Cast Metal Posts Research Articles

Evaluation of accuracy of fit in cast metal post fabricated with direct and indirect techniques using micro-CT - An in vitro study.

Accuracy of fit of cast metal posts fabricated with direct and indirect techniques. To evaluate the accuracy of fit of cast metal posts fabricated with direct and indirect techniques using micro-CT. Sixty extracted human maxillary central incisors were used. The teeth were decoronated leaving 2 mm at the cementoenamel junction. Four patterns for each tooth were made including one direct and indirect wax pattern and one direct and indirect resin pattern. In total, 240 patterns and castings were made. Each tooth was scanned using microcomputed tomography (μCT) system with a resolution of 14.5 μm. μCT analyzer Sky scanner software was used to calculate the volume of space between the post and the canals. Statistical analysis used: The student paired t-test and unpaired t-test were used to determine the significant differences between groups. The overall space between the canal walls and posts made with the direct wax and resin technique had an average mean value of 1.10 mm3, whereas with the indirect technique resin and wax pattern, the average mean was 1.30 mm3 which was significant. Within the limitations of the study, it was found that the accuracy of fit is better in direct technique using wax pattern.

Zinc Phosphate and Resin Cements Provide Similar Bonding of Cast Metal Post to Dentin

Background: Cast metal posts-and-core are frequently used to retain restorations to extensively destroyed teeth. However, the influence of different cements on the posts bond strength to dentin remains unclear. Objective: to evaluate the effect of different cements on the bond strength of cast metal posts and dentin. Methods: Forty roots (14 mm length) of extracted human teeth were endodontically treated and prepared. Impressions of each root canal were taken to obtain customized cast metal posts. The roots were randomly divided into 4 groups (n=10): (1) ZP: zinc phosphate cement (non adhesive); (2) ARC_Sin: Single Bond adhesive and RelyX ARC; (3) ARC_Sco: Scotchbond adhesive and RelyX ARC; (4) U200: RelyX U200. After cementation, the samples were cross-sectioned to obtain specimens of 1mm thickness. Push-out test was performed applying a compressive load (0.5 mm/min) to the center of the metal post until failure. Bond strength was calculated based on the diameter of the root canal and the thickness of each specimen. Data were analyzed using ANOVA and Tukey (α=0.05). The fracture mode was analyzed. Results: Bond strength values were statistically similar between the groups (p>0.05). The fracture analysis showed the prevalence of mixed fractures (cement partially attached to the dentin and/or post). Experimental groups showed inexpressive amount of adhesive fractures (complete detachment of the cement from dentin and/or post). The ARC_Sco and U200 groups presented higher prevalence of dentin cohesive fracture. Conclusion: Bonding had no influence on the immediate bond strength between cast metal posts and root canal dentin.

Post removal techniques: a systematic review and meta-analysis

Aim: This systematic review aimed to answer what is the best way to remove prefabricated metallic, fiber or cast metal posts. Methodology: An electronic search was conducted in Medline and Scopus databases to identify clinical and in vitro studies that assessed post removal techniques from 1950 to October 2018. Tables were generated to summarize the included studies and reports were assessed for bias using the Cochrane risk of bias tool. A meta-analysis was performed to evaluate the force necessary to remove posts (α=5%). Results: Of the 2,951 studies identified in the initial search, 33 were selected. The duration of using ultrasonic vibrations (and the number of surfaces where the vibration was applied) led to less time spent and less force needed to dislodge a metal post. Dentist’s expertise (more than 10 years) was also related to easier post removal. The use of adhesive cements resulted in a more difficult protocol for post removal. Conclusions: Although there is need for more consistent results, the data summarized and meta-analysis points toward the use of ultrasonic energy as the first option to remove posts, with best results for metal posts.

Fracture Resistance and Failure Mode of Custom-made Post-and-cores of Polyetheretherketone and Nano-ceramic Composite.

