Clinical experience with the use of dentine chips in pulpectomies

Dental Stem Cell Migration on Pulp Ceiling Cavities Filled with MTA, Dentin Chips, or Bio-Oss

MTA, Bio-Oss, and dentin chips have been successfully used in endodontics. The aim of this study was to assess the adhesion and migration of dental stem cells on human pulp ceiling cavities filled with these endodontic materials in an experimental model, which mimics the clinical conditions of regenerative endodontics. Cavities were formed, by a homemade mold, on untouched third molars, filled with endodontic materials, and observed with electron microscopy. Cells were seeded on cavities' surface and their morphology and number were analysed. The phenomenon of tropism was assessed in a migration assay. All three materials demonstrated appropriate microstructures for cell attachment. Cells grew on all reagents, but they showed a differential morphology. Moreover, variations were observed when comparing cells numbers on cavity's filling versus the surrounding dentine disc. The highest number of cells was recorded on dentin chips whereas the opposite was true for Bio-Oss. This was confirmed in the migration assay where a statistically significant lower number of cells migrated towards Bio-Oss as compared to MTA and dentin chips. This study highlights that MTA and dentin chips have a greater potential compared to Bio-Oss regarding the attraction of dental stem cells and are good candidates for bioengineered pulp regeneration.

Are referred inaccessible human primary molar teeth really inaccessible?

Despite a body of compelling evidence pertaining to the root canal accessibility of primary teeth, the number of referrals for inaccessibility of primary molars is considerable. The aim of the present study was to evaluate the prevalence of true and false primary molar inaccessibility among subjects who had been referred by general and pediatric dentists. We examined 199 primary molars in 156 patients (87 males, 69 females) aged 3-7 years who were referred by 215 general and 35 pediatric dentists. Problems related to inaccessibility were recorded for each tooth and any individual canal. One hundred seventy-five inaccessible teeth (87.9%) were successfully rehabilitated to accessible status (P < 0.001). The most frequent cause of inaccessibility was an inappropriate access cavity (42.3%), followed by difficult canals (32.6%) and orifice calcification (25.2%). The tooth most frequently reported as inaccessible was the maxillary first molar (40.2%), and that least frequently reported was the mandibular second molar (11.6%). The distobuccal canal of the maxillary first molar and the mesiolingual canal of the mandibular first molar were the most commonly inaccessible canals (P < 0.001). Only 1 out of 8 teeth referred as inaccessible was truly inaccessible. It seems that root canal inaccessibility is mostly attributable to lack of expertise among individual practitioners.

Quality-Shaping Factors and Endodontic Treatment amongst General Dental Practitioners with a Focus on Denmark

There is a gap between the endodontic outcome that can be achieved and the outcome observed on the basis of worldwide general dental practitioner data. The quality of root canal treatment (RCT) is shaped by the dentist's knowledge, attitude, and skills, but it may also be influenced by the patient's demands and degree of satisfaction. The topic has only been sparsely investigated. Although dental health has increased over the years in Denmark, the number of performed root fillings has also increased, probably because the number of tooth extractions have declined and more molar teeth have been treated. Caries appears to be the main cause for performing RCT and a preventive approach by employing stepwise excavation may reduce RCT, but this strategy does not remove the gap. Factors influencing RCT quality could be the status on adoption of nickel-titanium rotary technology, more focus on infection control (rubber dam use, knowledge of factors important for prognosis), as dentists often think that they are good at doing RCT, but often perform inadequately, an alteration of clinician's awareness of their performance in the context of dental practices, seems warranted. Finally, the development of new preventive modalities for pulp and apical inflammation are crucial.

Incidence of periapical lesions and clinical symptoms after pulpectomy—A clinical and radiographic evaluation of 1- versus 2-session treatment

OBJECTIVE

Outcome of pulpectomy in 2 treatment sessions with calcium hydroxide as an intracanal dressing was compared to a procedure comprising instrumentation and root-filling in 1 session.

STUDY DESIGN

Subjects with a vital pulp condition (N = 256) were recruited to a randomized clinical trial. Outcome parameters included radiographic signs of apical periodontitis and painful symptoms at clinical follow-ups 1 week and 1-3 years after treatment.

RESULTS

Of 244 subjects available for final recall, 17 presented with periapical radiolucency. Lesions were evenly distributed among the 2 treatment groups. Postoperative pain recorded 1 week after permanent filling was significantly associated with overfilling (P = .001), with no difference between treatment groups. There was no association with presence of overfilling and radiographic lesion at end point of recall.

CONCLUSIONS

Study confirms that pulpectomy may be carried out at a high rate of success if due attention is given to aseptic operating procedures, proper instrumentation and filling. Under these conditions an interappointment dressing with calcium hydroxide does not seem to influence outcome.

