspeed rotary instruments to a size 60 master apical rotary. After obturation Peeso Reamers were used to create a post space for Group I, while Groups 2, 3 and 4 incorporated the post space in the obturation (sectional technique) and did not require making a post space after obturation. The teeth were then stored in 100% humidity for 1 week and then kept in rhodamine B fluorescent dye for 3 weeks. The teeth were then split open, and the linear dye penetration from a coronal to apical direction (coronal seal) was evaluated with a fluorescent light microscope. Statistical analysis showed that Group I (cold lateral condensation followed by post space made with Peeso Reamers) leaked significantly more (P < 0.05) than the remaining three sectional obturation groups. It was concluded that stresses generated during post space preparation might be detrimental to the seal obtained by the obturation. Sectional obturations with their superior sealing ability offer a viable alternative.

Influence of post space preparation on the marginal integrity of a glass ionomer cement root end restoration : An in vitro study

This study aimed to determine the influence of post space preparation with peeso reamers on the marginal integrity of a glass Ionomer cement (GIC) root end restoration. Thirty maxillary anterior teeth were disinfected, decoronated to obtain 16mm root lengths, cleaned shaped and obturated rising cold lateral compaction with AH Plus as the scaler: Teeth were divided into three groups of ten teeth each. In Group 1, the post space preparation was done first, followed by GIC retrograde restoration. In Group II , the GIC retrograde restoration was placed first, allowed to set completely and then followed by post space preparation. Group Ill served as the positive control. Teeth were coated with trail varnish and immersed in Rhodamine B dye for 4(s hours and microleakage assessed under 20X magnification rising a sterecomicroscope. Mean leakage of 1211.36 Um was recorded for Group I, 2088.63 Um for Group II and a complete leakage of 3000 Um far Group III. Significant difference existed between Group I & II (p<0.05) and a vets highly significant difference between Group I &III and Group Il & III. It was concluded that after complete setting of GIC, the vibrational energy of post space preparation is capable of disrupting its seal, when it is used for root end restoration.

Chlorhexidine substantivity in root canal dentin

Objective The purpose of this investigation was to evaluate the substantivity of chlorhexidine (CHX) within a root canal system and to assess how long the CHX remains antimicrobially effective. Study design Bovine roots were sectioned and standardized to 8 mm. Sections, which served as controls, were treated with 1% sodium hypochlorite and 1 mol/L EDTA, then obturated with gutta percha and AH26 sealer. Experimental sections were treated similarly except they were placed in 2% CHX for 10 minutes prior to obturation. Control specimens were divided into 4 control groups and stored in saline for 1 day, 3 weeks, 6 weeks, and 12 weeks. Experimental specimens were divided into 4 groups and stored in saline for 1 day, 3 weeks, 6 weeks, and 12 weeks. After their respective storage periods, all specimens were halved and canal wall dentin was ground out with Peeso reamers. Dentin specimens were agitated in 700 μl of saline for 5 hours to release CHX. After centrifugation the supernatants were analyzed with UV spectrophotometry at 253 nm. To determine whether the CHX from dentin samples remained antimicrobial, the extracts from experimental and control groups were mixed with cultures of Enterococcus faecalis. Results After 1 day of storage, the dentin extract contained approximately 0.0048% CHX. After 3, 6 and 12 weeks, dentin extracts contained approximately 0.0023%, 0.0016%, and 0.0010% CHX respectively. Extracts from the storage groups were found to be highly antimicrobial corresponding to the CHX concentration. Conclusion The results of this study indicate that CHX is retained in root canal dentin in antimicrobially effective amounts for up to 12 weeks.

Effect of circumferential undercut placement in the root canal wall on the retention of a tapered post in large and small root canals