Custom-made post-and-cores of polyetheretherketone (PEEK) and nano-ceramic composite showed good fracture resistance and failure mode. Clinicians should be aware that these materials might be an efficient alternative for post-and-cores, because they promote esthetics while reducing the risk of root fractures. Purpose: The purpose of this study was to evaluate the fracture resistance and failure mode of custom-made post-and-cores manufactured with different esthetic materials.Methods and Materials: A total of 48 mandibular premolar extracted teeth were selected, endodontically treated, and prepared to receive the posts. Specimens were randomly divided into four groups (n=12/group): group 1, polyetheretherketone (PEEK, Degos; G1); group 2, nano-ceramic composite (Lava Ultimate, 3M ESPE; G2); group 3, cast metal post (NiCr alloy, control; G3); group 4, fiberglass post (Whitepost, FGM, control; G4) customized with a nano-hybrid resin composite (Z250, 3M ESPE). Experimental post-and-cores (G1 and G2) were manufactured with a computer-aided design/computer-aided manufacturing system. All posts were cemented with self-adhesive resin cement (Rely X U200, 3M ESPE), and specimens were stored in distilled water at 37°C for 60 days. A universal testing machine was used to measure the fracture resistance (0.5 mm/min at an angle of 45° to the long axis of the tooth). Fractures were classified as repairable or catastrophic. One-way analysis of variance with Tukey post hoc and χ2 tests for independence and Bonferroni adjustments were applied (α=0.05).Results: The fracture resistance values (mean ± SD, in newtons) were 379.4 ± 119.8 (G1), 506.4 ± 138 (G2), 939.6 ± 146.5 (G3), and 449.6 ± 66.5 (G4). Only G3 exhibited a significant difference (p<0.05). The χ2 test showed an association between failure mode and post-and-core material [χ2(3) = 23.65; p<0.001]. After Bonferroni adjustment, only G3 presented a higher than expected incidence of catastrophic failures (p<0.001). In the remaining groups, most failures were repairable and related to debonding.Conclusions: Customized post-and-cores of PEEK and nano-ceramic composites exhibited good mechanical performance. Their fracture resistance was comparable to that observed for fiberglass customized posts, yet lower than that for cast metal posts. For PEEK post-and-cores, in particular, additional studies are needed to improve adhesiveness and reduce the risk of debonding.

Retreatment of permanent incisors with fibre and cast metalposts

Retreatment of permanent incisors with fibre and cast metalposts - IJCE- Print ISSN No: - 2581-9534 Online ISSN No:- 2581-8988 Article DOI No:- 10.18231/j.ijce.2020.010, IP Indian Journal of Conservative and Endodontics-IP Indian J Conserv Endod

Randomized controlled trial comparing glass fiber posts and cast metal posts

ObjectiveThis study aimed to assess the survival and success of glass fiber posts compared to cast metal posts in teeth without ferrule. Material and MethodsAn equivalency, prospective, double-blind (patient and outcome evaluator) randomized controlled trial (RCT) with parallel groups was designed to compare the clinical performance of cast metal and glass fiber posts cemented in endodontically treated teeth without ferrule (NCT01461239). Teeth were randomly allocated to the glass fiber or cast-metal post groups. All teeth were restored with single metal-ceramic crowns. Kaplan-Meier analysis with the log-rank test was used to test the success and survival between glass fiber and cast metal posts considering a cut-off value of P = 0.05. The annual failure rates were calculated considering the survival data for all restorations and separated by type of post after five years. ResultsA hundred and nineteen patients and 183 posts (72 cast metal posts and 111 glass fiber posts) were analyzed. The median follow-up was 62 months (IQR 37–81). The log-rank test for success (P = 0.26) and survival (P = 0.63) analyses did not present statistically significant differences. The AFR of both posts after 5 years was 1.5%. Considering the posts separately and after 5 years, cast metal posts presented AFR of 1.2% and glass fiber posts AFR of 1.7%. Most failures were in posterior teeth (16/23), 10 failures were classified as root fractures and 5 as post debonding. The follow-up rate was 95.3%. ConclusionsGlass fiber and cast metal posts showed good and similar clinical performance. Clinical SignificanceResults of this randomized controlled trial can help dentists to answer how the best technique to rehabilitate endodontically treated teeth with no remaining coronal wall.

Surface characterization and bonding properties of milled polyetheretherketone dental posts.

