A comprehensive clinical competency-based assessment in periodontics

Traditional periodontics clinical examinations in dental education frequently assess a narrow set of clinical skills and do not adequately assess the ability of students to independently manage a periodontal patient. As an alternative, the authors developed a comprehensive periodontics competency case experience (CCCE) for senior dental students and surveyed students regarding their experience with the CCCE. Students challenging the CCCE must treat a patient with moderate periodontitis and must independently decide when a state of periodontal and oral health has been achieved. Students are also required to conduct an oral presentation to periodontology faculty. Dental students who completed the CCCE had a favourable impression of the experience, compared with the traditional clinical examinations taken in the junior year. The majority of students rated all the components of the CCCE as 'somewhat' or 'very helpful'. About 72.4% of students felt that being able to work independently on the examination was very helpful for learning about the clinical management of patients with periodontal disease, followed by 'simulation of care in private practice' (65.5%), and oral photography experience (55.2%). The greatest difficulty reported by students was finding an acceptable patient. About 62.1% of students rated 'finding the right patient' as very difficult. Students reported having to screen a mean of 5.9 patients (SD: 4.5) to find a qualified patient. The results of the survey will be useful in improving the examination as an assessment tool in periodontal therapy.

The prevalence of pathogenic periodontal microflora in healthy young adult smokers

BACKGROUND

Smoking is a major risk factor in periodontitis, although the mechanisms of its effects are not well understood. The overall goal of this clinical study was to determine if smoking enhances the colonization of the oral cavity by pathogenic bacteria in a periodontitis-free population. The prevalence of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Fusobacterium nucleatum, Campylobacter rectus, Eikenella corrodens, Bacteroides forsythus, and Treponema denticola was investigated in 25 smokers and 25 non-smokers by using DNA probes.

METHODS

The subjects were 21 to 35 years of age with a healthy periodontium or slight gingivitis and were systemically healthy. The test group included subjects who had a minimum of a 1.5 pack-year history of smoking, while the control subjects never smoked. Subgingival plaque samples were taken by paper point following the assessment of multiple clinical parameters.

RESULTS

This investigation showed: 1) no statistically significant differences were noted in any clinical parameter measured between the groups; 2) of the 8 subjects who were infected by at least 1 tested pathogen, seven were smokers (P= 0.02); 3) infected smokers had a 15.7+/-3.5 pack-year history and smoked a mean of 27+/-5 cigarettes/day versus 4.4+/-0.8 pack years and 15+/-1 cigarettes/day for the non-infected smokers (P = 0.0001 and P = 0.004); and 4) smokers were 18 times more likely to exhibit the presence of pathogens than non-smokers.

CONCLUSIONS

These data indicate that the prevalence of colonization of the sulcus by pathogenic bacterial species in periodontitis-free individuals is related to the quantity and duration of cigarette smoking.

The prevalence of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, and Bacteroides forsythus in humans 1 year after 4 randomized treatment modalities

The relationship between probing attachment changes in treated periodontal pockets and the prevalence of selected periodontal pathogens was assessed in 10 patients with adult periodontitis 1 year following randomized therapy. All patients had at least 1 tooth in each quadrant with an inflamed pocket of probing depth > or =5 mm and clinical attachment loss and harbored at least one of the following 3 major periodontal pathogens: Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, or Bacteroides forsythus. The number of target organisms per site was determined preoperatively; at 1 week; and at 1, 3, 6, and 12 months postoperatively utilizing DNA probes. The following clinical parameters were measured and recorded preoperatively and at 1, 3, 6, and 12 months post-treatment: gingival fluid flow, gingival index, plaque index, probing depth, probing attachment level, gingival recession, and bleeding on probing. One quadrant in each patient was randomly assigned to 1 of the following 4 treatments: 1) scaling and root planing; 2) pocket reduction through osseous surgery and apically-positioned flap; 3) modified Widman flap; and 4) modified Widman flap and topical application of saturated citric acid at pH 1 for 3 minutes. All 4 treatments were rendered in one appointment using local anesthesia. No postoperative antibiotics were used, but patients rinsed with 0.12% chlorhexidine for the first 3 months postoperatively and received a prophylaxis every 3 months. This investigation revealed: 1) 30.0% of the sites were infected by at least 1 species at 3, 6, and 12 months postoperatively. 2) Failing sites were infected by a high number of both Pg and Bf These sites had a mean of 24.2+/-9.0 x 10(3) Pg and 93.1+/-42.0 X 10(3) Bf while stable sites had a mean of 6.8+/-0.5 x 10(3) Pg and 7.2+/-1.2 x 10(3) Bf (P = 0.06 and P = 0.05, respectively). 3) The infected sites lost significantly more mean clinical attachment at 12 months (1.5+/-0.5 mm compared to a loss of 0.2+/-0.3 mm for uninfected sites, P = 0.017). 4) The infected sites had a significantly greater BOP (67+/-14% versus 25+/-8% for uninfected sites at 12 months, P = 0.012). 5) The choice of treatment modality did not affect the prevalence of the target species at 1 year post-treatment. These results suggest that prevalence of microbial pathogens negatively affects the 1 year outcome of periodontal surgical and nonsurgical therapy.

