Pulp capping with a modified bioglass formula (#A68-modified).

PURPOSE: To evaluate a modified Bioglass (Formula #68 (MBF68) when used as a pulp capping agent. MATERIALS AND METHODS: After exposure, the pulps were contaminated with saliva for 60s, rinsed, dried and treated with Consepsis, acting as a hemostatic and bactericidal agent. After drying the Consepsis, the MFB68, having been pre-mixed in sterile saline, was carefully deposited over the pulp exposure, covered with polycarboxylate cement and restored with the ProBond bonding resin system. A calcium hydroxide group was used as control. RESULTS: There was no evidence of mummification, the incidence of properly positioned dentin bridge formation was higher and the incidence of extruded dentin bridge formation was reduced.

Criteria for standardizing and increasing credibility of direct pulp capping studies.

There are many skeptics who condemn pulp capping but like to keep an eye on the research progress being made. Considerable literature emphasizes the negative aspects of vital pulp therapy and discourages its practice. Some clinicians and investigators continue to condemn pulp capping therapy for the same reasons reported in the literature 80 years ago despite the advances made in pulp biology. Clinicians are well aware of the immediate and long-term success rates after root canal therapy, but are less certain of the success of pulp capping. A number of nagging questions plague clinicians, when confronted with the choice of treatment. The research data on pulp capping is at times inadequate, confusing, misleading or even incorrect and diminishes the confidence of the practitioner in performing pulp capping.

The disastrous effects of the "total etch" technique in vital pulp capping in primates.

PURPOSE: To determine by means of a histopathological study in sub-human primates whether etching of an exposed pulp (the "Total Etch" technique) followed by capping with dentin bonding agents is a viable clinical treatment modality. MATERIALS AND METHODS: In six sub-human primates, 147 Class V preparations were made for five experimental and two control groups. After exposing the pulps, the preparations were intentionally contaminated, rinsed, dried and then disinfected with a 2% chlorhexidine solution for 60 s. In the five experimental groups, the entire preparation including the exposed pulp was etched with a 35% phosphoric acid gel, which was rinsed after 20 s. This was followed by a second application of chlorhexidine. In Groups 1-3, All Bond 2, ProBond and Permagen A&B dentin bonding agents were applied as pulp capping materials. In Group 4, a light-cured calcium hydroxide was tested while Group 5 was treated with a chemically-cured calcium hydroxide. Groups 6 and 7, the controls, were also contaminated, rinsed, dried and disinfected. After the exposed pulps had been protected with a chemically-cured calcium hydroxide (Group 6) or a light-cured calcium hydroxide (Group 7) the preparations were etched and restored with a bonded resin composite. The effect of the above described treatments were evaluated at 5, 25 and 75 days. After sacrifice and routine histological preparation, histological sections were graded among other parameters for inflammatory response, bridge formation, maintenance of vitality, presence of dentin chips and evidence of microleakage microorganisms. RESULTS: The 2% chlorhexidine applied immediately after exposure was an effective hemostatic agent. After subsequent etching, the hemostatic effectiveness was greatly reduced. Exposure size for all seven groups ranged from 0.13-1.55 mm. The average at 5, 25 and 75 days measured 0.74, 0.66 and 0.77 mm, respectively. In the five experimental groups, the 25- and 75-day groups had a total of 68 teeth of which 24 (35%) became non-vital and 23 (33%) teeth demonstrated bridge formation. In the three experimental groups using a bonding agent, the 25- and 75-day groups had a total of 40 teeth of which 18 (45%) became non-vital and 10 (25%) exhibited bridge formation. In the "No Etch" control groups, the 25- and 75-day groups had 28 teeth of which two (7%) became non-vital and 23 (82%) exhibited bridge formation. Microorganisms were found in a large percentage of all groups, although their numbers were few. However, they were present in vital and non-vital teeth, in the presence and absence of bridge formation and had no direct bearing on the success or failure of the pulp capping procedure.