Objectives. This study examined the influence of root canal space and circumferential undercut placement in the dentine wall on the retention of a prefabricated Root Keeper post. Methods. Twenty-four extracted single-rooted teeth, having narrow root canal spaces, were decoronated, treated endodontically, and then centrally embedded in resin blocks. All canal spaces were prepared with a no. 2 Peeso reamer to an 8 mm depth, and half the specimens were successively treated with a no. 3 Peeso to depths of 5 and 8 mm for the small canal group (SC) and large canal group (LC), respectively. An L-type keeper post (Aichi Steel Co.) was luted to each canal with resin cement. The assembly was thermocycled 2000 times (4–60 °C), and post retention was measured. Afterwards the dislodged post with the intact structure was sandblasted, and the canal was cleaned and slightly undercut using an inverted cone bur. Six treated posts were recemented for both grooved large canal (GLC) and grooved small canal (GSC) groups, and the repaired retentive strengths were measured. Results. Keeper posts cemented in SC (84.26±31.85 N) showed better ( p<0.05) retention than those cemented in LC (41.92±22.36 N). Interestingly, the repaired strengths of the recemented post increased in both GSC (104.29±11.89 N) and GLC (96.65±6.91 N). All posts, except for one in the GLC, failed at the keeper-post joint. Conclusions. Prefabricated Root Keeper posts had lower retentive strength in roots with a large canal space. Placement of a circumferential undercut in the root canal wall significantly enhanced the retention of the short tapered posts.

Preparation of root canal orifices by Er:YAG laser irradiation: in vitro and clinical observations.

The purpose of the present study was to evaluate the effectiveness of Er:YAG laser irradiation for preparation of root canal orifices in extracted human teeth and several clinical cases. Few studies with sufficient data have been conducted in this area. Orifices of 42 extracted human teeth were prepared by conventional methods using a Peeso reamer or Er:YAG laser device at 250 mJ/pulse and 8 Hz. In the clinical study, the orifices of 11 teeth from 11 patients with irreversible pulpitis were prepared by Er:YAG laser irradiation at 160 mJ/pulse and 8 Hz. Teeth were carefully irradiated using non-contact methods. Evaluation was performed by visual inspection, stereoscopy, radiography, and scanning electron microscopy (SEM). In addition, the efficiency of using the Er:YAG laser was evaluated. In the in vitro study, canal orifices were clearly exposed by laser irradiation in all specimens. In 31 of 36 teeth (86%), orifices were successfully prepared without ledge formation or perforation. SEM observations revealed that irradiated surfaces were slightly rough and scaly, but essentially free from debris and smear layer. In the clinical study, orifices were successfully prepared in 10 of 11 teeth (91%), and no ledge formation or perforation was observed. These results suggest that the preparation of root canal orifices by Er:YAG laser irradiation may be useful in most cases, if appropriate parameters are selected.

Radiographic Measurement of Residual Root Thickness in Premolars with Post Preparation

A minimum thickness of 1 mm has been suggested for the residual root wall in post preparation. The objective of this paper is to evaluate the reliability of radiography when used to measure root thickness. In 106 upper first premolars with one and two root canals, post preparations were made with Peeso reamers to a depth in the root equal to the crown length. Bucco-palatal radiographs were taken of each tooth. The films were processed and projected with a magnification of x20. The smallest thickness of the mesial and distal walls of each root at the apical end of the preparation was measured and recorded. The teeth were then cut at the level of the measurement, and the smallest thickness of the proximal walls was measured using a microscope with a micrometric eyepiece. Fourteen percent of the teeth with one root canal and 27% of the teeth with two root canals could not be measured due to blurred radiographic contours. Variance analysis showed a highly significant difference (p < 0.001) when radiographic and anatomical measurements were compared. The radiograph showed greater thicknesses than were actually present and should not therefore be considered to be a reliable method for measuring residual thickness of tooth walls after post preparation.

Thermographic assessment of heat generated on the root surface during post space preparation.

The mechanical preparation of a post space in a root filled tooth is commonly carried out using rotating instruments in a slow handpiece. This procedure creates frictional heat which may be transferred to the root surface. In this investigation, the temperature changes on the root surface of 12 root filled, extracted human premolar teeth during preparation of post spaces were analysed using an infrared thermal imaging camera. A rotational speed of 8000 r.p.m. was used and the teeth were prepared with size 2 and 3 Peeso reamers and a red Parapost drill to the optimal length. The results indicate that very large temperatures are generated on the root surface and that this is greatest during the Parapost preparation stage. The long-term clinical effects of post space preparation by engine driven drills would warrant further investigation.

