Biomedical subjects

B M Owens

Publications and source records attributed to B M Owens.

At least 19 recordsLinked to original sources

PubMed2001

The resin retained natural tooth pontic: a transitional esthetic solution.

This case report presents an alternative treatment option for the premature loss of a maxillary anterior tooth due to severe periodontitis. A natural tooth pontic acid-etch prosthesis was fabricated using the patient's clinical crown from the extracted tooth. This measure proved to be a very adequate, esthetic treatment solution before a permanent restorative plan could be developed for the patient's long term dental needs.

Adult↗

PubMed2001

Subcutaneous emphysema after restorative dental treatment.

Subcutaneous emphysema is an uncommon phenomenon in dentistry, usually occurring with the use of air-driven, high-speed handpieces during dental and oral surgery, operative, endodontic, or periodontal treatment. Air is forced into a surgical wound or subepithelial laceration in the oral cavity, dissecting through the different layers of tissue fasciae, and usually creating a unilateral enlargement of the facial and/or submandibular regions. This occurs with or without crepitus, pain, and airway obstruction. Treatment usually consists of antibiotic and mild analgesic therapy, close observation, and reassurance by the attending dentist. Symptoms generally subside in 3 to 10 days; however, consultation with a physician is necessary to rule out further complications.

Administration, Oral↗

PubMed2000

Apoptosis and P53 induction in human lung fibroblasts exposed to chromium (VI): effect of ascorbate and tocopherol.

Some forms of hexavalent chromium [Cr(VI)] are known to cause damage to respiratory tract tissue, and are thought to be human lung carcinogens. Because Cr(VI) is mutagenic and carcinogenic at doses that evoke cell toxicity, the objective of these experiments was to examine the effect of Cr(VI) on the growth, survival, and mode of cell death in normal human lung fibroblasts (HLF cells). DNA adduct formation was monitored as a marker for bioavailability of genotoxic chromium. We also examined the modulation of these endpoints by vitamins C and E. Long-term Cr(VI) exposures were employed, which decreased clonogenic cell survival by 25% to 95% in a dose-dependent manner. The predominant cellular response to Cr(VI) was growth arrest. We found that Cr(VI) caused up to 20% of HLF cells to undergo apoptosis, and documented apoptotic morphology and the phagocytosis of apoptotic bodies by neighboring cells. P53 levels increased 4- to 6-fold in chromium-treated cells. In contrast with previous studies using CHO cells, the present study using HLFs found that pretreatment with either vitamin C or E did not exhibit a significant effect on Cr-induced apoptosis or clonogenic survival. In addition, pretreatment with vitamin C did not affect the p53 induction observed after chromium treatment. Neither vitamin had any effect on Cr-DNA adduct formation. These data indicate that although pretreatment with vitamin C or E alters the spectrum of cellular and/or genetic lesions induced by chromium(VI), neither vitamin altered the initiation or progression of apoptosis in diploid human lung cells.

Antioxidants↗

PubMed2000

Student and faculty perceptions in the assessment of amalgam restorations.

The purpose of this in-vitro study was to compare the assessment of amalgam restorations made by dental students and faculty members. Extracted human teeth which contained old amalgam restorations were mounted in dental stone and labeled one through 25. All evaluators were instructed the restorations were those of a 35-year-old patient with no clinical symptoms. The restorations were examined by 57 dental students and 10 dental instructors. Each examiner was asked to accept the restorations or replace the restorations with accompanying reason(s). Approximately one year after the first assessment, the blocks were randomly relabeled and all examiners reevaluated the amalgam restorations. the mean number of replacements, reasons for replacement, and kappa values were calculated for this study. A total of 1,675 decisions to replace or not to replace were obtained. There were a total of 2,784 reasons for replacement made by the students and 410 total decisions made by the dental faculty at the initial and final assessments. The study showed that dental faculty were more conservative in their treatment decisions. Also, the intraexaminer scores (kappa values) showed lower reproducibility among the dental students.