PEEK has been used in many dental applications except intra-radicular post. The aim of this study is to test polyetheretherketone (PEEK) as a dental post material through tensile bond strength (TBS) and surface roughness (SR), and to compare it with glass-fiber and cast-metal posts. Thus, 60 human maxillary central incisors with a single root were endodontically treated and divided into three groups (n = 20) according to the type of post (Group P: PEEK, Group F: Glass-fiber, Group M: Cast-metal). Appropriate surface treatment was employed for each group and SR was determined by a three-dimensional non-contact profilometer before cementation. All posts were luted to the canal dentin using self-etch resin cement (Panavia F2.0). Pull-out test was performed on a universal testing machine at a speed of 0.5mm/min crosshead speed until failure, and TBS were calculated. One-way ANOVA, Tukey's HSD, and Pearson chi-squared tests were performed for statistical analyses (α = 0.05). According to the results, group F demonstrated the highest SR (2.93 ± 0.18µm) and lowest TBS values (10.05 ± 0.53MPa), while group P exhibited lowest SR (1.37 ± 0.11µm) and highest TBS values (14.33 ± 0.58MPa) (p < 0.001). No significant differences in failure modes were identified among groups, mostly adhesive (p = 0.243). As conclusion, PEEK may be a reliable and contemporary option for dental post systems when used with appropriate surface treatment and luting agent. This high-performance polymer may be a novel candidate as a contemporary dental post system due to its superior mechanical, chemical, thermal, and esthetical properties with low risk of fracture.

In vitro fracture resistance of zirconia, glass-fiber, and cast metal posts with different lengths.

Aim:Post-and-core restorations require sufficient length of the post for retention of the prosthesis and root strength. The effect of different lengths of prefabricated zirconia posts (ZPs) on the fracture strength of endodontically treated teeth needs evaluation. Hence, the aim of this study was to evaluate the in vitro fracture resistance of endodontically treated incisors restored with ZP, glass-fiber (GFP), and cast posts (CP) of different lengths.Settings and Design:Comparative in-vitro study.Materials and Methods:Sixty extracted incisors were endodontically treated, tooth preparations were carried out, and the impression of the coronal portion of each prepared tooth was made using polyvinyl siloxane impression material loaded in copper tubes. The coronal portion of each tooth was removed, maintaining a 2 mm ferrule. The teeth were restored with one of the three posts: CPs, GFP, or ZPs, with intraradicular lengths of either 6 or 8 mm (n = 10). The CP and core patterns were fabricated using post space impressions and core buildup and cast using Nickel–Chromium alloy. After composite resin core buildup of GFP and ZPs treated teeth using the previously made copper tube impressions, the teeth were loaded to fracture in an oblique direction in the universal testing machine.Statistical Analysis Used:Data were analyzed using two-way ANOVA and Tukey–Kramer tests (α = 0.05).Results:The highest and lowest values of fracture resistance were reported with ZP8 and GFP6 groups, respectively. There was no significant difference in fracture resistance between the posts of length 6 mm and 8 mm in CP, GFP, and ZP groups. There was no significant difference (P = 0.953) in fracture resistance between CP (284.8 N) and ZP (258.31 N) groups, while the GFP group (160.61 N) had a significantly lower value of fracture resistance than the CP and ZP groups. Two-way ANOVA test for fracture resistance of the post systems and post lengths showed that there was no significant correlation between the post systems and post length on the fracture resistance. There was a greater percentage of favorable fractures in GFP and ZP groups (65% each), than the CP group (20%).Conclusion:For the post systems tested, extending the post length does not significantly increase the fracture resistance of the restored teeth. The ZP represents a viable alternative to the cast metal post during the esthetic restoration of endodontically treated anterior teeth.

Retrospective clinical and radiographic evaluation of restored endodontically treated teeth.

ObjectivesThe aim of this study was to perform a clinical and radiographic analysis of endodontically treated teeth (ETT) restored with cast metal posts (CMPs) or prefabricated glass fiber posts (GFPs) and crowns.Materials and MethodsFifty ETT were restored with 25 CMPs and 25 GFPs at a private dental clinic between 2001 and 2016. The restorations consisted of 12 all-ceramic crowns, 31 metal-ceramic crowns, and 7 composite resin crowns. Demographic data, type of teeth, type of post-and-core system, time of placement, crown restorations, the number of proximal contacts, the type of antagonist, and reports of any complications after post-and-core placement were recorded for each patient. Assessments were performed at baseline (radiographic) and follow-up (radiographic and clinical). Data were analyzed by the McNemar test, the Pearson χ2 test, and Kaplan-Meier survival curves (α = 0.05). The mean follow-up was 67.6 months.ResultsNo significant difference was observed for any of the radiographic parameters when the baseline and final radiographs were compared. In the clinical evaluation, anatomical form (p = 0.009) and occlusion (p = 0.001) showed significant differences according to the type of crown restoration; specifically, metal-ceramic and all-ceramic crowns outperformed composite resin crowns.ConclusionsCMPs and GFPs showed favorable results for restoring ETT after 6 years of follow-up. All-ceramic and metal-ceramic crowns showed higher survival rates and better clinical outcomes.

