Ultrasonic vs. hand instrumentation in periodontal therapy: clinical outcomes.

Periodontal disease is the most common oral disease in adults. Traditional nonsurgical periodontal therapy involves subgingival removal of hard and soft deposits on the root surface, along with maintenance of good oral hygiene. Nonsurgical periodontal therapy can either be definitive or part of the initial phase before surgical therapy. Mechanical therapy, either with hand or ultrasonic instrumentation, is the keystone of nonsurgical periodontal therapy. This requires considerable amounts of time and a high level of operator skill. The use of appropriate instruments greatly increases clinical efficiency. This article discusses the use of ultrasonic and hand instrumentation, along with recent advances, and the benefits of adjunctive therapy during nonsurgical periodontal therapy.

Wound healing following surgical and regenerative periodontal therapy.

Clinical studies have evaluated the effect of conventional periodontal surgical therapy. In general, although some clinical gain in tissue support may be attained, these therapies do not support regeneration of the periodontal attachment. Even though the biological possibility of periodontal regeneration has been demonstrated, the clinical application of this intrinsic potential appears difficult to harness; thus also conceptually most intriguing candidate protocols face clinical challenges. In this review, we explore the bioclinical principles, condiciones sine quibus non, that unleash the innate potential of the periodontium to achieve clinically meaningful periodontal regeneration (i.e. space-provision, wound stability and conditions for primary intention healing). Moreover, limiting factors and detrimental practices that may compromise clinical and biological outcomes are reviewed, as is tissue management in clinical settings.

Sinus augmentation using rhBMP-2/ACS in a mini-pig model: relative efficacy of autogenous fresh particulate iliac bone grafts.

BACKGROUND: Implant dentistry in the posterior maxilla often requires bone augmentation. The gold standard, autogenous bone graft, requires additional surgery with associated morbidity, while bone biomaterials may not support relevant bone formation. Recombinant human bone morphogenetic protein-2 (rhBMP-2) in an absorbable collagen sponge (ACS), however, induces significant, clinically relevant bone formation in several settings including the maxillary sinus floor. OBJECTIVE: The objective of this study was to compare local bone formation and osseointegration following maxillary sinus augmentation using rhBMP-2/ACS or a particulate autogenous cancellous bone graft obtained from the iliac crest in conjunction with immediate placement of dental implants. MATERIALS AND METHODS: Bilateral sinus augmentation using an extraoral approach including rhBMP-2 (0.43 mg/ml)/ACS or the autogenous bone graft, alternated between left and right sinus cavities in five adult male Yucatan mini-pigs, was performed. Two 12-mm dental implants were inserted into the sinus wall protruding approximately 8 mm into the sinus cavity. Surgical sites were closed and sutured in layers; block biopsies collected for histometric analysis at 8 weeks. RESULTS: rhBMP-2/ACS induced bone of significantly greater and consistent quality compared with the iliac crest autogenous bone graft; bone density averaging 51.9 ± 3.0% vs. 32.9 ± 2.5% (P = 0.01). However, there were only numerical differences in augmented bone height (9.3 ± 0.5 vs. 8.6 ± 0.7 mm) and bone-implant contact (37.4 ± 3.0% vs. 30.7 ± 5.9%) between treatments. CONCLUSION: rhBMP-2/ACS induces bone of superior quality compared with an iliac crest particulate autogenous cancellous bone graft when used for maxillary sinus augmentation, and should perhaps be considered the new standard for this indication.

Chemoprevention by lipid-soluble tea polyphenols in diethylnitrosamine/phenobarbital-induced hepatic pre-cancerous lesions.

BACKGROUND: Green tea polyphenols (GTPs) have been proposed as promising candidates for chemoprevention. However, GTPs levels are maintained relatively low in the blood and are chemically-unstable. Lipid-soluble tea polyphenols (LTPs) are products of modified GTPs with ester linkage with fatty acids. LTPs are lipophilic and expected to provide improved absorption and utilization in the body compared with water-soluble polyphenols. The current study was designed to investigate the chemo-preventive property and the possible mechanisms of LTP action against diethylnitrosamine (DEN)-induced liver cancer in rats. MATERIALS AND METHODS: Oral administration of LTPs at doses of 0, 40, and 400 mg/kg/day was initiated 2 weeks prior to DEN injection and was continued for 30 weeks. At that time point samples were collected and liver histopathological analyses were performed. RESULTS: LTPs decreased the area and number of placental glutathione S-transferase-positive foci in liver samples of DEN-treated rats. Furthermore, LTPs counteracted DEN-induced fibrosis formation in liver. Immunohistochemical staining of rat liver showed that LTPs inhibited DEN-mediated elevations in numbers of cells positive for PCNA and 8-OHdG. CONCLUSION: For the first time, the present study demonstrated, that LTPs exert a chemo-preventive effect against precancerous lesions through inhibition of cellular proliferation and DNA damage in a rat liver model.

Antioxidant effects of lipophilic tea polyphenols on diethylnitrosamine/phenobarbital-induced hepatocarcinogenesis in rats.

BACKGROUND: The purpose of the present study was to compare the antioxidant potential of lipophilic tea polyphenols (LTP) against the one of naturally-occurring water-soluble green tea polyphenols (GTP) in a two-stage model of diethylnitrosamine (DEN)/phenobarbital (PB)-induced hepatocarcinogenesis in Sprague-Dawley rats. MATERIALS AND METHODS: GTP/LTP was given 5-times weekly by oral gavage with tea polyphenols equivalent to 0-, 40- and 400-mg/kg of body weight/day. GTP/LTP treatment was started 2 weeks prior to the initiation of DEN and continued for 30 weeks. RESULTS: Histopathological and electron microscopic examination of liver tissue confirmed the protective effect of LTP on DEN/PB-induced liver damage and pre-carcinogenesis. LTP treatment significantly increased total antioxidant capacity (T-AOC) and glutathione peroxidase (GSH-Px) activity in liver tissues. Immunohistochemical detection of cellular nuclear factor erythroid-2-related factor-2 (Nrf2) and peroxiredoxin-6 (P6) indicated a down-regulation in Nrf2 and up-regulation of P6 expression in the liver of LTP-supplemented rats. CONCLUSION: The present study provides evidence for the first time, that LTP exerts significant antioxidant effects on DEN/PB-induced liver damage and hepatocarcinogenesis through elevating T-AOC levels, enhancing GSH-Px activity and inducing P6 expression in rat liver tissues.