Decision Making↗

PubMed1999

1-year clinical evaluation of Compoglass and Fuji II LC in cervical erosion/abfraction lesions.

PURPOSE: This study was undertaken to compare the clinical performance of a polyacid-modified resin-based composite and a resin-modified glass-ionomer restorative material over 1 year. MATERIALS AND METHODS: Thirty-four pairs of restorations of Compoglass (C) and Fuji II LC (F) were placed in 31 patients, with no patient receiving more than two pairs, and with materials assigned at random within the pairs. Caries-free cervical erosion/abfraction lesions of the facial surface were restored without tooth preparation according to manufacturers' instructions, except that tooth structure to be restored was etched with 37% phosphoric acid prior to placement of Compoglass. Restorations were clinically evaluated by two blinded examiners at baseline, 6 months, and 1 year, using modified Ryge/USPHS criteria. Restorations receiving a score of "Charlie" in either retention or secondary caries were classified as failed restorations. The incidence of failures was statistically analyzed as a pairwise comparison, using an exact binomial test. RESULTS: Thirty-one pairs of restorations were available for recall at 1 year. The percentage of Alfa scores for each material in each category were: Retention (C = 84%, F = 100%), Color match (C = 81%, F = 100%), Marginal discoloration (C = 78%, F = 97%), Secondary caries (C = 88%, F = 100%), Anatomic form (C = 92%, F = 100%), and Marginal adaptation (C = 26%, F = 46%). Except for the failed restorations, no other Charlie scores were assigned. A significant difference in the incidence of failed restorations was found between the materials (P = 0.01).

Adult↗

PubMed1998

Postoperative dental bleaching: effect of microleakage on Class V tooth colored restorative materials.

The effect of 3 percent, 11 percent, and 16 percent carbamide peroxide bleaching solutions and 35 percent hydrogen peroxide bleaching gel on microleakage of Class V composite resins, resin modified glass ionomer cements, and compomer restorative materials together with corresponding (if indicated) fourth/fifth generation bonding agents was evaluated using previously extracted human teeth. Five groups of Class V cavity preparations were placed in enamel of the facial surfaces of 200 teeth. Groups A through D included 40 restorations each (4 different restorative materials and their accompanying bonding agent multiplied by 10 teeth) treated with 3 percent, 11 percent, and 16 percent carbamide peroxide bleach and 35 percent hydrogen peroxide bleach. Group E included 40 restorations without treatment of bleach and stood as the control. The restorative materials included were: Fuji II LC resin modified glass ionomer cement, Helioprogress composite resin/-Heliobond adhesive system, Aelitefil composite resin/Allbond 2 adhesive and Dyract compomer material/Prime & Bond adhesive system. Bleaching agents included were Rembrandt 3 percent peroxide gel, Perfecta 16 percent carbamide peroxide gel, White & Brite 11 percent carbamide peroxide solution and Superoxyl 35 percent hydrogen peroxide gel. All teeth were thermally stressed for 100 cycles and microleakage were assessed by dye penetration. The results were tabulated using Analysis of Variance (ANOVA) testing procedures. The Aelitefil composite resin material behaved the least favorably (relative to microleakage) compared to the other materials when exposed to various concentrations of dental bleaching agents.

Analysis of Variance↗

PubMed1998

Microleakage of tooth-colored restorations with a beveled gingival margin.