Adherence of "stuck" restorations to demineralized dentin following use of experimental primers.

PURPOSE: This in vivo study histopathologically evaluated the biocompatibility of four self-conditioning dentinal primer formulas in four bonding systems and evaluated the pulpal responses of the self-conditioning dentinal bonding systems for Class V tooth preparations in primates. MATERIAL AND METHODS: The basic formula consisted of proprietary carboxylic diacid monomer, dipentaerythritol pentaacrylate phosphoric acid ester, acetone, and ethanol that was used alone or mixed with other commercial priming agents. After application of primers, Prisma Universal Bond 3 was selected to restore the cavity preparations. RESULTS: All systems were judged histopathologically biocompatible. "Stuck" restorations that were resistant to acid demineralization necessary for processing of histologic slides, occurred more frequently with intact smear layers and increasing use of dehydrating agents. CONCLUSIONS: Tests should be performed to determine whether "stuck" restorations in in vivo studies that maintain dentin-pulpal relationships can support in vitro shear bond strength tests.

Using 45S5 bioglass cones as endosseous ridge maintenance implants to prevent alveolar ridge resorption: a 5-year evaluation.

Bioglass cones acting as space fillers after removal of tooth roots delay the resorption of alveolar ridges. In 1987, 242 implants in 29 patients with a mean postimplantation interval of 19.9 months were reported by the authors. Bioglass cones had been fitted snugly at least 2 mm below the alveolar crest, and dentures were placed no sooner than 6 weeks following tooth removal; 2.9% had been lost and 3.7% developed dehiscences. The present report on 168 implants in 20 recalled patients (mean postimplantation interval of 63.2 months) revealed a loss of 14.3% of the implants and 7.7% of the implants requiring recontouring. Literature indicates highest survival rates for implants in the anterior mandible; however, the present data demonstrate a statistically significant retention rate in the anterior maxilla. With this high rate of Bioglass cone retention (85.7%) after 5 years, their placement into fresh sockets to maintain the alveolar ridge is recommended.

Retention of a maxillary primary canine: fifty years above and beyond the call of duty.

A case is reported of a retained maxillary primary canine that functioned effectively over fifty years. At the time of exfoliation the tooth was still of normal length and was lost not because of ankylosis and root resorption, but because of periodontal disease. Excellent histological preservation of the specimen at the time of exfoliation, together with a very complete clinical history, permitted the development of a detailed description of a tooth and its dying pulp while under function over a long period of time.

The effect of age and everyday exercise on steady-state plasma digoxin concentrations.

Age-related physiologic changes may significantly alter the disposition and pharmacologic characteristics of many drugs. The elderly are the most frequent users of digoxin because of increased prevalence of atrial fibrillation and congestive heart failure. This study was conducted to confirm the decrease in digoxin concentrations during exercise, to determine if age is a factor in this decrease, and to explore the difference between chronologic age and physiologic age. Eighteen men age 50-85 years were treated with digoxin for more than 1 month before enrolling and had serum digoxin concentrations of 0.4-2.0 micrograms/L. They were evaluated during a 3-hour period in the morning (A.M. dose withheld). Blood samples were obtained every 10 minutes during sequential 60-minute periods of rest (phase I), walking (phase II), and rest (phase III). There were no significant differences in mean concentration between phases II and I (p < 0.76), phases III and phase I (p < 0.70), or phases II and III (p < 0.37). The effect of age was positively correlated with the mean concentration of phase II but was not statistically significant (p < 0.62). Statistically significant correlations were seen only between the exercise phase and serum albumin and Mini-Mental Status Examination scores. We conclude that exercise has minimal, if any, clinically relevant effects on plasma digoxin concentrations. Increasing chronologic age has no influence on a decrease in the concentrations with exercise; a younger physiologic age may play a role.

Pulp reaction to a dentin bonding agent.

