M. Lawrence Furst

A scanning electron microscopic evaluation of human dentinal tubules according to age and location

A scanning electron microscopic examination of human dentinal tubules was done according to the age of the subject and specific area of the tooth from which the specimen was obtained. Teeth from the following five age groups were examined: 20 to 34, 35 to 44, 45 to 54, 55 to 79, and 80 and above; while the specific tooth locations examined were: the apical, middle, and cervical root dentin and the coronal dentin. The results showed that the number of dentinal tubules decreased with increasing age (e.g. the mean number of tubules=242,775 for age group 20 to 34; 149,025 for age group 80 and above), and apical location (e.g. the mean number of tubules=265,460 for coronal dentin; 49,140 for apical root dentin). Both of these findings were statistically significant (p

The antimicrobial effect of various endodontic sealers

The antimicrobial activity of an endodontic sealer can be helpful in destroying any remaining root canal microbes. Therefore it was decided to test the antimicrobial activity of several commonly used endodontic sealers. The sealers used were Grossmans sealer, Tubliseal, Calciobiotic, Sealapex, Hypocal, eucapercha, Nogenol, and AH26. Also tested were dry calcium hydroxide powder, calcium hydroxide mixed with saline, and a Teflon formulation. The microbes used were Streptococcus mutans (a gram-positive microaerophile). Staphylococcus aureus (a gram-positive facultative anaerobe), and Bacteroides endodontalis (a gram-negative obligate anaerobe). The freshly mixed sealers were placed into the prepared wells of agar plates inoculated with the test microorganisms. After varying periods of incubation, the zones of inhibition of bacterial growth were observed and measured. Grossmans sealer had the greatest overall antibacterial activity. However, AH26 had the greatest activity against B. endodontalis. The zinc oxide-eugenol-based sealers had more antimicrobial activity than either the calcium hydroxide-based sealers or eucapercha.

Infectious flare-ups and serious sequelae following endodontic treatment: A prospective randomized trial on efficacy of antibiotic prophylaxis in cases of asymptomatic pulpal-periapical lesions

Without peritreatment antibiotics, infectious flare-ups (about 15% incidence) and serious sequelae follow endodontic treatment of asymptomatic teeth with necrotic pulps and associated periapical lesions. Antibiotics administered after endodontic treatment (4-day regimen) reduce the flare-up incidence to about 2%, but hypersensitivity responses, sensitization, resistant microbes, and drug-taking compliance are potential problems. To ascertain whether a specific prophylactic antibiotic (high-dose, 1-day regimen) would preferentially maintain this low flare-up incidence while overcoming antibiotic-related problems, 315 patients with quiescent pulpal necrosis and an associated periapical lesion were randomly given either penicillin V or erythromycin (base or stearate). Evaluations of flare-up after endodontic treatment were done at 1 day, 1 week, and 2 months. A 2.2% flare-up incidence was found, with no statistically significant differences for penicillin (0.0%), base (2.9%), and stearate (3.8%). No hypersensitivity responses occurred. Gastrointestinal side effects were found primarily with the erythromycins (12.4%). A comparative analysis of the data from our first study (no peritreatment antibiotics) and the pooled data from our last two investigations (including the current trial) showed that peritreatment antibiotic coverage significantly reduced flare-ups and serious sequelae after endodontic treatment (p less than 0.001).

A comparative leakage study of P-30 resin bonded ceramic, teflon, amalgam, and IRM as retrofilling seals

Thirty-six recently extracted teeth were used to evaluate the leakage characteristics of the following materials as retrofilling seals: cold-burnished guttapercha, P-30 with Scotchbond, a recently developed Teflon material, amalgam, and IRM. The teeth were instrumented and obturated with gutta-percha and Kerrs Sealapex. Apical bevels were placed on all of the teeth and class I preparations were prepared and obturation was with the various materials. The teeth were then subjected to an India ink solution. After splitting the teeth, a longitudinal measurement of dye penetration was done. The results showed that IRM, Teflon, and P-30 had statistically significantly less leakage than amalgam. The best results were shown by Teflon and P-30. Clinically, Teflon was the simplest to use.

