Efficacy of sugammadex in rocuronium-induced or antibiotic-induced anaphylaxis. A case-control study.

We report 13 cases of presumed rocuronium-induced anaphylaxis in which sugammadex was administered with the intention of reversing the immunological reaction. Of these 13 cases, eight (62%) were later confirmed to be type-1 hypersensitivity reactions to rocuronium, three (23%) were triggered by an antibiotic and two (15%) were non-immunologically mediated. Response to treatment was scored by the treating anaesthetist, and compared with haemodynamic and inotrope measurements from the resuscitation and anaesthetic records. Haemodynamic improvement was seen in only six (46%) cases, three of which were associated with a non-rocuronium trigger. Of the three cases in which the treating anaesthetist thought that sugammadex had been beneficial, one was not caused by rocuronium, one had no improvement in blood pressure and one required 8.5 times as much adrenaline in boluses after, compared with the period before, sugammadex administration. These data suggest that sugammadex does not modify the clinical course of a suspected hypersensitivity reaction.

Acrolein generation stimulates hypercontraction in isolated human blood vessels.

Increased risk of vasospasm, a spontaneous hyperconstriction, is associated with atherosclerosis, cigarette smoking, and hypertension-all conditions involving oxidative stress, lipid peroxidation, and inflammation. To test the role of the lipid peroxidation- and inflammation-derived aldehyde, acrolein, in human vasospasm, we developed an ex vivo model using human coronary artery bypass graft (CABG) blood vessels and a demonstrated acrolein precursor, allylamine. Allylamine induces hypercontraction in isolated rat coronary artery in a semicarbazide-sensitive amine oxidase activity (SSAO) dependent manner. Isolated human CABG blood vessels (internal mammary artery, radial artery, saphenous vein) were used to determine: (1) vessel responses and sensitivity to acrolein, allylamine, and H(2)O(2) exposure (1 microM-1 mM), (2) SSAO dependence of allylamine-induced effects using SSAO inhibitors (semicarbazide, 1 mM; MDL 72274-E, active isomer; MDL 72274-Z, inactive isomer; 100 microM), (3) the vasoactive effects of two other SSAO amine substrates, benzylamine and methylamine, and (4) the contribution of extracellular Ca(2+) to hypercontraction. Acrolein or allylamine but not H(2)O(2), benzylamine, or methylamine stimulated spontaneous and pharmacologically intractable hypercontraction in CABG blood vessels that was similar to clinical vasospasm. Allylamine-induced hypercontraction and blood vessel SSAO activity were abolished by pretreatment with semicarbazide or MDL 72274-E but not by MDL 72274-Z. Allylamine-induced hypercontraction also was significantly attenuated in Ca(2+)-free buffer. In isolated aorta of spontaneously hypertensive rat, allylamine-induced an SSAO-dependent contraction and enhanced norepinephrine sensitivity but not in Sprague-Dawley rat aorta. We conclude that acrolein generation in the blood vessel wall increases human susceptibility to vasospasm, an event that is enhanced in hypertension.

A syphilis outbreak in remote Australia: epidemiology and strategies for control.

This paper describes the epidemiology of a syphilis outbreak in remote Australia, and explores contributing factors and control strategies. Between 1 August 2000 and 31 January 2002, 74 cases of early syphilis (42 female, 32 male) were identified in 73 Kimberley residents. Syphilis rates in age groups 10-19 and 20-29 years were 583 and 439 per 100000 person years respectively. Factors contributing to the outbreak included incompleteness of sexually transmitted infection (STI) clinical management, untimely contact tracing, staffing and management issues, and poor community knowledge about STIs. Outbreak control strategies addressed factors that could be influenced by changes in health service delivery, and focused on providing education and support to health staff, and efforts to increase community knowledge about sexual health. Although some improvements have occurred, the outbreak is still continuing. Until open and honest discussion and a collaborative approach is taken toward STI problems affecting Indigenous Australians, outbreaks such as this will continue to occur.

Vasoactive effects of methylamine in isolated human blood vessels: role of semicarbazide-sensitive amine oxidase, formaldehyde, and hydrogen peroxide.