An assessment of the plastic Thermafil obturation technique

The effect of post space preparation on the apical seal of teeth roots treated with the plastic-cored Thermafil was studied in vitro. Single rooted teeth with mature apices were prepared chemomechanically and obturated with alpha-phase gutta-percha, Thermafil, on plastic core-carriers and sealer, Sealapex. The teeth were divided randomly into four groups of 18 teeth each. In two of the groups post space was prepared by hand using a Parapost drill (diam. 1.25 mm) after gutta-percha removal with Peeso reamers in a slow-speed handpiece, one group immediately after canal obturation and the other after storage in 100% relative humidity at 37 degrees C for 1 week; 5 mm of root filling was left intact. The time taken to remove the gutta-percha was recorded. Post space was not prepared in the control groups. Apical leakage was determined using black India ink. The teeth were demineralized, rendered transparent, and linear measurement of dye penetration was recorded. Results showed that there were no significant differences in leakage between any of the groups (P > 0.05). There was no statistically significant difference in the time required to remove the gutta-percha from the root canals in both groups (P < 0.05). It is concluded that under the conditions of this study post space preparation immediately after obturation, or after a delay of 1 week, does not affect the apical seal of Thermafil with plastic core-carriers.

Temperature rise at root surface during post-space preparation

This study compared the changes in temperature at the root surface of extracted human central incisors during post-space preparation using the following reamers (1) Peeso, (2) Kurer, (3) Gates-Glidden, (4) Para-Post, and (5) diamond burs. A mean temperature rise ranging from 2.3 °C to 15.6 °C from the baseline of approximately 28 °C was recorded. Peeso reamers recorded the highest temperatures followed by Kurer system and diamond burs, whereas Gates-Glidden and Para-Post systems were the lowest.

Effect of mechanical versus thermal removal of gutta-percha on the quality of the apical seal following post space preparation

The objective of this study was to compare the effects of a flame-heated endodontic plugger, an electrically-heated endodontic spreader, Peeso reamers, and GPX burs on the apical seal when gutta-percha was removed from the root canal for post space preparation. Eighty-nine human canines were instrumented and obturated with gutta-percha and sealer to a standardized working length of 15 mm. An 11-mm segment of gutta-percha was removed from the roots in each of the four experimental groups of 20 teeth to simulate post space preparation. The teeth were immersed in India ink for 7 days and rendered transparent. The extent of linear dye leakage was measured with a stereomicroscope. There was no statistically significant difference in linear dye leakage among any of the experimental groups when 4 mm of gutta-percha remained.

Effect of preflaring on canal transportation: Evaluation of ultrasonio, sonic, and conventional techniques

This study evaluated the effect on canal transportation when acrylic canals were preflared with Peeso reamers before the use of ultrasonic, sonic, and hand instrumentation techniques. Twenty resin blocks with simulated curved root canals were shaped with each technique to a size 40 file 0.5 mm from the apical foramen. Ten of the canals were preflared in the cervical region with No. 1 and No. 2 Peeso reamers before instrumentation; 10 canals that were not preflared served as controls. Transportation was measured on the inside canal curvature 3 mm from the canal orifice and 8 mm cervical to the working length, and on the outside canal curvature 1 mm cervical to the working length. Statistical analysis with Student'sttest did not show a significant reduction in canal transportation for the preflared groups. In some areas the amount of transportation was less for the preflared groups; in other areas it was greater.

Root canal wall thickness of mandibular molars after biomechanical preparation

A flaring technique for opening the cervical portion of mesial root canals in mandibular molars prior to canal instrumentation was compared with a conventional filing technique. The experimental technique explored the canals to the foramina. The canals were then filed sequentially with #15, 20, and 25 K files only to the begining curve length. Next a #1 Peeso reamer in an engine-driven handpiece was moved down the canal to the curve length. After this initial opening, the rest of the canal was instrumented with a conventional filing technique. The roots were then sectioned horizontally every 2 mm and the thickness of the distal canal wall was measured and compared with canals filed with a conventional filing method. These data were analyzed using paired <i>t</i> tests. There was no statistical difference between the distal wall thicknesses of the two techniques. The advantages of the experimental technique are increased mechanical efficiency and better access to the apical portions of the canal.

Linear and volumetric analysis of apical leakage in teeth prepared for posts

The effect of post preparation on the apical seal of endodontically treated teeth was studied. The canals of extracted human teeth were instrumented and obturated with gutta-percha using the lateral condensation technique. Post spaces were prepared immediately or 48 h after obturation by removing the gutta-percha with either heated endodontic pluggers, chloroform and files, or Peeso reamers. Linear and volumetric measurements of resultant apical dye leakage revealed that no significant differences existed between the gutta-percha removal techniques at either of the two time intervals studied.