Bacteriologic Conditions of the Apical Root Canal System of Teeth with and without Posttreatment Apical Periodontitis: A Correlative Multianalytical Approach.

INTRODUCTION: This study used a correlative multianalytical approach to investigate the bacteriologic conditions in the apical root canal system of treated teeth with or without apical periodontitis and their correlation with the technical quality of the previous root canal obturation and the presence and volume of apical periodontitis lesions. METHODS: Root apexes were obtained from recently extracted root canal-treated teeth with (n = 23) and without (n = 22) apical periodontitis lesions as demonstrated by cone-beam computed tomographic examination. The root apexes were sectioned and subjected to micro-computed tomographic (micro-CT) scanning. The specimens were cryopulverized, and DNA extracted from the powder was used as a template in real-time polymerase chain reaction assays to quantify total bacteria and members of the Streptococcus genus and Actinobacteria phylum. The bacteriologic findings were compared between the 2 groups and also evaluated for associations with cone-beam computed tomographic and micro-computed tomographic data. RESULTS: Bacteria were detected in all apical canal samples except 1. The mean counts of total bacteria, streptococci, and actinobacteria did not differ significantly between teeth with or without apical periodontitis (P > .05). Streptococcus levels were significantly lower by 80% in the apical canals of teeth with small lesions compared with those without lesions (P < .05). The limit of filling >2 mm short was significantly associated with more total bacterial counts compared with canals filled 0-2 mm short (P < .05). An adequate coronal restoration was significantly associated with lesser counts of Streptococcus (P < .05). CONCLUSIONS: Comparable bacterial loads were observed in the apical canal system of treated teeth with and without apical periodontitis, suggesting that factors other than only the total bacterial levels may also influence the development and progression of apical periodontitis. Bacteria were found in the apical canal in virtually all cases with a high prevalence of streptococci and actinobacteria. Streptococci counts were significantly higher in the apical canal of teeth with inadequate restorations and teeth with no lesions. Underfilled canals showed higher bacterial counts.

Regenerative Endodontic Therapy for Management of an Immature Permanent Tooth with Recurrent Post-treatment Apical Periodontitis: A Case Report.

This case report describes the treatment outcome and further retreatment of an immature permanent maxillary right central incisor with necrotic pulp and chronic apical abscess using regenerative endodontic therapy (RET). The patient had a history of traumatic injury. The initial periapical radiographic and cone-beam computed tomographic (CBCT) examinations revealed tooth #8 had incomplete root formation, thin dentinal walls, and pulp necrosis associated with a large apical periodontitis lesion. RET was conducted in two visits and included a disinfection protocol with 5.25% NaOCl irrigation and medication with a double antibiotic paste (metronidazole and ciprofloxacin). At the second visit, a blood clot was induced, and the cervical third was sealed with a mineral trioxide aggregate plug and the coronal portion with light-cure composite. The tooth was asymptomatic at the 12-, 24-, and 36-month follow-ups, and radiographs showed continued root development with healed periradicular tissues. However, the 4-year radiographic follow-up revealed a recurrent apical periodontitis lesion. A second attempt of RET was conducted in one visit using 1% NaOCl irrigation and stimulation of a blood clot. A double seal with silicate-based cement and composite was placed. At the 24-month follow-up, the tooth remained asymptomatic, and both radiographic and CBCT examinations showed apical closure and complete repair of the periradicular tissues. When a tooth develops recurrent apical periodontitis, a second attempt of RET is a feasible option to control infection, helping to promote tooth retention associated with healthy periradicular conditions.

Management of teeth with dens invaginatus and apical periodontitis: A case series.

