Clinical performance of a bioactive dental luting cement--a prospective clinical pilot study.

OBJECTIVE: To conduct a pilot study determining the clinical efficacy ofa new bioactive dental cement (Ceramir Crown & Bridge) for permanent cementation in fixed prosthodontics. The composition is a hybrid comprised of a calcium aluminate and a glass ionomer. METHODS: This study examined the performance of Ceramir Crown & Bridge after cementation of high-gold alloy and porcelain-fused-to-metal (PFM) single crowns and bridges. A total of 38 crowns and bridge abutments were cemented in 17 patients; 31 were on vital, seven on non-vital teeth. Six were bridges with 14 abutment teeth (12 vital/two non-vital). One fixed splint comprising two abutment teeth was also included in the study. Preparation parameters were recorded, as well as working time, setting time, seating characteristics, and ease of cement removal. Baseline data were collected on dispensing, mixing, and handling of the cement; gingival inflammation index (GI), and a visual analog scale (VAS) and categorical assessment measured pre-cementation sensitivity. Post-cementation parameters were post-cementation sensitivity, categorical and VAS, gingival tissue reaction, marginal integrity, and discoloration. A one-week post-op telephone call recorded subjectively the patients' comfort level. RESULTS: Working time (two minutes) and setting time (four minutes) were well within normal limits. Cement removal was determined to be very easy. Thirteen of 17 patients reported no post-cementation sensitivity after seven days; four reported a low-grade sensitivity. All 17 patients were seen for recall examinations at 30 days and six months. Of the four sensitivity cases, three were related to hyperocclusion, which disappeared spontaneously after adjustment. One case was due to post-cementation pressure from a three-unit bridge, which disappeared without intervention. After six months, no retentive failures were recorded, no sensitivity was subjectively reported, marginal integrity scored 38 alphas, one tooth had a 1 and two teeth a 0.5 GI score. Average VAS score for tooth sensitivity decreased from 7.63 mm at baseline to 0.44 mm at the six-month recall. Average GI score for gingival inflammation decreased from 0.56 at baseline to 0.11 at the six-month recall. CONCLUSION: After six months, Ceramir Crown & Bridge performed favorably as a luting agent for permanent cementation.

One year clinical performance and post-operative sensitivity of a bioactive dental luting cement--a prospective clinical study.

A one-year clinical study was performed on the efficacy of a bioactive dental cement (Ceramir C&B) with calcium aluminate and glass ionomer components. The study was performed on 38 crown and bridge abutments in 17 patients. Preparation parameters were recorded, as well as working-times, setting-times, and other handling characteristics. Baseline data were also recorded for gingival inflammation (GI) and pre-cementation sensitivity. Post-cementation parameters included sensitivity, gingival tissue reactions, marginal integrity and discolorations. All patients were seen for recall examinations at 30 days, and 6 months. For sixteen patients one-year recall data were collected on retention and subjective sensitivity. Fifteen subjects were available for one year clinical examinations. Three independent examiners found the working and setting time of the cement to be well within expected limits and that cement removal was easy. Four patients reported low-grades of immediate post-cementation sensitivity, however, this disappeared after an occlusal adjustment or without intervention within one month. At 12 months no retentive failures were recorded and no subjective sensitivity reported. All crowns were rated in the "Excellent" quality category for marginal integrity. Both GI-scores and scores for tooth sensitivity decreased during the course of the study. One year recall data yielded no incidence of secondary caries and no visible marginal discoloration. The new cement was thus found to perform favorably as a luting agent for permanent cementation.

Hardness of enamel exposed to Coca-Cola and artificial saliva.

