The effect of preoperative acetaminophen or a combination of acetaminophen and Ibuprofen on the success of inferior alveolar nerve block for teeth with irreversible pulpitis.

This study compared preoperative administration of acetaminophen or a combination of acetaminophen and ibuprofen versus placebo for potential increased effectiveness of inferior alveolar nerve (IAN) block anesthesia. There were 40 patients with irreversible pulpitis randomly assigned to a drug or placebo group. Thirty minutes after ingestion of medication, an IAN block was administered. A cold test was done 15 minutes after the block, and if the patients had no sensitivity, endodontic therapy was initiated. If the patient had no pain on access, the IAN was recorded as successful. If the patient had sensitivity to cold or to the access procedure, it was recorded as a failure. Overall success was 60% for all three groups. Success was 71.4% for the acetaminophen group, 75.9% for the acetaminophen and ibuprofen group, and 46.2% for the placebo group. There was no significant difference between the groups; however, there was a trend toward higher success in the medication groups.

The effect of formalin storage on the apical microleakage of obturated canals.

Infection control guidelines recommend disinfection of extracted teeth in 10% formalin for 2 weeks before use. Although extracted teeth are routinely used for in vitro endodontic research, the potential influence of formalin has not been evaluated. The purpose of this study was to investigate the effect of formalin storage on the apical seal integrity of obturated canals. There were 100 single-rooted human teeth decoronated, accessed, and randomly divided into four groups. Group 1 was composed of specimens that were instrumented and obturated after extraction without storage in formalin. Groups 2, 3, and 4 were stored in formalin for 2, 4, and 8 weeks, respectively, before treatment. Canals were instrumented to a master apical file size #7 ProFile .04 Taper Series 29 and obturated with Obtura II thermoplasticized gutta-percha and Roth 801 sealer. The teeth were immersed in India ink, cleared, and the greatest extent of linear dye leakage was measured. Microleakage testing displayed significantly less microleakage after 2 and 4 weeks of formalin storage. Leakage measurements after 4 weeks of storage were 62.3% lower than nonfixed specimens. The 8-week storage group demonstrated lower dye penetration compared with the nonfixed group; however, the difference was not statistically significant. Within the scope of this study, storage of extracted teeth in formalin for 2 and 4 weeks resulted in a significant decrease in apical microleakage compared with nonfixed specimens.

Apical leakage of root-end placed SuperEBA, MTA, and Geristore restorations in human teeth previously stored in 10% formalin.

The purpose of this study was to determine if storage of extracted teeth in 10% formalin affects microleakage of MTA, Geristore, or SuperEBA root-end fillings. There were 130 freshly extracted single-rooted teeth collected, immediately placed in phosphate buffered saline (PBS) and stored for less than 24 hours. Teeth were divided and either placed in 10% formalin for a 4-weeks immersion or immediately prepared. Preparation for all teeth consisted of canal instrumentation, obturation, apical resection, retrograde preparation, and placement of a root-end filling material. After 72 hours, the apical portions were immersed in India ink under vacuum pressure for 30 minutes, and then stored in ink for 1 week. Negative controls and positive controls performed as expected. In general, there was significantly less dye leakage of root-end restorations in teeth stored in 10% formalin when compared to the freshly extracted teeth (p < 0.0001). No difference in dye leakage was observed between Geristore restorations placed in teeth stored in formalin as compared to fresh teeth (p = 0.892). Less dye leakage was noted in teeth restored with Geristore as compared to MTA and SuperEBA, regardless of storage medium (p < 0.0001). No difference was observed between MTA and SuperEBA root-end restorations (p = 0.157). The results of this study provide evidence that storage of teeth in 10% formalin over a 4-week period may significantly influence dye leakage as compared to leakage in freshly extracted teeth.

Periapical actinomycosis: a review.

Actinomycosis has increasingly been recognized as a cause of persistent or recurrent periapical disease associated with endodontically treated teeth. This case report shows the classic clinical picture of periapical actinomycosis: persistent periapical disease with recurrent sinus tracts. Although there was no pain or swelling after clinically acceptable initial endodontic treatment, a periapical lesion developed. After retreatment, the periapical lesion persisted, and a sinus tract developed. The sinus tract healed with antibiotic therapy but recurred within a few months. This cycle of sinus tract to antibiotic therapy to recurrence of the sinus tract repeated several times over a period of 5 years. Upon biopsy, periapical actinomycosis was diagnosed, where classic "sulfur granules" were demonstrated in the histologic examination of the periapical lesion. Antibiotic therapy for a period of 6 weeks was prescribed subsequent to the histologic diagnosis because of the possibility of spread of the actinomycotic infection into the maxillary sinus. Considerable healing was evident within 5 months of surgical and antibiotic treatment.

