Biomedical subjects

M Trope

Publications and source records attributed to M Trope.

At least 73 records · Page 4Linked to original sources

PubMed1995

In vitro endotoxin penetration of coronally unsealed endodontically treated teeth.

The purpose of the study was to evaluate the penetration of bacterial endotoxin (L.P.S.) through obturated root canals. Twenty-four single-rooted teeth were instrumented in a uniform manner. The root canals of 16 teeth were obturated with guttapercha and Roth's sealer and 8 teeth were similarly obturated but without sealer. The teeth were then divided into three groups. Group 1-Positive control (4 teeth). Teeth obturated without sealer were used. Sticky wax was softened in an open flame and painted over the external root surface except the apical 2 mm and coronal canal orifice which were left free of the sticky wax. Group 2-Negative control (4 teeth). Again teeth without sealer comprised the teeth in this group. However, in this group the sticky wax covered the apical area of the root and the canal orifice coronally, in addition to the rest of the root. Group 3-Experimental (16 teeth). The teeth obturated in conjunction with sealer were used. Otherwise the teeth were treated as in group 1. The coronal root half was then hermetically sealed from the apical root half so that LPS placed coronally could move only through the obturated canal space to the apical segment. One ml of water containing 100 micrograms/ml endotoxin was placed in the upper chambers and pyrogen-free water in the lower chambers. The upper and lower chambers were then tested for endotoxin at different time periods upto 21 days. The upper chambers tested positive for endotoxin at all test times for all teeth. All 4 positive control teeth showed endotoxin in the lower chambers by 24 hrs.(ABSTRACT TRUNCATED AT 250 WORDS)

Aggregatibacter actinomycetemcomitans↗

PubMed1995

Short vs. long-term calcium hydroxide treatment of established inflammatory root resorption in replanted dog teeth.

This study examined, histologically, the healing of intentionally produced inflammatory root resorption of replanted teeth in beagle dogs, treated with short- or long-term placement of calcium hydroxide. Thirty beagle dog incisors were randomly divided into four groups. In group 1 (negative control), uninfected incisors were extracted, the roots were longitudinally grooved and the teeth were replanted within 2 min. In group 2 the root canals were artificially infected followed by extraction, longitudinal grooving, and replantation as in group 1. Radiographs were taken biweekly and at the first signs of inflammatory root resorption or at 4 weeks, the root canals were fully instrumented and medicated with calcium hydroxide. In group 2, the root canals were permanently obturated with gutta-percha and sealer after 1 week of calcium hydroxide. The teeth in group 3 were treated as described in group 2 but after 1 wk the calcium hydroxide dressing was repacked for the duration of the study. In group 4 (positive control) the teeth were treated as described in groups 2 and 3 but no endodontic treatment was performed. Twelve weeks after the initiation of the endodontic treatment, sacrifice and histological preparation were carried out. In group 1, complete cemental repair was seen in all teeth. In group 2, five of ten teeth showed complete cemental repair whereas in group 3 complete cemental repair was seen in nine of ten teeth. None of the teeth in group 4 showed cemental repair. It was concluded that long-term may be more effective than short-term calcium hydroxide treatment of established inflammatory root resorption.

Animals↗

PubMed1995

Nd:YAG laser irradiation in root canal disinfection.

The purpose of this study was to assess the efficacy of Nd:YAG laser irradiation in disinfecting the root canal system. Seventy-five teeth were uniformly instrumented and sterilized, and their root canals were infected for 60 min with an overnight culture of Enterococcus faecalis in Tryptic Soy Broth. The teeth were divided into 6 groups: 1--non-infected controls; 2--infected controls; 3--infected, laser treated; 4--infected, laser dummy (dye only); 5--infected, laser dummy (dye and air-water spray); 6--infected, NaOCl-treated (reference group). After treatment, the root canals were dried and dentinal shavings removed for a post-treatment culture. Quantitative analysis of bacteria surviving the various treatments were performed and the bacterial counts for each group were compared. SEM analysis of teeth split longitudinally was used to illustrate the effect of treatment on the smear layer and on surface bacteria. Nd:YAG laser irradiation (group 3) significantly reduced the number of bacteria while NaOCl irrigation (group 6) effectively disinfected the canals.

Aniline Compounds↗

PubMed1995

Clinical management of the avulsed tooth.

