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Background/Objectives: This study compared the accuracy and efficiency of different surgical-guide (SG)-assisted and freehand drilling techniques for removing fiber posts from maxillary anterior teeth performed by differently experienced operators. Methods: A fiber post was bonded to the root canal of 54 extracted maxillary anterior teeth. After mounting the teeth in the jaw models, SGs were designed by integrating cone-beam computed tomography (CBCT) and intraoral scanner data. Each SG included a custom sleeve. An experienced or inexperienced operator drilled the post using three different techniques: (i) SG-assisted incremental drilling at 2–3 mm (SG1), (ii) SG-assisted one-time drilling to a predetermined depth (SG2), and (iii) freehand incremental drilling without SG (FH; n = 9 in each group). Deviations in coronal, sagittal, and horizontal planes and the angle of deviation were measured. Results: The SG1 and SG2 groups showed significantly smaller sagittal and horizontal deviations than the FH group, regardless of the operator's experience. The SG2 group had a significantly shorter working time than the SG1 and FH groups. In the FH group, the experienced operator required a significantly shorter working time than the inexperienced operator. Conclusions: SG-assisted drilling techniques enhanced the accuracy and efficiency of removing fiber posts from the anterior teeth, irrespective of the operator's experience. [ABSTRACT FROM AUTHOR]

Purpose: Post removal may be necessary for many reasons and is inevitable after the re-application of a dental post. The present study investigated the bond strength between root dentin and a re-applied fibre-reinforced composite (FRC) post by a pull-out test. Materials and methods: After root canal treatments of 30 extracted human maxillary canine teeth, post spaces were prepared (10 mm), and FRC posts (Hi-Rem Post; Overfibres, İmola, Italy) were luted with self-adhesive resin cement. The samples were than randomly divided into test and control groups (n = 15 in each). The FRC posts were removed in the test group, and new posts were cemented. The pull-out test (1 mm/minute speed) was used to measure the bond strength. Failure types were determined using a stereomicroscope. Mann-Whitney U, chi-square and Fisher-Freeman-Halton exact tests were used for statistical analysis. Results: The bond strength values of the test (119.5 ± 36.86 N) and control (115.55 ± 55.44 N) groups did not differ significantly (p >.05). In terms of the percentage of failure types, there was a significant difference only in the test group between the mixed failure type and the other failure types (p

Post removal may be necessary for many reasons and is inevitable after the re-application of a dental post. The present study investigated the bond strength between root dentin and a re-applied fibre-reinforced composite (FRC) post by a pull-out test. After root canal treatments of 30 extracted human maxillary canine teeth, post spaces were prepared (10 mm), and FRC posts (Hi-Rem Post; Overfibres, İmola, Italy) were luted with self-adhesive resin cement. The samples were than randomly divided into test and control groups (n = 15 in each). The FRC posts were removed in the test group, and new posts were cemented. The pull-out test (1 mm/minute speed) was used to measure the bond strength. Failure types were determined using a stereomicroscope. Mann-Whitney U , chi-square and Fisher-Freeman-Halton exact tests were used for statistical analysis. The bond strength values of the test (119.5 ± 36.86 N) and control (115.55 ± 55.44 N) groups did not differ significantly (p >.05). In terms of the percentage of failure types, there was a significant difference only in the test group between the mixed failure type and the other failure types (p <.05). The re-application of FRC post did not seem to affect the bond strength. The distribution of failure types was similar between the control and test groups. [ABSTRACT FROM AUTHOR]

Background/Objectives: This study compared the accuracy and efficiency of different surgical-guide (SG)-assisted and freehand drilling techniques for removing fiber posts from maxillary anterior teeth performed by differently experienced operators. Methods: A fiber post was bonded to the root canal of 54 extracted maxillary anterior teeth. After mounting the teeth in the jaw models, SGs were designed by integrating cone-beam computed tomography (CBCT) and intraoral scanner data. Each SG included a custom sleeve. An experienced or inexperienced operator drilled the post using three different techniques: (i) SG-assisted incremental drilling at 2–3 mm (SG1), (ii) SG-assisted one-time drilling to a predetermined depth (SG2), and (iii) freehand incremental drilling without SG (FH; n = 9 in each group). Deviations in coronal, sagittal, and horizontal planes and the angle of deviation were measured. Results: The SG1 and SG2 groups showed significantly smaller sagittal and horizontal deviations than the FH group, regardless of the operator’s experience. The SG2 group had a significantly shorter working time than the SG1 and FH groups. In the FH group, the experienced operator required a significantly shorter working time than the inexperienced operator. Conclusions: SG-assisted drilling techniques enhanced the accuracy and efficiency of removing fiber posts from the anterior teeth, irrespective of the operator’s experience.

