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Background: Medium‐term evaluate the bond strength and tag formation in root dentin using self‐adhesive cements Maxcem Elite (MCE), Relyx U200 (RU2), SeT PP (SPP) and Megalink (MGL) compared to conventional cement Relyx ARC (ARC) for glass fibre post cementation. Materials and methods: One hundred bovine incisors roots were endodontically treated and divided into 5 groups (n = 20) according to the cementation system: MCE, RU2, SPP, MGL and ARC. All cementation systems were evaluated at 24 h (1) and 12 months (2) after post cementation. Specimens from the cervical, middle and apical thirds of the root were submitted to push‐out bond strength test and confocal laser microscopy to verify the dentin penetration. The adhesive failure mode was classified as adhesive, cohesive and mixed. Data were analysed by one‐way ANOVA and Tukey tests (α = 5%). Results: ARC‐1 and ARC‐12 showed the highest bond strength (P < 0.05). ARC showed the greatest tag extension, regardless of the third (P < 0.05). The most frequent failure mode in the 24‐h analysis was cohesive, regardless of the cement used. For the 12‐month analysis, mixed failure was the most frequent. Conclusion: Conventional cement (ARC) showed the highest bond strength and tag extension, regardless of the evaluation period. In all cementation systems, the bond strength decreased after 12 months. © 2023 Australian Dental Association. [ABSTRACT FROM AUTHOR]

Copyright of Dental Press Endodontics is the property of Dental Press International and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Acta Odontologica Latinoamericana: AOL is the property of Acta Odontologica Latinoamericana and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract This study aimed to evaluate the effect of endodontic sealer (ES) on bond strength (BS) of prefabricated or milled-CAD-CAM (computer-aided design and computer-aided manufacturing) glass-fiber-posts (GFP). Canals of 90 single-rooted teeth were prepared for filling by the single-cone technique with gutta-percha and one of the following ES: AH Plus (epoxy resin), Endofill (zinc-oxide and eugenol), and Bio-C Sealer (calcium-silicate). After post-space preparation, tooth-specimens were equally divided in half according to type of GFP to be used. In the half to receive milled-CAD-CAM posts, tooth specimens were molded with acrylic resin to obtain replicas. These were scanned to enable the laboratory to produce the milled-CAD-CAM GFPs (Fiber CAD Lab, Angelus) by the subtractive technique. The other half of samples received prefabricated GFPs (Exacto, Angelus) (n=15). The GFPs were cemented with dual-cure resin cement (Panavia F2.0, Kuraray). Each root was sectioned into two slices per root region (cervical, middle, apical) that were subjected to the push-out BS test, in a universal testing machine. Failure mode (FM) was classified by scores. The BS data were submitted to generalized linear model analyses, while FM was analyzed using the chi-square test (a=0.05). BS showed no significant difference among the three ES (p > 0.05). BS was significantly higher for prefabricated (mean 10.84 MPa) versus milled-CAD-CAM GFPs (mean 6.94 MPa) (p

This study aimed to evaluate the effect of endodontic sealer (ES) on bond strength (BS) of prefabricated or milled-CAD-CAM (computer-aided design and computer-aided manufacturing) glassfiber-posts (GFP). Canals of 90 single-rooted teeth were prepared for filling by the single-cone technique with gutta-percha and one of the following ES: AH Plus (epoxy resin), Endofill (zinc-oxide and eugenol), and Bio-C Sealer (calcium-silicate). After post-space preparation, toothspecimens were equally divided in half according to type of GFP to be used. In the half to receive milled-CAD-CAM posts, tooth specimens were molded with acrylic resin to obtain replicas. These were scanned to enable the laboratory to produce the milled-CAD-CAM GFPs (Fiber CAD Lab, Angelus) by the subtractive technique. The other half of samples received prefabricated GFPs (Exacto, Angelus) (n=15). The GFPs were cemented with dual-cure resin cement (Panavia F2.0, Kuraray). Each root was sectioned into two slices per root region (cervical, middle, apical) that were subjected to the push-out BS test, in a universal testing machine. Failure mode (FM) was classified by scores. The BS data were submitted to generalized linear model analyses, while FM was analyzed using the chi-square test (a=0.05). BS showed no significant difference among the three ES (p > 0.05). BS was significantly higher for prefabricated (mean 10.84 MPa) versus milled-CAD-CAM GFPs (mean 6.94 MPa) (p <0.0001), irrespective of ES. The majority showed mixed failures. It could be concluded that type of ES did not affect BS of GFPs to dentin, and prefabricated-GFPs had higher bond-strength than customized-milled-CAD-CAM GFPs. [ABSTRACT FROM AUTHOR]

Background: Endodontically treated teeth with extensive structural damage present higher fragility due to the low amount and worse quality of the reminiscent tissues of the crown. Materials and Methods: The present in vitro study evaluated the effect of different intraradicular retainers and cementation agents on the fracture resistance of devitalized teeth. Incisive teeth (n = 40) of bovine mandibles were used. After preparation of the root canals, they were immersed in polyether, in a polyvinyl chloride cylinder containing acrylic resin, to simulate the periodontal ligament. The specimens were randomly divided into four groups (n = 10), according to the type of retainer (anatomical or main with accessory posts) and resin cement used (conventional resin cement – RelyX ARC or self-adhesive resin cement – RelyX U200). The specimens were stored in distilled water at 37°C and submitted to fracture resistance testing. ANOVA and Tukey's test were applied for data analysis, with significance level set at 5%. Results: There was no interaction between cement type and intraradicular retainers (P = 0.56) or even between the types of cement used (P = 0.65). However, in the variation of the types of retainers, the group using main with accessory posts presented greater resistance to the fracture than the anatomical post (P = 0.04). Conclusion: Different cementing agents have no effect on the fracture strength of devitalized teeth, unlike the use of posts, in which the use of accessory post proved more resistant when compared to the anatomical post.