BACKGROUND: Dens invaginatus is a dental anomaly that can predispose the tooth to pulp and periapical pathology. CASE DESCRIPTION: Different endodontists treated 6 maxillary incisors with dens invaginatus associated with apical periodontitis. Cone-beam computed tomography was used to help with diagnosis and treatment planning in most patients. Four patients received diagnoses of Oehlers type II dens invaginatus and the other 2 as type III. In some patients with type II, the invagination had to be perforated to permit access to the apical part of the true root canal. Both the true canal and the invagination (pseudocanal) were treated in all cases using an antimicrobial regimen based on chemomechanical preparation with sodium hypochlorite irrigation and supplementary disinfection approaches. Calcium hydroxide medication was used in all but 1 case. The root canal and invagination were often filled using thermoplasticized gutta-percha techniques, sometimes using an apical plug with a bioceramic material in teeth with large apical openings. All treated patients had favorable clinical and radiographic outcomes. PRACTICAL IMPLICATIONS: Regardless of the complex anatomic variations, common strategic therapeutic approaches were identified that might serve as recommendations for proper management of teeth with dens invaginatus and apical periodontitis. These approaches include cone-beam computed tomographic planning, aggressive disinfection using sodium hypochlorite ultrasonic or sonic activation and calcium hydroxide intracanal medication, and thermoplasticized gutta-percha obturation of both the root canal and invagination.

Dens Invaginatus: Clinical Implications and Antimicrobial Endodontic Treatment Considerations.

Dens invaginatus or dens in dente is a developmental dental anomaly resulting from an invagination of the enamel organ into the dental papilla during odontogenesis. Radiographically, it is usually seen as a radiolucent invagination surrounded by a radiopaque area (enamel) limited to the tooth crown or extending into the root. Because the invagination is opened to the oral cavity, it can retain saliva, food remnants, and bacteria. In conditions where the enamel lining of the invagination is naturally absent or lost because of caries, bacterial cells and products can diffuse from the invagination through the dentin tubules to reach the pulp and cause disease. Management of teeth with dens invaginatus includes preventive sealing or filling of the invagination, or if the pulp is affected, therapeutic options include vital pulp therapy, nonsurgical root canal treatment, apexification or regenerative endodontic procedures, periradicular surgery, intentional replantation, or extraction. It is recommended that the invagination be always approached, regardless of the type of dens invaginatus. The root canal should be treated whenever the pulp is irreversibly inflamed or necrotic. Endodontic management of teeth with dens invaginatus is often tricky because of its anatomic complexity, and special and customized strategies should be devised. This review discusses the endodontic implications of this anomaly and the current treatment recommendations based on anatomic, pathological, and technologic considerations.

Cleaning efficacy using two engine-driven systems versus manual instrumentation in curved root canals: a scanning electron microscopic study.

INTRODUCTION: This ex vivo study evaluated the cleanliness of curved root canal walls after chemomechanical instrumentation using two automated systems versus manual instrumentation while using a standardized irrigation protocol. METHODS: Thirty mesial root canals of extracted human first and second mandibular molars were prepared with the TiLOS hybrid engine-driven instrumentation system (Ultradent Products Inc, South Jordan, UT) (n = 10), ProTaper engine-driven file series (n = 10), and manual instrumentation (n = 10). Irrigation was performed using alternately 5.25% sodium hypochlorite and 17% EDTA followed by rinsing with distilled water. After the roots were split longitudinally, the presence of debris and/or smear layer was visualized using serial scanning electron microscopic digital photomicrographs taken at 1, 5, and 10 mm from the working length. Mean scores for debris and the smear layer were calculated and statistically analyzed for significance (P < .05) between groups using the Kruskal-Wallis nonparametric analysis of variance and Dunn tests. The data obtained at each evaluation level for each group were analyzed using the Friedman and Tukey multiple comparison tests. RESULTS: No significant differences (P > .05) were found between TiLOS and ProTaper (Dentsply/Tulsa Dental, Tulsa, OK) groups, whereas both performed significantly better than the manual instrumentation group. CONCLUSIONS: Engine-driven TiLOS and ProTaper instrumentation systems combined with a standardized irrigation protocol produced cleaner root canal walls than the manual instrumentation technique although complete cleanliness was not achieved.