Effect of oxybenzone on PGE2-production in vitro and on plaque and gingivitis in vivo

OBJECTIVES: To study the effect of oxybenzone on prostaglandin E2 (PGE2) production in cell culture and to evaluate the effect of an oxybenzone-containing dentifrice on plaque and gingivitis in a 6-week clinical trial. MATERIAL AND METHODS: Human embryo palatal mesenchyme (HEPM) cells were used for testing the inhibition of IL-1beta-stimulated PGE2-production in vitro by different concentrations of oxybenzone. For the in vivo study, a total of 66 individuals with a Quigley & Hein plaque index of at least 1.5 and an Ainamo & Bay gingival index of at least 0.2 were included in a double-blind clinical trial with two cells and a parallel design. Two compositions of fluoride dentifrice were used, one with the addition of 0.5% oxybenzone, and one without. Plaque and gingival index were obtained at three time points: (1) at baseline, (2) after 3 weeks, and (3) after 6 weeks. RESULTS: A dose-dependent inhibition of PGE2-production was found in the HEPM cell culture following oxybenzone exposure. In the clinical trial, a 25% reduction of gingival index was observed in the oxybenzone group (p<0.001) after 6 weeks as compared with 2% for the placebo group. CONCLUSIONS: These findings indicate that PGE2-production is reduced by oxybenzone in vitro and that the use of oxybenzone in a dentifrice reduces gingivitis in vivo.     

Effect of grafting materials on osseointegration of dental implants surrounded by circumferential bone defects. An experimental study in the dog

Aims: This study was designed to evaluate the effect of gap width and graft placement on bone healing around implants placed into simulated extraction sockets in the mandibles of four beagle dogs. Materials and methods: Four Ti‐Unite^® implants (13 mm × 3.3 mm) were placed on each side of the mandible. Three implants were surrounded by a 1.35 mm circumferential and a 5 mm deep gap around the coronal portion of the implants. A fourth implant was inserted conventionally into both sides of the mandibles as a positive control. The gaps were filled with either Bio‐Oss^®, autogenous bone or with a blood clot alone. The study design was balanced for animal, side and modality. Ground sections were prepared from biopsies taken at 3 months, and computer‐aided histometric measurements of bone/implant contact and area of bone within threads were made for the coronal 5 mm. Data were analysed using analysis of variance. Results: The mean bone/implant contact was 9.8 mm for the control and ranged from 9.3 to 11.3 mm for the three test modalities. The corresponding values for area within threads were 1 mm² and 1–1.2 mm². Modality had a significant effect on both bone/implant contact (F=16.9; P<0.0001) and area within threads (F=16.7; P<0.0001). Conclusion: The results of this study suggest that both autogenous bone graft and Bio‐Oss^® played an important role in the amount of hard tissue fill and osseointegration occurring within marginal bone defects around implants.     

Pneumomediastinum secondary to isolated orbital floor fracture

Pneumomediastinum (PM) secondary to an isolated orbital blow-out fracture is a rare but potentially severe and life-threatening complication. Fortunately, airway obstruction, pneumothorax, pneumopericardium, and mediastinitis are rare complications of PM. Blowing the nose after a maxillofacial trauma increases pressure in the paranasal sinuses, which may lead to emphysema through a breach of the lining mucosa to the surrounding soft tissues in the head, neck, and, on occasions, to the mediastinum. We report here the rare case of a patient with PM after isolated orbital fracture. Only 3 similar cases have been previously reported in the literature.     