A prospective randomized double-blind trial on efficacy of dexamethasone for endodontic interappointment pain in teeth with asymptomatic inflamed pulps

To determine whether a relatively large dose of oral dexamethasone given for a short period of time would be effective in reducing endodontic interappointment pain, the current double-blind, placebo-controlled study was undertaken. After the visit for instrumentation, 40 patients with asymptomatic teeth having vital-inflamed pulps were randomly given either dexamethasone (3 tablets of 4 mg each) or a dextrose placebo identical in appearance (same dosage schedule). The outcome showed that the oral administration of dexamethasone resulted in a statistically significant reduction in endodontic interappointment pain at all three time periods evaluated, that is, at 8 hours, 24 hours, and 48 hours (p less than 0.01). It appears from the results of this study that this dosage schedule of oral dexamethasone is sufficient to significantly reduce endodontic interappointment pain for teeth with asymptomatic vital-inflamed pulps. Further studies are needed for teeth with other endodontic pulpal-periapical conditions and for symptomatic teeth.

Stress, Relaxation and Saliva: A Follow-up Study Involving Clinical Endodontic Patients

Dentally induced stress and relaxation-induced anxiety reduction recently have been correlated with salivary changes in private patients treated by a solo endodontist. Hypnosis was shown to be more effective than local anesthesia in anxiety reduction. Dental students and clinic patients were employed in this study in an attempt to replicate the previous findings. One additional salivary variable (pH) was examined. Twenty-nine endodontic clinic patients were treated, each by a different dental student. The patients completed dental anxiety questionnaires and had salivary samples taken prior to, and at the conclusion of, their initial endodontic treatments. Pain and anxiety were managed using local anesthesia, hypnosis, or nitrous oxide-oxygen, either alone or in combination. There were significant anxiety-reduction changes by the conclusion of the visits (p less than 0.001) as measured by increased salivary volume, increased salivary translucency, reduced salivary protein, increased salivary pH and reduced questionnaire-determined anxiety level. Hypnosis and nitrous oxide-oxygen were significantly more effective (p less than 0.05) than local anesthesia in anxiety reduction as measured by salivary changes and questionnaires. It can be concluded that saliva is an easily obtained fluid that can be used to determine levels of stress and relaxation.

A magnifying lens comparative evaluation of conventional and ultrasonically energized filing

Summary Eleven extracted human teeth were instrumented with hand-held files in a standardized technique (control) and compared with 11 extracted teeth that were instrumented with ultrasonically energized files. The teeth were sectioned longitudinally, and cervical, middle, and apical thirds were graded for residual debris observed under low magnification by five nonparticipating practitioners. In none of the categories examined was statistical significance found (p>0.05). However, certain trends were observed. The ultrasonically instrumented teeth tended to contain less debris than the hand-filed teeth. The middle third showed a trend toward less remaining debris than the cervical and apical thirds. The two longitudinal halves differed somewhat in the amount of remaining debris in each half. The interjudge reliability was relatively low. It was 40% in the cervical third, 72% in the middle third, and 61% in the apical third.

An evaluation of tricalcium phosphate as a treatment for endodontic perforations

In the rat, perforations of maxillary molars were created and treated with either tricalcium phosphate (Synthograft) or Cavit. At four time intervals (1 day, 1 wk, 2 wk, and 1 month), four evaluative factors (inflammation, bone resorption, cementum and dentin resorption, and epithelial proliferation) were analyzed and compared for the two materials. For the individual time periods, there were no statistically significant differences between the two materials. However, when all four time periods were combined, there was a statistically significant better result for tricalcium phosphate than for Cavit with respect to decreased inflammation (p less than 0.05).

A radiographic evaluation of the periapical status of teeth treated by the gutta-percha—eucapercha endodontic method: A one-year follow-up study of 458 root canals

In Part I, which appeared in the last issue, the authors discussed the variations that exist in nonsurgical endodontic therapy with respect to methods of treatment and analyses of success and failure. They then reported on the materials and methods that were used in their clinical study of 458 root canals treated by the gutta-percha--eucapercha method and gave the criteria that were used for the radiographic analysis of success and failure in those cases. In Part II, the results of the one-year follow-up of those 458 root canals is presented. Tables and illustrations are used to substantiate the results.

Stress, relaxation, and saliva: A pilot study involving endodontic patients

Thirty-four endodontic patients completed dental anxiety questionnaires and had saliva samples taken prior to and at the conclusion of their initial endodontic treatment. Pain and anxiety were managed with local anesthesia, nitrous oxide--oxygen psychosedation, hypnosis, and meditation, either alone or in combination. For most patients, by the conclusion of the treatment, anxiety had decreased, salivary volume had increased, and salivary protein was reduced. Meditation and hypnosis, either alone or in combination with local anesthesia, were most effective in anxiety reduction as measured by questionnaire and/or salivary changes.