In Vitro Fracture Resistance and Bond Strength of Self-Adhesively Luted Cast Metal and Fiber-Reinforced Composite Posts and Cores: Influence of Ferrule and Storage Time.

To evaluate the fracture resistance and bond strength of cast posts and cores (CPCs) and customized glass fiber posts (CFPs) with self-adhesive luting. A total of 56 recently extracted premolars were divided into four groups for the fracture resistance test (CPC and CFP, with and without ferrule) and four groups for the bond strength test (CPC and CFP, immediate and 6 months of storage). Differences for fracture resistance were found between CPCs and CFPs with ferrule. For bond strength, the interaction between post and root region was significant. Self-adhesive luting increased fracture resistance of CPCs with ferrule. The ferrule decreased root fractures. Bond strength was similar for both retainers but not for the apical third. Water storage affected bond strength positively.

The effect of conventional, half-digital, and full-digital fabrication techniques on the retention and apical gap of post and core restorations

Statement of problemConventional cast metal posts and cores are fabricated using direct and indirect techniques, both of which need impression materials and considerable laboratory work. Digital techniques have the capacity to substitute for conventional methods in fabricating the posts and cores. However, the accuracy of restorations resulting from a digital workflow is unknown. PurposeThe purpose of this in vitro study was to compare the retention of posts and cores fabricated using full-digital, half-digital, and conventional techniques and to define the accuracy of each technique in terms of the apical gap. Method and materialsThirty newly extracted mandibular first and second premolar teeth were selected for this in vitro study. Impressions were made using direct acrylic resin patterns (conventional), indirect silicone impressions of the intracanal which scanned with a 3Shape laboratory scanner (half digital), and intracanal scan posts captured with an intraoral 3Shape scanner (full digital). Casting and milling were conducted for the conventional impression and digital scans. The obtained posts were cemented using zinc phosphate cement. A universal pullout test was used to measure retention at a crosshead speed of 0.5 mm/min. The apical gap of each post in the canals was defined with parallel digital radiography. The data were analyzed using the Kruskal-Wallis test (α=.05) and Mann-Whitney test at the adjusted α=.016. ResultsSignificant differences were found among the conventional, full-digital, and half-digital techniques in terms of the apical gap (0.11, 0.29, and 0.66 mm; P<.001) and retention (171.6 ±1.9, 107.1 ±5.6 and 91.8 ±6.6 N; P<.001). The correlation between gap and retention in conventional (P=.43), full-digital (P=.09), and half-digital techniques (P=.06) was not statistically significantly different. ConclusionsThe conventional technique was more accurate and resulted in higher retention than both the full- and half-digital techniques. However, the retention and gap of all the posts fell within clinical guidelines.

Fracture resistance of metal-ceramic crown copings cemented to two types of intra-radicular posts

Abstract Introduction Endodontically treated teeth are more susceptible to root fracture than vital teeth. In order to reduce the risk of fracture, the use of intra-radicular posts and crowns is indicated. However, their own fracture resistance remains unclear. Objective To analyze the behavior of metal-ceramic crown copings cemented to two types of intra-radicular posts under tensile stress. Material and method Sixteen metal-ceramic crown copings cemented with zinc phosphate cement to cast metal posts and cores (group 1, n = 8) or with self-adhesive resin cement to glass-fiber posts rebased with composite resin (group 2, n = 8) were subjected to tensile testing after endodontic treatment and standardized preparation. Failure occurred when the crown coping and/or post-core assembly fractured and/or detached. Result In group 1, after the application of a mean tensile load of 46.83 N, 7 crown copings and metal cores separated as a whole, while in 1 specimen the coping detached from the metal core. In group 2, a mean tensile load of 127.68 N resulted in glass-fiber post fracture, and in 1 case the entire crown-post-core assembly was detached. Tensile strength differed significantly between the two groups (p = 0.0085). Conclusion Our findings suggest that metal-ceramic crown copings cemented with self-adhesive resin cement show strong adhesion to composite resin cores associated with glass-fiber posts, thus providing a safe alternative to the use of cast metal posts and cores.

