Introduction: While sharing a common causal link, both rheumatoid arthritis (RA) and periodontitis (PD) manifest similar inflammatory responses. With the progression of severity, both diseases result in bone loss. Hence, Ca and Zn, as structural components of the bones, are expected to be altered in saliva and serum in PD and RA respectively. Zinc and calcium concentrations have been studied previously in patients with PD or RA, with PD patients exhibiting increased salivary Ca and decreased Zn concentrations in serum, while RA patients have been reported to express low plasma concentrations of both Zn and Ca. The aim of this study is to evaluate the saliva and serum levels of Ca and Zn in PD patients with or without RA. Methods: Serum and saliva samples were collected from 82 patients from the Faculty of Dentistry, University of Malaya and the University Malaya Medical Centre rheumatoid clinic. Patients were grouped according to their periodontal health and RA status (healthy n=21; PD n=21; RA n=21; RAPD n=19). Results: Zinc concentration in serum was significantly higher (p
The impact strength of a newly developed experimental polyurethane-based polymer which is derived from palm oil (Experimental PU) was compared with denture polymers; heat-cured and self cured polymethyl methacrylate (PMMA) and ® Eclipse , light-activated urethane dimethacrylate prosthetic resin system. Ten specimens were ® prepared using heat-cured PMMA (Meliodent Heat Cure, Heraeus Kulzer, Germany), self cured PMMA ® (Meliodent Rapid Repair, Heraeus Kulzer, ® Germany), Eclipse baseplate resin (Dentsply, USA) and Experimental PU material. Specimens were prepared following manu- facturer’s instructions except for the Experimental PU material where it was prepared in bulk and sectioned to the desired dimension, 64 x 6 x 4 mm. A ‘V’ notch of approximately 0.8mm in depth was machine cut across the 6mm width. Prior to the Charpy type impact test, specimens were soaked in a water bath for 50 hours at 37ºC. ® Eclipse baseplate resin showed the highest 2 impact strength (2.73 kJ/m ±0.54) followed by ® 2 Meliodent Rapid Repair (2.50kJ/m ±0.65), ® 2 Meliodent Heat Cure (1.96kJ/m ±0.42) and 2 Experimental PU (1.04kJ/m ±0.29). One-way ANOVA showed significant interaction between materials (p