Retrospective radiographic study comparing unintentional extrusion of gutta-percha versus sealer on teeth with periapical radiolucency.

OBJECTIVES: The purpose of the present study was the radiographic evaluation of endodontically treated teeth presenting periapical radiolucency and unintentional overfilling with gutta-percha or sealer on treatment outcome and persistence of the extruded materials. METHOD AND MATERIALS: After assessment using periapical index (PAI), 202 roots filled with gutta-percha and zinc oxide eugenol sealer (Roth 811, Roth International), exhibiting unintentional overfilling and periapical radiolucency were selected. All cases had at least 1 year follow-up. Type of extruded material, periapical status, and removal/persistence of the extruded material were evaluated by two independent observers. Data were statistically analyzed using logistic and linear regression analysis. RESULTS: Tooth location (P <.001), follow-up period (P <.001), and type of extruded material (P =.004) significantly influenced treatment outcomes. Specifically, posterior roots exhibited better outcomes compared to anterior, and cases with overfilling of sealer showed superior healing potential compared to those with gutta-percha overfilling. Additionally, longer recall periods were associated with improved treatment success. It is also seen that the type of extruded material (P <.001) and follow-up period (P <.001) have significantly affected the presence of extruded material in the follow-up radiograph. The persistence of extruded material was greater when gutta-percha was extruded as well as extruded materials were less detected when the follow-up period was longer. CONCLUSION: Teeth with periapical radiolucency and unintentional overfilling require longer follow-up intervals for effective monitoring of healing. Treatment outcome was associated with the type of extruded materials used in the present study. The persistence of those materials in the periapex did not affect healing.

Comparative evaluation of neural tissue antigens--neurofilament protein (NF), peripherin (PRP), S100B protein (S100B), neuron-specific enolase (NSE) and chromogranin-A (CgA)--in both normal and inflamed human mature dental pulp.

The immunohistochemical detection of neurofilament protein (NF), peripherin (PRP), S100B protein (S100B), neuron-specific enolase (NSE) and chromogranin-A (CgA) has been studied in nerve fibres and bundles of human dental pulp. This was done in order to identify possible differences in the distribution pattern of the above markers between normal and inflamed pulp and, further, to evaluate their potential use as peripheral markers of dental innervation as well as objective markers for the determination of the extent of inflammation. Both normal and inflamed human dental pulp showed positive immunolabelling for NF, S100B and NSE and lack of labelling for PRP and CgA protein. An increased density of NF, S100B and NSE immunoreactive nerve fibres was observed in inflamed pulp samples compared to non-inflamed. The findings of this study suggest the possible application of NF, S100B and NSE as markers of dental innervation. Furthermore, they may be useful for the determination of the extent of pulpal inflammation, and might be utilized in alternative modalities of biological pulp therapy to reduce the inflammation process. The absence of CgA immunolabelling implies the presumptive absence of neuroendocrine antigens, while further research is required in order to clarify the involvement of PRP in dental pulp.

A new methodology for the comparative study of the root canal instrumentation techniques based on digital radiographic image processing and analysis.

OBJECTIVE: The objective of this study was to evaluate the utility of digital image processing and analysis procedures for the study and comparison of the efficiency of 2 root canal instrumentation techniques. STUDY DESIGN: Forty mandibular incisors with a single canal were randomly divided into 2 groups of 20 teeth. A step-back technique was followed for the instrumentation of the root canals of Group 1 teeth using hand stainless steel Hedström files (Dentsply Maillefer, Switzerland), while a crown-down technique using ProFile engine-driven nickel-titanium instruments (Dentsply Maillefer) was followed for the instrumentation of the Group 2 root canals. Radiographs of each tooth were taken in bucco-lingual and mesio-distal projections, both before and after instrumentation, under constant conditions and by using a direct digital intraoral radiography system. The postoperative radiographs were digitally subtracted from their respective preoperative radiographs. A contrast enhancement process was applied to the resultant digital subtractive images. The enlargement of the root canals created by each instrumentation technique regarding the apical 6 mm was assessed through the application of region segmentation and area measurement processes. RESULTS: Using this methodology no significant difference between the 2 preparation techniques was found in terms of configuration and enlargement of the root canals. CONCLUSIONS: The application of this methodology provided the ability to (1) visualize dentin lost during root canal instrumentation, (2) simultaneously compare root canal morphology before and after instrumentation, and (3) quantitatively evaluate the enlargement of the root canal area induced by each of the instrumentation techniques.

Digital radiograph registration and subtraction: a useful tool for the evaluation of the progress of chronic apical periodontitis.

The purpose of this study was to evaluate the suitability of a digital radiograph registration and subtraction software for a sensitive and reliable assessment of the progress of chronic apical periodontitis. Ninety cases of teeth with chronic apical periodontitis have been studied. In each case, a preoperative radiograph was taken, root canals were prepared, and a Ca(OH)2 paste was placed in the root canals. Radiographic control and replacement of Ca(OH)2 paste took place at 15-day intervals. The root canals were obturated 1.5 months after the first appointment. Recall radiographs were taken 0.5, 1.5, 3, 6, and 12 months after the obturation. All radiographs were taken for each case under constant conditions by using a direct digital radiography system. In each case, the preoperative, postoperative, and control and recall radiographs were digitally registered and pairwise subtracted. The resulting images were further processed by using contrast enhancement and pseudocoloring methods. Changes to the periapical tissue structure were easily detectable by using the above-mentioned methodology, even during short time intervals.