It is hypothesized that methylamine (MA) and semicarbazide-sensitive amine oxidase (SSAO) activity are involved in the cardiovascular complications in human diabetics. To test this, we 1) determined the acute vasoactive effects of MA (1-1,000 micromol/l) in uncontracted and norepinephrine (NE; 1 micromol/l)-precontracted human blood vessels used for coronary artery bypass grafts [left internal mammary artery (LIMA), radial artery (RA), and right saphenous vein (RSV)]; 2) tested whether MA effects in LIMA and RSV were dependent on SSAO activity using the SSAO inhibitor semicarbazide (1 mmol/l, 15 min); 3) determined the effects of MA metabolites formaldehyde and hydrogen peroxide in LIMA and RSV; 4) tested whether the MA response was nitric oxide, prostaglandin, or hyperpolarization dependent; 5) measured the LIMA and RSV cGMP levels after MA exposure; and 6) quantified SSAO activity in LIMA, RA, and RSV. In NE-precontracted vessels, MA stimulated a biphasic response in RA and RSV (rapid contraction followed by prolonged relaxation) and dominant relaxation in LIMA (mean +/- SE, %relaxation: 55.4 +/- 3.9, n = 30). The MA-induced relaxation in LIMA was repeatable, nontoxic, and age independent. Semicarbazide significantly blocked MA-induced relaxation (%inhibition: 82.5 +/- 4.8, n = 7) and SSAO activity (%inhibition: 98.1 +/- 1.3, n = 26) in LIMA. Formaldehyde (%relaxation: 37.3 +/- 18.6, n = 3) and H(2)O(2) (%relaxation: 55.6 +/- 9.0, n = 9) at 1 mmol/l relaxed NE-precontracted LIMA comparable with MA. MA-induced relaxation in LIMA was nitric oxide, prostaglandin, and possibly cGMP independent and blocked by hyperpolarization. We conclude that vascular SSAO activity may convert endogenous amines, like MA, to vasoactive metabolites.

The influence of dental alloys on three-body wear of human enamel and dentin in an inlay-like situation.

This in vitro study evaluated the effect of metal alloys on three-body wear resistance of enamel and dentin, and vice versa. Three-body wear of human enamel, dentin, a soft gold alloy (BiOcclus Inlay), a CoCr alloy (Remanium 2000), a resin cement (Variolink II) and a zinc oxide phosphate cement (Harvard) was investigated using the ACTA-machine. Sample chambers of eight sample wheels were prepared with pure materials or combinations of human tooth substance, alloys and cement, simulating an inlay-like situation. After 100,000 and 200,000 cycles in a millet suspension with a spring force of 20 N, the amount of abraded material was profilometrically measured and evaluated by 3D surface data analysis. After 200,000 cycles, the materials demonstrated a mean loss of 0.41 microm for CoCr, 51 microm for gold, 57 microm for enamel, 164 microm for dentin, 79 microm for Variolink and 369 microm for Harvard. Using ANOVA and the Games-Howell-test, resin cement, enamel and gold were a subset not shown to differ, as was zinc phosphate cement and dentin. CoCr demonstrated the least wear and differed significantly from all materials. Enamel wear was significantly reduced in mixed chambers with CoCr, and gold after 200,000 cycles compared to enamel in pure chambers. In summary, a soft gold alloy can be recommended for inlays when considering three-body abrasion since the wear rate of the "soft" gold alloy corresponded to that of human enamel.

Effects of chemical disinfectants on surface characteristics and color of three fixed prosthodontic crown materials.

STATEMENT OF PROBLEM: Dental restorations should reproduce similar optical effects as natural tooth structure to achieve a good color match. Mismatch can result in unsatisfactory shade matching. PURPOSE: This study determined whether chemical disinfectants affected the surface texture and color of 3 fixed prosthodontic materials. MATERIAL AND METHODS: Five chemical disinfectants (Clorox, Banicide, Cidex-7, Biocide, and Multicide) in combination with 3 restorative materials (Dicor, Vita VMK ceramometal porcelain, Midas ADA type III noble casting alloy) were evaluated at 4 different times of immersion (10 minutes, 30 minutes, 24 hours, and 7 days). Changes from baseline for surface roughness and color were evaluated. Surface roughness data were recorded with a surface analyzer and color data in CIE L*a*b* color space were measured with a colorimeter. Data were analyzed with repeated measures analysis of variance and single factor analysis of variance. RESULTS: There were no statistical differences in surface roughness among disinfectants and restorative materials. However, there were statistical differences of changes in color, increase in deltaE and decrease in deltaL, among disinfectants and the noble casting alloy. CONCLUSION: Only 2 of the 3 materials evaluated, Dicor and Vita VMK ceramometal porcelain, can be used with all 5 disinfectants up to 7 days of immersion. Three chemical disinfectants (Biocide, Clorox, and Multicide) caused clinically significant color changes with the noble casting alloy after 7 days of immersion.

