Evaluating Fracture Resistance And Failure Modes Of Root Filled Teeth Restored With CAD/CAM-Fabricated Post And Core
TL;DR: There was no significant difference between metal and zirconia samples in terms of nonfavorable fracture, while few PICN samples exhibited a favorable fracture.
Abstract: Objective The aim of this study was to measure the fracture resistance and failure modes of root-filled teeth restored with three different computer-aided design/computer-aided manufacturing (CAD/CAM)-fabricated post and core assemblies. Methods Thirty extracted intact maxillary central incisors were used in the study, and the teeth were endodontically treated and sectioned to a root length of 16 mm. The samples were divided into three groups (n = 10) according to the mean of the dimensions at the cervical portion of the root. The posts and cores were fabricated with CAD/CAM technology using metal, zirconia, and polymer-infiltrated ceramic network (PICN) material. The posts were luted using resin cement, and then, metal crowns were fabricated, cemented, and then subjected to a compression to determine the fracture resistance force. Fracture of the post and core or fracture of the root above the level of the acrylic resin was considered as a favorable fracture, while nonfavorable fractures were those where the root fracture occurred below the level of the acrylic resin. Statistical analysis was carried out using SPSS software, and one-way analysis of variance was used to analyze root fracture resistance in Newton. The number of failure modes, post-core fractures and/or root fractures was calculated. The differences between study groups were revealed using the chi-square test. Results The results of ANOVA revealed a nonsignificant difference in the resistance to fracture among the study groups (P = 0.114). The failure modes were nonfavorable for all metal and zirconia samples and seven PICN samples. However, three PICN samples exhibited a favorable represented by core fracture without root fracture. Conclusion There was no significant difference between metal and zirconia samples in terms of nonfavorable fracture, while few PICN samples exhibited a favorable fracture. PICN material can be used in the fabrication of post and core assemblies using CAD/CAM.
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TL;DR: A literature search was conducted, and a summary of articles describing fabrication techniques and materials used to fabricate post and cores with computeraided design and computer-aided manufacturing has been provided as discussed by the authors .
Abstract: Post and core restorations are a widely accepted method to restore endodontically treated teeth with compromised tooth structure. The use of computerized technology to fabricate customized post and cores is a simple and quick alternative to conventional methods. A literature search was conducted, and a summary of articles describing fabrication techniques and materials used to fabricate post and cores with computer-aided design and computer-aided manufacturing (CAD/CAM) has been provided. Several techniques have been reported to restore endodontically treated teeth with CAD/CAM post and cores, including direct and indirect methods. Zirconia, composite resin, and hybrid ceramic were the most commonly reported materials. Published reports on CAD/CAM post and core are limited; however, further studies are needed to investigate the long-term outcome of this treatment.
5 citations
01 Jun 2020
TL;DR: In this article, the authors studied the application of computer technology in mechanical design and manufacturing and its automation in China's industrial field and found that computer technology can solve complex technical problems in the field of modern engineering by exploring the process from the initial design to the final production of a variety of industrial mechanical equipment and mechanical and electrical products.
Abstract: Mechanical design and manufacturing and its automation is to solve and deal with a series of complex technical problems in the field of modern engineering by exploring the process from the initial design to the final production of a variety of industrial mechanical equipment and mechanical and electrical products, and to realize the intellectualization of products.For a long time, mechanical design and manufacture and its automation have been a hot topic in China's industrial field.With the development of computer technology, mechanical design, manufacture and automation are developing in the process of combining with computer technology.The purpose of this paper is to study the application of computer technology in mechanical design and manufacture and its automation.
3 citations
TL;DR: CAD/CAM-P+C of the ZIR can be recommended for fabrication in a fully digital workflow regarding the accuracy of fit within the limitations of this study.
Abstract: Current intraoral scanners (IOS) enable direct impression taking for computer-aided de-sign/computer-aided manufacturing (CAD/CAM) posts and cores (P+C) with subsequent milling out of monolithic materials. The aim of this in vitro study was to systematically investigate the accuracy of CAD/CAM-P+C in a fully digital workflow, considering different IOS impression methods (Primescan (PRI), Trios4 without (TRI) and with scanpost (TRI+SP)) (Part A), and CAD/CAM milling of zirconium dioxid (ZIR) and resin composite (COM)-P+C (Part B). Five human models were developed in this study. Micro-CT imaging was used as a reference (REF). For Part A, the models were scanned 12 times for each impression method. Then, IOS datasets (n = 180) were superimposed with REF, and scan accuracy was determined using 3D software (GOMInspect). For Part B, one CAD/CAM-P+C (n = 30) was milled for each model, impression method, and material. The triple-scan method was applied using an industrial scanner (ATOS) to determine the accuracy of the fit. Statistical analysis was performed using analysis of variance (ANOVA, p < 0.05). Part A showed for PRI significantly lower accuracy than TRI and TRI+SP (p < 0.05). The data of Part B revealed significantly higher accuracy for ZIR than for COM (p < 0.05). Within the limitations of this study, CAD/CAM-P+C of the ZIR can be recommended for fabrication in a fully digital workflow regarding the accuracy of fit.