Adhesion of human fibroblasts to root-end-filling materials.

This study evaluated the attachment of cultured explants of human periodontal ligament fibroblasts and gingival fibroblasts to different root-end-filling materials. Although periodontal ligament and gingival fibroblasts initially attached avidly to Geristore, these same cells displayed no significant attachment to ProRoot, Tytin amalgam, or SuperEBA. With further incubation on Geristore, the attachment of both periodontal ligament and gingival fibroblasts improved and these cells proliferated. In contrast, no improvement in attachment or proliferation was observed for cells incubated for greater times with ProRoot, Tytin amalgam, or SuperEBA. Because the attachment characteristics of these two groups of fibroblasts were identical, we examined the potential role of the extracellular matrix family of receptors (integrins) on the attachment of gingival fibroblasts. Gingival fibroblast attachment to collagen type I was determined to be dependent on alpha1beta1 and alpha2beta1 integrins, whereas their attachment to the RGD-binding sequence of fibronectin and vitronectin was partially inhibited by antibodies to the beta1 and alphaV integrin subunits. However, attachment of gingival fibroblasts to Geristore was not reduced by the addition of any of the attachment-perturbing anti-integrin antibodies examined. Thus, gingival fibroblasts attach to Geristore, but this attachment was mediated by mechanisms other than integrins.

The effect of irrigation with doxycycline or citric acid on leakage and osseous wound healing.

This study investigated the effect of doxycycline irrigation on wound healing and the apical seal of three filling materials. Part 1: 220 extracted teeth received root canal therapy followed by root resection (2 mm) and ultrasonic root end preparations (3 mm). Groups of 20 were irrigated with saline, citric acid, or doxycycline and filled with amalgam, Super EBA, or MTA. Leakage was measured (mm) after decalcification and clearing. Part 2: two defects were made on each side of the mandible of 10 New Zealand rabbits. On each side, one defect was irrigated with saline and one with either citric acid or doxycycline. The animals were killed in groups of five at 9 and 18 days. Sections of each defect were stained with hematoxylin and eosin for evaluation of healing and bone fill. Super EBA and MTA leaked significantly less than amalgam, regardless of irrigant. Leakage after irrigation with doxycycline compared to citric acid or saline was not significantly different for Super EBA or MTA but was lower for amalgam. There was no significant difference in healing or bone fill among irrigants at 9 or 18 days.

Multiple autoclave cycle effects on cyclic fatigue of nickel-titanium rotary files produced by new manufacturing methods.

INTRODUCTION: Novel nickel-titanium rotary files with proprietary manufacturing techniques have recently been marketed. The purpose of this study was to assess multiple autoclave cycle effects on cyclic fatigue of GT Series X files (Dentsply Tulsa Dental Specialties, Tulsa, OK) and Twisted Files (SybronEndo, Orange, CA) METHODS: A jig using a 5-mm radius curve with 90° of maximum file flexure was used to induce cyclic fatigue failure. Files (n = 10) representing each experimental group (GT Series X 20/.04 and 20/.06; Twisted Files 25/.04 and 25/.06) were first tested to establish baseline mean cycles to failure (MCF). Experimental groups (n = 20) were then cycled to 25% of the established baseline MCF and then autoclaved. Additional autoclaving was accomplished at 50% and 75% of MCF followed by continual testing until failure. Control groups (n = 20) underwent the same procedures except autoclaving was not accomplished. RESULTS: The GT Series X (20/.04 and 20/.06) files showed no significant difference (p = 0.918/p = 0.096) in MCF for experimental versus control files. Twisted Files (25/.04) showed no significant difference (p = 0.432) in MCF between experimental and control groups. However, the Twisted Files (25/.06) experimental group showed a significantly lower (p = 0.0175) MCF compared with the controls. CONCLUSIONS: Under the conditions of this evaluation, autoclave sterilization significantly decreased cyclic fatigue resistance of one of the four file groups tested. Repeated autoclaving significantly reduced the MCF of 25/.06 Twisted Files; however, 25/.04 Twisted Files and both GT Series X files tested were not significantly affected by the same conditions.