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Biomedical subjects

Stefan Renvert

Publications and source records attributed to Stefan Renvert.

At least 19 recordsLinked to original sources

IL-1RN gene polymorphism is associated with peri-implantitis.

OBJECTIVES: Interleukin (IL)-1alpha, IL-1beta and their natural specific inhibitor IL-1 receptor antagonist (IL-1ra) play a key role in the regulation of the inflammatory response in periodontal tissues. Polymorphisms in the IL-1 gene cluster have been associated with severe adult periodontitis. We aimed to investigate the IL-1 gene cluster polymorphisms in patients with peri-implantitis. MATERIAL AND METHODS: The study included 120 North Caucasian individuals. A total of 71 patients (mean age 68 years, 76% smokers) demonstrating peri-implantitis at one or more implants as evidenced by bleeding and/or pus on probing and bone loss amounting to >3 threads on Brånemark implants and 49 controls (mean age 66 years, 45% smokers) with clinical healthy mucosa and no bone loss around the implants were recruited for the study. The titanium implants, ad modum Brånemark, had been in function for at least 2 years. Mouthwash samples were collected and used for genotyping of the bi-allelic polymorphisms IL-1A(-889), IL-1B(+3953), IL-1B(-511) and a variable number of tandem repeat IL-1RN gene polymorphisms using PCR technique. RESULTS: Significant differences were found in the carriage rate of allele 2 in the IL-1RN gene between peri-implantitis patients and controls (56.5% vs. 33.3%, respectively; odds ratios (OR) 2.6; 95% confidence interval (CI) 1.2-5.6; P=0.015). Logistic regression analysis taking smoking, gender and age into account confirmed the association between the IL-1RN allele 2 carriers and peri-implantitis (OR 3; 95% CI 1.2-7.6; P=0.02). CONCLUSIONS: Our results provide evidence that IL-1RN gene polymorphism is associated with peri-implantitis and may represent a risk factor for this disease.

Age Factors↗

Nine- to fourteen-year follow-up of implant treatment. Part II: presence of peri-implant lesions.

OBJECTIVES: The aim of this study was to analyse the proportions of peri-implant lesions at implants after 9-14 years of function. MATERIAL AND METHODS: Two hundred and ninety-four patients underwent implant therapy during the years 1988-1992 in Kristianstad County. These individuals were recalled to the speciality clinic 1 and 5 years after placement of the suprastructure. Between 2000 and 2002, 218 patients with 999 implants were examined clinically and radiographically. RESULTS: Forty-eight per cent of the implants had probing depth > or =4 mm and bleeding on probing (peri-implant mucositis). In 20.4% of the implants, the bone level was located 3.1 mm apical to the implant shoulder. Progressive bone loss (> or =1.8 mm) during the observation period was found in 7.7% of the implants. Peri-implantitis defined as bone loss > or =1.8 mm compared with 1-year data (the apical border of the bony defect located at or apical to the third thread, i.e. a minimum of 3.1 mm apical to the implant shoulder), combined with bleeding on probing and or pus, were diagnosed among 16% of the patients and 6.6% of the implants. CONCLUSION: After 10 years in use without systematic supportive treatment, peri-implant lesions is a common clinical entity adjacent to titanium implants.

Alveolar Bone Loss↗

Nine- to fourteen-year follow-up of implant treatment. Part I: implant loss and associations to various factors.

OBJECTIVES: The aim of the present study was to evaluate the long-term result of implant therapy, using implant loss as outcome variable. MATERIAL AND METHOD: Two hundred and ninty-four patients had received implant therapy (Brånemark System) during the years of 1988-1992 in Kristianstad County, Sweden. The patients were recalled to the speciality clinic 1 and 5 years after placement of the suprastructure. Between 2000 and 2002, 9-14 years after implant placements, the patients were again called in for a complete clinical and radiographic examination. RESULTS: Two hundred and eighteen patients treated with 1057 implants were examined. Twenty-two patients had lost 46 implants and 12 implants were considered "sleeping implants". The overall survival rate was 95.7%. Implant loss appeared in a cluster in a few patients and early failures were most common. Eight patients lost more than one fixture. A significant relationship was observed between implant loss and periodontal bone loss of the remaining teeth at implant placement. Maxillary, as opposed to mandibulary implants, showed more implant loss if many implants were placed in the jaw. A significant relationship between smoking habits and implant loss was not found. CONCLUSION: A history of periodontitis seems to be related to implant loss.