2 citations
TL;DR: Anatomically customized posts presented highest fracture resistance among all groups and there was no significant difference in fracture mode across all groups.
Abstract: Objective To investigate the effect of different post materials and adaptability on fracture resistance and fracture mode of endodontically treated teeth. Materials and Methods Sixty extracted human mandibular premolars were selected and divided into 6 groups (n = 10) according to the restorative method after endodontic treatment: no ferrule presented and restored without fiber post (Group C), 2.0 mm ferrule presented and restored without fiber post (Group CF), restored with D.T. Light-Post (Group PDT), restored with anatomically customized D.T. Light-Post, relined with resin composite (Group ADT), restored with Hi-Rem prosthetic post (Group PHR), and restored with anatomically customized Hi-Rem prosthetic post, relined with resin composite (Group AHR). After restoring with core build-up materials, all specimens were loaded at 45° in a universal testing machine until failure. Visual inspection of all specimens for fracture modes was performed. The data were analyzed using one-way ANOVA, and the fracture mode was reviewed using the chi-square test. Results Anatomically customized groups presented statistically significant higher fracture resistance than prefabricated groups and group C (P < 0.05). Without post, group CF displayed significantly higher fracture resistance than group C (P < 0.05). Group C, CF, PDT, and PHR showed some specimens with unfavorable fractures. Conclusions Anatomically customized posts presented highest fracture resistance among all groups. There was no significant difference in fracture mode across all groups.
2 citations
TL;DR: The classification of the post andcore system is described and current perspectives on recent development of CAD / CAM post and core are reviewed to review current perspectives of material and fabrication techniques.
Abstract: BACKGROUND Nowadays, the use of computer aided design / computer aided manufacturing (CAD / CAM) in fabricating indirect restoration such as onlay, crown and bridge has increased tremendously. However, there is lack of clinical information and evidence on current material and fabrication techniques of CAD / CAM post and core. This paper describes the classification of the post and core system and review current perspectives on recent development of CAD / CAM post and core. An electronic search of the literature was performed via PubMed and Scopus database, using the keyword (post and core) and (CAD / CAM) and (CAD / CAM post and core) as MeSH term. Articles eligible for inclusion in the present review were published in English, journal article and dated from January 2000 until November 2020. A total of 31 publications consisting of 18 in-vitro studies, 7 case reports, 4 finite element analysis and 2 clinical techniques were included in this review. Analysis parameters included are options of chairside CAD / CAM materials, CAD / CAM system and milling machine used, advantages and disadvantages and future direction of CAD / CAM post and core. CAD /CAM post and core can be alternative option as compared to the custom-made post and core and prefabricated post and core. KEY WORDS Computer - Aided Design, Computer - Aided Manufacturing, Dental Material, Indirect Restoration, Post and Core
2 citations
References
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TL;DR: This review takes into account the main results achieved up to now, and is focused on the role that microstructural characteristics play on the TZP ceramics behaviour in ball heads, namely mechanical properties and their stability, wear of the UHMWPE paired to TZp, and their influence on biocompatibility.
2,380 citations
"Evaluating Fracture Resistance And ..." refers result in this paper
...06 N may be due to the fact that zirconia possesses chemical stability, elastic modulus, good mechanical strength, and toughness.(33) This is in agreement with the findings of Abduljabbar et al, who showed that CAD/CAM zirconia posts had the...
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TL;DR: Microscope investigation and X-ray diffraction revealed the important role played by the tetragonal to monoclinic phase transformation and by the relationship between the glassy matrix and the crystalline phase in the strengthening and toughening mechanisms of these ceramics.
828 citations
TL;DR: An overview of CAD/CAM-technologies and systems available for dentistry today is given, which enable the access to new, almost defect-free, industrially prefabricated and controlled materials and an improvement in precision and planning, as well as an increase in efficiency.
Abstract: As in many other industries, production stages are increasingly becoming automated in dental technology. As the price of dental laboratory work has become a major factor in treatment planning and therapy, automation could enable more competitive production in high-wage areas like Western Europe and the USA. Advances in computer technology now enable cost-effective production of individual pieces. Dental restorations produced with computer assistance have become more common in recent years. Most dental companies have access to CAD/CAM procedures, either in the dental practice, the dental laboratory or in the form of production centres. The many benefits associated with CAD/CAM generated dental restorations include: the access to new, almost defect-free, industrially prefabricated and controlled materials; an increase in quality and reproducibility and also data storage commensurate with a standardised chain of production; an improvement in precision and planning, as well as an increase in efficiency. As a result of continual developments in computer hardware and software, new methods of production and new treatment concepts are to be expected, which will enable an additional reduction in costs. Dentists, who will be confronted with these techniques in the future, require certain basic knowledge if they are to benefit from these new procedures. This article gives an overview of CAD/CAM-technologies and systems available for dentistry today.
