Cataldo W. Leone

Diminished Bone Formation During Diabetic Fracture Healing is Related to the Premature Resorption of Cartilage Associated With Increased Osteoclast Activity

Histological and molecular analysis of fracture healing in normal and diabetic animals showed significantly enhanced removal of cartilage in diabetic animals. Increased cartilage turnover was associated with elevated osteoclast numbers, a higher expression of genes that promote osteoclastogenesis, and diminished primary bone formation.

Human salivary gland-specific daily variations in histatin concentrations determined by a novel quantitation technique.

Histatins constitute a distinct family of human salivary antimicrobial peptides, of which histatins 1, 3 and 5 are the most abundant. To evaluate salivary gland-specific differences in histatin secretion, we used the recently developed histatin-zinc precipitation method to quantify histatins and to assess daily variations in secretions. Stimulated pure secretions from parotid glands (HPS) and submandibular/sublingual glands (SMSL) were collected from 10 different subjects at four different times of the day (9:35 a.m.; 12:40 p.m.; 2:50 p.m. and 5:00 p.m.). Zinc precipitation and subsequent reversed phase HPLC analysis were performed to determine concentrations of histatins 1, 3 and 5 with reference to purified histatin standards. Both HPS and SMSL secretions displayed daily variations in histatin concentrations. HPS values showed a maximum at mid-day and SMSL samples showed a maximum in the morning. Mean daily histatin concentrations were almost three fold higher in SMSL than in HPS. Mean histatin 1, 3 and 5 concentrations in HPS from 10 subjects ranged from 0.7 to 2.8, 0.6 to 4.3 and 1.0 to 4.3mg%, respectively. The corresponding means in SMSL were 2.8-12.2, 1.5-7.5 and 2.6-9.0mg%, respectively. Remarkably, although histatins constitute only 3-10% of total protein in these secretions, an almost perfect correlation between total protein and total histatin concentrations was observed for both glands. Despite a broad range in histatin concentrations between individuals, this study demonstrated a hitherto unidentified daily variation in histatin concentrations in HPS and SMSL secretions and a differential expression pattern which might have functional implications.

Vitamin D and Periodontal Health in Older Men

Vitamin D, an anti-inflammatory mediator, has potential benefits for physical and oral health. Although it is produced endogenously, some individuals have a greater need for dietary and supplemental sources. This repeated-measures cross-sectional study assessed associations between total vitamin D intake and periodontal health in older men. Participants were 562 members of the Department of Veterans Affairs Dental Longitudinal Study, mean age 62.9 years, who were examined 1 to 4 times between 1986 and 1998. A calibrated examiner measured probing pocket depth (PPD) and attachment loss (AL) on each tooth. Alveolar bone loss (ABL) was determined from radiographs. Severe periodontal disease was defined as PPD ≥ 5 mm on ≥ 1 tooth and AL ≥ 6 mm at ≥ 2 sites (not on same tooth), and moderate-to-severe alveolar bone loss as ABL ≥ 40% at ≥ 3 sites. Generalized estimating equations were used to compute the odds ratios (OR) and 95% confidence intervals (95% CI) of having periodontal disease by level of vitamin D intake. Total vitamin D intake ≥ 800 IU was associated with lower odds of severe periodontal disease (OR = 0.67, 95% CI = 0.55-0.81) and moderate-to-severe ABL (OR = 0.54, 95% CI = 0.30-0.96) relative to intake < 400 IU/day. Vitamin D intake may protect against periodontal disease progression.

Immunization Enhances Inflammation and Tissue Destruction in Response to Porphyromonas gingivalis

ABSTRACT It is well established that host-bacterium interactions play a critical role in the initiation and progression of periodontal diseases. By the use of inhibitors, it has been shown that mediators associated with the innate immune response significantly contribute to the disease process. Less is known regarding the role of the acquired immune response. To investigate mechanisms by which the acquired immune response to Porphyromonas gingivalis could affect connective tissue, we used a well-documented calvarial model to study host-bacterium interactions. Injection of P. gingivalis stimulated gamma interferon, interleukin 6, macrophage inflammatory protein 2, and monocyte chemoattractant protein 1 expression as determined by real-time PCR. Prior immunization against P. gingivalis significantly enhanced the mRNA levels of these cytokines and chemokines. Similarly, immunization significantly increased and prolonged the formation of a polymorphonuclear leukocyte and mononuclear cell infiltrate (P < 0.05). In addition, the area of connective tissue destruction, osteoclastogenesis, bone loss, mRNA expression of proapoptotic genes, and degree of fibroblast apoptosis were increased in immunized mice (P < 0.05). These results indicate that activation of the acquired immunity by P. gingivalis increases the inflammatory and destructive responses which occur in part through up-regulating the innate immune response and enhancing osteoclastogenesis and fibroblast apoptosis.