The purpose of this study was to determine the rate of change in indentation hardness of enamel in permanent teeth exposed to Coca-Cola. In a further experiment, the ability of a commercially available artificial saliva to remineralize enamel treated with Coca-Cola was tested. Ten enamel specimens were randomly chosen to be treated with Coca-Cola (experimental groups) and seven with water (control group). The fluids were applied for 1, 2, 3 h and overnight (15 h), washed off with a few drops of water and the moist enamel indentation hardness tested after each interval. With Coca-Cola treatment, the mean enamel hardness was 92.6% (s.d. = 7.9) of the original baseline hardness after 1 h, 93.25% (s.d. = 10.15) after 2 h, 85.7% (s.d. = 12.03) after 3 h and 80.3% after 15 h. The mean indentation hardness of control specimens treated with water was 108.7% (s.d. = 16.09) of the original hardness after 1 h, 99.09% (s.d. = 18.98) after 2 h, 98.97% (s.d. =11.24) after 3 h and 98.42% (s.d. = 22.78) after 15 h. In a separate experiment, the hardness of 9 enamel specimens was tested, as previously described, before and after treatment with Coca-Cola overnight and again after application of artificial saliva for 3 min. Coca-Cola reduced the mean indentation hardness of enamel in the teeth, but the hardness was partially restored with artificial saliva (Salivart) and increased by 18% from the demineralized enamel hardness.

Minimum lateral wall heights for conservative class I cavity preparations.

PURPOSE: To quantify the minimum necessary Class I cavity preparation lateral wall heights (LWH) for a cavity preparation 0.8 mm in width and extending to the dentin-enamel junction in a set of extracted human permanent posterior teeth. MATERIALS AND METHODS: 183 bucco-lingual or mesio-distal undecalcified sections were cut from a set of 73 posterior teeth. Macroscopic digital images were made of fissures within the sections and a computer-generated digital measuring device was superimposed to obtain LWH measurements corresponding to a cavity preparation 0.8 mm in width and extending to the dentin-enamel junction. Preparation LWH data was analyzed by tooth type and groups for mean, minimum, maximum, standard deviation, count, and frequency distribution. RESULTS: LWH varied between 1.2 mm and 2.5 mm for the 183 fissures tested. Mean LWH was 1.925 mm with a standard deviation of 0.262 mm. The most common LWH was 2.0 mm, found in 18% of the samples. Seventy percent of LWHs were 2.0 mm or less. Only two sections had LWHs of 1.2 mm, both in maxillary first premolars. Only two sections had LWHs of 2.5 mm, one in a mandibular second molar and the other in a maxillary first molar. Maximum LWH correlated positively (r = .469) with bucco-lingual crown width.

Use of an existing post to rerestore an endodontically treated tooth with a new post-and-core complex and crown: a case report.

Replacement of a post-and-core restoration that has failed because of caries or fracture presents a restorative challenge to the general dentist. This case report describes a new technique that enables the utilization of an unremovable preexisting post in the fabrication of a new post-and-core complex. This complex served as a foundation for a restoration that restored form and function to the patient's dentition.

Acquisition of a touching style.

A qualitative study investigated dental student perceptions of learning to use touch in dental treatment. A focus group design was used to allow volunteer participants (students, general dentistry residents, and dental faculty; n = 41) to discuss issues related to this question. Each focus group was audiotaped for accuracy and transcribed by an independent person. Data gathered were textually and thematically analyzed around the specific questions asked. The data indicated that learning to touch dental patients was often trial and error and uncomfortable for these students. Further, the data suggested that a fine line exists preventing students from asking for assistance and faculty in offering assistance.

Abrasion, erosion, and abfraction combined with linear enamel hypoplasia: a case report.

Linear enamel hypoplasia is a developmental disturbance of enamel resulting in clinically visible horizontal defects in enamel that are present on eruption of the tooth. Nondevelopmental lesions of the hard tissues of the tooth, including carious, abrasion, erosion, attrition, and abfraction lesions, require varying amounts of time after tooth eruption to develop. Because linear enamel hypoplasia lesions are present on eruption and are exposed to the factors responsible for abrasion, erosion, and abfraction, nondevelopmental lesions could occur within them in any combination. This report describes a patient with multiple teeth with linear enamel hypoplasia lesions containing nondevelopmental defects as well as nondevelopmental defects that occurred separately. Severe pain and a unique lesion morphology were associated with the linear enamel hypoplasia defects. Affected teeth were extracted because of advanced periodontitis and were sectioned to determine the nature of the enamel and dentin lesions.

Effects of angiotensin II on intracellular calcium and contracture in metabolically inhibited cardiomyocytes.

