Safety and efficacy of a novel nasal spray for maxillary dental anesthesia.

This study examines the efficacy, safety, and tolerability of a nasal spray to induce anesthesia of maxillary teeth. Forty-five healthy adults requiring restoration of one maxillary tooth were randomized in a 1:2 ratio to receive (1) an intra-oral lidocaine-epinephrine injection with buffered saline nasal spray bilaterally, or (2) a tetracaine hydrochloride-oxymetazoline hydrochloride nasal spray bilaterally with sham injection. Primary endpoints were use of rescue anesthesia and patient global pain assessment. Secondary outcomes included vital sign changes, soft-tissue anesthesia, and treatment-emergent adverse events. In intent-to-treat analysis, 25 of 30 patients given nasal spray (83.3%) did not require rescue anesthesia. Proportion of anesthesia successes for nasal spray was significantly different from the hypothesized placebo anesthesia success of 30% (one-sided p value < .0001 by exact binomial test). Mean duration of soft-tissue anesthesia did not differ significantly by treatment for 3 of 4 sites assessed. No serious adverse events or systemic effects were observed. Tetracaine hydrochloride-oxymetazoline nasal spray appears to provide adequate and safe anesthesia for the majority of maxillary dental procedures. Based on the results from this Phase 2 study, pivotal trials are warranted to validate these findings in an expanded patient population.

Trends in endodontic instruments and materials.

It is the skill and knowledge of the clinician using the technique or material that determines success. This article provides an overview of some current trends in endodontic instruments and materials.

Reliability of electric pulp testing after pulpal testing with dichlorodifluoromethane.

The purpose of this study was to determine if the sequence and interval between electric pulp testing and cold vitality testing with dichlorodifluoromethane affects the reliability of pulpal diagnostic testing. Sixty vital teeth in 15 volunteers were tested. Ten endodontically treated teeth were used as negative controls. After isolation and asepsis techniques, baseline threshold responses from a digital electric pulp tester were recorded from the maxillary incisors. A dichlorodifluoromethane-saturated cotton pellet was applied to teeth 8, 9, and 10. Electric pulp testing was repeated at 30-s, 1-min, and 2-min intervals on all test teeth after the cold test. The level of responses were recorded and statistically analyzed. The results of this study indicate that electric pulp testing is not adversely affected by the use of dichlorodifluoromethane.

Use of dental instruments for bridging during electric pulp testing.

It has been suggested that dental instruments can be used as bridging instruments to facilitate electric pulp testing of teeth with extensive restorations. This study reports a clinical investigation to evaluate the effectiveness of this procedure. One hundred seventeen vital teeth in 20 volunteers were tested. Ten endodontically treated teeth functioned as controls. Following appropriate isolation and asepsis technique, baseline recordings of the threshold response with the electric pulp tester were taken. With the use of dental explorers and endodontic files to bridge between the probe tip and the tooth surface, recordings were made of the threshold responses. Findings indicate that electrically conductive dental instruments can be reliably used as bridging instruments with the electric pulp tester.

Effect of coronal-radicular flaring on apical transportation.

The purpose of this study was to evaluate the effect early and late radicular flaring has on apical canal transportation when using balanced force instrumentation. Sixty-six extracted human teeth with curvatures ranging from 20 to 65 degrees were equally divided into two groups. Canals were cleaned and shaped using balanced force and one of two flaring techniques. A pre- and postoperative double exposure radiographic technique was used to evaluate apical canal transplantation. While early radicular flaring made instrumentation much easier, no significant differences were found when comparing apical transportation between the two experimental groups.

Chairside disinfection of radiographs.

Routine disinfection of materials that have contacted human blood products and body fluids during patient care is recommended by the American Dental Association and the Centers for Disease Control. The purpose of this study was to determine whether surface disinfection with sodium hypochlorite would be an effective means for disinfection of radiographic film packets used in chairside developers. Disinfection of exposed radiographic film packets for 30 seconds in 5.25% sodium hypochlorite has been found to be a simple procedure suitable for routine use. A suggested disinfection protocol for the use of chairside developing boxes is described. This procedure should be considered for adoption as an infection control guideline.

Longitudinal evaluation of the seal of endodontic retrofillings.