Aim: There are currently no high‐quality studies comparing the static navigation technique with conventional methods of fibre post removal. The aim of this ex vivo study was to compare the effectiveness of fibre post removal between a static navigation technique and a conventional freehand technique using ultrasonics by experienced and inexperienced operators. Methodology: Forty‐eight extracted single‐rooted human premolars were root‐filled. A fibre post was cemented in all 48 teeth, which were then divided randomly into the following groups: static navigation group using burs; static navigation‐ultrasonic group; and non‐guided group using ultrasonic tips. The following parameters were evaluated for both experienced operators and inexperienced operators: reaching the gutta‐percha root filling successfully, the time required to remove the entire post, the occurrence of lateral root perforations, and the amount of root dentine removed. The Kolmogorov–Smirnov test was used to examine the normality of the data; the anova test was used to compare the significant differences among groups; and Tukey tests were used for all two‐by‐two comparisons. The significance level was set at 0.05. Results: In the static navigation group, the gutta‐percha was reached significantly more frequently than in the non‐guided group (p <.05). The static navigation approach required significantly less time than the non‐guided approach to reach the gutta‐percha (p <.05). The total removal of posts was significantly different between groups (p <.05), but there was no significant difference between experienced and inexperienced operators in the static navigation group (p >.05). More perforations were associated with the non‐guided group than with the other two groups. The total mean loss of dentine in the non‐guided group in all directions was 0.39 (±0.17) mm, with 0.25 (±0.09) mm for experienced, and 0.42 (±0.16) mm for inexperienced operators. Conclusion: When compared to a conventional ultrasonic technique for the removal of fibre posts, the static navigation method using burs resulted in less dentine removal, more rapid access to the gutta‐percha root filling, less overall time to remove the posts, and fewer complications. When using static navigation, there was no difference in performance between experienced and inexperienced operators. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the efficiency of Er:YAG laser in translucent fibre post removal. 60 human single‐rooted anterior teeth were divided into three groups (n = 20) according to post diameters (Exacto1‐E1, Exacto2‐E2, Exacto3‐E3) and subdivided according to laser application. Fibre posts were cemented to endodontically treated teeth, and the specimens were sliced with a thickness of 1.0 ± 0.2 mm. Er:YAG laser was applied and the push out bond strength test was performed. Two‐way analysis of variance was used to perform the statistical analysis. Push out bond strengths at apical area were significantly lower in all test groups (p < 0.05). Laser application caused increase in all radicular thirds, but it was significant for E1 and E3 groups. Laser application to the post‐dentine interface enhances the connection between post and dentine. [ABSTRACT FROM AUTHOR]

Introduction: Glass fiber posts removal is a major obstacle in nonsurgical endodontic retreatment. The currently used removal techniques cause tooth structure loss in different amount. The aim of this study was to evaluate three glass fiber post removal techniques according to their effect on the amount of removed root dentin. Materials and Methods: Endodontic treatment was accomplished for 45 extracted single-rooted teeth. The teeth were decoronated and roots were cut apically at (11 mm) then fiber post spaces were prepared. Photographs of the apical cross-section for post space were taken using a camera at a magnification of 40. Fiber posts were cemented with dual cure resin cement. Then, the samples were divided into three groups (n = 15) depending on the fiber post removal technique: Group (I) DT post removal Kit, Group (II) ultrasonic tips E4D and Group (III) diamond bur and Peeso reamer. Posts were removed and images of the previous section were taken under the same magnification. AutoCAD program was used to compare the spaces difference between before and after removal images. Data were subjected to statistical analysis. Results: The average percentage of removed dentin was (1.89, 0.48, 0.09) cm2 in Groups I, II, and III, respectively. Group I showed the highest amount of removed dentin comparing to other groups, but no significant difference between Group II and Group III was recorded (P = 0.000). Conclusion: DT post removal kit group was the most aggressive technique for removing glass fiber.