Adult↗

Nine- to fourteen-year follow-up of implant treatment. Part III: factors associated with peri-implant lesions.

OBJECTIVE: The aim of the present paper was to analyse, on patient and implant basis, factors related to peri-implant lesions. MATERIAL AND METHODS: Two hundred and eighteen patients treated with titanium implants were examined for biological complications at existing implants 9-14 years after initial therapy. The effects of several potentially explanatory variables, both on patient and on implant levels, were analysed. RESULTS: On the implant level, the presence of keratinized mucosa (p = 0.02) and plaque (p = 0.005) was associated with mucositis (probing depth > or =4 mm + bleeding on probing). The bone level at implants was associated with the presence of keratinized mucosa (p = 0.03) and the presence of pus (p < 0.001). On the patient level, smoking was associated with mucositis, bone level and peri-implantitis (p = 0.02, <0.001 and 0.002, respectively). Peri-implantitis was related to a previous history of periodontitis (p = 0.05). CONCLUSIONS: Individuals with a history of periodontitis and individuals who smoke are more likely to develop peri-implant lesions.

Aged↗

Topical minocycline microspheres versus topical chlorhexidine gel as an adjunct to mechanical debridement of incipient peri-implant infections: a randomized clinical trial.

AIM: This randomized clinical trial presents a 12-month follow-up of the clinical and microbiological results after application of minocycline microspheres as an adjunct to mechanical treatment of incipient peri-implant infections compared with an adjunctive treatment using 1% chlorhexidine gel application. MATERIAL AND METHODS: Thirty-two subjects with probing depth > or =4 mm, combined with bleeding and/or exudate on probing and presence of putative pathogenic bacteria were given oral hygiene instructions and mechanical treatment of infected areas adjacent to implants. The subjects were then randomly assigned adjunctive subgingival antimicrobial treatment using either chlorhexidine gel or minocycline microspheres. Sixteen patients in the minocycline group and 14 in the chlorhexidine group completed the study. Follow-up examinations were carried out after 10 days, 1, 2, 3, 6, 9 and 12 months. RESULTS: The adjunctive use of minocycline microspheres resulted in improvements of probing depths and bleeding scores, whereas the adjunctive use of chlorhexidine only resulted in limited reduction of bleeding scores. For the deepest sites of the treated implants in the minocycline group, the mean probing depth was reduced from 5.0 to 4.4 mm at 12 months. This study could not show any significant difference in the levels of bacterial species or groups at any time point between the two antimicrobial agents tested. The present findings encourage further studies on adjunctive use of minocycline microspheres in the treatment of peri-implant lesions. CONCLUSIONS: The use of a local antibiotic as an adjunct to mechanical treatment of incipient peri-implantitis lesions demonstrated improvements in probing depths that were sustained over 12 months.

Adult↗

Bacterial profile and burden of periodontal infection in subjects with a diagnosis of acute coronary syndrome.

BACKGROUND: Periodontitis has been identified as a potential risk factor in cardiovascular diseases. It is possible that the stimulation of host responses to oral infections may result in vascular damage and the inducement of blood clotting. The aim of this study was to assess the role of periodontal infection and bacterial burden as an explanatory variable to the activation of the inflammatory process leading to acute coronary syndrome (ACS). METHODS: A total of 161 consecutive surviving cases admitted with a diagnosis of ACS and 161 control subjects, matched with cases according to their gender, socioeconomic level, and smoking status, were studied. Serum white blood cell (WBC) counts, high- and low-density lipoprotein (HDL/LDL) levels, high-sensitivity C-reactive protein (hsC-rp) levels, and clinical periodontal routine parameters were studied. The subgingival pathogens were assayed by the checkerboard DNA-DNA hybridization method. RESULTS: Total oral bacterial load was higher in the subjects with ACS (mean difference: 17.4x10(5); SD: 10.8; 95% confidence interval [CI]: 4.2 to 17.4; P<0.001), and significant for 26 of 40 species including Porphyromonas gingivalis, Tannerella forsythensis, and Treponema denticola. Serum WBC counts, hsC-rp levels, Streptococcus intermedius, and Streptococcus sanguis, were explanatory factors to acute coronary syndrome status (Nagelkerke r2=0.49). CONCLUSION: The oral bacterial load of S. intermedius, S. sanguis, Streptococcus anginosus, T. forsythensis, T. denticola, and P. gingivalis may be concomitant risk factors in the development of ACS.