720 citations
TL;DR: Within the limitations of this study, significantly higher failure loads were recorded for root canal treated teeth restored with quartz fiber posts, and Fractures that would allow repeated repair were observed in teeth restoredWith quartz fiber and glass fiber posts.
Abstract: Statement of Problem. Very little is known about the resistance to fracture of endodontically treated teeth restored with newly developed esthetic post systems. Purpose. This in vitro study compared the effect of 1 titanium and 3 esthetic post systems on the fracture resistance and fracture patterns of crowned, endodontically treated teeth. Material and Methods. A total of 40 recently extracted human maxillary canines with their crowns removed were endodontically treated. Four groups of 10 specimens were formed. Teeth were restored with titanium, quartz fiber, glass fiber, and zirconia posts and numbered as groups 1, 2, 3, and 4, respectively. All posts were cemented with Single Bond dental adhesive system and dual-polymerizing RelyX ARC adhesive resin cement. All teeth were restored with composite cores, and metal crowns were fabricated and cemented with glass ionomer cement. Each specimen was embedded in acrylic resin and then secured in a universal load-testing machine. A compressive load was applied at a 130-degree angle to the long axis of the tooth until fracture, at a crosshead speed of 1 mm/min. One-way analysis of variance and a Tukey test were used to determine the significance of the failure loads between groups ( P 2 test was conducted for evaluation of the mode of failure ( P Results. The mean failure loads (kg) were 66.95, 91.20, 75.90, and 78.91 for groups 1 to 4, respectively. Teeth restored with quartz fiber posts (group 2) exhibited significantly higher resistance to fracture ( P P >.05). Fractures that would allow repair of the tooth were observed in groups 2 and 3, whereas unrestorable, catastropic fractures were observed in groups 1 and 4 ( P Conclusion. Within the limitations of this study, significantly higher failure loads were recorded for root canal treated teeth restored with quartz fiber posts. Fractures that would allow repeated repair were observed in teeth restored with quartz fiber and glass fiber posts. J Prosthet Dent 2002; 87:431-7.
576 citations
TL;DR: The lowest incidence of clinical complications was associated with all-ceramic crowns and posts and cores, and resin-bonded prostheses and conventional fixed partial dentures were found to have comparable clinical complications incidences.
Abstract: The purpose of this article is to identify the incidence of complications and the most common complications associated with single crowns, fixed partial dentures, all-ceramic crowns, resin-bonded prostheses, and posts and cores. A Medline and an extensive hand search were performed on English-language publications covering the last 50 years. The searches focused on publications that contained clinical data regarding success/failure/complications. Within each type of prosthesis, raw data were combined from multiple studies and mean values calculated to determine what trends were noted in the studies. The lowest incidence of clinical complications was associated with all-ceramic crowns (8%). Posts and cores (10%) and conventional single crowns (11%) had comparable clinical complications incidences. Resin-bonded prostheses (26%) and conventional fixed partial dentures (27%) were found to have comparable clinical complications incidences. The 3 most common complications encountered with all-ceramic crowns were crown fracture (7%), loss of retention (2%), and need for endodontic treatment (1%). The 3 most common complications associated with posts and cores were post loosening (5%), root fracture (3%), and caries (2%). With single crowns, the 3 most common complications were need for endodontic treatment (3%), porcelain veneer fracture (3%), and loss of retention (2%). When fixed partial denture studies were reviewed, the 3 most commonly reported complications were caries (18% of abutments), need for endodontic treatment (11% of abutments), and loss of retention (7% of prostheses). The 3 most common complications associated with resin-bonded prostheses were prosthesis debonding (21%), tooth discoloration (18%), and caries (7%). (J Prosthet Dent 2003;90:31-41.) A complication has been defined 1 as “a secondary disease or condition developing in the course of a primary disease or condition.” Although complications may be an indication that clinical failure has occurred, this is not typically the case. It is also possible that complications may reflect substandard care. But once again, this is usually not true. Most of the time, complications are conditions that occur during or after appropriately performed fixed prosthodontic treatment procedures. Knowledge regarding the clinical complications that can occur in fixed prosthodontics enhances the clinician’s ability to complete a thorough diagnosis, develop the most appropriate treatment plan, communicate realistic expectations to patients, and plan the time intervalsneededforpost-treatmentcare.Althoughaplethora of articles present clinical complications data, none provide a comprehensive comparison of the complications associated with the most commonly used restorations/
501 citations
"Evaluating Fracture Resistance And ..." refers background in this paper
...with the least fracture resistance, it remains the material of choice because it has a fracture resistance force higher than the reported maximal occluding force (146 ± 44 N) exerted by a maxillary incisor.(32)...
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