PURPOSE: To determine the pulpal biocompatibility of Prisma Universal Bond 2 (PUB-2). MATERIALS AND METHODS: Class V preparations were made in eight subhuman monkeys to approximately 1 mm from the pulp. In Group 1, the enamel was etched, the primer was placed and dried, PUB 2 was painted, and Prisma-Fil inserted. In Goup 2, the cavity floor was covered with visible light-cured Dycal followed by the steps as in group 1. In Group 3, IRM was used as a negative control. In Group 4, MQ55 silicate cement was used as a positive control. The animals were sacrificed at 5, 25, and 60 days and the teeth processed for histological evaluation. RESULTS: After 5 days, a mild reaction of little concern, which had dissipated in the 25- and 6-day groups, was observed. The material compared favorably to the negative control.

Dental iatrogenesis, Part 2.

To substantiate biocompatibility of dental materials and techniques, and thereby reduce iatrogenesis, tests for pulp and dentinal responses have been developed. These have shown that high-speed tooth cutting techniques are superior to low-speed techniques even when both incorporate air-water coolant sprays; pressure when placing restorative materials intensifies pulp responses induced by the cutting procedure, and that chemically self-cured resin composites requiring the application of a matrix to enhance adaptation intensify pulp response as compared to visible light-cured equivalents applied incrementally, fully cured throughout, and not requiring the pressure of a matrix. Most cements are irritating to the pulp when used as luting agents and when used less than 0.5 mm from it. Conditioning agents using weak acids for short periods induce little irritation while bonding agents appear to be beneficial by providing protection from subsequently placed restorative material. Clinicians should make every effort to minimize the development of pulp responses and reduce iatrogenic efforts.

Dental iatrogenesis.

In order to substantiate biocompatibility of dental materials and techniques and thereby reduce iatrogenesis, tests for pulpal and dentinal responses have been developed. These have shown that: high-speed tooth cutting techniques are superior to low-speed techniques even when both incorporate air and water coolant sprays; pressure when condensing restorative materials intensifies pulpal responses induced by the cutting procedure, and that chemically self-cured resin composites requiring the application of a matrix to enhance adaptation intensify pulpal response as compared to visible light-cured equivalents applied incrementally, fully cured throughout and not requiring the pressure of a matrix. Most cements are irritating to the pulp especially when used as luting agents and when used less than 0.5 mm from it. Conditioning agents utilising weak acids for short periods induce little irritation whilst bonding agents appear to be beneficial by providing protection from subsequently placed restorative materials. Clinicians should make every effort to minimise the development of pulpal responses and reduce iatrogenic effects.

Local and systemic responses to dental composites and glass ionomers.

For many years, the dental profession worked mainly with rather inert restorative materials that had a limited contact with vital tissue, and the opportunity for local and systemic complications was minimal. However, conditions have changed in recent years where the two leading non-mercury-containing materials, resin composites and glass-ionomer cements, are chemically active compounds and can have detrimental effects on pulp tissue. With the advent of light-curing techniques with incremental layering, resin component formulae that were formerly found to be quite irritating to the pulp have become less so with the elimination of the need for matrices and pressure for good adaptation to be gained. As experience revealed the deficiencies and dangers of ultraviolet-light-curing techniques, visible-light-curing systems were developed that provided greater depth of cure, a higher degree of polymerization with less shrinkage with incremental layers, and less porosity. When glass-ionomer cements (GICs) were first introduced, with just one acid (polyacrylic), pulpal responses were classified as bland. With the addition of many more acids to enhance certain characteristics and reduce the setting time, GICs have become more irritating, especially when used as luting agents in areas where the remaining dentin thickness is 0.5 mm or less. Gold foil and amalgam are inert and innocuous restorative materials but require pressure for condensation which creates an exaggerated inflammatory response. This presentation emphasizes the pulpal responses and side-effects of these non-mercury-containing restorative materials and how to keep them within an acceptable range of biocompatibility. Despite the lack of any substantial appearance of soft tissue and systemic responses to resin composites and GICs, the results of a survey of recent literature are included.