Introduction: Fiberglass posts (FPs) are presented as a practical and economical alternative capable of rehabilitating endodontically treated teeth with 50% structural losses greater than 50%. Objective: To review the literature on the clinical protocol for the use of FPs, as well as explain the different techniques that can be used. Materials and methods: A literature review of studies published between 2000 and 2021 was carried out through a search on the Scielo (Scientific Electronic Library) and Google Scholar databases. The following descriptors were used for the research: Non-Vital Tooth, Dental Pins, and Technique for Intraradicular Retainer (Post and Core Technique). After careful screening, we selected 24 papers and 10 books, considered relevant for this review. Results: During planning, it is necessary to determine specific factors for clinical success, such as the amount of remaining tooth structure, the tooth position and the occlusal forces received, and restorative and esthetic needs required by the case and the patient. Given each case's particularities, the clinician must select among the most ideal techniques: the direct FP technique/conventional technique; the Anatomical fiberglass post technique, and the direct technique with FP associated with accessory posts. Conclusion: The FP technique has simplified clinical steps and its correct performance is successful in the treatment. Faced with situations in which the FP does not present adequate adaptation, the clinician must not use the conventional technique, using techniques for personalizing the FP. [ABSTRACT FROM AUTHOR]

Introduction: Every day, dentistry demonstrates great advances in techniques and materials applied to preserve the tooth structure. In this sense, fiberglass posts (FGPs) attract attention as an alternative to intraradicular posts for the rehabilitation of endodontically treated teeth with structural losses greater than 50%. Objective: Review the literature on aesthetic fiberglass posts, emphasizing their general aspects, properties, and biomechanical considerations. Material and Methods: A literature review of studies published in the last 21 years (2000-2021) through a search on the databases: PubMED / Medline, Scielo (Scientific Electronic Library), and Google Academic. The following descriptors were used: Tooth, Nonvital, Dental Pins, and Post and Core Technique. After careful filtering, 30 articles were selected for inclusion in the study, in addition to 10 books considered relevant to this review. Results: The FGPs demonstrate excellent aesthetic properties, easiness of execution and low cost, biocompatibility with dental and periradicular tissues, in addition to advantageous biomechanical characteristics, which result in the transmission of less stress to the tooth structure, reducing the probability of fractures. Conclusion: The numerous advantages and excellent biomechanical behavior of these pins explain their prominence concerning other intraradicular retainers, which, when properly indicated, are the first option for the rehabilitation of endodontically treated teeth with extensive coronary loss. [ABSTRACT FROM AUTHOR]

Copyright of Odontología Pediátrica is the property of Asociacion Sociedad Peruana de Odontopediatria and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The available options for restoring multiple surface cavities are: amalgam, composite resin, or indirect restorations. Adhesive system and intradentinal pin-retained composite resin restorations should have a similar performance to pin-retained amalgam, regarding resistance to support occlusal forces. Polymerization shrinkage is a major concern when performing direct posterior composite resin restorations and the incremental insertion technique can provide less stress and outstanding margin behavior. Intradentinal pins can potentially enhance composite resin's retention, while reducing gaps caused by polymerization shrinkage. This article reports a clinical case involving an extensive restoration on a posterior tooth with cusp loss that was successfully treated using an intradentinal pin and direct nano-hybrid composite resin restoration. [ABSTRACT FROM AUTHOR]

Indirect non-metal restorations restore the function and esthetics of severely carious or broken teeth. This report explores a novel approach for the impression, model fabrication and provisionalization of a pin reinforced onlay (pinlay) preparation.A dentoform molar was prepared for a pinlay indirect restoration. An impression, model and a provisional were fabricated with the employed pins and determined to be clinically acceptable. The pinlay may offer the patient and clinician another treatment option for oral rehabilitation.

Background: Endodontically treated teeth with extensive structural damage present higher fragility due to the low amount and worse quality of the reminiscent tissues of the crown. Materials and Methods: The present in vitro study evaluated the effect of different intraradicular retainers and cementation agents on the fracture resistance of devitalized teeth. Incisive teeth (n = 40) of bovine mandibles were used. After preparation of the root canals, they were immersed in polyether, in a polyvinyl chloride cylinder containing acrylic resin, to simulate the periodontal ligament. The specimens were randomly divided into four groups (n = 10), according to the type of retainer (anatomical or main with accessory posts) and resin cement used (conventional resin cement – RelyX ARC or self-adhesive resin cement – RelyX U200). The specimens were stored in distilled water at 37°C and submitted to fracture resistance testing. ANOVA and Tukey's test were applied for data analysis, with significance level set at 5%. Results: There was no interaction between cement type and intraradicular retainers (P = 0.56) or even between the types of cement used (P = 0.65). However, in the variation of the types of retainers, the group using main with accessory posts presented greater resistance to the fracture than the anatomical post (P = 0.04). Conclusion: Different cementing agents have no effect on the fracture strength of devitalized teeth, unlike the use of posts, in which the use of accessory post proved more resistant when compared to the anatomical post. [ABSTRACT FROM AUTHOR]