Purpose: The purpose of this in vitro study was to compare the post space volume changes following removal of glass fiber posts in endodontically treated teeth by using erbium, chromium:yttrium‐scandium‐gallium‐garnet (Er,Cr:YSGG) laser to the conventional ultrasonic method. Materials and Methods: Twelve single‐root human extracted teeth were cut into 13 mm near cementoenamel junction (CEJ), and then underwent endodontic treatment. The post spaces were prepared to 8 mm in length. Glass fiber posts were inserted with self‐curing resin cement. Specimens were randomly assigned to laser or ultrasonic methods for their post removal. Post space volumes were measured using microcomputed tomography (micro‐CT) before post cementation and after post removal. Dentin thickness was measured after post removal at coronal, middle, and apical third of the root canal space. Paired t‐test and t‐test were used to compare space volumes between before post cementation and after post removal, and between laser and ultrasonic groups, respectively. Results: Six specimens were tested for each group. The average volume change was 6.499 mm3 in laser and 7.418 mm3 in ultrasonic method. There was not a significant difference between laser and ultrasonic group in respect of post space volume changes (p = 0.71). Both methods showed significant volume increase following post removal (p < 0.05). Significantly less dentin was lost when laser was used for post removal in the coronal portion of the post space (p = 0.002). Conclusions: Er,Cr:YSGG laser can be used as effective option, comparable to the conventional ultrasonic method when removing posts in endodontically treated teeth. Laser has the potential to provide conservative post removal. [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate the accuracy and efficiency of the 3-dimensional dynamic navigation system (DNS) compared with the freehand technique (FH) when removing fiber posts from root canal–treated teeth. Twenty-six maxillary teeth were included. Teeth were root canal treated and restored with Parapost Taper Lux (Coltene/Whaledent, Altstätten, Switzerland) luted with RelyX Unicem (3M ESPE, St Paul, MN). A core buildup was then performed using Paracore (Coltene/Whaledent). Teeth were mounted in tissue-denuded cadaver maxillae. Teeth were divided into 2 groups: the DNS group (n = 13) and the FH group (n = 13). Cone-beam computed tomographic scans were taken pre- and postoperatively. The drilling path and depth were planned virtually using X-guide software (X-Nav Technologies, Lansdale, PA) in both groups. For the DNS group, drilling was guided with X-Nav software and the FH group under a dental operating microscope. Global coronal and apical deviations, angular deflection, operation time, and the number of mishaps were compared between the groups to determine the accuracy and efficiency. The 3-dimensional volume (mm3) of all teeth was calculated before and after post removal using the Mimics Innovation Suite (Materialise NV, Leuven, Belgium). The Shapiro-Wilk, 1-way analysis of variance, and Fisher exact tests were used (P <.05). The DNS group showed significantly less global coronal and apical deviations and angular deflection than the FH group (P <.05). DNS required less operation time than FH. Moreover, the DNS technique had significantly less volumetric loss of tooth structure than the FH technique (P <.05). The DNS was more accurate and efficient in removing fiber posts from root canal–treated teeth than the FH technique. [ABSTRACT FROM AUTHOR]

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Teeth with a history of non-successful surgical retreatment may present with particular difficulties interms of treatment planning and procedures.The presented cases illustrate the successful treatment of two maxillary central incisors following previous surgery and insertion of transfixation pins. A combined non-surgical and surgical approach was undertaken to remove the root canal filling and the transfixation pins, and to achieve apical seal. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the speed (efficiency) and effectiveness of 3 different fiber post removal systems. Method and Materials: Fiber posts (D.T. Light-Post no. 1 [Bisco Dental] and ParaPost FiberLux no. 5 [Coltène/Whaledent]) were cemented into 60 single-rooted teeth after endodontic therapy and post space preparation were completed. Three methods of fiber post removal were evaluated-D.T. Light-Post removal kit, the Kodex twist/Tenax ParaPost fiber post removal drill kit, and a combination of diamond bur/Peeso reamer. Results: The efficiency to remove either fiber post was not significantly different, nor was efficiency of any of the 3 post removal systems significantly different. For effectiveness, no difference was observed between post types, but effectiveness was higher with the diamond bur/Peeso reamer compared with the Kodex twist/Tenax ParaPost drills, which in turn was more effective than the D.T. Light-Post removal kit. Conclusions: Fiber posts are efficiently removed by all 3 methods, but effectiveness of removal is higher using the diamond bur/Peeso reamer. [ABSTRACT FROM AUTHOR]

