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Biomedical subjects

M Trope

Publications and source records attributed to M Trope.

At least 55 records · Page 3Linked to original sources

Root resorption of dental and traumatic origin: classification based on etiology.

While root resorption is a relatively common complication of dental trauma, classifications of root resorption are inconsistent and confusing. All pathological root resorption of dental origin is inflammatory in nature. For root resorption to occur, the protective superficial layer must be (internally or externally) damaged or changed and an inflammatory stimulator must be present. This article attempts to classify root resorption on the basis of etiology, i.e., the cause of the protective layer loss and the cause of the inflammatory response, to facilitate more efficient treatment.

Bacterial Infections↗

Subattachment inflammatory root resorption: treatment strategies.

Attempts have been made to classify root resorption according to its etiology in order to develop more efficient strategies for its treatment. This condition has been identified as resulting from damage to the protective attachment layer (predentin or precementum) of the root combined with inflammation adjacent to the root surface. This article demonstrates a series of treatment strategies focused on the reversal of each manifestation of subattachment root resorption, specifically emphasizing defects that extend apically and localized defects.

Humans↗

TNF-alpha release in monocytes after exposure to calcium hydroxide treated Escherichia coli LPS.

Lipopolysaccharide (LPS), a cell wall component of Gram negative anaerobic bacteria, has been implicated in the pathogenesis of periapical disease resulting from infected root canals. Calcium hydroxide [Ca(OH)2] has been shown to be an effective medicament in such infections, reducing the microbial titre within the canal. It has been proposed that the therapeutic effect of Ca(OH)2 may also be the result of direct inactivation of LPS. The aim of this study was to investigate whether the toxic potential of an Escherichia coli LPS could be reduced or eliminated by Ca(OH)2. Four concentrations of E. coli LPS ranging from 1-1000 ng/ml sterile water were incubated in duplicate either with 25 mg Ca(OH)2 or sterile water alone. Controls consisted of Ca(OH)2 without LPS or sterile water only. Monocytes were collected from peripheral blood by centrifuging through a gradient and plated to a specific density. Adherent monocytes were incubated for 4 days at 37 degrees C with 5% CO2 in M199 medium with 10% autologous serum. The different LPS solutions were added to the wells on day 5. After 4 h the supernatants were collected and quantitatively assayed for TNF-alpha using a commercial ELISA kit. Statistical analysis was performed with ANOVA. Results indicated that Ca(OH)2 is able to eliminate the ability of an E. coli LPS to stimulate TNF-alpha production in peripheral blood monocytes (P < 0.0001).

Calcium Hydroxide↗

Comparison of two laser Doppler systems on the measurement of blood flow of premolar teeth under different pulpal conditions.

An in vivo investigation was conducted to assess the ability of two laser Doppler flowmeters (DRT4, Moor Instruments Ltd; Laserflo BPM2, Vasamedics) to differentiate between vital pulp, ischaemically necrosed pulp, and an empty pulp chamber in premolar teeth in children. Sixteen intact, vital teeth in need of extraction for orthodontic purposes were identified. Laser Doppler blood flow readings were taken prior to (T1) and after the administration of adrenaline-free local anaesthetic (T2), after extraction and replantation of the teeth (T3), and after broaching the pulp tissue and replanting the teeth (T4). The data collected (flux values) for both instruments were analysed using a repeated measures ANOVA. Significant differences were found for vital pulp (T1, T2) versus ischaemically necrosed pulp (T3), and for vital pulp (T1, T2) versus an empty pulp chamber (T4), with the Moor DRT4 instrument. This instrument also detected a significant difference in pulpal blood flow to the vital pulp, before and after the administration of local anaesthetic. No other significant differences were found.

Analysis of Variance↗

Revascularization of traumatized teeth assessed by laser Doppler flowmetry: case report.

Infection of the pulp space in addition to the attachment damage of a traumatic injury to a tooth, results in serious complications and often tooth loss. Therefore, the prevention or treatment of root canal infection is a major consideration in these cases. In immature teeth, revascularization of a necrotic pulp is possible and highly desirable. Unfortunately, current sensitivity tests are poor indicators of revascularization, with the result that many pulps are removed unnecessarily. Laser Doppler flowmetry is an objective test of the presence of moving red blood cells within a tissue, which has been reported to be effective in the detection of tooth pulp vitality as well. A case is presented where an eight year old child severely luxated both maxillary central incisors. While only one of the incisors was weakly responsive to CO2 ice at 76 days after replantation, the laser Doppler flowmeter indicated that revascularization was occurring in both teeth at a much earlier time. Because of the laser Doppler readings, endodontic treatment was not initiated and the teeth developed normally.

Child↗

Periodontal healing of extracted dogs' teeth air-dried for extended periods and soaked in various media.