Bacteroides↗

High-sensitivity serum C-reactive protein levels in subjects with or without myocardial infarction or periodontitis.

BACKGROUND: Serum high-sensitivity C-reactive protein (hsC-rp) is a non-specific marker of inflammation. Elevated hsC-rp levels are found in subjects with cardiovascular diseases (CVDs). Periodontitis may influence hsC-rp levels. OBJECTIVES: To assess periodontal status and hsC-rp serum levels in consecutive subjects hospitalized and diagnosed with acute myocardial infarction (AMI) (n=85) and in a group of carefully matched subjects (gender, age social, ethnic, and smoking habits) without clinical evidence of CVD (n=63). METHODS: hsC-rp levels, other routine serum values, and clinical periodontal conditions were studied. RESULTS: Subjects with AMI had higher hsC-rp levels than control subjects (p<0.001, Mann-Whitney U-test). The odds that subjects in the control group with periodontitis (30% or more sites with>4.0 mm loss of alveolar bone) had serum hsC-rp>1.8 mg/l was 1.5 (95% CI: 1.1-7.3, p<0.05). Stepwise linear regression analysis failed to include periodontal parameters in an explanatory model to hsC-rp values. Only the serum leucocyte (white blood cell (WBC)) counts were explanatory to hsC-rp values (beta standard coefficient=0.45, t=3.2, p<0.001). Serum WBC counts were significantly higher in control subjects with periodontitis (p<0.03) but not in subjects in the AMI group (p<0.57). CONCLUSIONS: (1) As expected, elevated serum hsC-rp concentration and serum WBC counts are associated with acute coronary heart disease. (2) Elevated serum hsC-rp values are associated with radiographically defined periodontitis in subjects with no evidence of CVD. (3) Periodontal parameters are not explanatory to elevated serum hsC-rp values if serum WBC and low-density lipoprotein counts are included in the regression model.

Alveolar Bone Loss↗

Comparison between the Klemetti index and heel DXA BMD measurements in the diagnosis of reduced skeletal bone mineral density in the elderly.

Osteopenia/osteoporosis affect many elderly people and might not be detected until symptoms of fractures occur. Early detection of osteopenia/osteoporosis is important and would allow preventive measures and treatment. Access to screening for osteopenia/osteoporosis is often limited, whereas panoramic radiography is commonly used in dentistry. The aim of this study was to determine the validity of the Klemetti index (KI), measured on panoramic radiographs, in the diagnosis of osteopenia/osteoporosis as defined by a bone mineral density (BMD) measurement below -1.5 standard deviations (SDs) of a community based sample. In total, 211 consecutive participants (102 men and 109 women) 60-96 years in the SNAC-Blekinge study (Swedish National Study on Ageing and Care) underwent bone densitometry [by dual-energy X-ray absorptiometry (DXA)] of both heels. A panoramic radiograph was taken of each participant, and mandibular cortex on a panoramic radiograph was classified as '0' or normal (even and sharp endosteal margin), '1', moderately eroded (evidence of lacunar resorption or endosteal cortical residues), or '2', severely eroded (unequivocal porosity). From logistic regression, the odds ratio of having a BMD measurement below -1.5 SD was 8.04 (95% CI 2.39 to 27.12, P<0.001) in the 'osteopenic' (KI category 2), compared with the 'normal' group (KI categories 0 and 1). Receiver operating characteristic (ROC) curve analysis was used to measure the validity of the KI indicating osteopenia (KI category 2) in predicting reduced BMD. This point provided a sensitivity of 50% and a specificity of 89%. Positive and negative predictive values were 21% and 97%, respectively. There were 87% correctly classified subjects. The area under the ROC curve was 0.64. The present study demonstrated that a negative finding (KI category <2) is highly predictive of the absence of osteopenia/osteoporosis as defined by the DXA measurements.

Absorptiometry, Photon↗

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.

Adult↗

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.

Adolescent↗

Treatment of incipient peri-implant infections using topical minocycline microspheres versus topical chlorhexidine gel as an adjunct to mechanical debridement.

