Search

Objective: The number of older patients requiring restorative treatment are likely to increase due to improvements in oral health and increased longevity. However, aging odontometric data are lacking. The aim of this study was to determine possible changes in pulp cell density, pulp area, and dentinal thickness with age., Study Design: Incisors (50), canines (39), premolars (51), and molars (7) extracted from 60 patients aged between 10 and 59 years, were analyzed histomorphometrically for cell density (odontoblasts, subodontoblasts, and pulp core fibroblasts) and dentinal thickness., Results: With increasing patient age, in both crown and root aspects of teeth, dentinal thickness increased (P <.001), while the density of odontoblasts (P <.001), subodontoblasts (P = 0.001), and pulp fibroblasts (crown, P <.011; root, P =.0015) decreased. The degree of age-related changes in teeth appeared to be asymmetrical, with decreases in the root being greater than in the crown. At all ages pulp cell densities, including odontoblasts, within the crown were greater than in the root (P <.001), even though the calculated rate of dentinal deposition was greatest in the root., Conclusion: Decreases in pulp cell density may reduce pulp repair activity after restorative treatments, although increases in dentinal thickness may aid pulp protection. An understanding of these age-related changes will influence the provision of restorative and endodontic care and benefit older patients.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

Several formulas of a resin-filled cement that successfully passed a series of laboratory tests were evaluated for their pulp reactions in primates. Their performance was compared to three controls: a positive control (silicate cement), a negative control (zinc oxide-eugenol) and a control group with the protection of calcium hydroxide. The chemical cure resin cement scored the lowest reactions for the 5-day evaluation. The intermediate and prolonged periods demonstrated no significant differences while average, acceptable responses were recorded. No resin cement formula scored as low as the negative control for the three time periods. Silicate cement, the positive control, scored the greatest inflammatory reaction of any material in the intermediate period, but this response was resolved after 60 days. When the resin cements were used with calcium hydroxide, the traditional reactions to calcium hydroxide were observed; an initial mild irritation that diminished with time and was completely resolved after 60 days. The resin cements, with or without the calcium hydroxide, compared favorably to the negative control IRM after 60 days. If the resin cements are appropriately applied, they are expected to be well tolerated by the human pulp. The microorganisms associated with microleakage (MLM) were minimal and there appeared to be no correlation between the MLM and pulp inflammation.

Dental materials and devices are being treated more like drugs and now have to meet the safety and efficacy requirements of drugs and medical devices. Biocompatibility is the key word. The history of the development of controls, standards, and guidelines began almost 500 years ago and is detailed in a chronological fashion up to the present time. An outline of the latest revised draft of the international document (ISO Technical Report No. 7405), to be completed hopefully by 1993 in time for the harmonization of the European Standards within the EC, is presented. The types of tests (initial, secondary, and preclinical usage tests) are listed and described. No amount of experimental study can guarantee absolute safety for any substance. However, toxicological investigations provide data from which reasonable projections and predictions can be made about the conditions under which the product can be safely used. It is the intent that this Technical Report be reviewed regularly and revised, with the ultimate objective of converting it to an International Standard.

In this experiment, 64 crown preparations were made in four primates. Final impressions, die fabrication, wax patterns and castings were achieved using conventional established clinical and laboratory techniques. Vented and unvented crowns were cemented with a glass ionomer cement (GI) and a zinc phosphate cement (ZOP). Some preparations were protected with calcium hydroxide liquid. On the same animals, in teeth not used for crowns, Class V cavities were prepared and GI and ZOP inserted by means of a pressure technique imitating hydraulic pressure generated during crown cementation. After periods of 5 and 60 days, the animals were sacrificed, the jaws dissected, fixed in formalin and prepared for histological evaluation. Of the 64 cemented crowns, one was unaccounted for. Of the unvented crowns with GI (5 days), vented crowns with GI (60 days), unvented crowns with ZOP (60 days), Class V with ZOP (5 days) and GI (60 days) with a remaining dentin thickness (RDT) of less than 1 mm, inflammatory responses of greater than or equal to 1 degree (on a scale 1-4 degrees) were observed. The use of liquid calcium hydroxide reduced the intensity of the reactions, in particular when small RDTs were present. It can be concluded that when RDTs of 1 mm or more were present, the cements in all groups were non-toxic. When it is estimated that the RDT is less than or equal to 1 mm, the use of a calcium hydroxide liner is recommended. Placement of luting agents in Class V preparations with pressure resulted in reactions resembling crown cementation.(ABSTRACT TRUNCATED AT 250 WORDS)

When glass ionomer cements were initially introduced, the pulpal responses were considered milder relative to other cements. However, the results mainly came from the application of glass ionomer cements as restorative materials. When ultimately tested with the basic laws of biocompatibility required of other cements, especially a luting agents, little difference has been shown. The judicious use of calcium hydroxide is highly recommended.