The survival rate of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, and Bacteroides forsythus following 4 randomized treatment modalities

The overall goal of this clinical study was to determine the short-term anti-infective effects of four randomized treatment modalities on Actinobacillus actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), and Bacteroides forsythus (Bf) and determine the effects of bacterial survival on treatment outcomes in patients with adult periodontitis. Twelve adult patients requiring therapy for moderate periodontitis were selected for this study. All patients had at least one tooth in each quadrant that had an inflamed pocket of probing depth > or =5 mm with probing attachment loss that harbored at least one of the following three periodontal pathogens: Aa, Pg, or Bf. The number of target organisms per site was determined pre-operatively, at 1 week, and 1 month and 3 months postoperatively utilizing DNA probes. One quadrant in each patient was randomly assigned to each one of the following four treatment groups: 1) scaling and root planing (SRP group); 2) pocket reduction through osseous surgery and apically-positioned flap (OS group); 3) modified Widman flap (MWF group); and 4) modified Widman flap and topical application of saturated citric acid at pH 1 for 3 minutes (CA group). The 4 treatment modalities were performed in one appointment. No postoperative antibiotics were used. Patients were instructed to supplement their daily oral hygiene with chlorohexidine oral rinse during the study. The results of this investigation indicated that: 1) none of the treatment modalities was effective in eliminating the target species; 2) the incidence of infected sites for all groups was 100% preoperatively; 62.5%, 33.3%, and 31.3% at 1 week, and 1 and 3 months postoperatively, respectively; 3) these infected sites lost 1.1 +/- 0.4 mm of probing attachment compared to gain of 0.0 +/- 0.3 mm for uninfected sites; 4) the infected sites had higher plaque and bleeding on probing 0.9 +/- 0.3, 73 +/- 12%, respectively, compared to 0.3 +/- 0.1 and 30 +/- 8% for the uninfected sites; and 5) no statistically significant differences were detected among the infected sites in regard to gingival index (1.0 +/- 0.2 vs. 0.8 +/- 0.1) or probing depth (3.5 +/- 0.4 vs. 3.0 +/- 0.1 mm). These results indicate that bacterial survival negatively affects the short-term clinical outcomes of non-surgical and surgical periodontal therapy.

Repopulation of periodontal pockets by microbial pathogens in the absence of supportive therapy