OBJECTIVE: Microleakage of tooth-colored restorative systems was tested in preparations with and without beveled gingival margins. METHOD AND MATERIALS: A resin composite, Z-100, and two "compomer" restoratives, Dyract and Geristore, with their accompanying adhesive systems, were placed in nonretentive cervical cavity preparations (at the cementoenamel junction), with and without a beveled gingival margin (dentin or cementum) and beveled occlusal (enamel) margins in extracted bovine teeth. Microleakage was assessed as the ratio of the extent of methylene blue dye penetration at the tooth-restoration interface of the length of the wall. RESULTS: Z-100 restorations, without a gingival bevel, exhibited significantly less microleakage along the gingival wall and less microleakage overall than did the other materials. Dyract restorations without a gingival bevel and placed without a surface conditioner displayed greater microleakage overall than did the other groups. CONCLUSION: With all materials, Class V restorations with gingival bevels displayed greater microleakage than did nonbeveled margins.

Analysis of Variance↗

PubMed1998

Replacement and initial placement of tooth colored restorations: a review and discussion.

Disagreement exists among dentists concerning reasons for initial placement and replacement of composite restorations, although specific criteria have been established by several reports. According to numerous studies, the longevity of composite restorations appears to be lower than for amalgam restorations; however, with advances in dental materials, composite resin longevity should increase. Inadequate operator technique and poor patient compliance are contributing factors for restoration failure. Research regarding enamel and dentin bonding systems will produce better quality and more durable results for composite restorations.

Composite Resins↗

PubMed1997

Microleakage of cervical restorations etched with a weak organic acid.

This in-vitro study evaluated the microleakage of Class V restorations prepared using 10 per cent maleic acid and a composite resin. Thirty human premolar teeth were evenly distributed and randomly assigned to three groups. Conventional retentive preparations, etched with 10 per cent maleic acid for either 15, 30, or 60 seconds, were cut in the enamel on the facial surface of each tooth to a 1.5 mm depth (dentin). All teeth were restored with Z-100, a small particle composite resin. The teeth were then stored in deionized water for seven days, thermocycled, stained with methylene blue dye, invested, and sectioned vertically through the centre of the restoration. Leakage was established along each wall of the sectioned restoration. Analysis of variance (ANOVA) tests indicate that the restored teeth in Group 1 (15-second etch) had significantly greater microleakage (p < 0.05) on the enamel wall than the restored teeth in Group 2 (30-second etch) or Group 3 (60-second etch). In addition, Group 1 restorations had significantly greater overall microleakage (p < 0.05) than Group 2 or Group 3 restorations. Although the results were not statistically significant, it would appear that etching with 10 per cent maleic acid for 30 seconds could be clinically significant. Since a 30-second etch time was found to produce the least amount of microleakage (not statistically significant), it can be assumed that this etch time would also be optimal for etching enamel and dentin. Similarly, since Group 1 revealed the most overall microleakage, it can be assumed that a 15-second etch would be inadequate for etching enamel and dentin. Restorations in Groups 2 and 3 displayed statistically significant lower overall microleakage results.

Acid Etching, Dental↗

PubMed1997

Dental transplants: discussion and case report.

A 21-year-old Chinese male patient presented to an urban dental clinic with a transplanted molar, which had been removed from a human cadaver. The tooth was in occlusal function for three years, stable, and without mobility. Radiographs of the tooth showed root resorption and apparent ankylosis. Individual transplantation of human teeth has been considered surgical dental treatment of an empirical nature for centuries. Two types of human tooth transplantation are usually considered in the dental literature. An allotransplantation or allograft is a transplantation of tissue (tooth) between different individuals of identical species. An autotransplantation or autograft is a transplantation of tissue within the same individual (obviously within the same species). Replacement of an avulsed tooth, while technically an autograft is considered a replantation, rather than a transplant. Tooth transplantations in the late 20th century are usually performed in developing third world countries, where patient dental education is minimal, and the cost of more technology based forms of tooth replacement (prosthodontics, synthetic implants) are economically prohibitive. Transplantation of permanent teeth is rarely seen in the United States in the 1990's due to the use of titanium implants, although pediatric, adolescent, and disabled patients, especially those with limited incomes, could benefit from the re-introduction of dental transplants.

Adult↗

PubMed1997

Dental odontomas: a retrospective study of 104 cases.