Aim: The study aimed to evaluate the influence of irrigating solutions on bond strength (BS) of fiber posts using different luting systems after aging. Methods: Bovine teeth (N = 96) were randomly (8 groups, N = 12), sectioned, endodontically treated and root canals were prepared. The 96 bovine teeth were divided into four groups according to luting systems as conventional light-cure (RelyX ARC), self-adhesive (RelyX U200 and Panavia F),dual - cure self - etch, and self - adhesive (SeT PP). Each of the four groups was further divided into two subgroups using 2% chlorhexidine (CHX) gel or 5.25% sodium hypochlorite (NaOCl) as the irrigating solution. After post cementation, the metal-ceramic crowns were positioned. After 48 h, all samples were submitted to 1,000,000 thermal cycles. After water storage, push-out test was performed. The data were analyzed using two-way ANOVA and Tukey's test (P = 0.05). Results: CHX gel BS means were statistically higher than NaOCl means when posts were cemented with the conventional or dual-cure self-etch and self-adhesive resin cements; no significant statistical differences were observed between groups CHX gel or NaOCl treatments for the dual-cure self-adhesive resin cements. Conclusion: The irrigation solution used on endodontic treatment before luting procedures with conventional or dual-cure self-etch and self-adhesive resin cements of glass fiber posts improved long-term BS after aging. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to evaluate by finite element analysis the influence of the design of 3 different dental implants on micromovements, cervical shearing stress intensity, and stress distribution after occlusal loading. Materials and Methods: The first investigated implant was a classical cylinder, the second was reinforced by 2 bicortical locking pins, and the third was an expanding dental implant. The parameters analyzed were the implant's geometry, the quality of the cancellous bone, and the orientation of occlusal loading. Results: It was found that initial stability of the locking pin implant was greater than the initial stability of the other investigated implant designs, regardless of the quality of cancellous bone and orientation of occlusal loading; in low-rigidity cancellous bone, under a horizontal load (500 N), decreasing displacement compared to those of the other investigated implants was 16 μm. The apical expansion and locking pin implants exhibited favorable behavior regarding the distribution and intensity of cervical shearing stresses; in low-rigidity cancellous bone, under horizontal load, decreasing cervical stresses compared with those of the cylindric implant were 10 MPa for the apical expansion implant and 150 MPa for the locking pin implant. Discussion: For the cylindric implant, stresses were concentrated in the neck region; for the apical expansion implant, stresses were evenly distributed from the neck to the apex of the implant. For the locking pin implant, stresses around the neck were moderate and appeared concentrated around the pins. Conclusions: Initial stability of the pin implant was greater than that of the expanding implant, but the expanding implant showed the most favorable stress distribution. [ABSTRACT FROM AUTHOR]

Aim: The aim was to evaluate the bond strength at the cement/dentin interface in the post space, after specimens were treated with different final irrigation protocols, followed by cementation with a dual resin cement. Methods: Forty-eight extracted uniradicular human premolars were divided into four groups according to the irrigation (n = 12): control with distilled water; 2.5% sodium hypochlorite (NaOCl) + ethylenediaminetetraacetic acid (EDTA); 2.5% NaOCl + passive ultrasonic irrigation (PUI); and 2% chlorhexidine (CHX). The pull-out test was performed. The results were evaluated using ANOVA with Tukey’s paired comparisons, with a significance of 5%. Results: When all groups were compared, significant difference occurred (p = 0.006), and in the paired comparison, NaOCl + PUI and CHX differed (p = 0.005). The CHX showed significantly higher adhesive defects between cement and dentin than other groups. Conclusions: The final irrigation protocol for cleaning after preparation for post space directly influences the bond strength at the cement/dentin interface.

Aim: The aim was to evaluate the bond strength at the cement/dentin interface in the post space, after specimens were treated with different final irrigation protocols, followed by cementation with a dual resin cement. Methods: Forty-eight extracted uniradicular human premolars were divided into four groups according to the irrigation (n = 12): control with distilled water; 2.5% sodium hypochlorite (NaOCl) + ethylenediaminetetraacetic acid (EDTA); 2.5% NaOCl + passive ultrasonic irrigation (PUI); and 2% chlorhexidine (CHX). The pull-out test was performed. The results were evaluated using ANOVA with Tukey's paired comparisons, with a significance of 5%. Results: When all groups were compared, significant difference occurred (p = 0.006), and in the paired comparison, NaOCl + PUI and CHX differed (p = 0.005). The CHX showed significantly higher adhesive defects between cement and dentin than other groups. Conclusions: The final irrigation protocol for cleaning after preparation for post space directly influences the bond strength at the cement/dentin interface. [ABSTRACT FROM AUTHOR]

The article presents information on the design of superstructures to be placed in dental implants. It is stated that prosthetics dentistry involves fixed prostheses rigidly cemented to teeth or removable prostheses that anchor to teeth, but, both of them have risks and limitations. It is mentioned that in the design of the superstructure to be placed over the implant, the access opening for the connecting screw should guide the prosthetic framework to a defined position on the implant. It is stated that the site of the screw access opening is affected by the implant placement and inclination. The article describes several treatments for the screw access opening by using the Branemark implant.