An experimental study of the sealing ability of a dentinal apical plug treated with bonding agent

The purpose of this study was to evaluate the sealing ability of a dentinal apical plug treated with a bonding agent. Ninety human lower premolars were used. The teeth were divided into three groups. in groups 1 and 2, to prepare an apical isthmus of 1 mm in length, the first apical seat was prepared with a #45 K file 1 mm short of the anatomical apex and with a #60 K file 2 mm short for the second apical seat. Dry dentin fillings were packed in the apical isthmus with a #60 K file. In group 1, the root canal was obturated with gutta-percha and Canals root canal sealer by the lateral condensation method. In group 2, following an application of the bonding agent to the plug, the root canal was obturated in the same way. In group 3 (control), a single apical seat was prepared with a #60 K file 1 mm short of the apex and the root canal was obturated similarly. The teeth of three groups were immersed in a 1% methylene blue solution for 1, 2, and 4 wk. Dye penetration depth from the apical foramen was determined. Group 2 showed no leakage after 4 wk. Groups 1 and 3 showed dye penetration into the root canal, and in these two groups dye penetration increased with time.

Recent development in endodontic research

In essence, endodontics as a clinical discipline is concerned with the prevention and treatment of pulpal and periapical infection. In recent research the infective process has been investigated as well as the mechanisms by which the pulp and periodontium deal with microbial insults. With regard to the pulp, findings on the hemodynamics of pulpitis suggest that the inflammatory response in this tissue is much less influenced by the special anatomic environment of the tooth than was previously believed. Pulpal diseases are being underdiagnosed, mostly because of inadequate examination methods. Laser Doppler flowmetry which gives a vascular rather than a nervous response may gain importance in pulpal diagnostics in the future. It is established that apical periodontitis with bone resorption cannot develop in the absence of bacteria in the root canal system. Root canal infection is characterized by a wide variety of combinations of relatively few anaerobic bacteria, and bacterial synergism plays an important role in maintaining the infection. Microbial invasion of an apical granuloma may take place. Non-oral and environmental organisms like Pseudomonas aeruginosa are frequently isolated from treatment-resistant cases. Success of endodontic treatment depends on the reduction or elimination of the infecting bacteria. This may predictably be obtained after a thorough chemo-mechanical instrumentation and disinfection of the root canal with calcium hydroxide. The standardized technique which entails the preparation of a cylindrical apical box with removal of significant amounts of dentin near the root apex predictably gives a clean canal. This technique has provided excellent clinical and radiographic results in well documented follow-up studies.

Tissue reaction to endodontic materials: methods, criteria, assessment, and observations

The purpose of this study was to develop methods and criteria for the testing of the biocompatibility of endodontic materials. One hundred twenty-one teeth from 12 baboons (Papio anubis) were used to test three sealers: AH26, Kerr pulp canal sealer, and Kloroperka N.O. Gutta-percha cones were used as solid core in all cases. Under disinfected conditions, access preparation was performed, and with working length approximately 1.0 mm short of the foramen, the instrumentation of the root canal was started, using sodium hypochlorite (1%) for irrigation. After the root canals were cleaned and shaped, they were obturated with gutta-percha cones and the sealer, and by lateral condensation technique. Histologic periapical reactions were evaluated at 1, 7, 30, 365, 730, and 1095 days. The methods and criteria used were adequate for ranking of the biocompatibility of the tested materials in the short and long periods. At short observation periods (1 to 7 days) AH26 caused severe reactions, and Kerr pulp canal sealer and Kloroperka N.O., moderate and mild reactions, respectively. At 2- and 3-year observation periods the ranking was AH26, mild; Kerr pulp canal sealer, moderate; and Kloropercha N.O., severe.

The sealing ability of injection-moulded thermoplasticized gutta-percha

The root canals of 120 single rooted teeth were prepared with files and then divided randomly into twelve subgroups. Four operators each filled three of these subgroups, one group with laterally condensed gutta-percha, one group with thermoplasticized gutta-percha with sealer and one group with thermoplasticized gutta-percha without sealer. The fillings were assessed radiographically and a dye penetration test was used to investigate the leakage. The lowest leakage values were found in those canals filled with laterally condensed gutta-percha. The sealing ability of thermoplasticized gutta-percha was enhanced by the use of a sealer. There was greater variation between operators in those groups where thermoplasticized gutta-percha was used.

Endodontic materials

Endodontic sealing materials for permanent obturation of root canals are highly variable both in chemistry of setting and in their additives. Conventional materials are based on zinc oxide-eugenol, rosin-chloroform, or synthetic resins. These have been extensively tested for biological and technical properties. Most materials are slightly or moderately cytotoxic, and some - notably paraformaldehyde-containing materials- have been associated with clinical complications such as paresthesia of the mental and/or inferior alveolar nerve. Recently, Ca(OH)2-containing materials have been introduced with claims of improved clinical and biological performance. However, there is little documentation of the alleged benefits of new materials.

The virtual absence of comparative clinical studies on endodontic filling materials appears to be the major obstacle to critical assessment of old materials or to adequate documentation of new formulae. A recently introduced scoring system for the radiographic assessment of apical periodontitis may aid in the future testing of endodontic materials. Results with this scoring system on extensive clinical material indicate that it is possible to discriminate among endodontic materials with small differences in clinical performance.