Angiotensin II (A-II) is known to potentiate ischemic dysfunction during ischemia, but the mechanisms involved are not completely established. We examined the effects of A-II on intracellular calcium concentration ([Ca++]i) and cell contracture caused by metabolic inhibition in isolated adult rabbit ventricular myocytes. [Ca++]i was assessed by flow cytometry, using the Ca(++)-sensitive fluorescent probe, fluo-3. After 90 min of exposure to 2 mM cyanide (CN) and 0 glucose, there was a significant increase in myocyte [Ca++]i. This increase was slightly augmented in the presence of 100 nM A-II. In the presence of partial Na+/K+ ATP pump inhibition ([K+]o = 0.8 mM), there was a more significant increase in [Ca++]i associated with exposure to CN + A-II vs. CN alone. Similar results were obtained with CN plus 2-deoxyglucose, and the effect of A-II was inhibited by 10 microM 5-(N-ethyl-N-isopropyl)amiloride. Myocytes exposed to 2 mM CN and 0 glucose gradually developed contracture over a 3-hr period. Addition of 100 nM A-II significantly (P < .01) enhanced loss of rod shape morphology during 3 hr of CN exposure. Partial inhibition of the Na+ pump by exposure to 0.8 mM K+ had no effect on myocyte survival in the absence of CN, but augmented the harmful effect of A-II on cell contracture caused by CN exposure. This effect of A-II was completely reversed by the addition of 1 mM amiloride, a Na+/H+ exchange inhibitor. We conclude that A-II directly enhances cell injury during CN exposure in isolated rabbit ventricular myocytes. We postulate that this effect of A-II is mediated by stimulation of Na+/H+ exchange with resultant increased [Na+]i and subsequent [Ca++]i loading, possibly via reverse Na+/Ca++ exchange.

An accurate chairside technique for fabricating a temporary restoration for ITI single-tooth implant.

Current implant restoration techniques depend upon a well-fitting, anatomic provisional restoration--especially at the restoration margin--to promote healthy soft tissue contours, which are necessary for successful final restorations. The ITI implant system presents a particular challenge in this regard because of the configuration of the implant head and shoulder, especially when these are placed subgingivally. A chairside method for obtaining an accurate marginal fit and customized contours in the single-tooth provisional restoration is described and illustrated.

Cavosurface margin geometry in conventional and air abrasion Class V cavity preparations.

PURPOSE: To compare cavosurface angle and area of missing tooth structure at the cavosurface margin in cross-sections of Class V cavity preparations made with a conventional carbide bur and with an air abrasive cavity preparation system. MATERIALS AND METHODS: Class V cavity preparations were made with a #56 carbide bur or with a KCP 1000 air abrasive unit. They were restored and sectioned longitudinally, providing 43 margins for study. Cavo-surface angle and area of missing tooth structure were measured for each margin from digital images of the sections. The angle and area data was grouped according to margin location and cavity preparation system and analyzed for differences using the Kruskal-Wallis test. To determine if there was a relationship between the missing area and the angle at the cavosurface margin, Lomb periodograms were analyzed. RESULTS: Conventional cavity preparation margins had an average cavosurface angle less than 90 degrees while the air abrasion margin angle was greater than 90 degrees. Cavo-surface angles for conventional cavity preparations were significantly different from cavosurface angles for air abrasion cavity preparations. Missing areas at the cavosurface margin for conventional cavity preparations were not significantly different from missing areas at the cavosurface margin for air abrasion cavity preparations. Lomb periodograms showed no trend concerning the missing area as a function of the angle. CONCLUSIONS: There was no significant difference between the area of missing tooth structure at the cavosurface margin in conventional vs. air abrasion cavity preparation. Cavosurface angle in conventional preparations was less than 90 degrees, and greater than 90 degrees in air abrasion cavity preparations. Cavosurface angle and area of missing tooth structure at the cavosurface margin varied independently.

Hypersensitivity and pain induced by operative procedures and the "cracked tooth" syndrome.