The article presents a case study about a functional and esthetic oral rehabilitation of an oboe player by transdental fixation. The 56 year old professional oboe player was referred for extraction of his maxillary anterior teeth, while his central and lateral incisors showed high degree of mobility. The anterior teeth was preserved by means of transfixation with pliable titanium pins, even when the anatomical situation was not so favorable.

The article focuses on a study conducted on the tensile resistance of extensive amalgam restorations by using various auxiliary retention methods. Sixteen freshly extracted human molars were used in the study, and were embedded by using cold-curing acrylic resin. The retention methods investigated included the amalgam pin, the amalgam slot, and the circumferential amalgam slot. To determine the tensile resistance of extensive amalgam restorations, a matrix was used to restore the tooth and to transduce the tensile force to the restoration. A stainless steel nut was used as a matrix for inserting the restorations. It was found that there is a considerable difference in tensile resistance between a restoration with four amalgam pins and one with four amalgam slots.

The article presents information on the microdontic pin system (MPS) in dentistry, which is a specially designed pin and applicator system for dental restorations. It is stated that the MPS system is designed in such a way that it prevents trauma to the dentin and reduces the risk of crazing and cracking of dentin and enamel. The MPS pin is made of bioinert titanium. It is stated that the use of a noncorrosive material such as titanium prevents the corrosion and discoloration of the retentive pin.

The article presents information on a research on the effectiveness of self-threading dental pins on the resistance of teeth prepared for amalgam restorations. It is stated that the use of stainless steel pins has reduced the problems related to highly decayed teeth and the replacement of large, defective dental restorations. Several authors have demonstrated that self-threading pins are very effective for the retention of the dentin and amalgam. The study was conducted on 60 extracted human molar teeth, which were randomly divided into six groups of 10 teeth each. Each group received a self-threading pin of different number and size. It was concluded that increasing the number and size of pins resulted in a greater resistance to a force applied on the teeth.

The article presents a discussion on the possibilities and limits of treatment with endosseous implants. Several issues that creep into implant procedures include the reduced amount of force transferred to the implant bed and dampening of the stresses tips due to the use of polyoxymethylene screws in the implant cylinder. As to the techniques used in the procedure, a low sped handpiece is preferred, to avoid thermal insults when the deep bed is prepared in bone. It is concluded that there is no universally applicable implant or implant procedure and they normally depend on case to case basis.

The article evaluates several dental equipment and supplies including ragial pins from Denterials Ltd., the Den-Tal-Ez Advantage patient chair from Syntex Dental Products Inc. and a vinyl polysiloxane dental impression material from the firm Union Broach.

Several photographs are presented depicting coronal build-up for the devitalized tooth including one which shows fabrication of temporary restoration, temporary precision crowns and a dental model with plastic posts and pins.

The article discusses the technique in creating inlays with pins and use them in dental restorations. It provides step-by-step instructions for making screwed inlays as well as offers recommendations for dental cavity preparation which includes soldering and cementation. The author claims that the technique is primarily used for venting and retention of crown. He also cites the limitation of the technique and factors which contribute to its failure. The use of pin in ceramic metal restorations is also explained.

The article presents a systematic procedure of dental screw implantation from the making of impression to definitive insertion of bar-joint denture. It notes that the reduced serviceability of complete mandibular dentures is frequently due to the unequal base in which the dentures are fixed. It stresses that the implantation of alloplastic materials or a prosthetic surgical procedure are performed to improve the support of the denture. It furthers that the sealing of the connective tissue at the site was made possible by polishing the neck of the screw at the implant site.

The article focuses on periodontal splinting, which is defined as the fusion of two or more teeth in order to boost resistance to an applied force. The procedure is indicated for functional stability and comfort and to maintain the position of the teeth after dental treatment. It states that perforations are made at each enamel for a pin, an impression is then taken for the assembly of the model. A cast is made from the impression for a stone master model. Cementation is done and the pins are cut off at the ends.

The article focuses on the procedures of incorporating a crown in a removable partial prosthesis. It states that lengthening the usability of prosthesis and the tooth are possible if the abutment is repaired with a new crown. It cites the case of an old woman that has a broken prosthetic tooth, wherein it caused her partial denture. After evaluating the case of the old woman's damaged prosthesis, it was considered that her present prosthesis should be retained, a pin should be built to prolong the amalgam core and install a new crown to secure the denture's grasp.

Indirect non-metal restorations restore the function and esthetics of severely carious or broken teeth. This report explores a novel approach for the impression, model fabrication and provisionalization of a pin reinforced-onlay (pinlay) preparation. A dentoform molar was prepared for a pinlay indirect restoration. An impression, model and a provisional were fabricated with the employed pins and determined to be clinically acceptable. The pinlay may offer the patient and clinician another treatment option for oral rehabilitation. [ABSTRACT FROM AUTHOR]