Change in caries prevalence after implementation of a fluoride varnish program

Objective : In 1996 the caries prevalence of schoolchildren living in Neukölln, a district of Berlin, Germany, was higher than the mean of total Berlin. Hence, a special preventive program including the application of fluoride varnish was initiated. All 49 primary schools of the district joined the project. The aim of the present study was to evaluate in a cross‐sectional study whether the preventive program resulted in a reduced caries prevalence. Methods : The complete program included oral health education as well as the application of a highly concentrated fluoride varnish (Duraphat®). All children whose parents' consent was given could receive fluoride varnish twice a year. All children were examined once a year by four calibrated dentists. The baseline examination was conducted in 1995–96, the final examination in 1999–2000 (1995–96: n= 7,748; 1996–97: n= 15,673; 1997–98: n= 19,362; 1998–99: n= 19,822; 1999–2000: n= 17,984). Results : A total of 80,589 dental records were used for data analysis. A decline of DMFT‐values was observed in all age groups and school years. The major improvement was found in school year 1999–2000, when the program had been established for four years. Conclusion : The described program may be an effective public health measure for 6‐ to 12‐year‐old children with high caries prevalence.     

Gesichtsästhetik Teil 1: Die Bedeutung der Symmetrieebene des Gesichts

When humans observe a face, the eyes, mouth and nose regions are the preferred targets of the centre of gaze, with the outlines of eye position recordings approximating a triangle with vertices located in the centre of the eyes and mouth [31]. We studied the significance of cutaneous asymmetries inside and outside the Yarbus triangle on the basis of the assessment of digitally-manipulated images by 201 independent judges. We show that certain facial variations (such as naevi) are more attractive when asymmetrical than symmetrical (p<?0,001). They appear more attractive when located laterally rather than medially, particularly so when located outside the Yarbus triangle as compared to inside it (p<?0,001). The significance of facial symmetry increases significantly when approaching the Yarbus triangle or the midline, respectively.     

Provisional implants for anchoring removable interim prostheses in edentulous jaws: a clinical study

PURPOSE: The behavior of provisional implants in edentulous maxillae/mandibles used for anchoring removable interim overdentures was followed for the time of the intended healing of the definitive implants. MATERIALS AND METHODS: Twenty-eight edentulous arches (19 maxillae, 9 mandibles) were provided with 77 provisional implants (2 to 4 in maxillae; 2 or 3 in mandibles) for anchoring removable interim prostheses (overdentures). The provisional implants were to be maintained until final restoration (6 to 9 months in the maxilla and 3 months in the mandible). The loss rate of provisional implants and handling and behavior of the anchored overdenture were monitored until the definitive prosthetic restoration was placed. RESULTS: Twenty-three (29.8%) of the 77 provisional implants were lost prematurely. The loss rate of maxillary provisional implants (21/58; 36.2%) was significantly higher than that of mandibular implants (2/19; 10.5%) (P < .01). Determination of terminal stability (by means of the Periotest) of the provisional implants showed higher stability in the mandible (+3.8 +/- 2.3) than in the maxilla (+8.6 +/- 3.9) (P < .05). In obvious contrast to mandibular interim overdentures, handling of maxillary interim overdentures was found to improve significantly during the follow-up period (P < .01). DISCUSSION AND CONCLUSION: With both the low loss rate in the mandible and the higher loss rate seen in the maxilla, placement of provisional implants fulfills the requirements for initiating immediate prosthetic rehabilitation. The removable interim overdenture can be adequately stabilized and provides for added patient comfort and satisfaction as compared to a conventional complete denture. An important aspect of the continued use of provisional implants concerns the expectations placed in these implants by both clinician and patient, which are quite different than those for definitive implants.     

Life-threatening thrombotic thrombocytopenic purpura associated with dental foci. Report of two cases

OBJECTIVES: Thrombotic thrombocytopenic purpura (TTP) is a rare haematological disease of unknown aetiology. This thrombotic microangiopathy is characterized by microvascular lesions with platelet aggregation. It is found in adults and can be associated with pregnancy, cancer, autoimmune diseases, bone marrow transplantation, drugs and bacterial as well as viral infections. The therapy requires a multi-disciplinary team approach involving dentistry. Even if TTP is immediately treated in an adequate manner, it still shows a mortality of up to 20%. AIM: To define a specific treatment concept for periodontal disease and decayed teeth in patients suffering from TTP based on the experiences gained from two cases. CONCLUSION: The two patient cases revealed a possible association of TTP with dental foci. Because of the severity and mortality of this disease, both prognosis evaluation and treatment standards of periodontologically compromised or decayed teeth have to be strictly followed in patients suffering from TTP. In order to avoid recurrence of TTP, it seems important to remove radically teeth of questionable prognosis.     

