Biomedical subjects

I Rotstein

Publications and source records attributed to I Rotstein.

At least 37 records · Page 2Linked to original sources

PubMed1996

Conservative treatment of dens evaginatus of anterior teeth.

Dens evaginatus is a developmental malformation characterized by the presence of an extra cusp. In the anterior dentition, dens evaginatus is more commonly found in the maxilla and on the palatal surface of the tooth. Treatment may include root canal therapy followed by either an aesthetic restoration or a full crown coverage. In cases of mesiodens, supernumerary teeth or crowded dentition, extraction is often indicated. Presented is a case of a conservative treatment modality of dens evaginatus in a mandibular central incisor.

Child↗

PubMed1996

Mental nerve paresthesia associated with a non-vital tooth.

Apical periodontitis is a common development associated with teeth with necrotic pulp. Although rare, some cases may present further complications, such as neuropathies in areas adjacent to the affected tooth. A case is described in which mental nerve paresthesia was associated with a non-vital mandibular premolar. Endodontic therapy resolved the paresthesia completely without further clinical complications.

Adult↗

PubMed1995

Effect of bleaching agents on dentin permeability to Streptococcus faecalis.

Bacterial contamination of dentin may be a contributing factor in the development of bleaching-associated root resorption. In this study, the effect of commonly used bleaching agents on the permeability of dentin tubules to Streptococcus faecalis was evaluated. Sixty extracted bovine incisors were horizontally sectioned apically to the cementoenamel junction. In each tooth, a standard cavity was prepared, the pulp tissue extirpated, and remnants of soft tissue and smear layer were removed. Following rinsing and repeated autoclave sterilization, the teeth were divided into four groups, each treated with one of the following materials: 30% hydrogen peroxide, sodium perborate mixed with 30% hydrogen peroxide, sodium perborate mixed with distilled water, and distilled water alone that served as control. The bleaching agents were sealed in the teeth and incubated at 37 degrees C for 7, 14, and 21 days. At each time interval the bleaching agents were removed and the teeth incubated at 37 degrees C in brain heart infusion infected with S. faecalis. Histological sections were prepared, and the maximal bacterial penetration for each group was measured using a computerized morphometric system. Statistical analysis of the results revealed that teeth treated with either 30% hydrogen peroxide alone or in combination with sodium perborate were significantly more permeable to S. faecalis than those treated with sodium perborate mixed with water (p < 0.0001). Sodium perborate mixed with water did not cause an increase in dentin permeability to S. faecalis and was similar to the water control. In conclusion, it seems that bleaching agents containing hydrogen peroxide in high concentrations may increase bacterial penetration through dentinal tubules.

Analysis of Variance↗

PubMed1995

Effect of preflaring on tactile detection of the apical constriction.

The efficacy of tactile detection of the apical constriction in flared and nonflared root canals was examined in 120 root canals of adult patients. In 68 nonflared (group 1) root canals, a #15 or #20 K-file was used to detect ("feel") the apical constriction. In 52 teeth (group 2), Hedstrom files, Gates Gliden drills #2 to #4, and ultrasonic files were used to enlarge the canal orifice and flare the coronal portion of the root canals before testing the apical constriction. After placing a #15 or #20 file in each root canal, a radiograph was taken, and the distance between the tip of the file and the radiographic apex was measured. The location of the file tip was classified into three categories: (a) within 1 mm short of the radiographic apex; (b) underextended, more than 1 mm short of the radiographic apex; and (c) overextended beyond the radiographic apex. In group 1 (nonflared), 32.3% of the root canals were classified in category a, as compared with 75.0% in group 2 (preflared). Over 26% of the root canals in group 1 and approximately 4% of the canals in group 2 were included in category b. Files inserted in preflared root canals had a significantly lower incidence of overextension than those placed in nonflared canals (21% versus 41%). The ability to determine the apical constriction by tactile sensation was significantly increased when the canals were preflared (p < 0.0001).

Adult↗

PubMed1995

Efficacy of argon laser irradiation in removing intracanal debris.

Endodontic instrumentation, irrigation, or intracanal medication are unable to totally remove intracanal debris. The purpose of this study was to evaluate the efficacy of argon laser irradiation in removing debris from the root canal system. After cleaning and shaping, 12 single rooted teeth were randomly divided into two groups of six teeth each. The first group, which served as the control, was not lased. In the second group, a 300 microns argon laser fiber optic was introduced into the root canal of each tooth, to its working length. Fifteen pulses of 100 msec each with an energy of 2 watts were delivered for 5 seconds at the apex. The lasing procedure was repeated at 1 mm intervals along the root canal, and the fiber tip was retrieved from the apex to the orifice. Computerized scanning electron microscopy analysis revealed that the amount of debris in the lased group was significantly lower than that in the control (p = 0.0001). On the basis of these results, it appeared that intracanal argon laser irradiation was an efficient mean of removing intracanal debris.