The Effect of Intraradicular Multiple Fiber and Cast Posts on the Fracture Resistance of Endodontically Treated Teeth with Wide Root Canals.

Introduction The endodontically treated teeth (ETT) with thin remaining radicular dentin thickness are predisposed to fracture; hence it requires the diligent selection and the execution of endodontic post treatment. The objective of the study was to evaluate the reinforcing effect of both multiple fiber reinforced composite (FRC) and Ni-Cr cast metal posts at anterior and posterior regions. Material and Methods Forty recently extracted root canal treated canine and single rooted premolar teeth were used for the study. They were randomly divided into four groups (n=10) as: Group 1, single FRC post; Group 2, multiple FRC posts; Group 3, single Ni-Cr metal post, Group 4, multiple Ni-Cr posts. The posts were cemented with self-adhesive resin cement and subsequently restored with full veneer metal crown. The compressive static load at 1300 for canine and 450 for premolar was applied with the cross-head speed of 0.5mm/minute until the fracture. The obtained data was analyzed using the Kruskal–Wallis and Pairwise comparison tests with SPSS. Results The results indicate that multiple FRC post restored canine had the maximum fracture load (1843.80±7.13 N), followed by cast multiple posts (1648.99±26.84 N), single fiber post (1623±40.31 N), and cast metal single post (1493±27.33 N). A similar trend was observed in premolar with higher max fracture load with multiple FRC posts at 1920.86±20.61 N and multiple cast metal posts at 1735.43±6.05 N. Conclusion The restoration of ETT with larger canals by multiple FRC and metal posts provides substantially higher fracture resistance in comparison to wider single post.

Coronal Microleakage of Teeth Restored with Cast Posts and Cores Cemented with Four Different Luting Agents after Thermocycling.

The apical seal provided by a root canal filling may be breached via coronal leakage. This study aimed to compare the teeth restored with custom-made cast metal posts and cores cemented with different luting agents in terms of coronal microleakage after thermocycling. This in vitro study was conducted on 32 extracted single-canal teeth. Root canals were prepared by step-back technique and filled with gutta percha and sealer. The coronal 7mm of gutta percha was removed, and post space was prepared using peeso reamers #2 and #3 consecutively. After fabricating the acrylic resin patterns of the posts and cores, they were cast using Ni-Cr metal alloy. The specimens were divided into 4 groups in which the castings were cemented using one of the following luting agents: zinc phosphate (ZP), glass ionomer (GI), Panavia F 2.0, and Speed CEM. After cementation, the teeth were immersed in distilled water and incubated for 7days. Then, the teeth were subjected to thermocycling, immersed in silver nitrate for 6hours, and finally sectioned. The degree of dye penetration into the coronal part of the specimens was measured using a stereomicroscope. Data were analyzed using Kruskal-Wallis and Mann-Whitey U tests with significance level of 0.05. The median microleakage in ZP, Speed CEM, GI, and Panavia were 171.89, 114.76, 26.51, and 20.02μm, respectively. Pairwise comparisons among GI and ZP, GI, and Speed CEM, ZP and Panavia, ZP and Speed CEM, and Panavia and Speed CEM groups yielded significant differences (p<0.05). Complete coronal seal was not achieved with any of the luting agents. The highest and the lowest degree of microleakage was yielded by ZP and Panavia luting agents, respectively.

