Effects of plaque disclosing agents on esthetic restorative materials used in pediatric dentistry

The aim of study was to evaluate the color stability of tooth-colored restorative materials usually used in pediatric dentistry after the application of two plaque disclosing agents. Twenty specimens of each material: a resin-modified glass ionomer, a composite resin and an ion-releasing composite resin, were prepared. Baseline color evaluation was performed, samples were exposed to the plaque disclosing agents: a basic fuchsin solution and a fluorescent dye, and new color evaluations were made. The resin-modified glass ionomer stained with basic fuchsin presented the greatest color change in the present study, and the fluorescent dye did not show statistically significant changes among the restorative materials. In conclusion, basic fuchsin dyes should be carefully used in children with a great number of tooth-colored restorations.     

Effect of induction chemotherapy on changes of laminin and syndecan expression in oral squamous cell carcinomas: a prospective, randomized, clinicopathologic and immunohistochemical study

Sixty patients with tumors of the floor of the mouth or of the tongue (T2N0-1-2M0) were randomized into three treatment groups. The first two groups participated in low-dose inductive chemotherapy, surgery, and then radiotherapy, whereas the third control group underwent only surgery and radiotherapy. In all three groups, studies were made of the stage, grade, sex, localization, extents of expression of the pretreatment laminin and syndecan-1 and the cancer specific survival rate, and the correlations among these. The response to neoadjuvant chemotherapy was assessed by means of a method that we developed, involving measurement of the degree of histologic regression observed in response to chemotherapy. Immunohistochemical methods were applied to investigate the changes in degree of expression of laminin and syndecan-1 in response to the medication and their correlations with the survival. As concerns the overall tumorfree survival rate, a significant difference was not found between the two chemotherapeutic groups. However, there was a significant difference between the survival indices of those who participated in cytostatic treatment (70%) and the control group (40%). In the clinical and immunohistochemical examinations, the initial laminin and syndecan-1 levels obtained from biopsy samples could be used as prognostic factors. Our model measuring the extent of histologic regression clearly demonstrated that the survival indices of the patients who responded to the neoadjuvant cytostatic treatment with adequate tissue regression were better than those of the patients who responded to the treatment to only a decreased extent or not at all. The changes in the expressions of laminin and syndecan-1 in response to cystostatic treatment proved to be important predictive factors. The increase or stagnation of these clearly forecast a good prognosis, whereas their decrease was a definite indication of poor prognosis.     

Sinus grafting using recombinant human tissue factor, platelet-rich plasma gel, autologous bone, and anorganic bovine bone mineral xenograft: histologic analysis and case reports

PURPOSE: The purpose of this study was to analyze healthy bone formation by means of histology and immunohistochemistry after grafting with a mixture of autologous ground calvarial bone, inorganic xenograft, platelet-rich plasma (PRP), and recombinant human tissue factor (rhTF). MATERIALS AND METHODS: Maxillary sinus floor augmentation was performed on 3 patients by grafting with 5 to 10 mL of a paste consisting of autologous powder from calvarial bone (diameter < 1 mm), 50% v/v anorganic bovine bone mineral xenograft (PepGen P-15, a new tissue-engineered bone replacement graft material), PRP (1.8 x 10(6) platelets/mm3 plasma), and about 1 microg rhTF. Six and 10 months after grafting, bone cores were extracted for implant fixation and analyzed. RESULTS: Histology demonstrated a high degree of inorganic xenograft integration and natural bone regeneration. Both the xenograft and newly synthesized bone were colonized with osteocytes and surrounded by osteoblasts. Six-month-old bone cores demonstrated a ratio of synthesized bone to xenograft particles ratio of 0.5, whereas 10-month-old cores demonstrated a ratio of 2. A low degree of inflammation could also be observed using S100A8 immunohistochemistry. DISCUSSION: Autologous grafting in edentulous patients is a complex procedure; the successful substitution of synthetic analogs for ground bone is a major challenge. CONCLUSION: In this investigation, it was shown that inorganic xenograft in the harvested bone paste could be safe for patients and had high bone regeneration capacity over time. The sinus graft showed intense bone formation 6 months after grafting and a further increase in bone growth 10 months after grafting.     

Those who can, teach, but who teaches the learners to learn?

This article was stimulated by Mike Grace's editorial Can those who do--teach? I have been an undergraduate and postgraduate teacher for over 30 years and I agreed with everything that Mike said about the difficulties of combining doing and teaching. The best doers may not make the best teachers and conversely the best teachers are not always incapable of doing, whatever some colleagues may think to the contrary!     

Dendritic-NK cell interactions in P. gingivalis-specific responses

Patients with localized aggressive periodontitis have type-1 cytokines in gingival crevicular fluid and high titers of IFN-gamma-dependent IgG2 reactive with P. gingivalis in gingival crevicular fluid and serum. Localized aggressive periodontitis monocytes spontaneously differentiate into dendritic cells that can stimulate IFN-gamma production by NK cells. These relationships prompted the hypothesis that P. gingivalis-dendritic cell-NK cell interactions might promote type-1 cytokine responses. Although P. gingivalis is not a potent inducer of Th1 responses, it stimulated strong IL-12 responses by monocyte-derived dendritic cells in the presence of IFN-gamma, and IFN-gamma was produced by NK cells within 24 hrs in the presence of dendritic cells. Anti-P. gingivalis IgG2 responses were enhanced by dendritic cells, and removal of NK cells reduced IFN-gamma- and P. gingivalis-specific IgG2. Thus, P. gingivalis-dendritic cell-NK cell interactions apparently resulted in reciprocal stimulation and increased type-1 cytokine production by both dendritic cells and NK cells, and increased P. gingivalis-specific IgG2.     