Argon↗

PubMed1995

Efficacy of XeCl-308 excimer laser in fusing hydroxyapatite to seal the root apex.

Sealing the root apex during apical surgery is important for a successful outcome. The effect of XeCl-308 nm excimer laser irradiation on the fusion and seal of hydroxyapatite to the root apex was tested in extracted human teeth. Twenty-four roots of intact single-rooted premolars were instrumented to size 30 K-file at the apex leaving a patent apical foramen. The apex of each tooth was covered with a freshly prepared paste of hydroxyapatite powder mixed with saline. The samples were then divided into two groups. In 12 teeth, the apical area was irridiated with XeCl-308 nm excimer laser at a fluence of 0.7 J/cm2 for 5 s with pulse repetition rate of 25 Hz and a spot size of 0.13 cm2 immediately after the hydroxyapatite application. In the other 12 teeth, no laser treatment was performed after the hydroxyapatite application. The roots were mounted on a model for the detection of radicular leakage of hydrogen peroxide. The hydrogen peroxide leakage of each sample was measured and the difference between the test groups compared. The ability of the hydroxyapatite plug to prevent hydrogen peroxide leakage at the apex was also tested by applying compressed air from the triple syringe on the coronal access preparation for 2 min. Apical leakage was found in four teeth in the lased group and in eight teeth in the non-plased group. However, the difference between the groups was not statistically significant. Compressed air applied to the coronal access caused hydrogen peroxide leakage in all the teeth.(ABSTRACT TRUNCATED AT 250 WORDS)

Chi-Square Distribution↗

PubMed1994

Intraligamentary injection of slow-release methylprednisolone for the prevention of pain after endodontic treatment.

The intraligamentary injection of a slow-release steroidal, the anti-inflammatory agent slow-release methylprednisolone (Depomedrol), was compared to a placebo and to an active placebo (Mepivacaine) in preventing postoperative pain after root canal treatment. The results clearly demonstrated that the tested drug significantly reduced the frequency and intensity of postoperative pain sequelae in the experimental set-up.

Adult↗

PubMed1994

Effect of hydrogen peroxide and sodium perborate on the microhardness of human enamel and dentin.

The effect of 30% hydrogen peroxide and a paste of sodium perborate mixed with hydrogen peroxide at different temperatures and time intervals on the microhardness of human enamel and dentin was examined. Intact extracted human teeth were sectioned, embedded in acrylic resin, polished, and divided into four test groups related to surface treatment. The groups were 30% hydrogen peroxide at 37 degrees C, 30% hydrogen peroxide at 50 degrees C in an illuminated chamber, a paste of sodium perborate mixed with hydrogen peroxide at 37 degrees C, and a paste of sodium perborate mixed with hydrogen peroxide at 50 degrees C in an illuminated chamber. Teeth treated with distilled water at either 37 degrees C or 50 degrees C served as controls. The results indicated that treatment with 30% hydrogen peroxide reduced the microhardness of both enamel and dentin. This reduction was statistically significant after 5-min treatment for the dentin and after 15-min treatment for the enamel (p < 0.05). Treatment with sodium perborate mixed with hydrogen peroxide did not alter the microhardness of either the enamel or dentin at the tested temperatures and time intervals. It is therefore suggested that the use of high concentrations of hydrogen peroxide for bleaching purposes should be limited. Sodium perborate appears to be a less damaging bleaching agent.

Borates↗

PubMed1993

Catalase protection against hydrogen peroxide-induced injury in rat oral mucosa.

Hydrogen peroxide in contact with the oral mucosa induces vesicle formation and ulceration. This study assesses the protective effect of catalase against the hydrogen peroxide insult in the rat tongue mucosa. In addition, we report a detailed histologic characterization of the mucosal injury. Four repetitive applications of 30% hydrogen peroxide at 15 minute intervals produced a vast edema of the submucosal tissue including the tongue muscles that was seen immediately after the last application. Histomorphometric measurements indicated a substantial regression of the edema 1 day later with the appearance of a very large ulceration lined by a pyogenic membrane. Animals examined 7 days after the hydrogen peroxide administration revealed almost complete healing in terms of absence of edema and renewal of intact epithelial lining. Catalase applied to the tongue before the hydrogen peroxide fully prevented the pathologic tissue reaction. Thus testing of the clinical feasibility of catalase in protecting the oral mucosa against hydrogen peroxide-induced injury is strongly indicated.