This report presents the clinical results three months after application of minocycline microspheres as an adjunct to mechanical treatment of incipient peri-implant infections compared to adjunctive treatment employing 1% chlorhexidine gel application. Sixteen patients in the minocycline group and 14 in the chlorhexidine group completed the study. Each patient had one or more implants with probing depth > or = 4 mm combined with bleeding and/or exudate on probing and presence of putative pathogenic bacteria. At baseline, patients were randomly assigned to minocycline or chlorhexidine treatment. Follow-up examinations were carried out after 10, 30, 60 and 90 days. The combined mechanical/antimicrobial treatment for the chlorhexidine group did not result in any reduction in probing depth and only limited reduction of bleeding scores. The adjunctive use of minocycline microspheres, on the other hand, resulted in improvements in both probing depths and bleeding scores. For the deepest sites of the treated implants, mean probing depth was reduced from 5.0 mm to 4.1 mm. The reductions in bleeding scores, although greater than for the chlorhexidine group, were modest. Thus, the question as to what extent the combined mechanical/minocycline treatment could be considered adequate for the treated lesions remains to be answered. The present short-term findings, however, encourage further studies with longer observation intervals on adjunctive use of minocycline microspheres in the treatment of periimplant lesions.

Adult↗

Knowledge on periodontal disease before and after a mass media campaign.

The aim of this study was to evaluate if a mass media campaign regarding periodontal disease could increase the knowledge in the general population of diagnoses, symptoms and treatment options of periodontal disease. More specifically, the aim was to investigate the number of correct answers to knowledge questions before and after the campaign. The Swedish Association of Periodontology conducted the campaign through brochures, newspapers, radio and TV. The effect of the campaign was evaluated by a pre- and post campaign questionnaire with a cohort design. From a national population register of 50-75 year olds in Sweden, 900 persons were randomly sampled for the study. A total of 64% of the sample answered both questionnaires. The result of the study showed an improvement among the respondents. There was a significant increase in the number of correct answers regarding diagnoses, symptoms and treatments of periodontitis. In the questionnaire, correct answers regarding "Mobile teeth" increased from 57% to 65% (p=0.003) and "careful dental hygiene" from 65% to 73% (p=0.001). Kappa value's were calculated for consistency in the reply and all kappa values were low especially for the questions "X-ray" (0.36) and "Cleaning between the teeth" (0.38). It was concluded that the campaign probably was successful from a public health knowledge standpoint.

Aged↗

Chronic periodontitis, a significant relationship with acute myocardial infarction.

BACKGROUND: Chronic periodontitis (CP) has been associated with cardiovascular diseases. The study purposes were to identify the odds of acute myocardial infarction (AMI) and CP defined at different thresholds. METHODS AND RESULTS: We studied 80 subjects with clinically confirmed AMI and 80 matched control subjects with no evidence of cardiovascular disease all receiving a comprehensive periodontal examination. Statistical analysis demonstrated a difference in the proportion of sites with a periodontal probing depth >/=6.0mm (2.7% for non-AMI and 12.1% for AMI group, 95% CI: -2.8 to 0.01, P<0.05) but no difference in the extent of gingival bleeding was found between groups. The odds ratio of having AMI and periodontitis varied between 9.2:1 to 14.1:1 with the greatest odds ratio if bone loss exceeded 4mm at >/=50% of the teeth (OR: 14.1:1, 95% CI: 5.5 to 28.2, P<0.0001). The odds ratio remained significant also when only non-smokers were considered (51 subjects) (OR: 7.0:1, 95% CI: 2.0 to 24.3, P<0.01). CONCLUSIONS: Our findings suggest that patients who at routine dental visits demonstrate evidence of bone loss around several teeth can predictably be identified as being at risk for future AMI. Such subjects should be referred for medical and periodontal examinations and treatments.

Alveolar Bone Loss↗

Failure to induce supracrestal bone growth between and around partially inserted titanium implants using bone morphogenetic protein (BMP): an experimental study in dogs.

The effect of bone morphogenetic protein on supracrestal bone growth around partially inserted implants in a dog model is described. The lower premolar teeth (P1, P2, P3 and P4) were extracted on both sides of the mandible in six dogs. At a surgical exposure 12 weeks later, two 10-mm turned titanium implants were partially inserted, approximately 15 mm apart, in the areas of the P1 and P3 in each side of the mandible, allowing five threads to protrude from the bone crest. A titanium mesh was fastened to the coronal aspect of the two fixtures and the space beneath the mesh was filled with bone morphogenetic protein (S300 BMP) in combination with an insoluble bone matrix carrier, or with the carrier alone. The mesh was covered with an ePTFE membrane. Thus, a space for potential bone formation was created between the two implants. The surgical flaps were coronally positioned and secured with vertical mattress sutures. After 16 weeks of healing, biopsy specimens were retrieved and examined histologically. Bone was not formed around the protruding implants or in the created space between the implants in any case. The carrier was incompletely resorbed. We conclude that supracrestal bone growth beyond the crestal limit with or without BMP in such a large space as in this experimental design may not be possible.