The potential role of dentists in identifying patients' risk of experiencing coronary heart disease events

BACKGROUND: A substantial proportion of people with risk factors for cardiovascular disease (CVD) are not identified before they develop clinical signs and symptoms. A multidisciplinary approach that includes a cardiovascular screening by oral health care providers can affect the identification of people at risk of experiencing cardiovascular events. METHODS: The authors extracted data from the 1999-2000 National Health and Nutrition Examination Survey (NHANES) and the 2001-2002 NHANES for people aged 40 to 85 years with no reported specific risk factors for coronary heart disease (CHD) and who had not seen a physician in the previous 12 months but had seen a dentist. They used these data to estimate the 10-year Framingham-based risk calculation scores for each subject to determine their global risk of experiencing acute CHD events. RESULTS: Eighteen percent of the male subjects had an increased 10-year global risk of experiencing a CHD event (> 10 percent risk score), 14.3 percent had a moderate, above-average risk score (> 10-< 20 percent), and an additional 4.3 percent had a high risk score (> or = 20 percent). Only one female subject had a risk score greater than 10 percent. When the authors extrapolated these results to the 2000 U.S. census data, they found that among men aged 40 to 85 years without reported risk factors who had not seen a physician but had seen a dentist in the previous 12 months, 332,262 had a greater than 10 to less than 20 percent risk of experiencing a CHD event, and 72,625 had a 20 percent or greater 10-year risk of experiencing a CHD event. CONCLUSION: Dentists can play an important role in identifying people in need of primary prevention strategies for CVD.     

Platelet-derived growth factor stimulates bone fill and rate of attachment level gain: results of a large multicenter randomized controlled trial

BACKGROUND: Growth factors are generally accepted to be essential mediators of tissue repair via well-established mechanisms of action that include stimulatory effects on angiogenesis and cellular proliferation, ingrowth, differentiation, and matrix biosynthesis. The aim of this study was to evaluate in a large-scale, prospective, blinded, and randomized controlled clinical trial the safety and effectiveness of purified recombinant human platelet-derived growth factor (rhPDGF-BB) mixed with a synthetic beta-tricalcium phosphate (beta-TCP) matrix for the treatment of advanced periodontal osseous defects at 6 months of healing. METHODS: Eleven clinical centers enrolled 180 subjects, each requiring surgical treatment of a 4 mm or greater intrabony periodontal defect and meeting all inclusion and exclusion criteria. Subjects were randomized into one of three treatment groups: 1) beta-TCP + 0.3 mg/ml rhPDGF-BB in buffer; 2) beta-TCP + 1.0 mg/ml rhPDGF-BB in buffer; and 3) beta-TCP + buffer (active control). Safety data were assessed by the frequency and severity of adverse events. Effectiveness measurements included clinical attachment levels (CAL) and gingival recession (GR) measured clinically and linear bone growth (LBG) and percent bone fill (% BF) as assessed radiographically by an independent centralized radiology review center. The area under the curve (AUC), an assessment of the rate of healing, was also calculated for CAL measurements. The surgeons, clinical and radiographic evaluators, patients, and study sponsor were all masked with respect to treatment groups. RESULTS: CAL gain was significantly greater at 3 months for group 1 (rhPDGF 0.3 mg/ml) compared to group 3 (beta-TCP + buffer) (3.8 versus 3.3 mm; P = 0.032), although by 6 months, this finding was not statistically significant (P = 0.11). This early acceleration of CAL gain led to group 1 exhibiting a significantly greater rate of CAL gain between baseline and 6 months than group 3 as assessed by the AUC (68.4- versus 60.1-mm weeks; P = 0.033). rhPDGF (0.3 mg/ml)-treated sites also had significantly greater linear bone gain (2.6 versus 0.9 mm, respectively; P < 0.001) and percent defect fill (57% versus 18%, respectively; P < 0.001) than the sites receiving the bone substitute with buffer at 6 months. There was less GR at 3 months in group 1 compared to group 3 (P = 0.04); at 6 months, GR for group 1 remained unchanged, whereas there was a slight gain in gingival height for group 3 resulting in comparable GR. There were no serious adverse events attributable to any of the treatments. CONCLUSIONS: To our knowledge, this study is the largest prospective, randomized, triple-blinded, and controlled pivotal clinical trial reported to date assessing a putative periodontal regenerative and wound healing therapy. The study demonstrated that the use of rhPDGF-BB was safe and effective in the treatment of periodontal osseous defects. Treatment with rhPDGF-BB stimulated a significant increase in the rate of CAL gain, reduced gingival recession at 3 months post-surgery, and improved bone fill as compared to a beta-TCP bone substitute at 6 months.     

Clinical, radiographic, biochemical and histological findings of florid cemento-osseous dysplasia and report of a case

Florid cemento-osseous dysplasia has been described as a condition that characteristically affects the jaws of middle-aged black women. It usually manifests as multiple radiopaque cementum-like masses distributed throughout the jaws. This condition has also been classified as gigantiform cementoma, chronic sclerosing osteomyelitis, sclerosing osteitis, multiple estenosis and sclerotic cemental masses. The authors present a case of an uncomplicated florid cemento-osseous dysplasia in a 48-year-old black woman. Multiple sclerotic masses with radiolucent border in the mandible were identified radiographically. Histopathologic findings revealed formation of calcified dense sclerotic masses similar to cementum. All clinical, radiographic, biochemical and histological features were suggestive of the diagnosis of florid cemento-osseous dysplasia.