Relative potency of controlled-release oxycodone and controlled-release morphine in a postoperative pain model.

OBJECTIVE: The relative analgesic potency of single doses of oral controlled-release oxycodone and oral controlled-release morphine were compared in a randomized, double-blind trial using a postoperative pain model. METHODS: Women (n = 169) with moderate to severe pain following abdominal hysterectomy received single oral doses of controlled-release oxycodone, 20 mg or 40 mg, or controlled-release morphine, 45 mg or 90 mg. Assessments were made at 30 min, 60 min, then hourly after dosing for 12 h or until remedication. RESULTS: The most precise estimates of relative potency showed that controlled-release oxycodone was 1.8 times more potent than controlled-release morphine for total effect (95% confidence limits 1.09-2.42; lambda 0.44) and 2.2 times more potent for peak effect (95% confidence limits 0.96-4.59; lambda 0.71). Controlled-release oxycodone at doses of 20 mg or 40 mg was comparable with controlled-release morphine at doses of 45 mg or 90 mg, respectively, for total and peak analgesic effects. For the two higher doses, time to peak relief was approximately 1 h shorter with controlled-release oxycodone than with controlled-release morphine. Most patients reported onset of analgesia within 1 h with all doses. Side effects were similar with the two opioids. CONCLUSION: Oral controlled-release oxycodone was twice as potent as oral controlled-release morphine in this single-dose, relative potency assay. When converting patients from oral morphine to oral oxycodone, an initial oral oxycodone dose of one-half the oral morphine dose is recommended.

Retention of provisional crowns fabricated from two materials with the use of four temporary cements.

STATEMENT OF PROBLEM: Practitioners often choose resin materials and temporary cements with little understanding about their effect on provisional crown retention. PURPOSE: This study evaluated the retention of provisional restorations made with 2 materials and cemented with 4 temporary cements. METHODS AND MATERIAL: Recently extracted molars were prepared with a flat occlusal surface, 4-mm axial length and 20-degree angle of convergence. Specimens were distributed into equivalent groups. Provisional crowns were constructed for each preparation with polymethyl methacrylate (Temporary Bridge Resin) or bis-acrylic composite (Protemp Garant) and later cemented with Temp-Bond, Temp-Bond NE, Temrex, and an experimental calcium hydroxide temporary cement. A second group with Temrex was evaluated using half the recommended liquid. A cementing force of 2.5 kg for 5 minutes was used. After initial bench set followed by 24 hours in room temperature water, the crowns were removed with an Instron mechanical testing machine at 0.5 mm/min. A 2-factor ANOVA was used with alpha=.05 (n = 10). Mode of debonding was analyzed with a nonparametric chi-square test of association. RESULTS: Mean dislodgment stresses ranged from 670 to 1072 kPa for polymethyl methacrylate crowns and 554 to 884 kPa for those made of composite. Differences were nearly significant for the type of provisional material (P =.061) and the cross-product interaction (P =.376) was not significant, whereas there were significant differences among the cements (P =.002) and the mode of debonding (P =.0034). CONCLUSIONS: Excluding Temp-Bond to eliminate a cross-product interaction demonstrated that the polymethyl methacrylate crowns were 19.3% more retentive than the composite crowns (P =.015). There was no statistically significant difference among the 4 temporary cements when the manufacturer's mixing instructions were followed (P =.186). However, the thicker consistency Temrex was more retentive than the recommended Temrex mix and Temp-Bond.

An accuracy evaluation of four removable die systems.

STATEMENT OF PROBLEM: The advent of implant dentistry has redefined the need for accuracy of working cast models. Die stone expansion and errors introduced by removable die casts may exceed the accuracy required for the passive fit of implant prostheses. PURPOSE: Several removable die systems claim improved accuracy because of their design and/or technical advancements. This study evaluated the 3-dimensional accuracy of 4 removable die systems. All 4 systems tested use either 1 or 2 pins as the repositioning device. MATERIAL AND METHODS: Four removable die systems were evaluated (Belle de St. Claire, Pindex, DVA, and conventional brass dowel system). Master model impressions were made with polyvinyl siloxane material and were later cast with type IV die stone material. Comparative dimensional analysis between the master model and the solid and sectioned casts was made by placing the cast in a standardized position and fabricating an individual custom base for each cast. Landmarks were measured with a traveling microscope, and by mathematically rotating the casts. Discrepancies beyond that of stone expansion or residual stress release at the time of die separation were due to the inability to precisely reposition the removable die of the sectioned cast. Data were analyzed with multivariate analysis of variance and paired t tests at alpha = .05 (n = 10). RESULTS: Significant differences were found among die systems tested (P = .005). When sectioned dies were compared with the master model, the accuracy of all 4 die systems was within 0.055 mm of the master model. Once sectioned, the Pindex system had the least linear expansion in the y dimension, and the brass dowel system demonstrated the least reseating discrepancy in the z (occlusogingival) dimension. CONCLUSIONS: All 4 die systems provided a similar degree of dimensional accuracy, although Pindex showed the least horizontal movement and the brass dowel system produced the least occlusogingival reseating discrepancy.