Objective: Considering that periodontal ligament simulation may influence the stress distribution over teeth restored with intraradicular retainers, this study aimed to assess the combined effect of mechanical cycling and periodontal ligament simulation on both the bond strength between fiber posts and root dentin and the fracture resistance of teeth restored using glass fiber posts. Material and Methods: Ninety roots were randomly distributed into 3 groups (n=10) (C-MC: control; P-MC: polyether; AS-MC: addition silicone) to test bond strength and 6 groups (n=10) (C: control; P: polyether; AS: addition silicone, without mechanical cycling, and C-MC, P-MC and AS-MC with mechanical cycling) to test fracture strength, according to the material used to simulate the periodontal ligament. For the bond strength test, fiber posts were cemented, cores were built, mechanical cycling was applied (2×106 cycles, 88 N, 2.2 Hz, and 45º incline), and the teeth cut into 3 slices (2 mm), which were then subjected to the push-out test at 1 mm/min. For the fracture strength test, fiber posts were cemented, cores were built, and half of the groups received mechanical cycling, followed by the compressive strength (45° to the long axis and 1 mm/min) performed on all groups. Results: Periodontal ligament simulation did not affect the bond strength (p=0.244) between post and dentin. Simulation of periodontal ligament (p=0.153) and application of mechanical cycling (p=0.97) did not affect fracture resistance. Conclusions: The materials used to simulate the periodontal ligament did not affect fracture or bond strength, therefore periodontal ligament simulation using the tested materials could be considered optional in the conditions of the study.

Objectives This study aimed to evaluate the retention of composite restorations of primary anterior teeth reinforced with composite posts, glass fiber posts, para-pulpal pins with composite posts, and para-pulpal pins alone. Methods Forty freshly extracted sound primary canine teeth with at least two-third of the root length remaining were selected. After disinfection, the tooth crown was cut perpendicular to the longitudinal axis. Root canals were prepared and filled using zinc oxide eugenol paste. The teeth were randomly allocated into four groups and restored using one of the following: Composite posts, glass fiber posts, parapulpal pins with composite posts, and para-pulpal pins alone. Composite cores were constructed while a preformed U-shaped orthodontic wire was placed in the composite tip, samples were then placed in a universal testing machine for measurement of retention. The minimum force required to dislodge the restoration or cause fracture was considered as the retentive strength. The collected data were analyzed using one-way ANOVA and Tukey's test (P < 0.05). Results There were statistically significant differences between groups (P = 0.011). The mean retention in the para-pulpal pins with composite post group (131.72 ± 32.35N) was greater than that in composite posts (93.65 ± 24.45N), glass fiber post (95.92 ± 25.35N), and the para-pulpal pin group (95.34 ± 29.56N) (P < 0.05). Other differences were not significant (P > 0.05). Conclusion para-Pulpal pin alone may not help in improving the retention of full crown restoration of primary anterior teeth. However, when used along with a composite post, it appears to improve the retention of restoration. [ABSTRACT FROM AUTHOR]

The breaking pattern in teeth with glass fiber pins (GFP), anatomized and fixed with different cementing agents, is analyzed in vitro. Thirty bovine mandibular uni-radicular teeth were used. Roots were treated endodontically and randomly divided into two groups according to the cementing agent employed, or rather, G1: auto-adhesive resinous cement (RelyX U200-3M ESPE), and G2: conventional resinous cement (Allcem-FGM). After the anatomization and cementation of pins, the specimens were stored in a buffer at 37°C for 7 days. Roots were then cut under flowing water and six 1mm-thick slices were cut, totaling 180 specimens. The push-out test was performed for all specimens and then placed under a light microscope to assess the type of fracture. The most frequent type of fracture for the two groups comprised coesine in dentin (G1 = 32.2%; G2 = 30%). There was a statistically greater frequency in adhesive failures between dentin and cement in G2 (p=0.007), with a statistically higher frequency (p=0.027) of cohesive fracture in dentin in the third cervical (38.3%) when compared to the third apical (20.0%). Results suggest that auto-adhesive cement (RelyX U200-3M ESPE) had more positive results in the analysis of fracture patterns. [ABSTRACT FROM AUTHOR]

Objectives: This study aimed to investigate dentinal crack rate following parapulpal pin insertion in anterior primary teeth. Methods: Thirteen sound freshly extracted primary canine teeth were horizontally sectioned 1 mm above the cementoenamel junction (CEJ). All samples were thoroughly inspected to ensure that the teeth had no cracks. The teeth were then mounted in acrylic blocks, and subjected to drilling and insertion of a single parapulpal pin in the prepared hole. The teeth were then sectioned perpendicular to the already prepared surface at 1, 2 and 3 mm depths for further evaluation under a stereomicroscope (×12 and ×25 magnifications). Results: No crack or crazing was observed in teeth in the control group while one out of 11 teeth in the case group had a crack. Conclusion: The use of 0.53 mm diameter self-threading pin did not increase the risk of crack formation in dentin of anterior primary teeth prior to composite restoration. [ABSTRACT FROM AUTHOR]

Fiber-reinforced prefabricated intraarticular posts have gained popularity due to several favorable characteristics for clinical use compared to metallic intraradicular posts., Aim: To evaluate the light transmission capacity of two types of fiber posts, using two different methods., Materials and Method: The posts were divided into two groups: experimental group - quartz-glass fiber posts (n=10) and control group - glass fiber posts (n=10). The light transmittance of the samples was compared by means of light intensity test by photographs and ultraviolet-visible spectrophotometer. This test was analyzed by thirds: coronal, middle, and apical. The spectophotometer tested the luminous transmittance along the length of the post. The statistical analysis was conducted with a significance level of 0.05., Results: Light transmission was 97% on the coronal third, 68% in the middle third, and 27.66% in the apical third in the posts of the experimental group. In the posts of the control group, the light transmission was 95.33% in the coronal third, 80.66% in the middle third, and 41.33% in the apical third. Light transmission was significantly higher in the middle third of the posts of the experimental group when compared to the control group (p<0.05). The luminous transmittance of the posts of the experimental group was 97.4% with wavelengths of 400 nm, 97% at 450 and 500 nm, and 96.9% at 550 nm. In the posts of the control group, the luminous transmittance was 72.3% with wavelengths of 400 nm, 68.6% at 450 nm; 64.6% at 500 nm and 61.5% at 550 nm. The posts of the experimental group demonstrated significantly higher light transmittance than the control group (p<0.001)., Competing Interests: The authors declare no potential conflicts of interest regarding the research, authorship, and/or publication of this article.

