Differences between Biofilm Growth Before and After Periodontal Therapy
S. Resposo, J. Tobler, B. Alfant, J. Gollwitzer, C. Walker, and L. Shaddox, University of Florida, Gainesville, USA
Objective:
The purpose of this study was to evaluate in vitro subgingival biofilm growth from plaque samples collected before and after scaling and root planing (SRP).
Methods:
Subgingival samples were collected before and after SRP from a 5mm pocket or greater with bleeding, along with 5ml of saliva from 9 patients diagnosed with chronic periodontitis. Calcium hydroxyapatite discs were coated with 10% filtered sterilized saliva for 2hrs, placed in 5ml of Trypticase Soy Broth (TSB) and innoculated with 100ul of dispersed subgingival plaque. Biofilms were grown anerobically at 37?C for up to 10 days with transfer to fresh medium at 48 hour intervals. Biofilms were then processed at specific intervals for total viable counts and the species present were evaluated and semi-quantified by DNA-DNA hybridization. Biofilm composition was also analysed by Scanning Electron Microscopy (SEM).
Results:
Samples taken before SRP harbored more bacteria than after SRP (107 versus 106, p=0.004). However, both sets of biofilms grew at a similar rate, reaching a peak CFU of ~108 cells as early as day 3 (p>0.05). Samples taken after SRP presented the same species as those samples taken previous to the procedure, but in less quantity (p<0.001). Greater amounts of red complex bacteria and A.actinomycetencomitans (~104) were found both before and after SRP when compared to other species (~102). SEM analysis showed growth of a complex structure comprised of rods, cocci,fusiforms and filaments in both sets of mature biofilms.
Conclusion:
Subgingival biofilms before and after SRP treatment present the same composition of bacterial flora and are able to grow similarly if given proper conditions. Therefore, subgingival bacteria that remains after SRP therapy has the potential to recolonize to pretreatment levels if not properly maintained.
Minocycline HCl Microspheres Reduce Red-Complex Bacteria in Periodontal Disease Therapy
J. Max Goodson, John C. Gunsolley, Sara G. Grossi, Paul S. Bland, Joan Otomo-Corgel, Frances Doherty, and Judy Comiskey
Background:
The objective of this trial was to measure the antimicrobial effects of a minocycline HCl microsphere (MM) local drug-delivery system when used as an adjunct to scaling and root planing (SRP). DNA probe analysis for 40 bacteria was used to evaluate the oral bacteria of 127 subjects with moderate to advanced chronic periodontitis.
Methods:
Subjects were randomly assigned to either SRP alone (N = 65) or MM + SRP (N = 62). The primary endpoints of this study were changes in numbers and proportions of the red-complex bacteria (RCB) and the sum of Porphyromonas gingivalis, Tannerella forsythia (formally T. forsythensis), and Treponema denticola relative to 40 oral bacteria at each test site from baseline to day 30. Numbers of RCB from the five test sites were averaged to provide a value for each subject.
Results:
MM+ SRP reduced the proportion of RCB by 6.49% and the numbers by 9.4 · 105. The reduction in RCB proportions and numbers by SRP alone (5.03% and 5.1 · 105, respectively) was significantly less. In addition, MM + SRP reduced probing depth by 1.38 mm (compared to 1.01 mm by SRP alone), bleeding on probing was reduced by 25.2% (compared to 13.8% by SRP alone), and a clinical attachment level gain of 1.16mm(compared to 0.80mmby SRP alone) was achieved.
Conclusion:
These observations support the hypothesis that RCBs are responsible for periodontal disease and that local antimicrobial therapy using MM + SRP effectively reduces numbers of RCBs and their proportions to a greater extent than SRP alone. J Periodontol 2007;78:1568-1579.
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The Peer Review Process as it Relates to Dental Hygiene Publishing
By Rebecca S. Wilder, RDH, BS, MS
The review process of peer evaluation of research papers builds better articles for readers and strengthens the analytical skills of writers.
When I first started in academics, I had little writing experience. I had joined the dental hygiene faculty at the University of North Carolina on a tenure track, and was expected to begin conducting original research and writing in peer-reviewed journals. One of my first writing endeavors was a literature review paper on faculty calibration. At the time, the former editor of the Journal of Dental Education was a faculty member at my institution. He was teaching short courses on how to write papers for publication, so I decided to take advantage of his experience. During the course, I asked him to critique my paper before I sent it to Educational Directions, a former publication of ADHA.
I will never forget how the paper looked when he returned it to me. It looked as though it had been an editing nightmare! It had been torn apart! After I recuperated from the initial shock, I took the draft and revised it according to the suggestions he made. I sent it to him for review once again. Red ink once again appeared on that second revision. By the time I finished writing that paper, I learned to appreciate a critical review of my work and the process it takes to improve writing skills. To this day, I show that paper to my beginning graduate students so that they will know we all had to start somewhere!
The beginning writer needs the critique of others to grow in his or her work. This process takes an ego adjustment! The primary reason for the critique process is to improve research papers and ensure the accuracy of content and clarity of that piece. These are the primary functions of the peer-review process in a scientific journal. It is our job as reviewers to make certain that research is in the best possible form before it is published. In the long run, the process of critique builds stronger writers and offers the best quality research for our profession.
This is the third article in a series describing the process of conducting research and getting it published. The first article shared how research is conducted, the dental hygienist’s responsibility to read new research and what types of research can be found in the pages of the profession’s top publications. The second article reviewed the elements of a research article and how a dental hygienist may evaluate this material. This article will discuss how research articles get published so that dental hygienists may understand the process and the importance of peer review.
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