The CEJ: a biofilm and calculus trap.

There is a direct correlation between increasing periodontal probing depth and increasing presence of residual biofilms and calculus. One of the more common areas to find postscaling and root-planing residual biofilm and calculus is the cemento-enamel junction (CEJ)--an area that in most cases is easily accessible. Yet few studies have addressed the question of why the CEJ is a potential biofilm and calculus trap. This article discusses the various anatomical relationships of enamel, dentin, and cementum at the CEJ, the role of CEJ anatomy in the retention of biofilm (with SEM photographs as supporting evidence), and the biological and clinical implications of subgingival residual biofilm and calculus.

Subgingival microbiologic effects of one-time irradiation by CO2 laser: a pilot study.

BACKGROUND: Third-generation carbon dioxide (3-CO(2)) lasers have handpieces that accommodate a periodontal insert that permits irradiation directly into the periodontal pocket/sulcus. The purpose of this pilot study was to evaluate, by scanning electron microscopy (SEM), the surface effects of 3-CO(2) laser treatment on the root surfaces and soft tissues and to investigate the effects of 3-CO(2) laser on periodontal pathogenic bacteria compared to negative controls. METHODS: Five patients with chronic periodontitis and treatment planned for a maxillary immediate denture were included in the study. Periodontal pockets with a mean probing depth of 5.5 +/- 0.8 mm were irradiated one time by CO(2) laser (wavelength of 10,600 nm) at a power of 2.2 W, 50 Hz, an 80-millisecond pulse length, and an exposure rate of 1 mm per 5 seconds. DNA analysis of eight periodontal bacteria was performed on samples collected from laser-treated and control sites prior to and immediately following treatment and was compared between groups. In addition, block biopsies, including soft tissue, were harvested for SEM examination. RESULTS: SEM examination of test group specimens showed heat damage on the soft tissues in three of 17 specimens (17.6%). In addition, 11.7% (two of 17) of the 3-CO(2)-treated teeth exhibited localized slight damage to root surfaces. Microbiologic results of the control sites indicated that 90.6% of the bacterial counts remained the same, 6% increased, and 3% decreased. In the test group, 71.25% of the bacterial count analyses for the eight different periodontal microbes remained the same, 12.50% increased, and 16.25% decreased. CONCLUSION: A one-time use of the 3-CO(2) laser in periodontal pockets did not sterilize or substantially reduce subgingival bacterial populations compared to negative controls.

Root surface area of the mandibular cuspid and bicuspids.

BACKGROUND: The purpose of this study was to determine the total root surface area of extracted teeth by computerized image analysis and the amount of remaining attachment area assuming various amounts of bone loss due to periodontal disease. METHODS: One hundred fifty extracted mandibular teeth were evaluated, and measured from cusp tip to the cemento-enamel junction (CEJ), CEJ to root apex, and cusp tip to root apex. The fulcrum point of the tooth was also measured, along with the total root surface area of attachment and total surface area of attachment remaining following simulation of attachment loss in 2 mm increments. Measurements were made on 80 teeth on one proximal surface and either the buccal or lingual surface and multiplied by a factor of 2. Measurements on 70 teeth were made on all 4 root surfaces to predict the accuracy of measuring only 2 surfaces to determine root surface area. Images of the tooth surfaces were obtained by video camera and converted to computer image with measurement of the surface areas. RESULTS: The total root surface area for the mandibular cuspids and first and second bicuspids was 275.88 mm2, 251.45 mm2, and 271.81 mm2, respectively. The 2-sided and 4-sided measurements for the mandibular first bicuspid were 252.55 mm2 and 247.02 mm2, respectively (P>0.05). CONCLUSIONS: This study found the total root surface area to be greater than that in most previous studies. Increasing attachment loss is related to decreasing root surface area; however, this relationship is not directly proportional. No statistical difference was found between measuring 4 surfaces versus only 2 surfaces.

Analysis of patient factors impacting duration of periodontal maintenance appointments: an exploratory study.

PURPOSE: The periodontal maintenance (PM) appointment requires varying amounts of time and is absolutely essential for long-term successful periodontal therapy. This study assessed time requirements for PM and relative contribution of patient-level factors such as oral health status, complex medical history, maintenance compliance and demographics. METHODS: One hundred patients receiving PM in a graduate periodontal program at a dental school participated in this cross sectional, observational study and components of their PM were timed in minutes/seconds. Descriptive data were obtained for average total-time required for PM and relative time for each treatment component. Hierarchical multiple linear regression determined what patient-level factors demonstrated the greatest impact on total-time to complete PM. RESULTS: The average PM appointment interval, with radiographs, was 1 hour, 16 minutes, 23 seconds (SD 19:25 minutes). When cubicle preparation and disinfection was included, the total-time was 1 hour, 24 minutes, 31 seconds (±19:32 minutes). Multiple regression showed that BOP, dentist examinations, number of carious lesions and/or restorative defects, number of teeth/implants, taking radiographs, female gender and deposit aggregate (supragingival and subgingival calculus and stain) were significant predictors of total PM duration and explained 57% variance (p<0.05, R2=0.569). CONCLUSION: Based on the average comprehensive PM appointment time of 1:16 minutes, the typical appointment of 60 minutes is insufficient to achieve the goals of a comprehensive PM in this academic clinic setting. These findings suggest the need to utilize more customized models for scheduling PM in order to achieve time allocations that are individualized to address specific patients' needs.

Referring periodontal patients: clinical decision making by dental and dental hygiene students.

