Irving H. Sinai

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

Periodontal Effects of Root Perforations Before and During Endodontic Procedures

Periodontal tissue reactions to root perforations in the teeth of dogs and humans have been studied by Euler,l KUbler,2 Ruchenstein,3 Kaufmann,4 Taatz and Stiefel,5 and Lantz and Persson.6,7 In general, inflammatory reactions were more severe when the perforated regions were left open to saliva or when the entrance regions were closed with zinc phosphate cement. Reactions were less severe when the perforation canals were sealed with gutta-percha immediately after the perforations were made or soon thereafter. In a clinical and histologic investigation of endodontically treated teeth that had failed, Seltzer et a18 found that some of them had perforations of the floor of the pulp chamber, presumably made by improper access openings. Should such perforations occur without the operators knowledge, the failures of endodontically treated teeth might be attributed unjustly to some other factors. Therefore, knowing the outcome of endodontically treated teeth with perforated roots should contribute to an informed prognosis for such teeth. During endodontic experiments on monkeys,9-11 a number of teeth were accidentally perforated before or during treatment.

Biologic aspects of endodontics. IV. Periapical tissue reactions to root-filled teeth whose canals had been instrumented short of their apices.

Pulp extirpations and root canal instrumentation shy of the apices of the teeth were performed on thirty-four human anterior teeth and on thirty-two roots of sixteen teeth of Macaca rhesus monkeys. The root canals were then filled short of the apices of twenty-four human teeth and twenty-two roots of eleven monkey teeth. Root canal fillings were purposely forced beyond the apices of nine human teeth and ten roots of five animal teeth. Observations were made of the periapical tissue reactions to those procedures after time intervals ranging from 6 to 270 days in the human groups and 14 days to 270 days in the animal series. Comparisons were made between the periapical tissue reactions of the two groups. Periapical tissue reactions were similar in both groups, initially. There was an acute inflammatory response in the apical pulp and periapical tissues, which was gradually superseded by chronic inflammation. Dentine filings were found to have been impacted on the remaining apical pulp stump in the group in which the canals had been filled shy of the apex. When the filling material had been pushed beyond the apex, the dentine debris and root canal filling materials were found in the periapical tissues. In both groups, periapical inflammation was accompanied by root end and alveolar bone resorption. Within 3 to 6 months, repair of the resorptions by secondary cementum and bone elaboration occurred routinely in most of the teeth. From 6 to 12 months later such repair was generally complete in the group in which the canals were filled shy of the apices. Repair was delayed in the group in which the canals had been overfilled. In addition, in this group there was a greater tendency toward proliferation of cell rests of Malassez. Foreign filling material in the periapical tissues tended to become encapsulated by collagen fibers. It was concluded that, in cases of vital pulp extirpation, optimum results, in terms of tissue repair, were obtained when root canals were instrumented and filled short of the apices of the teeth.

Prophylactic use of penicillin V in teeth with necrotic pulps and asymptomatic periapical radiolucencies

As a result of (1) clinical experience with flare-ups occurring in teeth with necrotic pulps and asymptomatic periapical radiolucencies and (2) on apparent reduction to the incidence of such flare-ups by the administration of penicillin V at the first sign of swelling, this study on the prophylactic administration of penicillin V in similar cases was undertaken. The subjects were 100 consecutive clinic patients whose teeth had necrotic pulps and asymptomatic periapical radiolucencies. At the initial visit, all teeth were instrumented completely to the radiographic apex, with 0.5% to 2.54% sodium hypochlorite as the irrigant. Sterile, dry cotton pellets and ZOE restorations were used. Alternate patients were given 250 mg of penicillin V and an identical-appearing placebo with instructions to take two tablets every 6 hours for the first 24 hours, followed by one tablet every 6 hours until all tablets were taken. Pain and swelling were graded by the patients on five-point scales, and flare-ups were scored when either pain and/or swelling necessitated an unscheduled emergency visit. Fifteen patients developed flare-ups, with significantly more flare-ups in the placebo group (p less than 0.05). The findings indicate that, in selected cases, prophylactic penicillin can be used to prevent flare-ups.