The apical seal obtained with various retrofilling materials placed in prepared, extracted human anterior teeth was measured at various time intervals. Materials evaluated were cold-burnished gutta-percha, amalgam, amalgam with a cavity varnish, SuperEBA cement, and a glass ionomer restorative material (Ketac-Silver). Control groups included teeth retrofilled with either gutta-percha without sealer or TERM. The root canals were cleaned and shaped and the root ends were prepared for retrofilling. The materials were placed into the preparations and allowed to set for 24 h. Microleakage was measured at 24 h, 1, 2, and 3 wk, and 1, 2, and 3 months after insertion of the retrofilling using a fluid filtration technique. Multiple range analysis indicated that Ketac-Silver produced a significantly inferior seal when compared with the other materials at all time periods. There was no significant difference among SuperEBA, amalgam, and amalgam with a cavity varnish.

Indirect immunofluorescence microscopy for the identification of Actinomyces sp. in endodontic disease.

Indirect immunofluorescence microscopy was used to determine the presence of select Actinomyces sp. in a clinical survey of teeth with endodontic disease. Thirty canal samples were tested for the presence of Actinomyces sp.: A. israelii, A. odontolyticus, A. viscosus serotype I, and A. viscosus serotype II. Actinomyces sp. were identified in 18 (60%) samples. A. israelii was most frequently identified with immunofluorescence in 16 (53%) cases examined and was the test organism most often associated with endodontic disease within the restrictions of this study. Positive and negative controls were appropriate to support findings. Indirect immunofluorescence microscopy can be used for the clinical identification of Actinomyces sp. in endodontic disease without the necessity of performing a parallel culture study.

Microleakage of temporary endodontic restorations in teeth restored with amalgam.

Microleakage of seven temporary restorative materials was evaluated in endodontic access preparations made in teeth restored with amalgam. Ten teeth were used for each of the seven materials: Cavit, Cavit-G, TERM, zinc phosphate cement, polycarboxylate cement, glass ionomer cement, and IRM. A class I amalgam was placed in the occlusal surface of each experimental tooth and an endodontic access preparation was made entirely within the amalgam. Then the access preparation was restored with one of the temporary restorative materials, and microleakage was evaluated using a fluid filtration technique. The amount of microleakage was quantitated by measuring the fluid flow at 15 min, 1 h, 24 h, 1 wk, and 2 wk after insertion of the temporary restoration. Cavit, Cavit-G, TERM, IRM, and glass ionomer cement all provided excellent seals while zinc phosphate cement and polycarboxylate cement provided less effective seals.

A microleakage study of temporary restorative materials used in endodontics.

The purpose of this study was to quantitatively evaluate the sealing properties of various temporary restorative materials used in standard endodontic access preparations by using a newly introduced fluid filtration method. The materials tested were Cavit, Cavit-G, TERM, glass ionomer cement, zinc phosphate cement, polycarboxylate cement, and IRM. Extracted human incisor, canine, and premolar teeth were used, and each tooth served as its own control by testing for microleakage prior to access preparation. Following access preparation, cotton pellets were placed in the pulp chamber so that the space remaining for the restoration was 4 mm. Immediately after placement of the restoration, the teeth were immersed in Ringer's solution and incubated at 37 degrees C. Microleakage was measured after various time intervals. The results indicated that Cavit, Cavit-G, TERM, and glass ionomer cement provided leakproof seals during the 8-wk testing period, while leakage was observed in 4 of the 10 teeth restored with zinc phosphate cement. IRM and polycarboxylate cement were the least effective of the materials tested for preventing microleakage.

A comparison of Flex-R files and K-type files for enlargement of severely curved molar root canals.

A double exposure radiographic technique is introduced and used to evaluate the magnitude of apical canal transportation that occurs during preparation procedures. The balanced force technique and a step-back method for cleaning and shaping root canals were evaluated in mesiobuccal root canals from 80 extracted human molar teeth with curvatures ranging from 30 to 73 degrees. Pre- and posttreatment file positions were examined from clinical and proximal radiographic views by computer digitization. Statistical analysis indicated significantly less apical transportation with the use of the balanced force technique when compared with a step-back technique in canals exhibiting both more and less than 45 degrees of curvature.

A dye penetration study of retrofilling materials.

The apical sealing ability of amalgam, cold-burnished gutta-percha, amalgam with cavity varnish, and SuperEBA cement was evaluated in extracted human teeth. For each experimental group, the roots of 20 single-rooted teeth were sectioned from their crowns. Canals were cleaned, shaped, and obturated with vertically condensed warmed gutta-percha and Kerr Pulp Canal Sealer. Following apical preparation and placement of test materials, root ends were placed in 1% methylene blue dye for 2 wk, after which the roots were sectioned longitudinally, and linear measurements of dye penetration were recorded. Results demonstrated statistically less linear dye penetration in the test group sealed with amalgam and cavity varnish. Statistical differences were not detected among the other test groups.