Various dental conditions are responsible for tooth hypersensitivity and pain. They include hypersensitive dentin; the "cracked tooth" syndrome; pulp and periapical irritation, inflammation and/or degeneration; barodontalgia (aerodontalgia); and periodontal pathoses, particularly the pulpal-periodontal syndrome. Each operative condition is reviewed with respect to its etiology, symptomatology, and diagnosis. Some treatment recommendations are made to prevent or reduce symptoms.

Adhesive liner incorporation in dental amalgam restorations.

Previous studies have indicated that adhesive liners can affect the mechanical properties of set amalgam and, therefore, may become incorporated within the amalgam. The purpose of this in vitro study was to determine the distribution of two adhesive liners within standardized Class I amalgam restorations. Cavity preparations were restored with dental amalgam or with dental amalgam and either of two adhesive liners. Thin sections were cut from the restored teeth in various planes and examined radiographically and with a reflecting microscope. Radiographs were digitized and computer enhanced for improved observation. Amalgam restorations placed with adhesive liner had greater amounts of nonamalgam substance than did the nonadhesive liner restorations. Both Amalgambond Plus and Resinomer used with All-Bond II were capable of becoming incorporated within the body of a Class I restoration placed with a standard restorative amalgam bonding technique.

Survival of metabolically inhibited ventricular myocytes is enhanced by inhibition of rigor and SR Ca2+ cycling.

During severe ATP depletion, sarcolemmal rupture resulting from rigor- and/or Ca(2+)-induced myofilament force development is considered to be an important cause of irreversible cell injury. Recent experiments in our laboratory demonstrated that during prolonged metabolic inhibition (MI) in adult rabbit ventricular myocytes, in which rigor was prevented by exposure to 30 mM 2,3-butanedione monoxime (BDM), cyclic uptake and release of cystolic Ca2+ occurred and was associated with strong phasic contractions. To investigate the relative contribution of this sarcoplasmic reticulum Ca2+ cycling and associated force development to energy depletion injury, the effects of BDM together with 7 mM caffeine were examined in isolated rabbit ventricular myocytes subjected to MI with 2 mM NaCN and 20 mM 2-deoxyglucose (2-DG). During 90 min of MI with CN and 2-DG, no cells retained a rod shape in the absence of BDM or caffeine. In the presence of both 30 mM BDM and 7 mM caffeine during MI, preservation of rod morphology was enhanced, and 52 +/- 6.2% of cells retained a rod shape 48 h after metabolic inhibition and had normal ATP content and resting membrane potential. Both systolic and diastolic functions of cells that survived MI, however, were impaired. We conclude that exposure to caffeine together with BDM markedly enhances survival of myocytes during severe prolonged ATP depletion. After recovery, these isolated myocytes show some characteristics of stunning.

Management of intracoronary thrombosis complicating percutaneous transluminal coronary angioplasty.

With technological advances in equipment and increased experience of operators, the success rates of percutaneous transluminal coronary angioplasty (PTCA) now exceed 90%. However, acute periprocural occlusion continues to complicate approximately 6% of all procedures, and many of these occlusions are due to intracoronary (IC) thrombus. Patients at highest risk for this complication include those with acute ischemic syndromes or with angiographically apparent thrombus. These individuals may be candidates for the use of prolonged heparin infusions prior to dilatation, intracoronary thrombolytic therapy, or monoclonal antibody directed against the platelet glycoprotein IIb/IIIa receptor. All patients undergoing PTCA should receive adequate antiplatelet therapy, including aspirin, and heparin with dosing monitored by activated clotting times (ACT). In addition, some recommend the use of ionic contrast material. When IC thrombus accumulates following intervention, initial therapy should include IC nitroglycerin followed by a combination of redilatation and IC urokinase infusion. Prolonged balloon inflations may be useful, particularly with the use of autoperfusion catheters. Platelet glycoprotein IIb/IIIa receptor antagonists may prove to be beneficial in this situation as well. If the patient's clinical status deteriorates in spite of these measures, emergency coronary artery bypass graft surgery may be required.

E-Z Gold: the new Goldent.