This clinical study evaluated the reinfection incidence by Actinobacillus actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), and Prevotella intermedia (Pi) in periodontal pockets following scaling and root planing (SRP) and intra-pocket irrigation with antimicrobial agents in a patient population who did not receive supportive maintenance therapy. The number of target organisms was determined utilizing DNA probes. Forty-one (41) inflamed pockets > or = 5 mm with attachment loss and containing at least one target species were selected in 6 adult patients. Following a baseline clinical and bacterial examination, all patients received thorough SRP. In addition, 1 to 2 teeth in each patient were randomly assigned to each of the following 4 treatment modalities: 1) control group, no irrigation; 2) saline group, irrigation with 2 cc of 0.85% saline; 3) tetracycline group, irrigation with 2 cc of aqueous tetracycline HCl, 50 mg/ml (5%); and 4) chlorhexidine group, irrigation with 2 cc, respectively. All selected sites were non-adjacent. No additional therapy was rendered during the entire 1-year observation period. Clinical parameters and microbial analyses were recorded again at 1 week, and 1, 3, 6, 9, and 12 months post-treatment. The effect of antimicrobial irrigation on the reinfection rate of sites by Aa, Pg, and Pi was compared with that of the control groups (1 and 2) by ANOVA. No statistically significant differences were observed among the irrigation treatment groups with regard to any of the clinical or bacterial parameters studied. Therefore, the 4 treatment groups were combined into a single group whereby the rate of bacterial repopulation following extensive scaling and root planing could be ascertained. The infection incidence of sites at baseline (of total sites), 1 week and 12 months (of sites originally infected at baseline) was 14/41, 3/14, and 7/14 for Aa; 33/41, 6/33, and 12/33 for Pg; and 37/41, 3/37, and 12/37 for Pi, respectively. Thus, half or fewer of the originally infected sites became reinfected at 12 months despite lack of maintenance therapy. The results suggest that 1) a single episode of pocket irrigation with antimicrobial agents following thorough scaling and root planing did not affect the rate of repopulation of periodontal pockets by the tested pathogens; 2) thorough scaling and root planing has a lasting suppressive effect on selected periodontal pathogens for the majority of sites in patients with adult periodontitis; 3) pre-operative probing depth, the amount of gingival fluid flow and the composition of the subgingival microflora may serve as predictors for reinfection in the absence of maintenance care; and 4) reinfection of the treated sites by Aa, Pg, and/or Pi may constitute a risk factor that diminishes the effect of therapy in the absence of supportive maintenance care.

DNA probe analyses of the survival of selected periodontal pathogens following scaling, root planing, and intra-pocket irrigation

This clinical study evaluated the survival rates of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, and Prevotella intermedia in periodontal pockets following scaling and root planing and intra-pocket irrigation with antimicrobial agents in patients with moderate and severe periodontitis. The number of target organisms was determined utilizing DNA probes. Adult periodontitis patients were selected on the basis that the subgingival flora contained at least one of the target organisms. Forty-eight (48) inflamed pockets > or = 5 mm in depth with probing attachment loss and containing at least one of the target species were then selected in 7 adult patients who harbored these bacteria. Following baseline clinical and bacterial examination, all patients received thorough scaling and root planing. In addition, 1 or 2 teeth in each patient which harbored the target flora at baseline were randomly assigned to each of the following 4 treatment modalities: 1) control group, no irrigation; 2) saline group, irrigation with 2 cc of physiologic saline; 3) tetracycline group, irrigation with 2 cc of aqueous tetracycline hydrochloride, 50 mg/ml (5%); and 4) chlorhexidine group, irrigation with 2 cc 0.12% chlorhexidine. All selected sites (5 to 8 per patient) were nonadjacent teeth. Clinical parameters and microbial analysis were recorded again at one week, and one month post-irrigation. The survival rate of the target microorganisms was determined and the effect of irrigation with antimicrobial agents on this microflora was compared with the control groups (1 and 2).(ABSTRACT TRUNCATED AT 250 WORDS)

The role of subgingival irrigations in the treatment of periodontitis

While the efficacy of oral irrigations with antimicrobial agents on the clinical and microbial parameters of gingivitis is well established, the study of the efficacy of intrapocket irrigants on periodontitis has yielded conflicting and inconclusive results regarding both clinical and microbiological parameters. The overall goal of this review paper is to summarize the available information on the efficacy of intrapocket irrigation in the treatment of patients with periodontitis. The following topics are addressed: 1) the penetrability of the irrigant; 2) pocket irrigation without scaling and root planing; 3) professional pocket irrigation following scaling and root planing; 4) irrigations between recalls; and 5) safety of intrapocket irrigation. Single irrigation of periodontal pockets for short periods of time before or after scaling and root planing has limited effects on periodontal healing. However, continuous irrigation of the periodontal lesion with agents such as povidone iodine during thorough scaling and root planing, such as that carried out under local anesthesia, has promise as an antimicrobial adjunct in periodontal therapy.