Purpose: We present our institutional experience in treating brain metastases with GK-SRS and a headframe fixed to the skull with only 3 pins to avoid collisions between the headframe and the Gamma Knife (GK) machine. Methods and materials: Among 3500 consecutive patients who received GK-SRS in 2011-2017, 50 had 1 of the 2 anterior pins removed immediately before treatment of ≥1 brain lesion. Endpoints were local control, dosimetric parameters, and toxicity. Results: Median follow-up time for the 49 patients with follow-up was 7.0 months (range 0.2- 57.0). Median number of lesions treated per session was 6 (range 1-18); a median 1 lesion was treated with 3-pin fixation (range 1-2) and a median 5 lesions treated with 4-pin fixation (range 0-17) during the same session. Lesions treated with 3-pin fixation were in the occipital lobe (n=41), cerebellum (n=9), or temporal lobe (n=1). No local failures were noted. The sole grade 2 toxicity (partial seizure) was attributed to treatment of a 4-pin-fixed lesion. Except for gradient index, dosimetry did not vary for lesions treated with 3-pin versus 4-pin fixation. Conclusions: Treating brain metastases with 3-pin fixation did not compromise treatment outcome and is a good option for posterior brain metastases that cannot otherwise be treated with 4-pin GK-SRS. [ABSTRACT FROM AUTHOR]

Purpose To measure tooth volume change before and after post removal using micro-CT and to compare the difference among various combinations of prefabricated post and cement systems. Materials and Methods Forty-eight extracted maxillary anterior teeth and mandibular canines were sectioned 13 mm from the apex. Root canals were properly instrumented. Preparations were filled with gutta percha using lateral condensation. Post space was prepared with a touch and heat device, leaving 5 mm of gutta percha from the apex. Specimens were scanned with micro-CT to establish objective baseline volume and divided into two groups of post systems: stainless steel (SS) ParaPost and glass-fiber reinforced composite (FRC) post. Half the posts for each group were cemented with Ketac Cem radiopaque glass-ionomer cement, and the other half with SpeedCEM dual-curing resin cement. The posts and residual cement were removed by the same operator, using the ultrasonic vibration technique under an endodontic operating microscope. The remaining tooth root structure was scanned again using micro-CT with volume reported (mm3). The statistical difference between the combination of posts and cements was measured using the Kruskal-Wallis ANOVA test (α = 0.001). The independent variables were evaluated separately using post hoc Tukey examination to determine which groups resulted in a statistically significant difference. Results There was a statistical difference of tooth root volume change among the groups. Post hoc exam revealed a statistically significant difference in tooth root volume change between group 1 (SS + GI) and the other groups (α = 0.0002). Conclusion Compared to other post and cement combinations, serrated parallel-sided SS posts cemented with GI cement had the most tooth root structure loss upon post removal using the ultrasonic vibration technique. [ABSTRACT FROM AUTHOR]

Background: Ultrasonic vibrations are used to remove a cemented post from a root canal requiring endodontic retreatment. Various results have been reported from the studies that evaluated the effect of ultrasonic instruments in removing the posts cemented with resin cements. The aim of this study was to evaluate the effect of ultrasonic energy on the retention of prefabricated metal post cemented with Panavia or Maxcem Elite cements. Materials and Methods: In this in vitro study, forty eight extracted single root premolars were decoronated with a diamond disc leaving a 13 mm long root and endodontically treated. The root canals were obturated by gutta-percha up to 5 mm with vertical condensation method and the 8 mm post-space was prepared to receive a no. 2 long Dentorama post. The roots were placed in an incubator for 48 h in 37΀C and 100% humidity. After mounting the teeth in acrylic blocks, posts were cemented in the root canals using Panavia F2.0 in 24 specimens and Maxcem Elite in 24 others. For half of the specimens in each subgroup, an ultrasonic device was applied for 4 min. Universal testing machine was used to measure the force needed to remove the posts with a crosshead speed of 1 mm/min until the post came out of the canal. Kruskal-Wallis test was used for statistical analysis at 5% level of significance. Results: The removal force was not significantly different among the groups (P > 0.05). Conclusion: Ultrasonic energy did not decrease the retention of posts cemented with Panavia or Maxcem Elite cements. Furthermore, it seems that there is no significant difference between removal force of self-etch (Panavia) and the self-etch self-adhesive (Maxcem Elite) resin cements.