Objective: The aim of the present study was to analyze the influence of root canal and glass fiber post diameters on the biomechanical behavior of the dentin/cement/post interface of a root-filled tooth using 3D finite element analysis. Material and Methods: Six models were built using micro-CT imaging data and SolidWorks 2007 software, varying the root canal (C) and the glass fiber post (P) diameters: C1P1-C=1 mm and P=1 mm; C2P1-C=2 mm and P=1 mm; C2P2-C=2 mm and P=2 mm; C3P1-C=3 mm and P=1 mm; C3P2-C=3 mm and P=2 mm; and C3P3-C=3 mm and P=3 mm. The numerical analysis was conducted with ANSYS Workbench 10.0. An oblique force (180 N at 45º) was applied to the palatal surface of the central incisor. The periodontal ligament surface was constrained on the three axes (x=y=z=0). Maximum principal stress (σmax) values were evaluated for the root dentin, cement layer, and glass fiber post. Results: The most evident stress was observed in the glass fiber post at C3P1 (323 MPa), and the maximum stress in the cement layer occurred at C1P1 (43.2 MPa). The stress on the root dentin was almost constant in all models with a peak in tension at C2P1 (64.5 MPa). CONCLUSION: The greatest discrepancy between root canal and post diameters is favorable for stress concentration at the post surface. The dentin remaining after the various root canal preparations did not increase the stress levels on the root.

The aim of this study was to evaluate the effect of parallel and tapered threaded post placement on the strain and stress distribution of endodontically treated teeth. Fifteen bovine incisors were sectioned 15 mm from their apices, endodontically treated, and divided into three groups (n = 5) according to three different threaded posts: parallel threaded post (Radix-Anker, RA); tapered threaded post (Euro-Post, EP) and tapered threaded post (Reforpost II, RII). A strain-gauge was fixed on the proximal surface perpendicular to the long root axis, 2 mm from the cervical limit. Strain generated during post placement was recorded and compared using one-way ANOVA and Tukey's test (α= .05). A scanning electron microscope was used to examine the longitudinal root sections. Stress was evaluated for each group in a two-dimensional finite element analysis. The models were meshed with tetrahedron elements and loaded with 2 N at an angle of 135° to the lingual face. The equivalent Von Mises stress was calculated. The one-way ANOVA showed significant difference among the groups. The RA group (150.0 ± 12.2 A) produced higher external strain than the RII (80.0 ± 12.2 B) and the EP (70.0 ± 6.1 B) groups. The inner strain was approximately five times greater than the external dentin strain. High stress concentrations in each thread of the posts were observed. Scanning electron micrographs showed cracks that started in the threads of the posts. The threaded post placement induced root strain mainly on the parallel side post. Root strain and stress concentration on the post threads tended to create cracks in the inner root canal dentin.

