Effects of adhesion promoters on resin-enamel retention.

The adhesive effects of three adhesion promoters were compared utilizing three different filled resins on acid-etched human permanent teeth. The results demonstrated a significantly greater resistance to dislodgement of resins by shear forces when an NPG-GMA type of adhesion promoter was utilized. Type of resin did not influence resin retention.

Influence of a ferric chloride mordant solution on resin-dentin retention.

The effects of ferric chloride mordant solution, two cleansing solutions, and three chemical adhesion promoters were examined on resin-dentin adhesion. Adhesion was increased with the use of ferric chloride solution. An NPG-GMA or butyl acrylate-acrylic acid copolymer type of adhesion promoter also increased resistance to shear separation.

An investigation of bonding systems for the polycarbonate crown restoration.

Tensile retentive strengths for six polycarbonate crown cementation systems were examined with use of extracted human teeth prepared with and without retentive grooves. From the results of this study, use of unfilled intermediary resins followed by polycarboxylate or zinc phosphate cements is recommended. Retentive grooves did not contribute to overall retention.

The effect of supplemental lecture, evaluation method and instructional type on student performance in a preclinical technique project.

This study examined two types of instruction, two methods of evaluation, and the effects of a supplemental lecture in teaching a laboratory technique exercise. Students were randomly assigned to one of four groups: (1) self-instruction, self-evaluation; (2) self-instruction, teacher-evaluation; (3) teacher-aided instruction, self evaluation; and (4) teacher-aided instruction, teacher-evaluation. In addition, half of the students in each of the four groups received a supplemental lecture. Ratings of technical performance, a didactic posttest, and project completion time, were used as outcome measures. Of 27 main treatment effects tested, 25 demonstrated no significant differences. This study fails to demonstrate any major advantage of using self versus traditional forms of instruction and evaluation when student performance is the primary consideration.

Longitudinal evaluation of a teacher education course presented to dental faculty.

A three-day course on teaching methods was held for dental educators who were at various stages of their careers. The course was presented by the staff of the Academic Instructor and Allied Officer School of the Department of the Air Force. The purpose of the course was to aid in acquiring new knowledge of teaching methods and to produce behavioral changes in the participants' teaching techniques. A longitudinal evaluation demonstrated that participants changed teaching behaviors related to the courses' goals, and acquired and retained a significant amount of factual information presented in the course.

Parents' perception of access to dental care for children with handicapping conditions.

Access to dentistry for people with handicapping conditions may be influenced by attitudes within the dental team, financial considerations, self-image problems, medical conditions, or physical access. This paper reports on a survey of the parents or guardians of children with handicapping conditions regarding perceptions of possible problems in obtaining dental care. Almost half of the respondents to this survey reported having problems in obtaining dental treatment for their child or in accessing the building. Respondents with problems in obtaining dental care were more likely to have longer periods between dental treatment visits, have had an extraction at their last dental visit, be treated at a hospital, be treated with sedative agents, not have insurance, report their child's dental problems were more severe than other problems, and have terminated their education at an earlier age.

Dental school Special Patient Care Program during 1977-1979 and 1987-1989: comparisons of regional and state disabled populations.

New patients referred to the Special Patient Care Program at UCLA School of Dentistry during the period of 1977-1979 were compared with new patients referred during the period of 1987-1989. Parameters measured were age, gender, geographic distance from the treatment facility, and primary disability. The UCLA profile of disabilities was then compared with local, regional, and state data on disabilities. The mean patient age decreased from 47 years of age in 1977-1979 to 34 years in 1987-1989 while gender distribution remained approximately the same. The distance from patient's residence to the dental treatment facility increased from the 1977-1979 period to the 1987-1989 period with more new patients traveling over 5 miles for treatment. The 1987-1989 special patient care new patient population was highly representative when disability type was compared with a juvenile population (less than 21 years of age) from the five Regional Centers in LA County and the LA County and State of California Department of Developmental Disabilities populations. The patient training base of an undergraduate dental school program for persons with disabilities is representative of the disabled population of LA county and the state of California.

Fluoride content of Los Angeles County water.

A series of tap water samples were collected from residents in various areas of Los Angeles County. Three samples were collected each week over a period of three weeks, for a total of nine samples from each of the 45 residences. Samples were analyzed for fluoride content, and the data compared to information received from the agencies supplying the source water. Fluoride levels varied an average of .11 ppm during the three-week collection period; mean levels were consistently higher than values reported by the various agencies.

Intraoperative and postoperative physiological monitoring practices by pediatric dentists.

The medical and dental literature has described successful sedations and those which have resulted in injury and death. Physiologic monitoring of patients is essential in assuring the success and safety of sedations in the dental office. The purpose of this study was to investigate the utilization and preferences of various physiologic monitoring methods and utilization of dentist anesthesiologists by pediatric dentists during sedations. Pediatric dentists in California were surveyed [n = 261] regarding monitoring methods in five different case scenarios. The most frequently utilized methods were clinical observation, pulse oximeter, and precordial stethoscope. Eighty seven percent of the pediatric dentists who use sedation do so without the involvement of a dentist anesthesiologist. Eighteen percent of pediatric dentists do not use any sedative agents in their practice. In the five case scenarios described in the survey, clinical observation was the most frequently utilized monitoring method during intra- and postoperative periods, followed by the pulse oximeter and precordial stethoscope. Intra- and postoperative monitoring varied with the complexity of the case scenario and most respondents monitored continuously. The trends observed from this study indicate that recent graduates use more sedative agents and find the pulse oximeter to be useful for physiologic monitoring during sedation.