The aim of this study was to determine the periodontal healing of replanted dogs' teeth which, after extended extra-oral dry times, had been soaked in various media before replantation. Incisors and premolars of beagle dogs were root canal treated, extracted and bench dried. The teeth were grouped according to dry times of 30, 45 and 60 minutes. Each group of teeth was soaked in one of three media, Hank's balanced salt solution, ViaSpan (Belzer UW-CSS, Dupont Pharmaceuticals), or Conditioned Medium (supernatant of confluent culture of human gingival fibroblasts) for 30 minutes before replantation. Controls consisted of teeth extracted and replanted without drying on soaking (negative control), and bench-dried teeth replanted without soaking in the media (positive control). The dogs were killed 6 months after replantation of the teeth, which were prepared for histologic evaluation. Five microns cross-sections (every 70 microns) of the root and surrounding tissue were evaluated for healing/resorption according to Andreasen's criteria. The best healing occurred for the roots which had been immediately replanted. Healing in the positive control groups decreased with increased dry time. For the 30-minute dry time groups, soaking in media had no beneficial effect on periodontal healing compared with the controls. Soaking in ViaSpan resulted in an increased healing incidence for both the 45- and 60-minute bench-dried groups while soaking in the other media had no consistent beneficial effect. It appears from this study that an avulsed tooth that has been left dry for 30 minutes should be replanted immediately without soaking. However, teeth that have been dry for 45 or 60 minutes would benefit from soaking for 30 minutes in ViaSpan.

Adenosine↗

The role of the socket in the periodontal healing of replanted dogs' teeth stored in ViaSpan for extended periods.

In a previous study on the extended storage of extracted dogs' teeth, it was hypothesized that changes in the socket environment might play a role in the periodontal healing of these teeth. The purpose of this study was to evaluate the role of the socket in the periodontal healing of replanted dogs' teeth. Extracted endodontically treated dogs' teeth were stored in ViaSpan for 6 hours and replanted into sockets after 6, 48 or 96 hours. Controls included teeth extracted and replanted immediately, 48-hour stored teeth replanted into 48-hour sockets and 96-hour stored teeth replanted into 96-hour sockets. After 6 months the dogs were killed and the teeth prepared for histologic evaluation according to Andreasen. Overall healing for the groups and healing for teeth within the groups were evaluated and compared. The best results were obtained when the teeth were replanted immediately. For the teeth stored in ViaSpan for 6 hours, complete healing decreased significantly as the age of the socket increased. In addition, the rate of replacement resorption increased significantly with increasing socket age for the 6-hour stored teeth. Forty-eight-hour stored teeth replanted into 48-hour sockets had the lowest healing rate with levels of inflammatory resorption not seen in the other groups. According to the results of this study, the socket environment plays an important role in the healing of replanted teeth in dogs.

Adenosine↗

Tritiated thymidine uptake in periodontal ligament cells of dogs' teeth stored in various media for extended time periods.

The purpose of this study was to evaluate a new storage solution, Conditioned Medium, vs Hank's balanced salt solution and ViaSpan with respect to the viability of periodontal ligament cells of exarticulated teeth. Teeth were stored for periods of 6, 48, and 96 hours in Hank's balanced salt solution, ViaSpan (Dupont Pharmaceuticals), or Conditioned Medium. Teeth were cultured for 24 hours in Dulbecco's medium supplemented with tritiated thymidine. The cultured teeth were sectioned and evaluated with autoradiography. Control teeth were extracted and immediately treated as above without storage. Mitotic activity was indicated by clusters of five or more grains over the nuclei of fibroblasts in the remaining periodontal membrane. The ratio of labeled to unlabeled cells (labeling index) was calculated for each treatment group. When storage time was compared across all groups, 96 hours was significantly different from 6 and 48 hours (P < 0.001 and P < 0.012 respectively). Storage time of 6 hours was not significantly different from 48 hours (P > 0.10). After comparison of the nine experimental groups with the control group, only Hank's balanced salt solution at 96 hours was significantly different (P < 0.004).

Adenosine↗

Cervical root resorption.

This article describes cervical root resorption, an external inflammatory root resorption arising immediately below the attachment level of the root. The pathogenesis is not fully understood, although many theories have been presented. Clinically, cervical root resorption is usually asymptomatic. The radiographic appearance is variable and is easily mistaken for that of internal root resorption. Histologically, the presentation is identical to that of other inflammatory root resorptions.

Humans↗

Healing of apical periodontitis in dogs after apicoectomy and retrofilling with various filling materials.

OBJECTIVE: To histologically assess the efficacy of various retrofilling materials in apical surgery. STUDY DESIGN: The pulps of mandibular premolars in seven beagle dogs were infected; this resulted in periapical lesions. Apical surgery was performed without disinfection of the root canals. Super EBA (Harry J. Bosworth Co., Skokie, III.), two formulations of glass ionomer cement, amalgam with varnish, IRM,(Caulk Co., Ltd., Densply International, Milford, Del.) and a light-cured composite resin were the retrofilling materials used. Roots infected and apicoectomized without retrofilling were positive controls. After 6 months the dogs were killed. The experimental roots and surrounding apical tissues were prepared and histologically examined and relative percentages of bone and inflammation were calculated. RESULTS: Super EBA was consistently the best. In overall periapical condition, Super EBA was statistically superior to all materials except IRM. IRM was superior to the glass ionomer cements but not the other materials. As to percentage of bone, Super EBA was the best overall; it was superior to glass ionomer, composite resin, and the positive control but not different from amalgam or IRM. When comparing remaining numbers of inflammatory cells, Super EBA was superior with the lowest number of inflammatory cells present. CONCLUSION: Although not statistically different from IRM, Super EBA was consistently the best retrofilling material tested when compared with all retrofilling materials studied.