INTRODUCTION: Esthetic post and core systems were recently introduced. There are few reports regarding their behavior under cyclic loading. OBJECTIVES: This study compared the effect of cyclic loading on survival rate, residual strength and mode of fracture of endodontically treated teeth restored with esthetic and direct metallic post systems subjected to mechanical cyclic loading. MATERIALS AND METHODS: Thirty canines were endodontically treated, decoronated and prepared for metal free ceramic crowns, leaving 1.5 mm of dentin for ferrule effect. They were distributed in 3 groups and restored as follows: group 1 with zirconia posts (Cosmopost) and glass-ceramic cores (IPS Empress Cosmopost); group 2 with fiber reinforced composite posts (FibreKor) and group 3 with titanium posts (AZthec Anchor). Direct resin composite (Build It FR Resin Composite) was used as core in groups 2 and 3. All specimens were restored with all ceramic crowns (IPS Empress 2). A resin cement/adhesive system (Cement It/Bond It Primer A+B) was used to lute the posts to root canals and metal free porcelain crowns to the teeth preparation. Specimens were subjected to mechanical load of 250 N for 500,000x at a frequency of 1.7 Hz and then to static load until failure in a universal testing machine. Data were analyzed using One-way ANOVA and Fischer Exact tests alpha=0.05. RESULTS: All groups had 100% survival rate after cyclic loading; fracture strength values (SD) in N were: group 1 = 886.5(170.6), group 2 = 762.2(113.6) and group 3 = 768.9(72.9); there was no difference among groups (p=0.08); the percentage of mode of favorable fracture found was: group 1 = 60%, group 2 = 90% and group 3 = 50%; there was no correlation between the mode of failure and post and core system used (P=0.142). CONCLUSIONS: Esthetic post and core systems showed statistically equivalent fracture strength values, mode of failure and survival rate compared to conventional direct metallic post and resin composite core system after cyclic loading.INTRODUÇÃO: Os sistemas de núcleos intra-radiculares estéticos foram recentemente introduzidos no mercado. Não existem muitos trabalhos na literatura comparando seu comportamento em relação aos sistemas de pinos metálicos convencionais quando submetidos à testes com carga cíclica. OBJETIVOS: este estudo comparou a taxa de sobrevivência, resistência à fratura e modo de fratura de dentes tratados endodonticamente reconstruídos com sistemas de núcleos intra-radiculares metálicos convencionais e estéticos, restaurados com coroas de porcelana pura e submetidos à carga cíclica. MATERIAIS E MÉTODOS: trinta caninos tiveram as coroas removidas 1,5mm acima da junção cemento-esmalte e preparados para coroa de porcelana pura deixando 1,5mm de dentina acima do término do preparo. Os dentes foram distribuídos em 3 grupos de 10. O grupo 1 foi restaurado com pinos de cerâmica de zircônia e núcleos de preenchimento em cerâmica vítrea termo-injetada. O grupo 2 foi restaurado com pinos de resina composta reforçada por fibra de vidro e o grupo 3 com pinos de titânio. Nos grupos 2 e 3 foi usada resina composta reforçada com fibra de vidro como material para núcleo de preenchimento; os dentes foram restaurados com coroas totais e tanto os pinos quanto as coroas de porcelana foram cimentados com um sistema de cimentação resinosa de polimerização dupla. Os espécimes foram incluídos em resina acrílica e submetidos à uma carga de 250N por 500,000 ciclos, numa freqüência de 1,7Hz sendo em seguida submetidos à carga estática em uma máqina de testes universal até a falha. Os dados foram analisados estatisticamente com os testes ANOVA a 1 critério e Exato de Fischer (alfa=.05). RESULTADOS: a taxa de sobrevivência foi de 100%; os valores de resistência à fratura em N (DP) foram: grupo 1 = 886,50(170,6), grupo 2 = 762,2(113,6) e grupo 3 = 768,9(72,9). Não houve diferença estatística de resistência à fratura entre os grupos (P=0.08). O percentual de modo de fratura favorável encontrado foi: grupo 1 = 60%; grupo 2 = 90% e grupo 3 = 50%. Não houve correlação entre o tipo de pino e modo de fratura (P=0.142). CONCLUSÃO: dentes restaurados com sistemas de núcleos intra-radiculares estéticos e coroas totais de porcelana tiveram as mesmas taxas de sobrevivência, valores de resistência à fratura e modo de fratura que os metálicos convencionais diretos após aplicação de carga cíclica.

This research evaluated the sealer ability of 2 temporary filling materials (white Cimpat and IRM) and 1 restorative cement (glass ionomer), in canals prepared for root posts. Sixty human palatal roots of maxillary first molars were used. They were divided into 3 groups, according to the cements used: Group I (Cimpat), Group II (IRM) and Group III (glass ionomer). The roots were rendered impermeable, filled with the respective cements and soon after immersed into 0.2% Rhodamine B dye and maintained for 72 hours in an oven for 37°C. Microleakage was measured with a light microscope, cutting the roots longitudinally in buccolingual direction. The results showed that Group I presented significantly more leakage than Groups II and III, which were not significantly different from each other.Esta pesquisa avaliou a capacidade seladora de dois cimentos temporários (Cimpat branco e IRM) e um cimento restaurador em canais preparados para pinos intra-radiculares. Foram usadas 60 raízes palatinas de primeiros molares superiores humanos. Elas foram divididas em 3 grupos, conforme os cimentos usados: grupo I (Cimpat), grupo II (IRM) e grupo III (ionômero de vidro). As raízes foram impermeabilizadas, preenchidas com os respectivos cimentos e em seguida imersas em tintura de Rhodamina B a 0,2% e mantidas por 72 horas em uma estufa a 37ºC. A micro infiltração foi mensurada com um microscópio de luz nas raízes cortadas longitudinalmente, na direção vestíbubo-lingual. Os resultados mostraram que o grupo I apresentou, de modo significante, mais infiltração do que os grupos II e III, enquanto que entre estes não houve diferença significante.