Three-dimensional finite element analysis of glass fiber and cast metal posts with different alloys for reconstruction of teeth without ferrule

The aim of this study was to evaluate different materials for restoration of teeth without ferrule by three-dimensional (3D) finite element analysis (FEA). Five models simulating the maxillary central incisor and surrounding bone were simulated according to the type of post: glass fibre post (GFP) or cast metal post (CMP) with different alloys such as gold (Au), silver–palladium (AgPd), copper–aluminum (CuAl) and nickel–chromium (NiCr). Models were designed using Invesalius and Rhinoceros. FEAs were made using FEMAP and NeiNastran, with an applied axial force of 100 N and oblique occlusal load at 45°. Stress distribution among groups was analysed by two-way analysis of variance (ANOVA), followed by post-hoc Tukey’s test. The GFP showed the best stress distribution in the post, followed by CMP with Au, AgPd, CuAl and NiCr alloys, respectively (p < .001). No statistically significant difference in the stress distribution in teeth was found under application of axial load (p > .05). Under oblique load, the GFP generated the highest values of tension among the models, followed by the CMP with NiCr alloy than other models (p < .001). The use of GFP resulted in a lower stress concentration in the post, but increased stress in the tooth without ferrule. The CMP with NiCr alloy exhibited the highest stress distribution among other CMP. To avoid higher stress in teeth, alloys of Au, AgPd and CuAl, respectively, are recommended.

Radiographic analysis of 1000 cast posts in Sergipe state, Brazil

Abstract Introduction Endodontically treated teeth with extensive coronary destruction require posts and cores to enable prosthetic restoration. Despite the increasing use of prefabricated posts, cast metal posts and cores are still widely used. The quality of the latter is important for the longevity of restorative treatment, and failure can occur if the fundamental principles are not followed. Objective To radiographically evaluate the prosthetic principles of 1000 cast metal post-and-core restorations performed in single-rooted teeth and their coherence with the principles used for their confection. Material and method Digital periapical radiographs of 1000 endodontically treated, single-rooted teeth with cast metal posts and cores were selected from the collection of a radiology clinic (Centro de Imagem, Aracaju/SE, Brazil). The images were analyzed using a measurement software (ImageJ, USA) in accordance with the fundamental prosthetic principles: length and diameter of the post, ratio between post and bone crest, contiguity of post to the root canal, gap between post and the remaining root canal filling, amount of remaining root canal filling, and absence of periapical lesion. The data were qualitatively analyzed, classified into ideal and not ideal, and submitted to the chi-square test (α=0.05). Result Only 6.7% of the cast metal posts analyzed were satisfactorily fabricated. Conclusion Many prosthetic criteria are neglected during the manufacturing of cast metal post and cores, resulting in inadequate work that may compromise the longevity of restorative treatments.

Assessment of a Cavity to Optimize Ultrasonic Efficiency to Remove Intraradicular Posts

IntroductionThe study assessed an in vitro protocol for the removal of cast metal posts using ultrasonic vibration in multirooted teeth by drilling a cavity in the coronal portion of the post followed by ultrasound application in the cavity. MethodForty endodontically treated molars received intraradicular cast posts and were divided into 4 groups according to the removal protocol: the control group, no cavity and no ultrasonic vibration; the ultrasonic group, no cavity and ultrasonic vibration in the coronal portion of the core; the cavity group, a cavity in the core and no ultrasonic vibration; and the cavity ultrasonic group, a cavity in the core and ultrasonic vibration inside the cavity. The traction test was performed on all samples using a universal testing machine (EMIC DL-2000; EMIC Equipamentos e Sistemas de Ensaio LTDA, São José dos Pinhais, PR, Brazil) at a speed of 1 mm/min, obtaining values in Newtons. The data were statistically analyzed using analysis of variance and the Tukey-Kramer test (P < .05). ResultsThe results showed statistically significant differences between the tested groups (control group = 322.74 N, ultrasonic group = 283.09 N, cavity group = 244.00 N, and cavity ultrasonic group = 237.69 N). The lowest mean strength was found in the group that received ultrasonic vibration inside the cavity. ConclusionsPreparing a cavity in the coronal core followed by ultrasonic vibration reduces the traction force required for removal. The removal protocol was effective for removing posts in multirooted teeth cemented with zinc phosphate.