Alveolar Process↗

Root perforations: classification and treatment choices based on prognostic factors.

Root perforations are common complications of endodontic treatment or post preparation and often lead to tooth extraction. Successful treatment depends mainly on immediate sealing of the perforation and prevention of infection. Several factors affect the achievement of these goals, most important of which are: time of occurrence, size, and location of the perforation. A classification of root perforations, based on the above factors, is presented to assist the clinician in the choice of the treatment protocol which will give the best possible results when a perforation is diagnosed.

Dental Instruments↗

Protocol for treating the avulsed tooth.

Avulsion of a tooth requires decisive action by the dental practitioner. Replantation of the tooth at the earliest possible time, along with the avoidance of further periodontal damage, is paramount to achieving a successful result. The accident site, time the tooth is out of the socket, storage media and endodontic protocol influence the prognosis. Appropriate endodontic management and tooth restoration will ensure long-term success.

Clinical Protocols↗

Protocol for treating the avulsed tooth.

Avulsion of a tooth requires decisive action by the dental practitioner. Replantation of the tooth at the earliest possible time, along with the avoidance of further periodontal damage, is paramount to achieving a successful result. The accident site, time the tooth is out of the socket, storage media and endodontic protocol influence the prognosis. Appropriate endodontic management and tooth restoration will ensure long-term success.

Clinical Protocols↗

Antimicrobial and toxic effects of established and potential root canal irrigants.

Three dilutions of the commonly used irrigant sodium hypochlorite (0.5%, 2.5%, and 5.25%) and the potential irrigants Peridex, chlorhexidine gluconate (0.12%), and Therasol were tested. Alcohol and saline served as controls also. The in vitro portion of this study used four different microorganisms (Streptococcus mutans, Peptostreptococcus micros, Prevotella intermedius, and Porphyromonas gingivalis) to determine antimicrobial effect. Presterilized 7-mm diameter Whatman paper disks soaked with the test solution were prepared, and disks were placed onto the previously seeded agar petri dishes. Each dish was incubated aerobically or anaerobically according to the microorganisms used. An in vivo animal model (guinea pig) was used to examine subcutaneous local tissue reactions using the same materials; 0.1 ml of each test solution was injected subcutaneously into predetermined locations on the animal dorsum. Test site histological examination was done 2 h, 2 days, and 2 wk after the injections. The results of this comparative study indicate Peridex (chlorhexidine gluconate) and Therasol may have good potential for endodontic usage.

Animals↗

Evaluation of success and failure after endodontic therapy using a glass ionomer cement sealer.

The purpose of this multicenter, prospective clinical study was to assess the treatment results following endodontic therapy using a glass ionomer cement sealer (Ketac-Endo) and to relate the results to various clinical factors. A total of 486 teeth were treated by three operators, using the "standardized technique" for canal preparation and either single cone or laterally condensed gutta-percha, in one or multiple treatment sessions. Six to 18 months postoperatively, the treatment results were assessed clinically and radiographically, and related to preoperative, intraoperative, and postoperative factors using a chi 2 analysis with 5% level of significance. Of 378 followed-up teeth, there was a 78.3% success, 15.6% incomplete healing, and 6.1% failure. Statistically, differences in the results were related to the number of canals (p < 0.04), primary treatment and retreatment (p < 0.02), pulp vitality (p < 0.001), periapical lesion (p < 0.001), preoperative symptoms (p < 0.003), operative complications (p < 0.001), and absence of restoration (p < 0.03). It was concluded that these treatment results were compatible with those reported in previous studies, and supported the clinical use of Ketac-Endo as an acceptable endodontic sealer.

Adolescent↗

Periapical status of endodontically treated teeth in relation to the technical quality of the root filling and the coronal restoration.

The purpose of this study was to evaluate the relationship of the quality of the coronal restoration and of the root canal obturation on the radiographic periapical status of endodontically treated teeth. Full-mouth radiographs from randomly selected new patient folders at Temple University Dental School were examined. The first 1010 endodontically treated teeth restored with a permanent restoration were evaluated independently by two examiners. Post and core type restorations were excluded. According to a predetermined radiographic standard set of criteria, the technical quality of the root filling of each tooth was scored as either good (GE) or poor (PE), and the quality of the coronal restoration similarly good (GR) or poor (PR). The apical one-third of the root and surrounding structures were then evaluated radiographically and the periradicular status categorized as (a) absence of periradicular inflammation (API) or (b) presence of periradicular inflammation (PPI). The rate of API for all endodontically treated teeth was 61.07%. GR resulted in significantly more API cases than GE, 80% versus 75.7%. PR resulted in significantly more PPI cases than PE, 30.2% versus 48.6%. The combination of GR and GE had the highest API rate of 91.4%, significantly higher than PR and PE with a API rate of 18.1%.

Chi-Square Distribution↗