OBJECTIVE: This study investigated the compressive fracture strength and failure pattern in premolars submitted to endodontic treatment and internal bleaching with 37% carbamide peroxide for 21 days, with application of different restorative procedures. MATERIAL AND METHODS: Six groups were employed (n = 10): 1) non-bleached teeth and pulp chamber sealed with IRM; 2) bleached teeth and pulp chamber sealed with IRM; 3) bleached teeth and pulp chamber filled with light cured composite resin; 4) bleached teeth, root canals prepared at 10mm, filling of the root canal and pulp chamber with IRM; 5) bleached teeth, root canals prepared at 10mm, luting of prefabricated metallic post with zinc phosphate and pulp chamber sealed with composite resin; 6) bleached teeth, root canals prepared at 10mm, luting of glass fiber post with resin cement and pulp chamber sealed with composite resin. After 24-hour storage in distilled water, the specimens were submitted to compressive fracture strength testing in a universal testing machine. RESULTS: The following values were found: Group 1 - 56.23kgf; Group 2 - 48.96kgf; Group 3 - 53.99kgf; Group 4 - 45.72kgf; Group 5 - 54.22kgf; Group 6 - 60.12kgf. The analysis of variance did not reveal statistically significant difference between groups (pOBJETIVO: O objetivo do estudo foi investigar a resistência à fratura sob compressão e padrão de falha de pré-molares tratados endodonticamente e clareados internamente por 21 dias com peróxido de carbamida a 37%, aplicando-se diferentes procedimentos restauradores. MATERIAL E MÉTODOS: O objetivo deste estudo foi investigar a resistência à fratura sob compressão e padrão de falha de pré-molares unirradiculares tratados endodonticamente e clareados internamente com peróxido de carbamida a 37%. Foram constituídos 6 grupos (n = 10): 1) dentes sem clareamento e câmara pulpar vedada com IRM; 2) dentes clareados e câmara pulpar vedada com IRM; 3) dentes clareados e câmara pulpar preenchida com resina composta fotopolimerizável; 4) dentes clareados, condutos preparados com 10mm, e preenchimento do conduto e câmara pulpar com IRM; 5) dentes clareados, condutos preparados com 10mm, cimentação de pino metálico pré-fabricado com fosfato de zinco e câmara pulpar vedada com resina composta; 6) dentes clareados, condutos preparados com 10mm, cimentação de pino de fibra de vidro com cimento resinoso e câmara pulpar vedada com resina composta. Após 24 horas de armazenamento em água destilada, os espécimes foram submetidos ao teste de resistência à fratura sob compressão em máquina de ensaios universal. RESULTADOS: Os seguintes valores foram encontrados: grupo 1 - 56,23kgf; grupo 2 - 48,96kgf; grupo 3 - 53,99kgf; grupo 4 - 45,72kgf; grupo 5 - 54,22kgf; grupo 6 - 60,12kgf. A Análise de Variância não mostrou diferença estatisticamente significante entre os grupos (p < .05), sugerindo que o clareamento interno com peróxido de carbamida a 37% não enfraqueceu os tecidos dentais. O maior número de fraturas desfavoráveis foi encontrado nos grupos 2 (50%), 4 (40%), e 5 (30%). O grupo 6 exibiu o padrão de falhas mais favorável. CONCLUSÃO: Os resultados sugerem que o clareamento interno com peróxido de carbamida a 37% não causou enfraquecimento importante dos dentes. Entre os dentes clareados, aqueles com restaurações temporárias de IRM ou com pinos metálicos mostraram o padrão mais desfavorável de fratura, enquanto o padrão de fratura mais favorável ocorreu em dentes restaurados com resina composta e pinos de fibras de vidro.

The aim of this study was the evaluation about the influence of the quantity and the localization of resin patterns to cast metallic posts in its diameter and length reproduction. Seventy-two patterns for posts were fabricated by using prefabricated FKG plastic posts and divided for casting in 3 groups: G1-small ring/4 patterns, G2- medium ring/6 patterns, G3- big ring/8 patterns. Half of the patterns of each group were placed on the right side of the ring midline and the other half, on the left side, in order to guide the ring inside of the centrifuge. Using the comparative microscope, measures of diameter and length in different places were obtained before and after casting. The results were submitted to statistic analysis (ANOVA two way and Tukey's test), to make possible these observations: 1°) the position of patterns didn't influenced the measured dimensions. 2°) the same happened with the quantity of patterns inside the ring. 3°) only the pins of group G3 have presented statistically significant diameter differences. In conclusion, 1°) the position of patterns inside the ring and its quantity did not result in significant changes in pins length and diameter. 2°) Although there were no significant length alterations, significant ones were observed in the diameters 3, 6, and 9mm of Group G3.O objetivo deste trabalho foi avaliar a influência do número e localização de padrões de resina para fundição de núcleos metálicos fundidos (NMF), na reprodução do diâmetro e comprimento dos pinos. Foram confeccionados 72 padrões de resina utilizando pinos plásticos pré-fabricados e divididos para fundição em 3 grupos: G1- anel pequeno/4padrões, G2- anel médio/6 padrões e G3-anel grande/8 padrões. Metade deles foi posicionada à direita da linha média do anel e metade à esquerda, servindo de orientação para posicionar o anel na centrífuga. Através do microscópio comparador foram obtidas medidas antes e depois da fundição, tanto do comprimento quanto do diâmetro em diferentes locais. Os resultados foram submetidos à análise estatística (ANOVA a dois critérios e Tukey), possibilitando as seguintes observações: 1°) a posição dos padrões não exerceu influência nas dimensões mensuradas. 2°) o mesmo ocorreu com a quantidade de padrões dentro do anel. 3°) apenas em relação ao diâmetro (3 e 6mm) dos pinos do grupo G3, houve diferença estatisticamente significante. Conclui-se que: 1°) a posição do padrão dentro do anel e o número de padrões não resultou em alteração significativa do comprimento e diâmetro dos pinos. 2°) A variação de diâmetro (3, 6, e 9mm) foi significante apenas para os pinos do grupo G3.

This case study describes the esthetic and functional reconstruction of a fractured maxillary central incisor. Due to the requirement for additional retention, treatment was performed using the homogenous technique of biological restoration associated with cementation of posts made from human dentin (biopins). This type of treatment is a new alternative to conventional techniques and favors the dental esthetic and function, as well as biocompatibility, and is an inexpensive procedure. [ABSTRACT FROM AUTHOR]