The treatment of acute necrotizing ulcerative gingivitis

The destruction of the interdental papillae and formation of permanent gingival craters are common sequelae of acute necrotizing ulcerative gingivitis. These craters can be disfiguring, especially in the anterior gingiva, and can act as a nidus for recurrent episodes. Traditional therapy has emphasized a surgical approach for elimination of these defects, often increasing the esthetic problems. The purpose of this paper is to review the treatment modalities of acute necrotizing ulcerative gingivitis and illustrate an alternative treatment approach of periodic scaling, root planing, and antimicrobial rinses with 0.12% chlorhexidine. With this therapeutic regimen, the disease process can be reversed and damaged papillae may regenerate.

Blood nitrates and infantile methemoglobinemia

Infantile methemoglobinemia is of much more frequent occurrence among hospitalized newborns and young infants than is generally appreciated. When present, acute diarrhoea of different etiologies is almost exclusively the cause of hospitalization. No correlation between this condition and ingestion of food or water containing high concentrations of nitrates or nitrites was found. This study demonstrates for the first time that high blood nitrates are a regular part of the syndrome. The evidence presented is interpreted as indicating that diarrhoea results in endogenous, de novo synthesis of nitrites, and this is the principal cause of infantile methemoglobinemia.

The clinical effects of citric acid and laterally positioned pedicle grafts in the treatment of denuded root surfaces. A pilot study

A new technique of a combined mechanical-chemical root preparation to enhance reattachment of pedicle grafts to previously denuded root surfaces is described. The clinical results of two documented cases are presented. The findings of this pilot study indicate that the technique is well tolerated by the patients, yielding a normal postoperative healing pattern and a clinical gain in the attachment level. These preliminary results may be attributed to: (1) Total elimination of bacterial endotoxin from the root surfaces by instrumentation and topical application of saturated citric acid at pH 1.0 for 3 minutes; (2) chemical exposure of dentin collagen fibrils, into which the graft may reattach; and (3) induction of cementogenesis by the exposed dentin.

Developmental variations of tooth morphology and periodontal disease

Some developmental variations of tooth morphology may influence the potential for periodontal disease by allowing accumulation of bacterial plaque and calcified deposits. Mechanical plaque control becomes difficult even for the conscientious patient. Periodontal disease may be hastened in these cases. The therapist must be aware of these variations and their significance in the etiology of isolated periodontal lesions. Recognition of these anomalies and early diagnosis may improve the prognosis of the involved tooth.

Phospholipase B activity of a purified phospholipase A from Vipera palestinae venom

Phospholipase was isolated (in two fractions) from Vipera palestinae venom and it was shown to possess phospholipase A activity (hydrolyzing diacyl-sn-glycerophosphorylcholines, e.g., lecithin, in the 2-position) as well as lysophospholipase (phospholipase B) activity (hydrolyzing 1-monoacyl-sn-glycerophosphorylcholines, e.g., lysolecithin, yielding free fatty acid and glycerophosphorylcholine). Each of the two purified enzyme fractions was homogeneous as judged by electrophoresis on acrylamide gel and by immunodiffusion and immunoelectrophoresis, and both had essentially equal activities. The ratio of the specific activity, at various purification stages, to the specific activity of the whole venom was the same for A activity (substrate lecithin) as for B activity (substrate lysolecithin). The enzyme has a molecular weight of 16,000, six S-S bridges, and no free thiol groups. At pH 7, dimerization was observed in the ultracentrifuge. A dissociation constant of about 10(-5) m was estimated. The amino acid composition for both fractions (140 amino acid residues) was found to be essentially the same. The A activity had a pH optimum at 9; B activity was low at this pH but increased steadily beyond pH 10.5. For the hydrolysis of lysolecithin the Lineweaver-Burk plot was found to be linear, giving K(m) = 1.1 mm and k(cat) = 0.55 sec(-1) at 37 degrees C and pH 10. 2-Deoxylysolecithin was also hydrolyzed by the enzyme at pH 10, with k(cat) = 0.01 sec(-1) (zero-order kinetics in the range 0.5-2.5 mm). For lecithin these constants could not be determined, but at 0.25 mm substrate the hydrolysis rate (at pH 9) of lecithin was about 1000 times the hydrolysis rate of lysolecithin (at pH 10).