Incisor malalignment and the risk of periodontal disease progression

Introduction: The objective of this study was to investigate the association between incisor crowding, irregularity, and periodontal disease progression in the anterior teeth. Methods: Data collected over 35 years from men enrolled in the Veterans Affairs Dental Longitudinal Study included information concerning pocket depth and alveolar bone loss. Plaster casts of the maxillary (n = 400) and mandibular (n = 408) arches were available for baseline measurements. Periodontal disease in the anterior teeth was defined as per arch sum of pathologic pocket depth and sum of teeth with any alveolar bone loss in the anterior sextants. Incisor malalignment status was defined by the anterior tooth size‐arch length discrepancy index and Littles Irregularity Index. Adjusted mixed effects linear models computed the beta (&bgr;) estimates and 95% confidence intervals (95% CI) of the amounts of change in periodontal disease outcomes by the level of malalignment. Results: In the anterior maxillary arch, crowding and spacing were significantly associated with an increased per‐arch sum of pathologic pocket depth (&bgr;, 0.70 mm; 95% CI, 0.20‐1.21, and &bgr;, 0.49 mm; 95% CI, 0.06‐0.91, respectively). In the anterior mandibular arch, incisor crowding and irregularity were significantly associated with an increased per‐arch sum of pathologic pocket depth (mild crowding: &bgr;, 0.47 mm; 95% CI, 0.01‐0.93; severe irregularity: &bgr;, 0.94 mm; 95% CI, 0.50‐1.38), and the sum number of teeth with alveolar bone loss (mild and moderate‐to‐severe crowding: &bgr;, 0.45 teeth; 95% CI, 0.08‐0.82; and &bgr;, 0.45 teeth; 95% CI, 0.13‐0.83, respectively; moderate irregularity: &bgr;, 0.34 teeth; 95% CI, 0.06‐0.62). Conclusions: Certain incisor malalignment traits (ie, maxillary incisor crowding, maxillary incisor spacing, mandibular incisor mild crowding, mandibular incisor moderate‐to‐severe crowding, mandibular incisor moderate irregularity, and mandibular incisor severe irregularity) are associated with significant periodontal disease progression.

Presence or absence of periodontal pathogens does not distinguish between chronic and aggressive periodontitis

Data Sources Data sources were Medline, with hand searches of the Journal of Dental Research, Journal of Clinical Periodontology, Journal of Periodontal Research and Journal of Periodontology dated from 1990 up to July 2001, and the reference lists of articles selected for inclusion.Study selection Studies included were cross-sectional or longitudinal with microbiological data from at least two cohorts.Data extraction and synthesis Information regarding quality and study characteristics was extracted independently by two reviewers. Kappa scores determined their agreement. Sensitivity and specificity of the microbiological tests were calculated for each selected study individually, with values being expressed as a Receiver Operator Characteristic (ROC) diagram.Results The presence or absence of Actinobacillus actinomycetemcomitans could be evaluated in 11 papers; of Porphyromonas gingivalis in seven papers; and of Prevotella intermedia in six studies. Bactericides forsythus and Campylobacter rectus were each analysed in two papers. ROC diagrams indicated the limited discriminatory ability of all of the test parameters to identify subjects with aggressive periodontitis. An additional assessment showed that the highly leukotoxic variant of A. actinomycetemcomitans was uniquely associated with patients suffering from aggressive periodontitis. In a high proportion of patients diagnosed with the aggressive form of the condition, however, the presence of this variant could not be detected.Conclusions The presence or absence of A. actinomycetemcomitans, P. gingivalis, P. intermedia, B. forsythus and C. rectus could not distinguish subjects with aggressive periodontitis from those with the chronic form.

The predictors of periodontal disease progression following treatment need more research

Data sources Sources used were MEDLINE, Embase and the Cochrane Oral Health Group Trials Register. Reference lists from relevant articles were hand-searched, as were selected journals. Only English-language studies were included.Study selection Clinical trials and cohort studies were selected when they lasted a minimum of 12 months’ after initial healing and addressed the predictive value of residual probing depths (PD), bleeding on probing and furcation involvement in determining further loss of attachment and tooth loss following initial-cause-related periodontal therapy (ICRT).Data extraction and synthesis Information regarding quality and study characteristics was extracted independently by two reviewers. Kappa scores determined their agreement.Results Only one study of 16 subjects provided patient-based data from longitudinal case studies related to ICRT and provided treatment outcomes with data from initial follow-up at 3 months through to 12 months after initial therapy.Conclusions Data based on a single study suggest that residual probing depths may be predictive of further disease progression. There are clear implications for carefully designed multicentre randomised clinical control trials.