Treatment outside the dental office: Replant immediately after gentle washing if practical. If replantation is not practical, store the tooth in the best medium available. Storage media in order of preference are Hank's Balanced Salt Solution (HBSS), milk, saline, and saliva (buccal vestibule). Water is the least desirable storage medium. Treatment in the office: Emergency visit; Place tooth in HBSS while exam is conducted and history is taken. Prepare socket for gentle repositioning of the tooth. Prepare the root. Extraoral dry time < 20 minutes: Closed apex--replant immediately after gentle washing. Open apex--soak in 1 mg doxycycline in 20 mg saline for 5 minutes. Extraoral dry time 20 to 60 minutes: Soak in HBSS for 30 minutes and replant. Extraoral dry time > 60 minutes: soak in citric acid, 2% stannous fluoride, and doxycycline and replant. Endodontics can be done extraorally. Semirigid splint for 7 to 10 days. (If alveolar fracture is present, rigid splint for 4 to 8 weeks). Suture soft-tissue lacerations, particularly in the cervical area. Administer systemic antibiotics (penicillin V potassium if possible) Chlorhexidine rinses and stringent oral hygiene while the splint is in place (7 to 10 days). Analgesics as required. Second visit after 7 to 10 days: Endodontic treatment: Tooth with open apex and extraoral dry time of < 60 minutes: No endodontic treatment initially. Recall every 3 to 4 weeks to examine for evidence of pathosis. If pathosis is noted, disinfect the pulp space and start apexification procedure. Tooth with open apex and extraoral dry time > 60 minutes: If endodontics was not completed in the emergency visit, start endodontics and follow apexification procedure. Tooth with closed apex: Endodontics should be initiated after 7 to 10 days. Careful chemomechanical instrumentation under strict asepsis. Splint removed at end of visit. Obturation visit: If endodontics was initiated 7 to 10 days after the avulsion, obturation can take place after short-term calcium hydroxide treatment. If endodontics was initiated more than 14 days after the avulsion or inflammatory resorption, long-term calcium hydroxide for 6 to 24 months, obturated when an intact lamina dura is traced. Restorations: Temporary restorations: Should be 4 mm deep. Reinforced zinc-oxide-eugenol, acid-etch composite resin, glass-ionomer cement. Permanent restoration: Placed immediately after obturation. Acid-etch resin and dentin bonding agents. Follow-up care: Twice per year for 3 years and yearly for as long as possible. Late complications are common.

Dental Restoration, Permanent↗

PubMed1994

Multidisciplinary approach to apical surgery in conjunction with the loss of buccal cortical plate.

The treatment of advanced periodontal breakdown as a result of an associated endodontic lesion continues to challenge the practitioner. Two cases of teeth with endodontic pathologic conditions that required apical surgery are presented. On raising the flap, no buccal cortical plate was found, significantly lowering the prognosis of the surgery. A barrier membrane was used in addition to the apical surgery, which on postoperative follow-up appears to have resulted in the reestablishment of the buccal cortical plate.

Adult↗

PubMed1994

Retreatment efficacy 3 months after obturation using glass ionomer cement, zinc oxide-eugenol, and epoxy resin sealers.

The efficacy of ultrasonic retreatment, 3 months after obturation, in conjunction with Ketac-Endo, Roth's 801, and AH26 sealers was evaluated. Seventy-two root canals were prepared and obturated with gutta-percha and one of the sealers mentioned above. After 90 days, the canals were retreated by an ultrasonic technique and the retreatment time was recorded. The roots were split and the amount of debris that remained on the canal walls in three separate levels was scored. Compared by one-way and two-way analysis of variance, the mean scores of remaining debris at the different canal levels for the three sealer groups, as well as for each group, were not significantly different. The only significant difference was found in retreatment time for which Ketac-Endo was significantly slower to retreat than the other two sealers (p < 0.002). Thus, the results of this study showed that the amount of debris remaining on the root canal walls following retreatment 3 months after obturation is similar for Ketac-Endo, Roth's 801, and AH26 sealers, but the retreatment time for Ketac-Endo is significantly longer.

Analysis of Variance↗

PubMed1994

Resistance to fracture of endodontically treated premolars restored with new generation dentine bonding systems.