Animals↗

PubMed1993

Prognosis of intracoronal bleaching with sodium perborate preparation in vitro: 1-year study.

Bleaching materials containing hydrogen peroxide have been used for treating discolored nonvital teeth but their use was occasionally associated with external root resorption. In a previous study it was found that the immediate results of bleaching teeth in vitro were equal for sodium perborate mixed with either water or hydrogen peroxide. The purpose of this study was to compare the bleaching prognosis of sodium perborate mixed with water or hydrogen peroxide over a 1-yr period. Extracted human teeth with intact crowns were discolored with human erythrocytes and bleached by sodium perborate mixed with either 30% hydrogen peroxide (group A), 3% hydrogen peroxide (group B), or water (group C). The bleaching materials were placed in the pulp chambers of the discolored teeth and sealed with IRM. They were replaced with fresh preparations after 3 and 7 days. After 14 days the coronal access cavities were sealed with composite resin and the teeth photographed with a color slide film under standardized conditions. The teeth were stored in artificial saliva for 1 yr and photographed after 3, 6, and 12 months. Two separate evaluators ranked the teeth by comparing them with the shades before and after bleaching. The bleaching success rates of the tested groups at each time interval were compared and analyzed statistically. It was found that after 1 yr all of the teeth in groups A and C maintained their shades. In 20% of the teeth in group B there was color regression. Statistically, these differences were not significant.(ABSTRACT TRUNCATED AT 250 WORDS)

Borates↗

PubMed1993

Role of catalase in the elimination of residual hydrogen peroxide following tooth bleaching.

Hydrogen peroxide at high concentrations may cause damage to the tooth structure and to the surrounding periodontal tissues. The efficacy of catalase applied following intracoronal bleaching to eliminate residual hydrogen peroxide was examined and compared with prolonged water rinses. Extracted human premolars were treated endodontically and bleached with 30% hydrogen peroxide. Upon completion of the bleaching procedure, the teeth were treated with either catalase or water. Radicular hydrogen peroxide penetration was measured immediately after bleaching and following each catalase and/or water rinse. A correlation between the number of water rinses and the reduction in the radicular hydrogen peroxide penetration was found. Three cycles of 5-min water rinses and 1-h immersion of the teeth in water significantly reduced the residual hydrogen peroxide penetration. One treatment with catalase applied for 3 min totally eliminated the residual hydrogen peroxide. It is therefore suggested that catalase be used as an adjunct following intracoronal bleaching of nonvital teeth to effectively eliminate the residual hydrogen peroxide from the pulp chamber and from the surrounding periodontal tissues.

Catalase↗

PubMed1992

Tissue response following CO2 laser application in apical surgery: light microscopic assessment in dogs.

The potential advantages of CO2 laser in apical surgery have not been established histologically. Therefore, the long-term effects of CO2 laser on the apical and periapical tissues were examined histologically in dogs 6 months after apical surgery. Lased specimens and unlased controls showed periapical inflammatory and osteogenic reactions. Lased root surfaces revealed craters with a superficial charred layer closely associated with new cementum-like matrix. The subjacent dentin appeared tubule-free and eosinophilic. Lased bone trabeculae showed a charred layer with a deeper osteocyte-free zone. The charred layer was covered by new bone. Detached charred segments in the marrow space and periapical inflammatory infiltrate were intimately associated with multinucleated giant cells, some containing minute char particles. Such cells were absent from the root and trabecular char linings. In addition, the charred surfaces were free of hard tissue resorption. These results suggest that CO2 laser does not hinder healing when applied in apical surgery.

Alveolar Process↗

PubMed1992

Effect of bleaching agents on inorganic components of human dentin and cementum.