Abstract: Introduction: This study investigated the influence of clinical experience in relation to the efficacy and effectiveness of removal of 2 different fiber posts. Methods: In total, 48 intact single-rooted teeth were treated endodontically and obturated. Then, 10-mm post spaces were prepared, and fiber posts were luted. Twenty-four #1 D.T. Light-Posts were used in group 1, and 24 #2 Hi-Rem Prosthetic Posts were used in group 2. A pullout test (n = 8 per group) was performed by using a universal testing machine to compare bond strength. Then, fiber post removal efficacy and efficiency were tested. Each group was divided into 2 subgroups (n = 8) according to operator experience. In group 1, fiber posts were removed with an ultrasonic handpiece by using a #3 Start-X tip. In group 2, a size 25/0.04 ProFile was used to remove the central soft polymer macrofiber, and a #2 Largo drill was used to remove the fiber post and luting cement remnants. Post removal times were recorded to evaluate efficacy. Weight change was determined, and post space walls were analyzed microscopically to evaluate effectiveness. Results: Bond strength did not differ significantly (P = .7569) between post systems. Post hoc Tukey tests indicated that removal time was affected significantly by operator experience in group 1 (P < .001) but not in group 2. Weight change was affected significantly by experience level in both groups. No difference in post space wall characteristics was observed between subgroups. Conclusions: The Hi-Rem post was easier to remove than the D.T Light-Post. [Copyright &y& Elsevier]

Background: Ultrasonic vibrations are used to remove a cemented post from a root canal requiring endodontic retreatment. Various results have been reported from the studies that evaluated the effect of ultrasonic instruments in removing the posts cemented with resin cements. The aim of this study was to evaluate the effect of ultrasonic energy on the retention of prefabricated metal post cemented with Panavia or Maxcem Elite cements. Materials and Methods: In this in vitro study, forty eight extracted single root premolars were decoronated with a diamond disc leaving a 13 mm long root and endodontically treated. The root canals were obturated by gutta-percha up to 5 mm with vertical condensation method and the 8 mm post-space was prepared to receive a no. 2 long Dentorama post. The roots were placed in an incubator for 48 h in 37°C and 100% humidity. After mounting the teeth in acrylic blocks, posts were cemented in the root canals using Panavia F2.0 in 24 specimens and Maxcem Elite in 24 others. For half of the specimens in each subgroup, an ultrasonic device was applied for 4 min. Universal testing machine was used to measure the force needed to remove the posts with a crosshead speed of 1 mm/min until the post came out of the canal. Kruskal-Wallis test was used for statistical analysis at 5% level of significance. Results: The removal force was not significantly different among the groups (P > 0.05). Conclusion: Ultrasonic energy did not decrease the retention of posts cemented with Panavia or Maxcem Elite cements. Furthermore, it seems that there is no significant difference between removal force of self-etch (Panavia) and the self-etch self-adhesive (Maxcem Elite) resin cements. [ABSTRACT FROM AUTHOR]

Abstract: Introduction: This study was designed to calculate probabilities for tissue injury and to measure effectiveness of various coolant strategies in countering heat buildup produced by dry ultrasonic vibration during post removal. Methods: A simulated biological model was used to evaluate the cooling efficacy of a common refrigerant spray, water spray, and air spray in the recovery of post temperatures deep within the root canal space. The data set consisted of cervical and apical measures of temperature increase at 1-second intervals from baseline during continuous ultrasonic instrumentation until a 10°C increase in temperature at the cervical site was registered, wherein instrumentation ceased, and the teeth were allowed to cool under ambient conditions or with the assistance of 4 coolant methods. Results: Data were analyzed with analysis of variance by using the independent variables of time of ultrasonic application (10, 15, 20 seconds) and cooling method. In addition to the customary means, standard deviations, and analysis of variance tests, analyses were conducted to determine probabilities that procedures would reach or exceed the 10°C threshold. Both instrumentation time and cooling agent effects were significant at P <.0001. Conclusions: Under the conditions of this study, it was shown that injurious heat transfer occurs in less than 1 minute during dry ultrasonic instrumentation of metallic posts. Cycles of short instrumentation times with active coolants were effective in reducing the probability of tissue damage when teeth were instrumented dry. With as little as 20 seconds of continuous dry ultrasonic instrumentation, the consequences of thermal buildup to an individual tooth might contribute to an injurious clinical outcome. [ABSTRACT FROM AUTHOR]