Clinical evaluation of the effects of ketamine sedation on pediatric dental patients.

This study was undertaken to determine the dosages, treatment times and side effects of ketamine HCI with and without two benzodiazepines when used for sedation on a group of precooperative children at the UCLA Children's Dental Center. Ketamine was evaluated when used alone, and in conjunction with two benzodiazepines, diazepam or a new water-soluble midazolam. An anti-muscarinic, atropine or glycopyrrolate, and nitrous oxide-oxygen were included in all sedations. Mean treatment times were increased significantly when ketamine and a benzodiazepine were used in combination. Additionally, mean ketamine dosages were decreased significantly when ketamine was utilized in combination with a benzodiazepine. All children tolerated the sedation well and there were no severe adverse reactions. Side effects included nausea, vomiting, and a rise in post-operative temperatures.

Practice characteristics of dual trained pediatric dentistry and orthodontic specialists.

Most respondents to this survey are providing both pediatric dental and orthodontic services to their patients. Almost half of the respondents reported that both specialties are fully integrated without separate times or days. Patient treatment time was reported as 41 percent pediatric dental services and 59 percent orthodontic services; when asked how they would like to adjust patient treatment time in ten years, however, the response was 20 percent pediatric dentistry and 73 percent orthodontics. A high percentage of respondents (44 percent) were involved in teaching full or part time or in continuing education courses.

Bond strength of light-cured glass ionomers to carious primary dentin.

The pre-cooperative or handicapped child with decay presents a special challenge to the practitioner and may require sedation or general anesthesia. Treatment with an interim restoration may delay treatment until the child is more mature and can accept dental treatment and is a more conservative approach than sedation, extractions or general anesthesia. Glass ionomer materials have been utilized for this application, but little is known about their retention to carious dentin. The purpose of this study was to determine whether the presence of artificial dentin decay will affect the shear bond strength of two light-cured glass ionomer materials. VariGlass and Vitrebond glass ionomer materials were attached to carious and non-carious primary dentin surfaces and bond strengths determined. There were no significant differences in shear bond strengths between the decayed and non-decayed surfaces [p < or = .001]. VariGlass had higher shear bond strengths than Vitrebond only after a pre-treatment with the PAA containing liquid. Pre-treatment with the liquid provided with each light-cured glass ionomer was beneficial in all instances except for Vitrebond on non-decayed surfaces.

Antibacterial and mechanical properties of restorative materials combined with chlorhexidines.

Chorhexidine gluconate or chlorhexidine dihydrochloride were added to a composite resin and a glass ionomer restorative material in concentrations of 0, 1, 2, 3, 5, and 10% by weight. Antibacterial activity was measured by inhibition of growth of S. viridans, S. pyogenes, S. mutans, L. acidophilus, and E. coli, for 4 days. Compressive, tensile, and restorative material-enamel adhesive shear strength tests were performed. The addition of chlorhexidine gluconate or chlorhexidine dihydrochloride increased the antibacterial activity of the composite resin and the glass ionomer restorative material and changed the mechanical properties of the restorative materials. The addition of chlorhexidine dihydrochloride resulted in mechanical properties closest to controls.

Effects of surface treatments on the retention of restorative materials to dentin.

The effect of various pretreatments on shear bond strengths between dentin and three restorative materials was investigated. Pretreatments included use of cleansing agents and adhesion promoters in combination. Results indicated that: (1) phosphoric acid (50%) and EDTA (10%) were not effective in improving bonding between restorative materials and dentin; (2) NPG-GMA significantly increased resin-dentin adhesion with Cervident and Simulate resin. Silane adhesion promoter in combination with Fuji provided the greatest resistance to shear forces; and (3) Fuji Type II restorative material demonstrated more resistance to shear forces than Cervident and Simulate resins.

Shrinkage stresses associated with incremental composite filling techniques.

It is commonly accepted that stresses associated with polymerization shrinkage of composite restoratives can be reduced by utilization of an incremental filling procedure. A recent report using finite element analysis on a simple box preparation has shown that such a procedure actually produces higher stresses. The purpose of this investigation was to visualize the stresses generated by composite resin placed into photoelastic models of two surface preparations using different incremental techniques. Primary molar preparations were cast life-sized in a photoelastic material. Cavity walls were cleansed, primed and coated with unfilled resin. Incremental filling techniques of a hybrid composite resin were gingivo-occlusal, oblique, and facio-lingual. Comparisons were made with the bulk placement technique. The stresses developed within the model teeth were observed in the field of a circular polariscope under magnification. Generally few differences in shrinkage-induced stresses, were observed between the incremental filling techniques tested. The lowest shrinkage stresses were generated by the bulk placement technique.

Shrinkage stresses associated with incremental composite filling techniques in conservative Class II restorations.

Conservative Class II preparations are widely utilized, however the stresses produced by incremental composite placement/curing has not been demonstrated. The purpose of this investigation was to visualize the stresses generated by composite resin placed into photoelastic models of conservative Class II preparations using different incremental techniques. Conservative Class II preparations on three different primary molar replicas were cast life-sized in a photoelastic material. Incremental placement/curing techniques used were oblique, gingival-occlusal, and facial-lingual and were compared with bulk placement/curing. The photoelastic stresses produced with conservative Class II restorations were of lower intensity than conventional Class II and larger composite restorations previously reported. Few differences in shrinkage-induced stresses were observed between the incremental placement/curing techniques tested. Lowest shrinkage stresses were generated by the bulk placement/curing technique.