Eight ingredients of composite materials were evaluated individually for pulp irritation. None caused significant inflammation as evidenced by its average response. No abscess formations or lesions predominating in leukocytes occurred.

A case of cervical resorption in a bleached, pulpless tooth is reported. The tooth has not been traumatized, and no other reason for the resorption could be found except the possible effects of a caustic bleaching agent. This case further supports the evidence in the literature that a cause-and-effect relationship exists between Superoxol bleaching and cervical resorption.

The results of this study, plus those of a previous study, show that a layer of CaOH lining the floor of the tooth cavity will protect the dental pulp against toxic irritants inherent to an UV light-polymerized cavity liner and a UV light-polymerized composite restorative resin. This study also showed that a layer of CaOH lining the floor of the cavity will protect the dental pulp against acid irritants inherent in the enamel etching solution. It is recommended to restorative dentistry that all primary dentin within clinically accessible areas of the cavity preparation be covered with a layer of CaOH before the enamel is etched with the acid-conditioning solution. Precautionary protection of primary dentin in this manner affords a margin of safety should the conditioning solution inadvertently spill onto the primary dentin during the enamel-etching procedure. Second, if the conditioning solution does accidentally spill onto the previously placed protective layer of CaOH during the enamel-etching procedure, then it logically follows that this acid-contaminated layer of CaOH should be mechanically removed and a new layer of CaOH that completely lines at least the floor of the tooth cavity should be placed before the resins are applied.

In reviewing 356 instances of pulp capping during the past 25 years, 149 cases were recalled with posttreatment intervals greater than five years. One hundred thirty teeth (87.3%) were still vital and functioning with an average posttreatment interval of 11.7 years. The criteria for pulp capping procedures are in need of revision. Restrictions based on tooth size and age of the patient are unfounded.

In an effort to maintain the height of the residual alveolar ridge, Bioglass cones were placed in fresh sockets after tooth extraction. Today the emphasis is on maintaining the residual alveolar ridge instead of letting it resorb and subsequently resorting to heroic efforts for augmentation. To date, 242 cone implants have been placed in 29 patients. Implant follow-up observation time ranged from 12 to 32 months with an average of 19.9 months. Twenty-seven patients have been fitted with dentures. To date seven implants (2.9%) have been lost. The Bioglass implants appear to be highly biocompatible as evidenced by absence of infection, normal mucosal healing, and radiographic evidence of bone healing around the implants. Evaluation of several implants reexposed surgically revealed new bone in direct contact with the immobile implants circumferentially. The problem of implant dehiscence that started to occur after approximately 10 months in other investigations had not manifested itself in the Bioglass implant patients who have been wearing their dentures for at least 12 months.

Emphasis has shifted from the "doomed" organ concept of an exposed pulp to one of hope and recovery. The era of vital-pulp therapy has been greatly enhanced with the introduction of calcium hydroxide (CH) products. The sequence of events leading to dentinal bridge formation with various CH formulas is detailed. Those factors usually considered liabilities to direct pulp capping (pulps cariously exposed, contaminated by saliva, previously carious or restored, periodontally involved, or from older patients and primary teeth) are disputed. Those factors that must be considered to improve the success rate of pulp capping are emphasized: control bleeding, make certain the CH contacts vital-pulp tissue, minimize dentinal chip invasion, avoid embolization of CH particles, and be aware of the depth of penetration of the chemical cautery effect.

In order for the dental profession to obtain reliable data as to whether new or experimental restorative materials and adjunct agents are more or less irritating to pulp tissues than dental products currently in use, pulp studies at the national and international level are being standardized to enhance corroboration. The purpose of this study was to reduce the number of human teeth required in any experimental pulp toxicity study by controlling the problem of cavity depth. Many valuable teeth are wasted by making cavity preparations that are either too shallow or too deep, with consequent pulp exposures. This needs to be corrected.

The antimicrobial activity of six commonly used pulp-capping agents was compared to reagent Ca(OH)2 by means of an in vitro microbiologic assay. Microbial samples were collected from deep carious lesions in each of twelve teeth and plated onto T-soy blood agar. Uniform disks of each pulp-capping agent were pressed slightly below the surface of each agar dish, and zones of bacterial inhibition were measured at 24 hours to the nearest 0.1 mm. All agents, including IRM, demonstrated significantly more antimicrobial activity than reagent Ca(OH)2 with the exception of Pulpdent. This tends to indicate that the antibacterial properties associated with these capping compounds are not entirely due to the high pH associated with Ca(OH)2.

Generalized obliteration of the pulp chambers and canals by irregular secondary dentin was observed in an individual with the Sanfilippo syndrome. Heretofore unreported, this dental finding may represent a manifestation of this mucopolysaccharide disorder.