An odontoma refers to any tumor of odontogenic origin. Three distinct types of odontomas have been distinguished in the dental literature: complex, compound, and ameloblastic fibro-odontoma. Odontomas are usually associated with overly retained primary and unerupted permanent teeth. The exact etiology of odontomas is unknown, but local trauma, infection, inheritance, and genetic mutation have been postulated as possible causes of odontomas. Studies have found that males are more likely than females to have odontomas, with most frequent occurrence in the second decade of life. One hundred four biopsy reports with a diagnosis of odontoma were analyzed for age, race, gender, location, pre-operative diagnosis, and postoperative laboratory findings. Most odontomas occurred in the 11-20 age group, with Caucasians predominating. The majority were located in the maxilla, and 85 percent were correctly diagnosed clinically by the attending dentist prior to confirmation by histologic pathology reports of the biopsy specimens. The vast majority were compound odontomas (64.4%) with complex odontomas comprising 31.0% of the total lesions. No ameloblastic fibro-odontomas were diagnosed.

Adolescent↗

PubMed1997

Perimylolysis of the permanent dentition in an adolescent.

During a routine dental appointment at a dental school clinic, a fifteen-year-old black male patient was diagnosed with severe erosion of the dentition together with several carious lesions and a crowded dentition. During treatment of the carious lesions, severe erosion (perimylolysis) of the maxillary and mandibular teeth were observed, which at first alerted the attending clinician to a preliminary diagnosis of anorexia and/or bulimia. Because of the age, gender and social and medical history of the patient, these preliminary diagnoses were discounted, with a hypothesis of gastrointestinal disorder presented to the patient and his parents after consultation with oral medicine and oral pathology faculty. Saliva pH analysis, along with further research concluded that gastrointestinal reflux disease (GERD), surreptitious rumination, or a combination of both were possible diagnoses. Referral to a gastroenterologist for further examination was recommended, while a night-guard was fabricated for the patient to wear at night with fluoride gel. Root canal therapy together with prosthodontic care are often treatment options for patients suffering from gastrointestinal problems. This paper demonstrates how important routine dental examinations are, especially since dentists can often recognize systemic disorders whose symptoms first appear in the oral cavity.

Adolescent↗

PubMed1997

Compound odontoma associated with an impacted permanent central incisor.

In this case report, an eleven-year-old female presented to a rural dental clinic for routine dental examination. Upon evaluation of the dentition, the attending dentist discovered an over-retained primary tooth. Radiographically, a compound odontoma was present, gingival to an unerupted permanent maxillary left central incisor (number nine) and apical to the erupted primary central incisor (F). The odontoma and its overlying primary tooth were removed by an oral surgeon. The extraction site has healed uneventfully and an Orthodontic treatment plan was formulated. The etiology of odontomas is unknown but thought to be caused by trauma, infection, inheritance and/or genetic mutation. These lesions are usually found in the second decade of life and are more common in male patients. Treatment consists of complete enucleation and curettage of the odontoma site.

Child↗

PubMed1996

Initial placement and replacement of amalgam restorations: a retrospective review.

Restorative dentistry comprises a large amount of dental treatment. There is subjectivity among dentists concerning the reasons for initial placement and replacement of amalgam restorations. Different instructional methods and learned experiences while in private practice has much to do with this subjectivity even though, specific criteria have been established for standardization of initial placement and replacement of amalgam restorations. There are many reasons for the failure of amalgam restorations. Recurrent caries and material/tooth interface defects have been and are among the leading reasons for replacement. There are also differences in opinion among dentists concerning diagnosis of primary carious lesions.

Dental Amalgam↗

PubMed1996

Microleakage of composite resin restorations with a 10 percent maleic acid etchant.

