http://www.endoexperience.com/filecabinet/Endo%20Related%20Restorative%20Dentistry/Post%20and%20Cores/scwartz%20post%20review%20article.pdf

Post placement and restoration of endodontically treated teeth: a literature review.

http://www.biofilling.com/article/7_1Mineral.pdf

Mineral trioxide aggregate: a comprehensive literature review--part II: leakage and biocompatibility investigations.

The hard tissue repository of the human dental pulp takes on numerous configurations and shapes. A thorough knowledge of tooth morphology, careful interpretation of angled radiographs, proper access preparation and a detailed exploration of the interior of the tooth are essential prerequisites for a successful treatment outcome. Magnification and illumination are aids that must be utilized to achieve this goal. This article describes and illustrates tooth morphology and discusses its relationship to endodontic procedures. A thorough understanding of the complexity of the root canal system is essential for understanding the principles and problems of shaping and cleaning, for determining the apical limits and dimensions of canal preparations, and for performing successful microsurgical procedures.

/pdf/root-canal-morphology-and-its-relationship-to-endodontic-5ra1gdn1i6.pdf

Root canal morphology and its relationship to endodontic procedures

Aim

The aim of this study was to identify a possible mechanism that would explain how E. faecalis could survive and grow within dentinal tubules and reinfect an obturated root canal.



Methodology

Cells of Streptococcus gordonii DL1, Streptococcus mutans NG8, or E. faecalis JH2–2 were grown in brain heart infusion broth containing various amounts of human serum for 56 days. The ability of the three species to invade dentine and bind to immobilized type 1 collagen in the presence of human serum was assessed by dentine invasion and microtitre well experiments.



Results

All three species remained viable over the period of the experiment when grown in human serum. Cells of all three bacteria were able to invade dentine and bind to immobilized collagen. Both of these properties were inhibited by the presence of collagen in the cell solution. Human serum inhibited dentine invasion and collagen adhesion by S. gordonii DL1 and S. mutans NG8, whilst dentine invasion by E. faecalis JH2–2 was reduced in the presence of serum, but not inhibited, and binding to collagen was enhanced.



Conclusions

It is postulated that a virulence factor of E. faecalis in failed endodontically treated teeth may be related to the ability of E. faecalis cells to maintain the capability to invade dentinal tubules and adhere to collagen in the presence of human serum.

Enterococcus faecalis--a mechanism for its role in endodontic failure.

Aim of the study was to compare the trimming and non-trimming variants of the microtensile technique with the 'micro' push-out test in the ability to measure accurately the bond strength of fiber posts luted inside root canals. In 15 endodontically treated teeth (Group A), fiber posts were cemented with Excite DSC in combination with Variolink II (Ivoclar-Vivadent). In 15 roots RelyX Unicem (3M-ESPE) was used for fiber post luting (Group B). Within each group, the bond strength of cemented fiber posts was assessed with the trimming and non-trimming microtensile technique, as well as with the push-out test. The great number of premature failures (16.9% in Group A, 27.5% in Group B) and the finding of high standard deviation values make questionable the reliability of the trimming microtensile technique. With the non-trimming microtensile technique, only five sticks were obtained from a total of six roots. The remaining specimens failed prematurely during the cutting phase. With the push-out test no premature failure occurred, the variability of the data distribution was acceptable, and regional differences in bond strength among root levels could be assessed. Relatively low values of bond strength were, in general, recorded for luted fiber posts. In conclusion, when measuring the bond strength of luted fiber posts, the push-out test appears to be more dependable than the microtensile technique.

The adhesion between fiber posts and root canal walls: comparison between microtensile and push-out bond strength measurements.

Violich DR, Chandler NP. The smear layer in endodontics – a review. International Endodontic Journal, 43, 2–15, 2010. Root canal instrumentation produces a layer of organic and inorganic material called the smear layer that may also contain bacteria and their by-products. It can prevent the penetration of intracanal medicaments into dentinal tubules and influence the adaptation of filling materials to canal walls. This article provides an overview of the smear layer, focusing on its relevance to endodontics. The PubMed database was used initially; the reference list for smear layer featured 1277 articles, and for both smear layer dentine and smear layer root canal revealed 1455 publications. Smear layer endodontics disclosed 408 papers. A forward search was undertaken on selected articles and using some author names. Potentially relevant material was also sought in contemporary endodontic texts, whilst older books revealed historic information and primary research not found electronically, such that this paper does not represent a ‘classical’ review. Data obtained suggests that smear layer removal should enhance canal disinfection. Current methods of smear removal include chemical, ultrasonic and laser techniques ‐ none of which are totally effective throughout the length of all canals or are universally accepted. If smear is to be removed, the method of choice seems to be the alternate use of ethylenediaminetetraacetic acid and sodium hypochlorite solutions. Conflict remains regarding the removal of the smear layer before filling root canals, with investigations required to determine the role of the smear layer in the outcomes of root canal treatment.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-2591.2009.01627.x

The smear layer in endodontics – a review

Prior to root canal treatment at least one undistorted radiograph is required to assess canal morphology. The apical extent of instrumentation and the final root filling have a role in treatment success, and are primarily determined radiographically. Electronic apex locators reduce the number of radiographs required and assist where radiographic methods create difficulty. They may also indicate cases where the apical foramen is some distance from the radiographic apex. Other roles include the detection of root canal perforation. A review of the literature focussed first on the subject of electronic apex location. A second review used the names of apex location devices. From the combined searches, 113 pertinent articles in English were found. This paper reviews the development, action, use and types of electronic apex locators.

https://www.onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-2591.2004.00835.x

Electronic apex locators.

The aim of this study was to investigate sodium hypochlorite (with and without EDTA), chlorhexidine, and hydrogen peroxide in varying concentrations when used in sequence or in combination as endodontic irrigants. Sterile saline served as the control. Six standardized bovine incisor root specimens, which had been infected with Enterococcus faecalis (CG 110), were exposed to each solution. Following exposure to the test agents dentine samples were taken from within the lumina using ISO 023 to 035 burs. The dentine powder samples were incubated and the quantity of bacteria present assessed using spectrophotometry. All irrigant regimens were more effective than saline in killing bacteria. Chlorhexidine and sodium hypochlorite were similarly effective. At specific concentrations a synergistic effect was noted when mixtures of chlorhexidine and hydrogen peroxide were under test.

Antimicrobial effect of irrigant combinations within dentinal tubules

Calcium hydroxide-based root canal sealers: a review.

The anatomical and clinical significance of the maxillary sinus in relation to conventional and surgical endodontic therapy is considered The discussion includes a review on the development, anatomy and physiology of the maxillary sinus, the diagnostic evaluation of the sinus and the differential diagnosis of sinusitis Endodontic implications of the maxillary sinus include extension of periapical infections into the sinus, the introduction of endodontic instruments and materials beyond the apices of teeth in close proximity to the sinus and the risks and complications associated with endodontic surgery

https://onlinelibrary.wiley.com/doi/pdf/10.1046/j.0143-2885.2001.00524.x

Nicholas P. Chandler

Papers

The smear layer in endodontics – a review

Electronic apex locators.

Antimicrobial effect of irrigant combinations within dentinal tubules

Calcium hydroxide-based root canal sealers: a review.

Endodontic implications of the maxillary sinus: a review