Analysis of periodontal risk profiles in adults with or without a history of myocardial infarction

BACKGROUND: An association between periodontitis and cardiovascular diseases has been suggested. AIMS: To study whether a combination of clinical variables in a functional risk diagram enhanced the ability to differentiate between subjects with or without an immediate history of acute myocardial infarction (AMI). MATERIAL AND METHODS: A functional periodontal pentagon risk diagram (PPRD) with five periodontal risk vectors was created. The surface of individual PPRDs was calculated using data from 88 subjects with recent AMI and 80 matched control subjects with no history of AMI. RESULTS: Age, gender, number of remaining teeth (mean value: 21.1 versus 21.6 teeth), smoking status, and pocket probing depth (PPD) distribution did not differ by group. Gingival recession was greater in control subjects (mean difference: 5.7, SD: +/- 1.9, p<0.01, 95% CI: 1.8-9.6). Bone loss > or = 4.0 mm was at all levels studied was significantly greater in subjects with AMI and bone loss > or = 50% (> or = 4 mm) was the best individual predictor of AMI (beta = 2.99, p < 0.000, 95% CI: 7.5-53.4). Only PPRD scores were associated with AMI status when factors not included in the PPRD were studied (beta = 22.1, SE: 5.9, p < 0.0001, 95% CI: 10.3-33.7). The best association between AMI status and study variables was the combination of > or = 4 mm of bone loss > or = 50%, proportion of bleeding on probing (%BOP), %PPDs > or = 6 mm, and tooth loss (Nagelkirke r2 = 0.46). CONCLUSIONS: The combination of five periodontal parameters in a PPRD added predictive value, suggesting that comprehensive data should be used in studies of associations between periodontitis and heart diseases. Radiographic evidence of bone loss was the best individual parameter.     

In vitro, clinical, and microbiological evaluation of a linear oscillating device for scaling and root planing

BACKGROUND: The purpose of this study was to conduct an in vitro and short-term clinical and microbiological evaluation of a linear oscillating device for scaling and root planing (SRP). A comparison was made between conventional ultrasonic scaling (US) and hand scaling (HS) with and without chlorhexidine. METHODS: In vitro, SRP was carried out on human teeth with calculus. Roots and cross-sections thereof were microscopically examined for the efficacy of calculus removal, hard tissue loss, and surface smoothness. In vivo, 11 patients with chronic periodontitis and single-rooted teeth in all quadrants with probing depths of > or =5 mm were selected. One quadrant was treated with linear oscillation and compared to US with chlorhexidine irrigation in the contralateral site. The other arch was treated with HS and compared to HS followed by laser disinfection. One hundred twenty teeth were assessed for clinical attachment level, probing depth, bleeding on probing, and suppuration at baseline and 7, 28, 90, and 180 days. Microbiologically, total numbers of bacteria and six specific periodontal pathogens were determined by quantitative polymerase chain reaction prior to and 1 and 28 days after SRP. Clinical and microbiological data were analyzed statistically with respect to the SRP method, patient specificity, and time effect. RESULTS: In vitro, linear oscillation preserved more root tissues but left more calculus (P <0.05). Significant improvements of all clinical and microbiological parameters were observed for all groups. However, 21 out of 24 tests demonstrated that the clinical microbiological correlations between linear oscillation and control groups did not differ (P <0.05). CONCLUSION: Linear oscillation scaling was clinically acceptable and microbiologically comparable to the control groups despite microscopic remnants of calculus observed in vitro.