Referral of periodontal patients requires development of a complex set of decision making skills. This study was conducted to determine criteria used by dental and dental hygiene students regarding the referral of periodontal patients for specialty care. Using mixed methods, a thirteen-item survey was developed to elicit the students' perceptions of their knowledge, confidence regarding managing patients, and clinical reasoning related to periodontal patients. The instrument was administered during the summer prior to (T1) and at the end of the students' final year (T2) of training. Seventy-nine dental students (81 percent of total class) and thirty dental hygiene students (83 percent of total class) completed T1. At T2, forty-two dental (44 percent of total class) and twenty-six dental hygiene students (87 percent of total class) completed the questionnaire. While 90 percent of dental and 96 percent of dental hygiene respondents reported a willingness to refer patients with active disease to specialists, only 40 percent of dental and 36 percent of dental hygiene respondents reported confidence in diagnosing, treating, and appropriately referring such patients. The students' ability to recognize critical disease and risk factors influencing referral was good; however, clinical application of that knowledge indicated a gap between knowledge and applied reasoning. The students' attitudes about the importance of periodontal disease and their perceived competence to identify critical disease risk factors were not significantly related (p>0.05) to correct clinical decisions in the case scenarios. The study concludes that dental and dental hygiene curricula should emphasize both the acquisition and application of knowledge regarding criteria for referral of periodontal patients.

Student evaluation of clickers in a combined dental and dental hygiene periodontology course.

The purpose of this report is to describe the general use of clickers as an active learning tool and how they were used in teaching a combined periodontology course for second-year dental and junior dental hygiene students. A survey was used to capture student perceptions following completion of the course. Specific domains were active learning, improved performance, and expectations. The survey response rate was 94.5 percent (121/128). Descriptive analyses showed that, in the domain of active learning, 102 (84.3 percent) agreed/strongly agreed that the use of clickers made the lectures more interactive; sixty-six (54.5 percent) agreed/strongly agreed that the clickers made them focus; and ninety-two (76 percent) agreed/strongly agreed that the clickers encouraged active participation. In the domain regarding improved performance, sixty-three (52 percent) agreed/ strongly agreed that the review sessions utilizing clickers helped them prepare for tests. In the domain of expectations, ninety-three (76.9 percent) had a better idea of what to expect on the examination due to the use of clickers, and seventy-three (60.3 percent) thought that the clickers should be used in future semesters for this class. In addition, faculty members appreciated the greater participation afforded through the use of clickers to obtain a better understanding of the students' grasp of course content. Learning theory suggests that students must actively engage in the learning process in order for meaningful learning in the form of critical thinking and problem-solving to take place. In this study, students confirmed that the use of clicker technology encouraged their active participation in a periodontology course.

Can application of exogenous fibronectin enhance periodontal regeneration?

BACKGROUND: Although fibronectin (FN) is an important extracellular glycoprotein involved in periodontal wound healing, it is not clear whether the application of exogenous fibronectin (ExoFN) offers any clinical benefit. The purpose of this preliminary in vitro study was to determine the binding of FN from three different sources, viz. endogenous EDTA-plasma, endogenous serum and exogenous commercial purified human fibronectin in PBS buffer, to demineralized and non-demineralized root powder. METHOD: The binding of FN to a known quantity of mineralized and non-demineralized root powder by overnight incubation at 15 degrees C was studied by enzyme immunoassay (EIA) technique. The criteria for optimal performance of EIA procedure for the determination of FN was established. Particle size of powdered root structure was standardized using a Vibratory Sieve Shaker. RESULTS: The EDTA-plasma and the serum FN exhibited binding of (17.8 +/- 2.1 microg) and (6.5 +/- 4.5 microg), respectively, to the non-demineralized root powder. However, the binding was only significant for the EDTA-plasma FN (p < 0.01) when compared to controls. In the demineralized group there was no ascertainable binding of FN from either endogenous or exogenous sources. ExoFN in buffer exhibited no binding at all to the non-demineralized or demineralized root powder. CONCLUSION: The preliminary data suggest that additional plasma and serum factors may facilitate the binding of FN to root powder. High levels of FN in blood do not necessarily indicate that FN is available for binding to the root surface during periodontal surgery.

A TEM/SEM study of the microbial plaque overlying the necrotic gingival papillae of HIV-seropositive, necrotizing ulcerative periodontitis.

The purpose of this study was to examine by transmission (TEM) and scanning electron microscopy (SEM) the supragingival microbial plaque overlying the ulcerated gingival papillae of necrotizing ulcerative periodontitis (NUP) lesions in HIV-seropositive patients. The microbiota of NUP and HIV-seropositive patients with periodontitis has been reported to be similar to that of conventional periodontitis in non-infected subjects, although several investigators have also reported high recovery rates of microbes not generally associated with the indigenous oral microbial flora. Light and electron microscopic observations and microbial culture studies indicate a similar high prevalence of spirochetes in both necrotizing ulcerative gingivitis (NUG) and NUP. In addition, several studies have reported more frequent isolation of Candida albicans from diseased periodontal sites in HIV-seropositive patients than from non-diseased sites. Ten male and six female patients, each HIV-seropositive and exhibiting NUP, constituted the study population. Two biopsies of involved gingival papillae from between posterior teeth were obtained from each patient and processed for examination by both TEM and SEM. Microscopic examination revealed a surface biofilm comprised of a mixed microbial flora of various morphotypes in 81.3% of biopsy specimens. The subsurface flora featured dense aggregations of spirochetes in 87.5% of specimens. Zones of aggregated polymorphonuclear leukocytes and necrotic cells were also noted. Yeasts were observed in 65.6% of specimens and herpes-like viruses in 56.5% of the specimens. Collectively, except for the presence of yeast and viruses, the results suggest that the microbial flora and possibly the soft tissue lesions of NUP and necrotizing ulcerative gingivitis are very similar.