MOD cavities in 60 endodontically treated teeth were restored using six different methods. Copper rings were filled with commercial hard-setting cement and the teeth were placed up to the level of the cemento-enamel junction. The teeth were grouped according to restorative method, mounted in an Instron TT machine, and the buccal walls subjected to a slowly increasing compressive force until fracture occurred. The force of fracture of the walls of each tooth was recorded and the results in the various groups compared. All teeth fractured in a similar manner irrespective of the restorative method used. All groups restored with the newer bonding system had higher resistance to fracture than those restored with an acid etch chemically cured composite resin technique. The groups restored with Den-Mat Tenure Core Paste or a Variglass VLC base and Prisma APH were significantly stronger than the acid etch Concise restored teeth (P < 0.05). No statistically significant differences were found between the other groups (P > 0.05).

Acrylic Resins↗

PubMed1993

Residue of gutta-percha and a glass ionomer cement sealer following root canal retreatment.

A previous report indicates that root canals obturated with a new glass ionomer cement endodontic sealer (Ketac-Endo, Espe, Germany) and laterally condensed gutta-percha can be retreated by ultrasonic instrumentation. To address the possibility of Ketac-Endo being used without condensation of gutta-percha, the purpose of this study was to evaluate the efficacy of ultrasonic retreatment in canals obturated with single-cone gutta-percha and Ketac-Endo. Thirty root canals were prepared in a standardized way to ISO size 40 and obturated with gutta-percha and Ketac-Endo. Either a size 40 gutta-percha cone was used with and without lateral condensation, or a size 25 single cone, without condensation. After 14 days, the canals were retreated using chloroform and ultrasonic instrumentation. The roots were split vertically, and the amount of residual debris on the canal walls was assessed by three examiners using a dissecting microscope. Debris was recorded in the apical, middle and coronal canal levels according to a preset evaluation scale. The mean scores for each group were compared by ANOVA and Mann-Whitney U-test, with a 5% level of significance. In the roots obturated with lateral condensation the amounts of residual debris in the coronal and middle canal levels was lower than in the other two groups, whereas in the apical level it was higher. Statistically, only the differences in the apical level were significant (P < 0.03). It was concluded that ultrasonic retreatment may be performed effectively in root canals obturated with single-cone gutta-percha and Ketac-Endo.

Analysis of Variance↗

PubMed1993

Resistance to vertical fracture of roots, previously fractured and bonded with glass ionomer cement, composite resin and cyanoacrylate cement.

A recently developed glass ionomer bone cement (Ionos) may be suitable for bonding vertically fractured teeth, but the resulting resistance to repeated fracture of the bonded teeth is unknown. The purpose of this study was to assess in vitro the resistance to repeated fracture of roots which were previously fractured and bonded with Ionos cement and other bonding agents. Thirty-six roots were separated at the cervix and grooved on the coronal surface. Each root was mounted in an Instron machine and a vertical force was exerted until fracture occurred. Both the force required to fracture the root (F) and the root surface area (A) were recorded, and the root halves were bonded with one of the following materials: Ionos bone cement without dentin etching, Permabond 910 cyanoacrylate adhesive, and Gluma bonding system. The bonded roots were maintained in a wet sponge. One week later the roots were re-fractured in the Instron machine, and the forces were recorded (RF). Each one of F, RF, A, and the ratios RF/F and RF/A were compared statistically among the three experimental groups. Overall, RF was at the most 20% of F. Statistically significant differences were obtained only in RF, RF/F, and RF/A (p < 0.0003). Roots bonded with Ionos cement demonstrated significantly lower values than roots bonded with Permabond and Gluma, both of which did not differ significantly. It was concluded that roots bonded with Ionos cement were the least resistant to re-fracture, due to a lesser bonding strength of Ionos bone cement as compared with Permabond and Gluma.

Acid Etching, Dental↗

PubMed1992

Efficacy of removing glass ionomer cement, zinc oxide eugenol, and epoxy resin sealers from retreated root canals.

Removal of gutta-percha and various sealers was assessed during retreatment of the root canal system. Sixty root canals were prepared and obturated with gutta-percha and Ketac-endo, Roth's 801 cement, or AH26. After 14 days, the canals were retreated by hand or ultrasonic technique and the retreatment time was recorded. The roots were split and the amount of debris that remained on the canal walls in three separate levels was recorded by use of a dissecting microscope. The mean scores were compared by one-way and two-way ANOVA. The total score was significantly the highest for Ketac-endo (p less than 0.04), followed by AH26 and Roth's 801 cement. The largest amount of debris was consistently found in the apical third, and generally it was comparable for both retreatment techniques. The ultrasonic technique was significantly faster than the hand technique for all sealers tested (p less than 0.0004, p less than 0.0003, p less than 0.02, respectively). Hand retreatment of Ketac-endo was the slowest, whereas ultrasonic retreatment of Roth's 801 cement was the fastest. The results indicated that Ketac-endo endodontic sealer can be effectively removed from the root canal by ultrasonic instrumentation.