Crown retention with use of a 5% glutaraldehyde sealer on prepared dentin.

STATEMENT OF PROBLEM: A previous study showed that a resin sealer decreased casting retention with zinc phosphate cement. PURPOSE: This study determined whether a nonresin sealer applied to prepared dentin affected the retention of cemented castings. MATERIAL AND METHODS: Extracted molars were prepared with a flat occlusal, 20-degree taper and 4 mm axial length. The axial surface area of each preparation was determined and samples were distributed to achieve equivalent groups. Gluma Desensitizer sealer was used to seal the dentin before provisionalization and again before crown cementation. An Olympia alloy casting was produced for each preparation and cemented with a seating force of 20 Kg with either Mizzy's zinc phosphate, Ketac-Cem glass ionomer, or Resinomer material in combination with One Step adhesive. Castings were thermocycled, then removed along the path of insertion with an Instron testing machine. A two-factor analysis of variance was used with alpha = 0.05 and n = 9.10. RESULTS: Mean dislodgment stresses for unsealed and sealed conditions were 6.3 and 6.4 MPa for zinc phosphate, 9.1 and 10.1 MPa for glass ionomer, and 12.1 and 12.6 MPa for the resin cement. The means for the three cements were statistically different (p < 0.001). The effect of sealer (p = 0.369) and cross product interactions (p = 0.820) were not significant. CONCLUSIONS: The use of the glutaraldehyde-based system as a desensitizing treatment for prepared teeth had no effect on crown retention for any of the three cements evaluated and the modified resin cement produced the highest mean dislodgment stress that exceeded the strength of the tooth.

Dimensional stability and detail reproduction of irreversible hydrocolloid and elastomeric impressions disinfected by immersion.

STATEMENT OF PROBLEM: Because irreversible hydrocolloid impressions imbibe blood and saliva, immersion rather than spray disinfection may be more effective. Polyether has been shown to be dimensionally sensitive to immersion disinfection. PURPOSE: The aim of this study was to determine whether irreversible hydrocolloid and polyether impressions could be disinfected by immersion without sacrificing accuracy and surface quality. MATERIAL AND METHODS: Impressions were made of a master mandibular arch containing a crown preparation. Changes between the master and working casts were assessed. Irreversible hydrocolloids (Jeltrate; Palgaflex), a polyether (Impregum F), and an addition silicone (President) were used. Disinfectants were an iodophor (Biocide), a glyoxal glutaraldehyde (Impresept de), and a phenol glutaraldehyde (Sporicidin). The control was without disinfection. Casts were formed in Type IV gypsum. The roughness of working dies was also recorded and an analysis of variance was used for statistical evaluation. Results. Casts from disinfected irreversible hydrocolloid and elastomeric impressions maintained accuracy for anteroposterior and cross arch dimensions where differences from the master was less than 0.1%. Buccolingual and mesiodistal dimensions of working dies (disinfected and control) were 6 to 8 microm larger than the master for addition silicones and 11 to 16 pm for polyethers. The occlusogingival dimension of dies for control and disinfected polyether was 9 pm longer than the master compared with -3 microm for addition silicone. The range of mean surface roughness of working dies made from irreversible hydrocolloids was 1.4 to 1.7 microm and ranged from 0.5 to 0.7 microm for elastomeric impressions. Conclusion. Immersion disinfection of Jeltrate material with iodophor and Palgaflex material with glyoxal glutaraldehyde produced casts and dies as accurate as the control. Control and disinfected elastomeric impression produced dies as clinically accurate and smooth as the master. Disinfection of irreversible hydrocolloid impressions with the glyoxal and phenol glutaraldehyde produced a surface smoother than controls.

Clinical success of class V composite resin restorations without mechanical retention.