E-Z Gold is a new direct filling gold material that is similar to existing powdered gold formulations but more user-friendly. It is a mixture of pure gold powder and wax (less than 0.01% organic wax), wrapped in gold foil introduced to the dental profession in the late 1980s, and similar metallurgically to gold foil and powdered gold (Goldent) in that, when properly and thoroughly compacted, it has comparable properties: inertness (biocompatibility) and permanence. E-Z Gold's manipulative characteristics are similar to that of a very stiff amalgam, yet more sticky (cohesive) than gold foil, hence the name E-Z Gold. There is no reported research related to physical properties regarding shear, tensile, and cohesive strength. One can assume that E-Z Gold is similar to old Goldent but with improved softness and working characteristics. Clinical experience in the use of this new restorative direct filling gold material has been encouraging. We anticipate that in the near future, clinical and laboratory research comparing this gold to other types of direct filling golds will be forthcoming.

Caries diagnosis with dye-staining at amalgam restoration margins.

PURPOSE: To determine the strength of agreement between detection of caries at the margin of amalgam restorations with a caries detector dye, and detection of caries histologically utilizing light/polarizing light microscopy. MATERIALS AND METHODS: 17 permanent molars with intact amalgam restorations, determined to be caries-free by visual inspection and explorer probing, cleansed with an air/water/abrasive slurry system, and with evidence of amalgam enamel marginal staining from application of a 1% solution of sulforhodamine B caries detector dye were utilized. Longitudinal, undecalcified sections, 80-100 micrometers thick, were prepared including stained and unstained regions of the amalgam/enamel margin of each tooth, providing 34 margins for study. The sections were examined in the light/polarizing light microscope for evidence of marginal caries. The Kappa Index was calculated to determine the strength of agreement between the caries dye method and the light/polarizing light microscopic method of caries diagnosis. RESULTS: Microscopically, caries was detected in 14 of 34 margins (41%). Agreement for presence of caries was 5 of 34, and for absence of caries 8 of 34 (total agreement 38%). 12 of 17 dye-stained margins were microscopically caries-free, and 9 of 17 unstained margins had caries microscopically. Kappa Index for these findings was 0.23, indicating poor strength of agreement.

Safety, efficacy, and lipid profile of doxazosin at a VA medical center.

The Veterans Administration Lakeside Medical Center (VALMC) is a 500-bed hospital located in downtown Chicago providing a broad scope of inpatient and outpatient medical services for more than 12,000 veterans. The VALMC Pharmacy and Therapeutics Committee requested a study to evaluate doxazosin mesylate (Cardura) to determine if this agent would be an acceptable alternative to other formulary agents. It appears that doxazosin provides several therapeutic advantages, including once-daily dosing, when compared with other more costly antihypertensive agents.

Resistance to fracture of endodontically treated premolars restored with new generation dentine bonding systems.

MOD cavities in 60 endodontically treated teeth were restored using six different methods. Copper rings were filled with commercial hard-setting cement and the teeth were placed up to the level of the cemento-enamel junction. The teeth were grouped according to restorative method, mounted in an Instron TT machine, and the buccal walls subjected to a slowly increasing compressive force until fracture occurred. The force of fracture of the walls of each tooth was recorded and the results in the various groups compared. All teeth fractured in a similar manner irrespective of the restorative method used. All groups restored with the newer bonding system had higher resistance to fracture than those restored with an acid etch chemically cured composite resin technique. The groups restored with Den-Mat Tenure Core Paste or a Variglass VLC base and Prisma APH were significantly stronger than the acid etch Concise restored teeth (P < 0.05). No statistically significant differences were found between the other groups (P > 0.05).

Histobacteriological analysis of acid red dye-stainable dentin found beneath intact amalgam restorations.

This study determined histologically the incidence of acid red dye-stainable dentin and its correlation to bacterial presence beneath intact clinically sound amalgam restorations. Fourteen of 16 clinically sound amalgam restorations (88%), serving an average of 11 years, had microscopically evident microorganisms in the subjacent dentin. Eleven of the 14 specimens containing bacteria (79%) exhibited acid red dye-stainable dentin. There was no obvious correlation between dye-stainable dentin and the presence of bacteria on the walls of the cavity preparations studied. The question of how much dye-stainable dentin can be present beneath an amalgam restoration before the restoration fails is still unanswered.