Influence of Cremophor El on the bioavailability of intraperitoneal paclitaxel

It has been hypothesized that the paclitaxel vehicle Cremophor EL (CrEL) is responsible for nonlinear drug disposition by micellar entrapment. To gain further insight into the role of CrEL in taxane pharmacology, we studied the pharmacokinetics of paclitaxel in the presence and absence of CrEL after i.p. and i.v. dosing. Patients received an i.p. tracer dose of [G-(3)H]paclitaxel in ethanol without CrEL (100 microCi diluted further in isotonic saline) on day 1, i.p. paclitaxel formulated in CrEL (Taxol; 125 mg/m(2)) on day 4, an i.v. tracer of [G-(3)H]paclitaxel on day 22, and i.v. Taxol (175 mg/m(2)) on day 24. Four patients (age range, 54-74 years) were studied, and serial plasma samples up to 72 h were obtained and analyzed for total radioactivity, paclitaxel, and CrEL. In the presence of CrEL, i.v. paclitaxel clearance was 10.2 +/- 3.76 liters/h/m(2) (mean +/- SD), consistent with previous findings. The terminal disposition half-life was substantially prolonged after i.p. dosing (17.0 +/- 11.3 versus 28.7 +/- 8.72 h), as was the mean residence time (7.28 +/- 2.76 versus 40.7 +/- 13.8 h). The bioavailability of paclitaxel was 31.4 +/- 5.18%, indicating insignificant systemic concentrations after i.p. treatment. CrEL levels were undetectable after i.p. dosing (<0.05 microl/ml), whereas after i.v. dosing, the mean clearance was 159 +/- 58.4 ml/h/m(2), in line with earlier observations. In the absence of CrEL, the bioavailability and systemic concentrations of i.p. paclitaxel were significantly increased. This finding is consistent with the postulated concept that CrEL is largely responsible for the pharmacokinetic advantage for peritoneal cavity exposure to total paclitaxel compared with systemic delivery

Clinical performance of bonded partial lithium disilicate restorations: The influence of preparation characteristics on survival and success

OBJECTIVES The aim of this study was to investigate the influence of preparation characteristics on the survival, success, and clinical performance of partial indirect lithium disilicate restorations with immediate dentin sealing. METHODS This retrospective clinical study evaluated partial indirect lithium disilicate restorations placed in conjunction with Immediate Dentin Sealing (IDS) in (pre)molar teeth between March 2018 and May 2021. The restorations were luted using pre-heated composite. The study focused on survival, success, and clinical performance, which was evaluated using the modified United States Public Health Service (USPHS) criteria. Results were analyzed using the Kaplan-Meier estimates, log-rank tests, and Fisher exact tests. RESULTS Partial indirect lithium disilicate restorations (N = 454) were evaluated in 214 patients. The mean evaluation time was 37 months, with a cumulative survival rate of 99.2 % and a cumulative success rate of 97.6 %. Fourteen failures occurred, with endodontic pathology as the predominant failure mode, followed by secondary caries, debonding, and tooth fracture. No statistically significant influence of the preparation variables on survival and success was observed (p > .05). The short-term clinical performance was clinically acceptable in > 90 % of the evaluations. CONCLUSIONS This retrospective study on partial indirect lithium disilicate restorations in conjunction with IDS demonstrates survival and success rates of 99.2 and 96.7 % over a mean evaluation period of 37 months. A marked influence of the studied preparation characteristics on the survival, success and clinical performance of lithium disilicate partial restorations could not be demonstrated. Partial lithium disilicate restorations exhibit good clinical performance in >90 % of the cases. CLINICAL SIGNIFICANCE The results of this study suggest that preparation characteristics had no significant impact on the survival, success, and clinical performance of partial lithium disilicate restorations in conjunction with IDS. Results show good clinical performance and high survival and success rates, regardless of preparation characteristics

Mechanical Strength and Stiffness of Biodegradable and Titanium Osteofixation Systems

Purpose:\ud To present relevant mechanical data to simplify the selection of an osteofixation system for situations requiring immobilization in oral and maxillofacial surgery.\ud \ud Materials and Methods:\ud Seven biodegradable and 2 titanium osteofixation systems were investigated. The plates and screws were fixed to 2 polymethylmethacrylate (PMMA) blocks to simulate bone segments. The plates and screws were subjected to tensile, side bending, and torsion tests. During tensile tests, the strength of the osteofixation system was monitored. The stiffness was calculated for the tensile, side bending, and torsion tests.\ud \ud Results:\ud The 2 titanium systems (1.5 mm and 2.0 mm) presented significantly higher tensile strength and stiffness compared with the 7 biodegradable systems (2.0 mm, 2.1 mm, and 2.5 mm). The 2.0 mm titanium system showed significantly higher side bending and torsion stiffness than the other 8 systems.\ud \ud Conclusion:\ud Based on the results of the current study, it can be concluded that the titanium osteofixation systems were (significantly) stronger and stiffer than the biodegradable systems. The BioSorb FX (Linvatec Biomaterials Ltd, Tampere, Finland), LactoSorb (Walter Lorenz Surgical Inc, Jacksonville, FL), and Inion (Inion Ltd, Tampere, Finland) 2.5 mm systems have high mechanical device strength and stiffness compared with the investigated biodegradable osteofixation systems. With the cross-sectional surface taken into account, the Biosorb FX system (with its subtle design) proves to be the far more superior system. The Resorb X (Gebrüder Martin GmbH & Co, Tuttlingen, Germany) and MacroPore (MacroPore Biosurgery Inc, Memphis, TN) systems present to be, at least from a mechanical point of view, the least strong and stiff systems in the test

Prospective clinical evaluation of 765 partial glass-ceramic posterior restorations luted using photo-polymerized resin composite in conjunction with immediate dentin sealing

OBJECTIVES: To evaluate the clinical performance of partial glass-ceramic (IPS e.max Press) posterior restorations. MATERIALS AND METHODS: A total of 765 restorations in 158 patients were placed between 2008 and 2018 and evaluated in a prospective study during regular dental care visits between 2015 and 2018. The restorations were luted with a conventional photo-polymerized resin composite (HFO) in conjunction with an Immediate Dentin Sealing procedure (IDS). Intra-oral photographs and radiographs were made and evaluated using USPHS criteria. RESULTS: The mean observation time was 53.3 months (range 3-113 months). Three absolute failures occurred (tooth fractures, n = 2; apical re-infection, n = 1) all leading to the loss of the restored tooth. Repairable and salvageable failures occurred in 9 teeth (endodontic complications, n = 7; secondary caries, n = 1; debonding, n = 1). The survival and success rates according to Kaplan-Meier after 5 years cumulated to 99.6% and 98.6%, respectively. Location (premolar/molar and mandibula/maxilla), pre-restorative endodontic status (vital/devitalised) and extension of the indirect ceramic restoration (number of sides and cusps involved) did not significantly affect the cumulative success rate (log rank test, p > 0.05). The condition of the vast majority of the restorations remained unaffected for 5 years. CONCLUSIONS: Partial glass-ceramic posterior restorations (pressed lithium disilicate (IPS e.max press, Ivoclar Vivadent) luted by means of a conventional photo-polymerized resin composite in conjunction with the use of an IDS procedure have an excellent medium-term prognosis. CLINICAL RELEVANCE: Partial glass-ceramic posterior restorations can be considered as a highly reliable treatment option. Location and extension of the restoration and pre-restorative endodontic status do not affect success rate