Microleakage of Class V composite resin restorations with margins all in enamel were compared in this in-vitro study using Scotchbond MultiPurpose Adhesive (SMP) (3M Corp.), and Scotchbond II (SB II) (3M Corp). Twenty extracted human molars were randomly separated into two groups: Group One, which used the SMP system and Group Two, which used the SB II system. Circular Class V preparations were cut 1.8 mm deep and 3 mm in diameter using a #556 fissure bur. Cavosurface margins, all in enamel, were beveled. The enamel and dentin were treated following manufacturer's directions for each group, and a microfilled composite resin, Silux Plus (3M Corp), was applied in two hand-placed increments. All teeth were finished with Sof-Lex discs, stored in water for seven days, then thermocycled in a water bath for 100 cycles, alternating from 4 degrees C to 58 degrees C. The teeth were placed in a 5 percent solution of methylene blue, rinsed and then invested in resin. All teeth were sectioned vertically and horizontally and a ratio (percentage) of wall length to amount of leakage along each wall was established. The overall mean leakage of Group One was 15.27 percent and Group Two was 13.84 percent. Looking at individual walls, the mean occlusal wall leakage of Group One was 28.41 percent and Group Two was 12.45 percent. Mean gingival wall leakage of Group One was 15.96 percent and Group Two was 21.80 percent. Comparing the two groups, using a student's t test, there was no significant difference between the overall mean leakage or between the gingival wall leakage (p > 0.05); however, there was a significant difference between the occlusal wall leakage (p < 0.05), with SMP exhibiting more leakage.

Acid Etching, Dental↗

PubMed1996

Survey of hepatitis B exposure and sharps injuries in dental health-care professionals.

Injuries associated with the category of dental surgical instruments known as "sharps" (i.e., syringe needles, glass, scalpel blades, dental burs, and hand instruments) are a serious concern for dental professionals because of the possible transmission of communicable diseases such as tuberculosis, hepatitis B virus, hepatitis C virus, and human immunodeficiency virus (HIV). Hepatitis B virus has been recognized as an occupational hazard for dentists and other health-care professionals for several decades. The transmission of HIV from dentist to patient in the dental office has been known to occur in only one practice, and the vector of transmission remains unknown. No dentist has ever been reported to have contracted HIV from a patient. Adherence to infection-control procedures, especially barrier protection, has been linked closely to keeping the incidence of these infections low. This article discusses the results of an anonymous survey about "sharps" injuries and communicable diseases that was given to dentists/faculty, students, and support staff at an urban dental-school clinic.

Dental Instruments↗

PubMed1995

Compound composite odontoma associated with an impacted cuspid.

This case report involved the removal of a compound composite odontoma from a fourteen year-old male patient at an urban dental school. The pathology report did indeed reveal the tissue mass was that of a compound composite odontoma. These lesions usually occur in the second decade of life, in the anterior maxilla or mandible, with no gender or race predilection. Three types of odontomas are identified, including are: compound composite odontoma, complex composite odontoma, and ameloblastic fibro-odontoma. The etiology of these lesions is unknown, although environmental (trauma, infection) and hereditary influences play a role. Treatment consists of complete enucleation and curettage followed by histological verification by an oral pathologist.

Adolescent↗

PubMed1995

Noncarious dental "abfraction" lesions in an aging population.

A new classification for noncarious dental lesions has evolved from the dental literature. The name given to these lesions, dental "abfractions," is a theory propounding tooth fatigue, flexure, and deformation through biomechanical loading of tooth structure, primarily at the cervical regions of the dentition. These lesions are typically wedge shaped with sharp line angles, but occlusal abfractions have been observed as circular invaginations. Dental abfractions can occur alone and are sometimes associated with toothbrush abrasion and erosion from endogenous or exogenous acids. Treatment consists of the application of composite resin or glass-ionomer cement restorations and/or the discontinuance of the etiology of these lesions. If esthetics are not a primary concern of the patient and the tooth is not structurally compromised, many of these lesions can be observed, provided that the patient is informed that bruxism or malocclusion problems exist.

Aged↗