The effect of bleaching agents on the inorganic composition of human dentin and cementum was examined. Intact teeth were crushed, pulverized, and separated to dentin and cementum powders. The pulverized tissues were exposed to treatments with 30% H2O2, 3% H2O2, 2% sodium perborate in 30% H2O2, 2% sodium perborate in 3% H2O2, and 2% sodium perborate in bidistilled water for periods of 15 min and 1, 24, and 72 h. The degree of dissolution and the percentage of inorganic material for both dentin and cementum were measured. Thirty percent H2O2 and 2% sodium perborate in 30% H2O2 treatments significantly increased the solubility of dentin and cementum. The degree of dissolutions and the percentage of inorganic material remaining in the undissolved dentin and cementum increased with time progression. The greatest increase occurred with 30% H2O2 and 2% sodium perborate in 30% H2O2 after 24- and 72-h treatments. It is concluded that 30% hydrogen peroxide treatment may cause alteration in the chemical structure of the dentin and cementum making them more susceptible to degradation.

Borates↗

PubMed1992

Incidence of interappointment emergency associated with endodontic therapy.

Endodontic interappointment emergency (EIE) occurs in a low incidence following treatment by qualified operators. The purpose of this study was to assess the incidence of EIE after treatment by undergraduate students and to examine its correlation with preoperative and operative parameters. Randomly selected 334 records were retrospectively surveyed for unscheduled emergency appointments following endodontic treatment by undergraduate students. Treatment included step-back canal preparation in multiple visits with formocresol interappointment dressing. The incidence of EIE was 4.2%, and unrelated to the patients' sex and age or to tooth location. It was significantly higher in nonvital than in vital teeth (p < 0.05), with the highest occurrence in nonvital teeth unassociated with periapical radiolucency. Clinically, EIE was associated with swelling in half of the cases. It is concluded that the incidence of EIE following treatment by undergraduate students is low and related to tooth vitality.

Acute Disease↗

PubMed1992

Effect of trichloracetic acid on the microhardness and surface morphology of human dentin and enamel.

Trichloracetic acid is recommended for the treatment of external cervical root resorption. The present study examined the effect of 90% trichloracetic acid on the microhardness and surface morphology of human dentin and enamel. Intact extracted human teeth were sectioned and embedded in acrylic resin. Each tooth was grinded and highly polished exposing a flat surface of dentin and enamel. The teeth were treated with 90% trichloracetic acid for 30, 60 and 90 s. Vicker's microhardness of the dentin and enamel was assessed for each tooth before and after each treatment. In addition the surface morphology of a trichloracetic acid treated tooth was examined via SEM. The results showed that 90% trichloracetic acid caused a second order type reduction of the microhardness, as well as structural changes in both dentin and enamel.

Acid Etching, Dental↗

PubMed1992

Effect of cervical coating of ethyl cellulose polymer and metacrylic acid copolymer on the radicular penetration of hydrogen peroxide during bleaching.

Extraradicular leakage of oxidizing agents during bleaching is an undesirable event and thus need to be prevented. The effect of external cervical coating of ethyl cellulose (EC) and metacrylic acid copolymer (MAC) on the radicular penetration of hydrogen peroxide during intracoronal bleaching was examined. Single rooted human premolars extracted for orthodontic reasons were used. The cementum covering the cemento-enamel junction was mechanically removed and the teeth treated endodontically and bleached with 30% hydrogen peroxide. Radicular hydrogen peroxide penetration was measured before coating the teeth and after applications of 1-3 layers of EC or 3 layers of MAC external cervical coatings. It was found that the radicular penetration of 30% hydrogen peroxide was related to the number of layers of cervical EC coatings. Application of one layer of EC did not reduce the hydrogen peroxide penetration. Two and three layers of EC reduced the hydrogen peroxide penetration by 38% and 85% respectively. Three layers of MAC reduced the radicular hydrogen peroxide penetration in 83%. Statistically, a highly significant difference was found between the teeth coated with three layers of either EC or MAC and the noncoated teeth (p < 0.001). It was concluded that application of ethyl cellulose or metacrylic acid copolymer to exposed cervical root surfaces may effectively prevent extraradicular leakage of bleaching agents.

Cellulose↗

PubMed1992

[Lasers in endodontics].

Laser technology has been developed rapidly in the last decade. New lasers with a wide range of characteristics are available now which are being used in various branches of dentistry. The application of these new technologies in endodontics has always been challenging. Today more experience and knowledge in applying lasers in endodontics is available.

Animals↗

PubMed1992

Nifedipine-induced gingival hyperplasia.

Gingival hyperplasia is an adverse reaction of nifedipine therapy. Oral manifestations of this condition include enlarged and painful gingiva accompanied by spontaneous bleeding. Nifedipine-induced gingival hyperplasia may be reversible once a proper drug substitution is made. Two cases of gingival hyperplasia resulting from nifedipine are described and the drug's possible mode of action is discussed.

Adult↗