Adjunctive efficacy of systemic metronidazole in the surgical treatment of periodontitis: a double-blind parallel randomized clinical trial.

OBJECTIVES: The purpose of this study was to evaluate the clinical and microbiological impact of adjunctive metronidazole to periodontal surgery. MATERIALS AND METHODS: Systemically healthy patients, with stages III-IV, grades B-C periodontitis, were randomly assigned to receive metronidazole or placebo adjunctive to periodontal surgery, after subgingival instrumentation. Clinical variables were recorded at the initial visit, 6 weeks after subgingival instrumentation, and 3, 6, and 12 months after surgery. Microbiological samples were taken at initial and final visits and analyzed by quantitative polymerase chain reaction. RESULTS: Our results showed no statistically significant differences in the reduction of probing depth between the initial and final (1 year) visits in the two treatment groups. Additionally, no statistically significant differences were observed between study groups when comparing the post-subgingival instrumentation and final visits. However, 3 months after surgery, probing depth (mean difference, MD = 0.31 mm, 95% confidence interval, CI [0.13; 0.49]; p = 0.001) and clinical attachment level (MD = 0.64 mm, 95% CI [0.02; 1.27]; p = 0.044) were significantly lower in the test group. CONCLUSIONS: The adjunctive use of systemic metronidazole to periodontal surgery has a limited clinical and microbiological impact in the present study, and therefore, its use is not recommended. CLINICAL RELEVANCE: There are no studies that have evaluated the clinical and microbiological impact of the adjunctive use of systemic metronidazole to periodontal surgery (step 3 of periodontal therapy). The results of the present study do not support the adjunctive use of systemic metronidazole to periodontal surgery.

Effects of extruded whole maize, polydextrose and cellulose as sources of fibre on calcium bioavailability and metabolic parameters of growing Wistar rats.

The aim of this study was to evaluate the influence of diets with different types of fibres on Ca bioavailability and metabolic parameters in growing Wistar rats. Twenty four male Wistar rats were fed with 3 different diets: control (C), polydextrose (PD), and extruded whole maize (M) during a 60 day period. Apparent Ca absorption percentage (%Ca Abs), total skeleton bone mineral content (t BMC), total bone mineral density (t BMD), femur (F), spine (S) and tibia (T) BMD, cecum weight, and pH were evaluated. Malondialdehyde (MDA) and lipid (TG and cholesterol) contents in serum and liver were also evaluated. The results showed that rats fed with M and PD had the same cecum weight, but higher than that of C (1.53 ± 0.02 vs. 0.94 ± 0.01). There was moderate acidification of the cecal content in rats fed with M compared to C (pH 5.93 vs. 6.98) and the fecal weight was 1.06 ± 0.02, 3.07 ± 0.03 and 4.81 ± 0.05 for PD, M and C, respectively. There were significant differences in %Ca Abs between PD and C (87.57 ± 1.20 vs. 71.10 ± 1.11). The PD group had the highest values of F-BMD, S-BMD, and T-BMD, but there were no differences between M and C groups. Regarding lipids, there was a significant lowering effect in the M liver triglycerides content. Moreover, liver MDA levels significantly decreased with M and PD diets. The consumption of PD and grain fibres can exert some beneficial gastrointestinal effects such as lowering of the pH, hepatic TG and MDA content related to fibre colon fermentation.

Development of naturally activated edible films with antioxidant properties prepared from red seaweed Porphyra columbina biopolymers.

The aim of this work was to study the physicochemical and antioxidant properties of phycobiliproteins-phycocolloids-based films, obtained from mixtures of two aqueous fractions extracted from Porphyra columbina red seaweed, one enriched in phycocolloids (PcF) and the other in phycobiliproteins (PF). Films with different ratios of PF:PcF (0, 25, 50, 75, 100% [w/w]) and without plasticizer addition were prepared by casting. PcF films had excellent mechanical properties (tensile strength ∼50MPa, elongation at break ∼3% and an elastic modulus ∼17.5MPa). The addition of PF to formulations exerted a plasticizing effect on the PcF matrix, which was manifested in moisture content, water solubility and mechanical properties of the resulting films but not in its water vapour permeability. The antioxidant capacity (TEAC) of the PcF films was significantly increased by the addition of PF and a direct relationship between TEAC and the total phenolic compounds (r(2)=0.9998) and R-phycoerythrin (r(2)=0.9942) was observed.