The authors describe a study in which they placed 126 Class V composite resin restorations without mechanical retention, divided into three groups of 42, in 23 patients. They followed the performance of the restorations over a three-year period. For all three groups, restorations were placed using All-Bond 2 dental adhesive and Z100 composite resin; A.R.T. Bond and Brilliant Dentin composite; and Prisma Universal Bond 3 and Variglass VLC polyacid-modified composite resin. The authors evaluated retention as well as color stability, wear resistance, sensitivity, sulcular depth, loss of attachment, bleeding on probing and crevicular fluid flow. Based on their results, the authors propose that restoration of Class V lesions without using mechanical retention could be expected to succeed in seven of 10 restorations over a three-year period using these restorative systems.

Effect of mixing technique on surface characteristics of impression materials.

STATEMENT OF PROBLEM: Previous studies have shown a relationship between the disinfection process, wettability, and mass change of impression materials. Hand-mixed high viscosity impression materials usually result in a material with numerous voids, which contribute to surface roughness and affect the surface characteristics of the material. PURPOSE: This study evaluated the effect of mixing technique on advancing contact angle, receding contact angle, imbibition, and mass loss of various high and low viscosity polyether and polyvinyl siloxane materials. The null hypothesis tested was no differences exist between the different mixing systems. MATERIAL AND METHODS: The Wilhelmy technique was used for deriving wetting properties of the materials used (Impregum F and Penta, Permadyne Syringe, Garant and Penta, Dimension Penta and Garant L, Aquasil). Conditions included no disinfection (0 hours) and 1, 5, and 18 hours of immersion disinfection in a full-strength solution of 2% acid glutaraldehyde disinfectant (Banicide). Weight changes before and after disinfection were measured to detect weight loss or mass increase over time. Weight loss in air was also measured to detect mass loss. Data were analyzed with a one-way analysis of variance at alpha = 0.05. RESULTS: All materials displayed some degree of imbibition of the disinfectant and experienced mass loss with polymerization, except the light viscosity polyvinyl that gained 0.18% at 5 hours. No significant differences were found in wettability among the polyether materials after 1 hour of disinfection. Less imbibition was observed for high viscosity mechanically mixed materials compared with the hand-mixed materials for both polyether and polyvinyl siloxane at 1-hour disinfection time. CONCLUSIONS: Polyether materials were more wettable than polyvinyl. Imbibition of high viscosity polyether and polyvinyl materials after 1 and 18 hours of disinfection were affected by the mixing system used.

Accuracy of polyether and addition silicone after long-term immersion disinfection.

STATEMENT OF PROBLEM: Some studies have demonstrated that short-term immersion disinfection does not affect the accuracy of polyether or addition silicone materials. Impressions are often disinfected for longer than recommended time periods. PURPOSE: This study evaluated these materials after simulating overnight disinfection. MATERIAL AND METHODS: Impressions were made of a master model with Extrude Extra material with Extrude Wash addition silicone and Impregum F material in combination with Permadyne Garant polyether material. Nondisinfected impressions served as controls, whereas the disinfected samples were immersed for 18 hours in a full strength 2% acid glutaraldehyde solution. Anteroposterior and cross arch dimensions of the working cast and occlusogingival, mesiodistal, and buccolingual dimensions of working die were assessed. The data were analyzed with one-way analysis of variance at "alpha" = 0.05. RESULTS: No significant differences were observed for anteroposterior and cross arch dimension when compared with the master model. However, significant differences were found for occlusogingival dimension at 18 hours of disinfection for both materials. The addition silicone 18-hour disinfection group was significantly less accurate in the mesiodistal dimension. CONCLUSION: Accuracy of both impression materials was adversely affected with 18 hours of immersion disinfection. Long-term (18 hours) immersion disinfection will affect the fit of fixed partial prostheses.

Bromfenac sodium, acetaminophen/oxycodone, ibuprofen, and placebo for relief of postoperative pain.