Absorbable Implants↗

Osseointegration on implant surfaces previously contaminated with plaque. An experimental study in the dog.

This study investigated whether osseointegration can occur on a surface which had previously been coated with dental plaque. The mandibular premolar regions of four young adult Labrador dogs were used for the study. The lower premolars (P1, P2, P3, and P4) were extracted on either side of the mandibles. Following a 12-week healing period, three 3.75 mm x 13 mm commercially pure titanium implants (Nobel BiocareAB, Gothenburg, Sweden) were partially inserted in one side of each mandible. This resulted in some threads protruding from the tissues into the oral cavity. Plaque was allowed to accumulate on the exposed implant surfaces. Following a 5-week healing period, the contaminated parts of each implant were treated using three different cleaning techniques: (1) swabbing with supersaturated citric acid for 30 s on a cotton pellet followed by rinsing with physiological saline, (2) cleansing with a toothbrush and physiological saline only for 1 min, and (3) swabbing with 10% hydrogen peroxide (H2O2) on a cotton pellet for 1 min followed by rinsing with physiological saline. The treated implants and one previously unused implant (control) were then placed into freshly prepared tapped sites to the full implant length on the contralateral sides of the mandibles. Following 11 weeks of healing, biopsies were obtained and ground sections prepared for histomorphometric analysis. All treatment modalities were associated with direct bone to implant contact on the portion of implant surface previously exposed to the oral environment. In conclusion, The results demonstrate that osseointegration can occur to surfaces that were plaque contaminated and cleaned by different methods.

Animals↗

Treatment of peri-implant infections: a literature review.

OBJECTIVES: The purpose of the present paper is to review available information on the treatment of peri-implant mucositis and peri-implantitis. MATERIALS AND METHODS: The results of animal research and human studies are presented. Proposed strategies for the treatment of peri-implantitis presented in the literature are also included. RESULTS: Most of the information accessible at this time derives from case reports. The reports provide evidence that efforts to reduce the submucosal infection may result in short-term improvements of the peri-implant lesion. They also indicate that regenerative procedures in intrabony peri-implant defects can result in the formation of new bone. CONCLUSIONS: Several uncertainties remain regarding the treatment of peri-implantitis. Properly conducted long-term follow-ups of consecutively treated cases would seem to be a realistic avenue for accumulation of more information. This may assist in establishing the predictability, magnitude and stability of improvements that can be achieved.

Animals↗

Five-year clinical, microbiological, and radiological outcome following treatment of peri-implantitis in man.

BACKGROUND: The aim of this study was to evaluate the long-term outcome of a combined surgical and antimicrobial treatment of peri-implantitis lesions in humans. METHODS: Nine partially dentate individuals with titanium implants demonstrating a marginal bone loss of > or = three threads as compared to baseline measurements made from 1-year intra-oral radiographs, bleeding on probing, and/or suppuration from the peri-implant sulci were included in the study. In each individual, subgingival bacterial samples were obtained and subjected to microbiological analysis by culture. Surgical exposure of the lesions and cleaning of the implants using hydrogen peroxide were performed. The patients were given systemic antibiotics according to a susceptibility test of target bacteria. The treatment was evaluated clinically, microbiologically, and radiograpically at 6 months, 1 year, and 5 years. RESULTS: Seven out of 26 implants with peri-implantitis at baseline were lost during the 5-year follow-up period despite a significant reduction in the presence of plaque and gingival bleeding. Four implants continued to lose bone, 9 had an unchanged bone level, and 6 gained bone. Five of the patients were treated with antibiotics directed against putative periodontopathogens, i.e., A. actinomycetemcomitans, P. intermedia, or P. gingivalis; three patients were treated for presence of enterics (E. coli and E. cloace); and, in one patient, treatment was directed against S. aureus. CONCLUSIONS: Despite treatment and retreatment, seven implants were lost. However, the applied surgical and antimicrobial treatment strategy for advanced peri-implantitis lesions was successful in 58% of the implants treated during the 5-year follow-up period. Smoking seemed to be a negative risk factor for treatment success.

Aged↗