Analysis of Variance↗

PubMed1992

Resistance to fracture of endodontically treated roots.

The root canals of 48 single-canal canine teeth were prepared by four different methods. The coronal lingual wall and root canal space were lowered to 2 mm below the buccal wall of the roots. The prepared root was placed into acrylic resin so that 12 mm of buccal root was exposed. A slowly increasing force was applied at the junction of the buccal wall and root canal space until fracture occurred. The force of fracture of the buccal root wall of each root was recorded and the results in each group were compared. All teeth fractured at the buccal wall/acrylic resin junction. Instrumentation of the root canals significantly weakened the roots. Obturation of the canals in conjunction with Roth's 801 sealer did not strengthen the roots. Obturation of the canals in conjunction with a glass ionomer sealer significantly strengthened the roots as compared with roots instrumented but not obturated and those obturated with gutta-percha and Roth's 801 Sealer.

Analysis of Variance↗

PubMed1992

Dual wavelength spectrophotometry as a diagnostic test of the pulp chamber contents.

The purpose of this in vitro study was to determine the feasibility of using dual wavelength spectrophotometry to identify teeth with pulp chambers that are either empty, filled with fixed pulp tissue, or filled with oxygenated blood. In phase I of the experiment, a human third molar was prepared so that its pulp space could be filled with oxygenated blood and later emptied. In phase II, the lower jaw of a beagle dog was removed and placed in formalin, thereby fixing the pulps of the teeth. The pulp of the right canine was removed via an apical approach, and attachments were placed in a similar position to those on the human tooth, to allow filling and emptying of the pulp space. Cavit was placed over the exposed fixed pulp in the left canine. Ten readings, which were separated by light source and detector removal and replacement, were taken of the right canine pulp space when it was empty or filled with oxygenated blood, or the left canine pulp space when it was filled with fixed tissue. Distinct and reproducible changes were measured for pulp spaces filled with air, tissue, or oxygenated blood. In phase III, simulated pulp testing on a dog tooth model was performed. Blood was introduced into the root canal space, the chamber was rinsed with water and replaced with air, according to a predetermined code. Spectrophotometer readings were recorded. The identification of pulpal contents was correctly determined in all 20 of the predetermined conditions. The findings indicate that continuous wave spectrophotometry may become a useful pulp testing method.

Animals↗

PubMed1992

Multidisciplinary approach to the repair of vertically fractured teeth.

This case report describes the treatment of a vertically fractured upper left second molar. The two segments were extracted separately. The periodontal ligament was protected from damage extraorally by soaking it with Hanks' balanced salt solution. The two segments were bonded with the use of a biocompatible glass ionomer bone cement and replanted in conjunction with an expanded polytetrafluoroethylene (gore-tex) membrane. After 1 yr the tooth functions normally and is clinically and radiographically within normal limits.

Adult↗

PubMed1992

Effect of different endodontic treatment protocols on periodontal repair and root resorption of replanted dog teeth.

This study examined, histologically, the healing of intentionally damaged root surfaces of replanted teeth with either uninfected or infected root canals treated with short- and long-term calcium hydroxide. Thirty beagle dog incisors were randomly divided into four groups. In group 1, uninfected obturated incisors were extracted, the roots were longitudinally grooved and the teeth were replanted within 2 min. In group 2 the root canals were artificially infected followed by extraction, longitudinal grooving, and replantation as described in group 1. Fourteen days after replantation, the root canals were fully instrumented and medicated with intracanal calcium hydroxide. One week later the root canals were permanently obturated with gutta-percha and sealer. The teeth in group 3 were treated as described in group 2 but after 1 wk the calcium hydroxide dressing was repacked for the duration of the study. In group 4 (positive control) the teeth were treated as described in groups 2 and 3 but no endodontic treatment was performed. After 8 wk, sacrifice and histological preparation were carried out. In group 1 complete cemental repair was seen in all teeth. In groups 2 and 3, complete and incomplete cemental repair was seen in seven and two teeth, respectively. An ankylotic area was present in one tooth in group 3. None of the teeth in group 4 showed cemental repair. It was concluded that short- and long-term calcium hydroxide treatment resulted in similar healing patterns when endodontic treatment is initiated 14 days after replantation of teeth.