The objective of this double-masked, parallel-group, multicenter, inpatient study was to compare bromfenac with an acetaminophen/oxycodone combination and ibuprofen in patients who had pain due to abdominal gynecologic surgery. In the 8-hour, single-dose phase, 238 patients received single oral doses of bromfenac (50 or 100 mg), acetaminophen 650 mg/oxycodone 10 mg, ibuprofen 400 mg, or placebo. In the multiple-dose phase, 204 patients received bromfenac, acetaminophen/oxycodone, or ibuprofen for up to 5 days. In the single-dose phase, both bromfenac doses produced peak analgesic responses equivalent to acetaminophen/oxycodone, but the responses to bromfenac were longer lasting. Bromfenac produced significantly better overall (8-hour) analgesic summed scores than acetaminophen/oxycodone. Ibuprofen was less efficacious than the other analgesics. The remedication rate was lower in both bromfenac groups than in the other treatment groups. The acetaminophen/oxycodone group reported more somnolence and vomiting. Single doses of bromfenac provided analgesia at least equivalent to that of the acetaminophen/oxycodone combination, with a longer duration of action. Both doses of bromfenac and acetaminophen/oxycodone were superior to ibuprofen in this study.

Safe and cost-effective laparoscopic removal of adnexal masses.

STUDY OBJECTIVE: To evaluate laparoscopic removal of adnexal masses using a plastic bag to avoid peritoneal spillage. DESIGN: An observational study. SETTING: A university-affiliated private hospital. PATIENTS: Thirty-one women (mean age 48.7 yrs) with adnexal masses. INTERVENTIONS: Laparoscopic removal of adnexal masses ranging from 3 to 12 cm (18 complex, 5 septated cystic masses, 8 persistent simple cysts). The masses were placed in plastic sandwich bag and removed through the umbilical incision. Hospital costs, length of stay and operating times were compared with those of 24 patients undergoing the removal of similar masses by laparotomy. MEASUREMENTS AND MAIN RESULTS: Three masses were functional cysts, 4 were tubal cysts, 4 were endometriomas, and 20 were benign ovarian neoplasms. There were no malignancies. Peritoneal spillage occurred during one ovarian cystectomy. The only complication was bleeding from the cannula site. Comparing laparoscopy and laparotomy, average operating time was 73.45 minutes (range 34-148 min) and 81 minutes, average length of hospital stay was 17.4 hours (range 6-73 hrs) and 2.92 days, and average hospital cost was $2401 and $3539, respectively. CONCLUSION: Laparoscopic access provides a cost-effective method of removing adnexal masses with a very small risk of peritoneal spillage. When managed in this manner, rather than laparotomy, the cost reduction was significant.

Effects of chemical disinfectants on the surface characteristics and color of denture resins.

PURPOSE: Because dentures are disinfected repeatedly and for various amounts of time, it was of clinical interest to determine whether chemical disinfectants altered the surface texture or inherent color. MATERIAL AND METHODS: Five chemical disinfectants (Clorox, Banicide, Cidex-7, Biocide, and Multicide) in combination with five denture resins (Dentsply reline material, Hygenic HyFlo, Hygenic Perm, Lucitone 199, and Triad VLC reline resin) were evaluated at four different times of immersion (10 minutes, 30 minutes, 24 hours, and 7 days). Changes from baseline for surface roughness and color were recorded. Surface roughness data were recorded with a surface analyzer. Color data in CIE L*a*b* color space were measured with a colorimeter. Data were analyzed with repeated-measures analysis of variance and single-factor analysis of variance. RESULTS: Although statistical differences were demonstrated among disinfectants and resins for both measured parameters, the magnitudes of change in color and roughness was most often clinically insignificant. CONCLUSIONS: One disinfectant (Multicide) cannot be used on all five resins, and the remaining four disinfectants can be used on any of the five resins for up to a period of 30 minutes. All resins tested can be immersed in the four remaining disinfectants for up to 30 minutes without appreciable alteration to surface texture or color. Lucitone 199 resin can be immersed in any of the four disinfectants for up to 7 days without perceivable color change.

Tensile dislodgment evaluation of two experimental prefabricated post systems.

This study tested the tensile dislodgment forces of two experimental post designs that are threaded 7 mm into the most coronal aspect of the root. Experimental post systems ParaPost XT-7 (XT-7), and ParaPost XT-10 (XT-10) were compared to the Flexi-Post (FP) and to the Standard ParaPost (SP). The XT-7 prototype post measured 7 mm in length, while all other post systems were 10 mm. The XT-7 and the FP are active post systems that are threaded throughout their entire length. The SP is a passive serrated post system, and the XT-10 is a combination active/passive design that has a 7 mm coronal thread with a passive serrated apical end. All systems tested were titanium alloy except the SP system, which was stainless steel. The purpose of this study was to compare an active and a passive post design to the experimental designs of the XT-7 active post and the combined active/passive design of the XT-10. This study clearly demonstrated highest retention for the active post system, least retention for the passive post, with an intermediate retentiveness for the combined design.