Tetracycline impregnated bone grafts in the management of peri-implantitis and guided bone regeneration around dental implants: A systematic review.

Background: Rehabilitation of dental arches with the help of dental implants has been revolutionary and a significant part of research is devoted to increasing its success rate. One of the most common causes of failure of dental implants is peri-implantitis caused due to microbial invasion. Newer strategies are being adapted for the treatment of peri-implantits and recent surgical management with the help of antibiotic-impregnated bone grafts shows a promising future. Aim and objectives: This study aimed to test the efficacy of bone grafts incorporating tetracycline and its derivatives in the treatment of peri-implantits and guided bone regeneration with the estimation of clinical and radiographic parameters. Methods: A thorough search was made on eminent databases such as PubMed, Embase, Scopus, and Cochrane Library database for published literature on tetracycline impregnated bone grafts used either in the management of peri-implantitis or for guided bone regeneration around dental implants.The measures of outcome were clinical attachment loss or probing depth around dental implants and radiographic bone height. Results: Nine potentially eligible full-text published articles including case reports, case series, observational studies, and randomized controlled trials were selected for review. Most of the studies reviewed; reported a reduction in probing depth and an increase in bone height and density after placement of tetracycline bone grafts around the dental implant. Conclusion: The incorporation of tetracycline into the bone grafts shows promising results as an agent of local delivery around dental implants in the management of peri-implantitis and for guided bone regeneration. Future trials are required to produce a body of evidence and to facilitate the translation of this procedure into clinical practice.

LEPTOSPIROSIS IN URBAN AND SUBURBAN AMERICAN BLACK BEARS ( URSUS AMERICANUS) IN WESTERN NORTH CAROLINA, USA.

American black bear ( Ursus americanus) populations in North Carolina, US have recovered significantly in recent decades and now occupy much of western North Carolina, including urban-suburban areas. We used the black bear as a potential sentinel for leptospirosis, a bacterial zoonotic disease caused by Leptospira spp., which is maintained by domestic and wild mammals. We determined whether Leptospira spp. were present across a gradient of housing densities in the urban and suburban black bear population in and around Asheville, North Carolina using serologic and molecular surveys. We collected blood from captured black bears ( n=94) and kidneys and bladders from carcasses ( n=19). We tested a total of 96 (47 females, 47 males, and 2 unknown) serum samples by microscopic agglutination test (MAT) and had positive results (titer >1:100) for L. kirschneri serovar Grippotyphosa (L. Grippotyphosa) in 4 females (8%) and 5 males (10%). No other serovars showed elevated titers in MAT. We tested a total of 125 samples using PCR ( n=96 serum, n=20 kidney, and n=9 bladders) and obtained positive results from one serum (1%), one kidney (5%), and one bladder (11%). The presence of Leptospira spp. in black bears occupying an urban and suburban landscape may indicate a more extensive occurrence of the bacteria among animals in the study region because black bears are the top carnivore in that ecosystem. Potential threats of widespread contamination during natural events such as flood or drought must be considered.

Buteo Nesting Ecology: Evaluating Nesting of Swainson's Hawks in the Northern Great Plains.

Swainson's hawks (Buteo swainsoni) are long-distance migratory raptors that nest primarily in isolated trees located in areas of high grassland density. In recent years, anthropogenic conversion of grassland habitat has raised concerns about the status of the breeding population in the northern Great Plains. In 2013, we initiated a study to investigate the influence of extrinsic factors influencing Swainson's hawk nesting ecology in north-central South Dakota and south-central North Dakota. Using ground and aerial surveys, we located and monitored nesting Swainson's hawk pairs: 73 in 2013 and 120 in 2014. We documented 98 successful breeding attempts that fledged 163 chicks; 1.52 and 1.72 fledglings per successful nest in 2013 and 2014, respectively. We used Program MARK to evaluate the influence of land cover on nest survival. The top model, SDist2Farm+%Hay, indicated that nest survival (fledging at least one chick) decreased as nests were located farther from farm sites and as the percent of hay cover increased within 1200-m of the nest site (34.4%; 95% CI = 27.6%-42.3%). We used logistic regression analysis to evaluate the influence of landscape variables on nest-site selection; Swainson's hawks selected for nest sites located closer to roads. We suggest that tree belts associated with farm sites, whether occupied or not, provide critical breeding sites for Swainson's hawks. Additionally, poor breeding success may be related to the late migratory behavior of this species which requires them to occupy marginal habitat due to other raptors occupying the most suitable habitat prior to Swainson's hawks arriving to the breeding grounds.