Aim To evaluate several protocols for the application of ultrasound during removal of cast posts with varying core configurations cemented with zinc phosphate. Methodology Sixty maxillary canines were distributed into three groups ( n = 20): group 1 – core with 5 mm diameter/height and post diameter of 1.3 mm; groups 2 and 3 – core with the same diameter as the post (1.3 mm) and heights of 5 mm and 3 mm, respectively. Posts/cores were cemented using a standard technique with zinc phosphate cement. Each group was divided into two subgroups according to the ultrasonic vibration mode: point vibration – ultrasonic vibration applied to the core surface for 5 s, on each face totalling 25 s; alternate vibration – intermittent application of ultrasonic vibration for 10 s to the labial and lingual surfaces, 10 s to the mesial and distal surfaces and 5 s to the incisal surface, totalling 25 s. The specimens were submitted to the tensile test using an Instron machine (1 mm min−1) and results were analysed byanova and t-test. The failure type was also analysed. Results Statistical analysis showed significant differences between groups relating to the core preparations ( P < 0.05). The lowest mean values of traction force were obtained for group 3 (46.1 ± 7.7 N), followed by group 2 (89.0 ± 2.7 N) and group 1 (160.4 ± 7.5 N). Regarding ultrasonic vibration, the lowest mean was observed with alternate vibration (81.1 ± 10.1 N), which was significantly lower than the point vibration (115.9 ± 9.5 N) ( P < 0.05). Cohesive failure occurred in all cases. Conclusion A reduction in core diameter/height and intermittent ultrasonic application improved the removal of cast posts cemented with zinc phosphate. [ABSTRACT FROM AUTHOR]

Abstract: The purpose of this study was to investigate the potential for temperature increase along the external root surface during ultrasonic post removal in a simulated clinical environment. Thirty-seven extracted teeth were decoronated, instrumented, and then obturated with gutta-percha and sealer. Post spaces were prepared, followed by cementation of stainless steel posts. A simulated clinical environment was created by using a polymethylmethacrylate sheet with holes custom fitted for the extracted teeth and then suspended over a heated water bath. Two thermocouples were attached at 6 and 12 mm from the top of the post along the external root surface. Teeth were divided into 3 test groups, no coolant, air-cooled, and water-cooled. Temperature changes were recorded by using a Vishay 5000 Strain Smart system. Results demonstrated that a significant difference existed in the average heat rates between the upper and lower thermocouples for no coolant and water-cooled groups at the medium setting and the air-cooled group at the high setting. The average heat rates were significantly different between the 2 thermocouples for all 3 groups when comparing the 2 ultrasonic power settings. Results indicated that the average heat rate was less for the water-cooled group when using a medium power setting. [Copyright &y& Elsevier]

Aim To determine the temperature rise on the root surface caused by ultrasonic post removal using different devices and techniques in a laboratory setting. Methodology Two ultrasonic devices, one piezoelectrical (Pi) and one magnetostrictive (Ma), were investigated. A serrated titanium post was placed into the distal root canal of a human mandibular first molar. Four coolant parameters were utilized: no air, no water, no evacuation (NN), air only with high-speed evacuation (A), 15 mL min−1 water coolant with high-speed evacuation (W15) and 30 mL min−1 water coolant with high-speed evacuation (W30). Five simulated post removals were measured at two locations, the post (P) and the root (R), for each coolant parameter. Temperature rise was measured at 30, 60, 90 and 120 s intervals using calibrated infrared thermography ( n = 80). Temperatures were recorded at 45 ms intervals. Data were analysed using repeated measures anova with the Scheffe post hoc test ( P ≤ 0.05). Results The overall mean pooled effect showed that temperature rise for P = 20.1 ± 27.9 °C and R = 10.9 ± 7.9 °C were significantly different. Significant differences in temperature rise were: Pi > Ma, P > R, NN > A = W15 = W30 however, A > W30. Conclusions There were significant differences in temperature rise as a function of ultrasonic device, location on the tooth and cooling method utilized for post removal. [ABSTRACT FROM AUTHOR]