Animals↗

PubMed1992

Periodontal healing of replanted dog teeth stored in Viaspan, milk and Hank's balanced salt solution.

This study examined, histologically, periodontal healing and root resorption of replanted dogs teeth stored in Viaspan for different time periods and compared these healing patterns to those after storage in milk or Hank's balanced salt solution (HBSS). Seventy-two beagle incisors were endodontically treated, extracted, randomly divided and placed in Viaspan or milk for 6, 12, 24 and 36 h, and Viaspan or HBSS for 36, 48, 72 and 96 h, after which they were replanted. Four negative control teeth were immediately replanted while four positive controls were allowed to dry for one hour before replantation. All replanted teeth were splinted for 14 days. Two months after replantation the dogs were killed and the teeth histologically examined for healing of the supporting tissues. For Viaspan neither replacement nor inflammatory root resorption was seen after 6 and 12 h storage. A statistically significant rise in the incidence of replacement resorption was seen at 24, 36 and 48 h which decreased again at 72 and 96 h to levels equal to storage for 6 and 12 h. The occurrence of inflammatory root resorption was low and significantly increased only at 48 h after which it decreased significantly again. Viaspan proved superior to milk as a storage medium. Teeth stored in HBSS showed healing results similar to those stored in Viaspan.

Adenosine↗

PubMed1991

Human immunodeficiency virus infection of fibroblasts of dental pulp in seropositive patients.

Presence of human immunodeficiency virus (HIV) within noninflamed human dental pulps was documented by polymerase chain reaction assays in 11 of 12 pulps from HIV-seropositive patients. The purpose of the present study was to determine the cellular location of HIV in vivo within these tissues by means of in situ hybridization. Results of the in situ hybridization indicated HIV within fibroblasts of the pulp. These results are especially relevant because fibroblasts lack the CD4 receptor thought necessary for in vivo infection with HIV. These results suggest the fibroblast as a possible reservoir for HIV in the body.

CD4-Positive T-Lymphocytes↗

PubMed1991

Leakage after lateral condensation with finger spreaders and D-11-T spreaders.

The purpose of the study was to determine the leakage after lateral condensation with the use of finger spreaders and D-11-T spreaders. Fifty root canals were instrumented, and laterally condensed with gutta-percha and Grossman's cement. In 20 canals finger spreaders were used for the condensation and in a further 20 canals D-11-T spreaders were used. After 24 h in 100% humidity, the roots were painted with nail polish except for their apical 2 mm, which remained exposed. Five canals were not obturated (negative control) and five canals were obturated and the apices sealed with sticky wax (positive control). The expressed root tips were suspended in 2% methylene blue dye for 48 h. The teeth were then split longitudinally and the apical leakage measured and compared for each group. The results obtained by the positive and negative control teeth confirmed the effectiveness of the methodology used. Average dye penetration for the finger spreaders was statistically significantly less than for the D-11-T spreaders. Dye penetration of more than 0.5 mm occurred in 6 roots for the finger spreaders and in 12 roots for the D-11-T spreaders.

Dental Leakage↗

PubMed1991

Resistance to fracture of endodontically treated premolars restored with glass ionomer cement or acid etch composite resin.

MOD cavity preparations in 64 endodontically treated premolars were restored using four different methods. Copper rings were filled with commercial hard-setting cement and the teeth were placed into the cement up to the level of the cementoenamel junction. The teeth were grouped according to restorative method, mounted in an Instrom T.T. machine, and the buccal walls subjected to a slowly increasing compressive force until fracture occurred. The force of fracture of the walls of each tooth was recorded and the results in the various groups compared. All teeth fractured in a similar manner irrespective of the restorative method used. The resistance to fracture of the teeth was the same when they were restored with glass ionomer cement as a base over which an amalgam or composite resin was placed or with acid-etched resin. When the entire cavities were filled with glass ionomer cement the resistance to fracture of the teeth decreased significantly compared with the acid etch resin technique.

Acid Etching, Dental↗