Survey of dentists to determine contemporary use of endodontic posts

Statement of problemAlthough the scientific literature provides sound decision-making tools for the restoration of endodontically treated teeth, dentists have different opinions on the rationale for the use of endodontic posts (dowels) and selection of post systems. The decision to place a post is at times contrary to the literature. Updated information on the treatment of endodontically treated teeth among general dentists is lacking. PurposeThe purpose of this survey was to gain insight into the rationale for choice of endodontic posts and the different endodontic post systems currently used by dental practitioners. Post and core restorations distribute stress and replace missing tooth structure in endodontically treated teeth. Guidelines exist to help select post systems. With the advent of new materials, prefabricated posts have gained popularity among dentists. However, cast-metal post-and-core systems are still considered the gold standard. Material and methodsSurveys were distributed to dentists attending continuing education meetings in the United States, Canada, Scotland, Ireland, and Greece. The questions addressed years of practice, specialty training, and brand, type, shape, and material of the endodontic post systems used. ResultsDescriptive statistical analysis was used to assess the percentage of respondents. Ninety-two percent of the participants were general practitioners with 25.94 ±13.35 years of experience. The majority agreed upon using endodontic posts when insufficient coronal tooth structure remains and for stress distribution. Passive, parallel posts were the most commonly reported type and shape. With regard to post material, fiber posts were the most frequently used (72.2%), followed by prefabricated alloys (38.6%), cast-metal posts (33.9%), prefabricated titanium posts (30.1%), and stainless-steel posts (21.7%). For cementation, resin-modified glass ionomer (40%) was most frequently used, followed by self-adhesive resin (29.6%). ConclusionsThe majority of the practitioners used fiber posts. This may be because, in terms of fracture, they compare favorably with cast-metal post and core, although little evidence in the literature validates this claim.

Randomized clinical trial of the influence of impression technique on the fabrication of cast metal posts

Statement of problemDirect and indirect techniques are used for intracanal impression and fabrication of cast metal posts. However, whether those techniques affect the accuracy of cast metal posts is unknown. PurposeThe purpose of this randomized clinical trial was to evaluate the accuracy of cast metal posts depending on tooth position and impression technique. Material and methodsEndodontically treated teeth (anterior or posterior) planned to receive cast metal posts and complete crowns were randomized according to impression technique (direct or indirect). Impressions were made by 2 operators, and time for the impression was recorded. All impressions and cast metal posts were photographed to assess any possible differences between techniques in length of the cast metal post. ResultsAll cast metal posts were shorter than the impressions. The mean reduction for the metal posts was 2.3% for direct in anterior teeth, 5.7% for direct in posterior teeth, 6.3% for indirect in anterior teeth, and 7.2% for indirect in posterior teeth (all P<.05). Statistically significant differences were found between time of technique and tooth position (P=.031), with the direct technique more time consuming than the indirect technique (P<.001) for both tooth positions. For the indirect technique, the impression times for both tooth groups were similar (P=.459). ConclusionsBoth of the intracanal impression techniques resulted in cast posts that were shorter than the impressed post space. The discrepancy was greatest for the indirect technique. Nevertheless, all posts were considered clinically acceptable and were cemented.

Evaluation of Effect by Different Surface Treatment Agents on Retention of Custom Made Cast Metal Post and Prefabricated Glass Fibre Post-A Comparative Study

AbstractPosts are widely used for restoring endodontically treated teeth with insufficient coronal tooth structure. Custom made cast metal post and core systems have a long history of successful use due to their superior physical properties. Prefabricated post systems have recently become more popular because they can provide satisfactory results, while saving time and reducing costs. Materials and Method: Post spaces were prepared in 60 extracted caries free teeth, and divided into two main groups of 30 teeth each for cast metal and glass fibre posts. These groups were further divided into 3 subgroups of 10 specimens each I) Control group without any surface treatment, II) Specimens treated with 57% ethanol, III) Specimens air abraded with 50um air borne alumina particles. Teeth were mounted in acrylic blocks prepared from a specially fabricated metal device. Posts were luted in the prepared post spaces with glass ionomer luting cement. Retentive strength was tested by Universal testing machine at 2mm/min crosshead speed. Results: Sand blasting of cast metal posts showed more significant improvement in retention compared to both control group and ethyl alcohol treated groups. In case of glass fibre posts, sand blasting significantly improved its retention compared to control group but no significant difference was observed between control and ethyl alcohol treated groups. There was also no significant difference between ethyl alcohol treated and sand blasted group. Conclusion: It was concluded that, sand blasting is an effective method to improve retention of both cast metal and glass fibre posts.