Abstract Castrisos T, Palamara JEA, Abbott PV. Measurement of strain on tooth roots during post removal with the Eggler post remover. International Endodontic Journal , 35 , 337–344, 2002. Aim The aim was to measure root surface strains in teeth when removing cast post/cores with the Eggler post remover. Methodology Two groups of 10 teeth each were tested: group 1 had 1 mm thickness of dentine coronally, and group 2 had 2 mm thickness of dentine. After root filling, 10 mm long cast post/cores were constructed and cemented with zinc phosphate cement, and strain gauges were applied to the roots. The post/cores were removed with the Eggler post remover whilst strain measurements were being recorded. Posts were removed twice: initially along the long axis of the tooth and then at a 10° angle to the long axis. Comparisons between groups 1 and 2 were analysed statistically with the Mann–Whitney U -test whilst strains within each group were analysed with the Wilcoxon Signed Rank test at the 95% level of confidence. Results There was no significant difference in the strains measured between groups 1 and 2, and no significant difference within each group when removing posts along the long axis of the tooth and at a 10° angle. Three teeth in group 1 and one tooth in group 2 fractured when removing posts at the 10° angle. Three fractures were small slivers of dentine at the point where the Eggler’s repeller arms contacted the tooth mesially and distally, whilst one tooth (from group 1) fractured obliquely. Conclusions Post removal with the Eggler device is a relatively safe procedure but care must be taken when there is a possibility of pulling the post out in a nonaxial direction or when less than 1 mm of dentine surrounds the apical end of the post. [ABSTRACT FROM AUTHOR]

Abstract Aim The aims of this study were to determine the attitudes of endodontists toward the risk of root fracture when removing posts and to determine which methods they commonly used to remove posts from root-filled teeth. Methodology A survey was sent to all 74 members of the Australian and New Zealand Academy of Endodontists. The survey was divided into three parts to gather information concerning root canal retreatment performed in specialist endodontic practice, attitudes about the risk of root fracture when removing posts and the methods used to remove different post systems. Results Responses were received from 62 (84%) of the Academy members. When a post was present in a tooth that required root canal retreatment, 66% of the endodontists preferred to remove the post, whilst 27% considered either post removal or periapical surgery. Forty-five per cent reported that a root fracture had occurred during post removal, but this represented less than 0.002% of the estimated number of posts removed by all respondents. Ultrasonic vibration was the most common method used to remove posts, although post removal devices were used more often in anterior teeth; the Eggler post remover was the most commonly used device. Conclusions Most endodontists preferred to remove posts rather than perform periapical surgery. Few root fractures were reported. Ultrasonic vibration was the most common method used to remove posts from all tooth types, with the Eggler post remover used most commonly for posts in anterior teeth. [ABSTRACT FROM AUTHOR]

Abstract Aim This study was undertaken to determine the incidence of root fractures during post removal, as well as the methods used and the success rates achieved with various post removal devices and techniques. Methodology Patient records from a specialist endodontic practice were examined. A total of 1600 teeth from which posts were removed were identified. These teeth had no preoperative signs or symptoms to suggest root fractures. The incidence of root fractures was determined and a subset of 234 patient records were examined in detail to determine the methods used to remove different types of posts. Results Only one tooth fractured during post removal (0.06%) and all posts were successfully removed, typically in about 3 min. Most cast posts were removed with an Eggler post remover but some dislodged when the crown was removed; ultrasonics was used occasionally. Most parallel-sided posts were removed with ultrasonics and threaded posts were unscrewed. The Masserann kit and ultrasonics were combined to remove fractured cast posts and some parallel-sided posts. Conclusions This study indicates that, with good case selection, post removal is a predictable procedure. If appropriate techniques and devices are used for the particular type of post being removed, then root fracture is a rare occurrence. [ABSTRACT FROM AUTHOR]

Gomes APM, Kubo CH, Santos RAB, Santos DR, Padilha RQ. The influence of ultrasound on the retention of cast posts cemented with different agents. International Endodontic Journal , 34 , 93–99, 2001. --> Aim: The aim of this study was to evaluate the influence of ultrasound during the removal of posts cemented with either zinc phosphate cement, glass ionomer cement or resin cement. Methodology: Eighty‐four single‐rooted teeth were prepared and after cementation of cast posts, they were randomly divided into six groups of 14. Groups 1, 2 and 3 did not receive ultrasonic vibration, whilst groups 4, 5 and 6 received ultrasonic vibration for 10 min. The force necessary for post removal was determined using a universal testing machine. Results were statistically analysed using anova and Tukey tests (5%). Results: The application of ultrasonic vibration reduced the retention provided by zinc phosphate and glass ionomer cements by 39% and 33%, respectively. Conclusions: A statistically significant reduction in the force necessary to remove posts cemented with zinc phosphate and glass ionomer cements occurred following application of ultrasound. The application of ultrasonic vibration did not influence the retention of cast posts cemented with resin cement. [ABSTRACT FROM AUTHOR]