Donald R. Morse

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

Age-related changes of the dental pulp complex and their relationship to systemic aging

The dental pulp and its associated structures, the dentin and the cementum, are discussed. Because many of the age-related pulpal changes have components considered in several of the current theories of aging, these theories are briefly reviewed. Part 2 describes the age-related changes of the dental pulp, the dentin, and the cementum (the dental pulp complex). An attempt is made to differentiate inherent aging changes from physiologic defensive changes and pathologic irritant-induced changes. Part 3 describes the relationship of age-induced changes in the dental pulp complex to components of the current aging theories together with a unified concept of the dental pulp complex aging. Part 4 considers whether dental pulp complex aging can be used as a biomarker for generalized aging. Whether age-related changes of the dental pulp complex can be altered by interventions is discussed.

A Physiological and Subjective Evaluation of Meditation, Hypnosis, and Relaxation

&NA; Ss were monitored for respiratory rate, pulse rate, blood pressure, skin resistance, EEG activity, and muscle activity. They were monitored during the alert state, meditation (TM or simple word type), hypnosis (relaxation and task types), and relaxation. Ss gave a verbal comparative evaluation of each state. The results showed significantly better relaxation responses for the relaxation states (relaxation, relaxation‐hypnosis, meditation) than for the alert state. There were no significant differences between the relaxation states except for the measure “muscle activity” in which meditation was significantly better than the other relaxation states. Overall, there were significant differences between task‐hypnosis and relaxation‐hypnosis. No significant differences were found between TM and simple word meditation. For the subjective measures, relaxation‐hypnosis and meditation were significantly better than relaxation, but no significant differences were found between meditation and relaxation‐hypnosis.

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.

A comparative tissue toxicity evaluation of established and newer root canal sealers

Grossmans sealer, eucapercha, Endo-Fill, CRCS, Sealapex, Hypocal, and sterile saline solution (0.3 ml of each) were injected into specific dorsal subdermal tissue sites of 12 guinea pigs. The animals were killed after 6 days, 15 days, and 80 days (four per time period). Analysis of tissue response showed that, overall, Sealapex and Endo-Fill had less severe inflammatory reactions than any of the other test materials. Grossmans sealer, CRCS, and Hypocal showed principally severe inflammatory responses at both 6 and 15 days, but mild reactions at 80 days. Overall, eucapercha showed less severe inflammatory responses than Grossmans sealer, CRCS, and Hypocal. Diffuse calcification was induced by the three calcium hydroxide preparations (CRCS, Sealapex, and Hypocal). Eucapercha and Endo-Fill had minute local areas of calcification. Both Grossmans sealer and CRCS did not have overall favorable histologic reactions; however, Grossmans sealer and CRCS have been used successfully clinically. Further clinical studies are needed.

Electrophoretic differentiation of radicular cysts and granulomas

Abstract Polyacrylamide-gel electrophoresis was used for differential diagnosis of radicular cysts and granulomas. Root canal fluids were aspirated from forty anterior teeth with radiographic evidence of periapical pathosis, and from one pulpless anterior tooth with no radiographic evidence of periapical pathosis. Endodontic therapy was performed on all the teeth, and all the periapical lesions were surgically removed. The lesions were examined histologically, and the histopathologic diagnoses were then compared with the electrophoretic patterns. Analysis of the root canal fluids showed the following: (1) An albumin pattern was found in all thirty-one of the cases diagnosed histologically as being granulomas. The same pattern was also found in the case of the pulpless tooth without an area of rarefaction. (2) In eight of the nine cases diagnosed histologically as cysts, there was a much more intense albumin pattern and other patterns in the globulin regions. In the one case of a cyst that was misdiagnosed, the apical portion of the canal was calcified and the cyst lumen was never penetrated.

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.

Infection-related mental and inferior alveolar nerve paresthesia: Literature review and presentation of two cases

A review of the literature on infection-related mental and inferior alveolar nerve paresthesia is given. This is followed by 2 case reports. The first case is of a mandibular left second molar in which a chloropercha overfill puff occurred in the vicinity of the inferior alveolar canal. The tooth remained asymptomatic until 2 and 1/2 yr later, when the periapical lesion enlarged and swelling, pain, and paresthesia developed. The paresthesia resolved 2 weeks following periapical surgery. The second case is of a mandibular right first premolar in which paresthesia began 1 day after the initial endodontic treatment. The intracanal medication was formocresol on a cotton pellet that was squeezed dry. The paresthesia was treated by irrigation, antibiotics, and dexamethasone. The paresthesia lasted 7 weeks, and when it resolved the root canal was filled with gutta-percha/eucapercha. Almost 9 months later, the tooth remained asymptomatic.

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.