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 comparison of engine and air-driven instrumentation methods with hand instrumentation

Sixty-four roots of freshly extracted human maxillary first and second molars were divided into four groups and were instrumented as follows: group 1, Endosonic Air 3000 handpiece with Rispisonic files; group 2, Endosonic Air 3000 handpiece with Shaper files; group 3, Giromatic contra-angle with Rispi files; and group 4, hand instrumentation using K-Flex files. Each group had the same number of curved and straight canals. After instrumentation the roots were then sectioned longitudinally. A dissecting microscope was used to observe the degree of cleanliness in the coronal, middle, and apical thirds. The results showed that for straight canals the Endosonic Air 3000 with Rispisonic files cleaned best in all three zones. For curved canals, the Endosonic Air 3000 with Shaper files cleaned best in the apical third. The Endosonic Air 3000 with either Rispisonic or Shaper files performed better than the other two instrumentation methods.

Management of a vertical root fracture.

M cated by the extrusion of root canal filling material to the distal aspect in the cervical region. The fracture was probably due to the forces of condensation. The patient was referred to our office again in June 1965 for treatment of the mandibu la r left lateral incisor. At that time, it was confirmed that there was a vertical root fracture of the mandibular right lateral incisor (Fig 3). No clinical symptomatology was manifested at that time, and no treatment was rendered. The patient was next seen in March 1967. She had some discomfort and swelling in the region of the mandibular right lateral incisor. In addition, it was possible to probe the distal pocket of the tooth to more than 10 mm. A radiograph taken at that time showed further separation of the fractured segment from the main body of the root (Fig 4). In an a t tempt to retain the tooth for the child, a surgical procedure was begun. A full-height flap was reflected, and the root segment was removed and the area curetted. In addition, because the fracture involved the root canal, the root canal filling was removed and the canal was curetted as well. A postsurgical radiograph was taken (Fig 5). Healing was uncomplicated. The patient was seen in Ju ly 1967 with continued uncomplicated healing (Fig 6). She was seen again in October 1967, and the tooth mobility was much reduced, al though it persisted at approximately Class 1. The distal pocket could be probed to a depth of 5 mm. Significant formation of bone could be seen radiographically at these two examinations (Fig 7). Unfortunately, it was not possible to observe the pat ient after October because of a lack of cooperation. The patient subsequently married and

Proplast as an apical barrier in root canal therapy

Proplast is a felt-like implant of polytetrafluorethylene (Teflon) and carbon. This study investigates its use as an apical barrier to reduce inflammation caused by gutta-percha and zinc oxide root canal sealer. The results of this study indicate that Proplast does not measurably reduce the inflammatory response when compared with conventional filling material.

Endodontic flare-ups: The tape

A discussion is given of the pros and cons of the recently distributed audio tape on endodontic flare-ups. Highlighted is the relationship of endodontic flare-ups to infection and how specific antibiotics and certain intracanal medicaments can reduce flace-ups and non-flare-up-associated pain and swelling.

The management of an anterior radicular fracture

Trauma involving an upper incisor is an unfortunateoccasional occurrence in childhood. “By the age of seven years, 28% of girls and 32% of boys have suffered a traumatic dental injury to the primary dentition. In the permanent dentition a marked increase is seen for boys aged 8 to 10…” (1). The most common sequelae of this event are avulsion, partial avulsion or subluxation, and coronal or radicular fracture. “Root fractures, defined as fractures involving dentin, cementum and pulp are relatively uncommon among dental trauma, comprising 0.5 to 7 percent of the injuries affecting the permanent dentition…” (2). “In younger individuals with permanent incisors in various stages of eruption and with incomplete root development root fractures are unusual…” (2). Radicular fracture, when it occurs, usually occurs in cases of completely or nearly completely formed roots. In these instances, it is usually a horizontal radicular fracture (3. 4). In cases of incomplete root formation, the consequences of trauma is usually avulsion or subluxation (5).