Clinical and radiographic evaluation of NobelActive(TM) dental implants.

OBJECTIVES: To conduct a randomised controlled trial to evaluate the short-term clinical and radiographic efficacy of the NobelActive™ system and to evaluate the relative importance of achieving primary stability at placement. MATERIALS AND METHODS: A total of 32 subjects were recruited and, using a split-mouth design, the NobelActive(TM) implant was compared with a contralaterally matched Brånemark implant. Both implants were placed in a single surgical procedure into healed sites using a one-stage protocol and reviewed at monthly intervals. NobelActive(TM) implants were functionally loaded with provisional restorations at 1 month and all implants were restored with final crowns 3 months post-implant placement. The implant was assessed using peak insertion torque values, resonance frequency analysis (RFA), clinical parameters, digital subtraction radiography, and cone beam computed tomography. RESULTS: The insertion torque was significantly greater for the NobelActive(TM) implant group (P = 0.02), although no observable difference in RFA values were found. Preliminary results of 6 months follow-up suggest comparable clinical and radiographic healing responses between the test and control implants. Within the limits of the sample population, the survival rates were lower with the test implants, although this difference was not statistically significant. CONCLUSIONS: The NobelActive(TM) implant system requires higher insertion torques and can also achieve greater primary stability compared with a control implant system. Short-term survival and marginal bone levels of NobelActive(TM) and control implants are comparable, although the NobelActive(TM) implant system appeared to be more technique-sensitive.

The correlation of serum and gingival crevicular fluid cytokines in obese subjects.

OBJECTIVE: To investigate the correlation between the gingival crevicular fluid (GCF) levels of IL-6 and TNF-alpha with the levels in serum in obese patients. DESIGN: Twenty-six obese adults (BMI > or = 30, age 33-74) provided serum and GCF samples. Smokers and uncontrolled diabetics (HbA1c > 8%) were excluded. Serum and GCF samples were analysed for IL-6 and TNF-alpha using commercially available ELISA kits. Within each subject GCF was collected from two healthy sites (n = 26 subjects) and two gingivitis sites, defined by bleeding on probing (n = 22 subjects). The levels of IL-6 and TNF-alpha in the GCF were compared and correlated with the levels found in serum using Spearman's correlation analysis. A Bland-Altman analysis was used to determine the level of agreement between serum and GCF samples. RESULTS: IL-6 was more frequently detected than TNF-alpha. This was consistent in serum (100% vs 64%) and GCF samples from healthy (73% vs 52%) and gingivitis (95% vs 36%) sites. There were no significant correlations between the TNF-alpha in serum and GCF samples from healthy (r = 0.27, p = 0.22) and gingivitis (r = -0.19, p = 0.40) sites. In contrast, positive correlations were found for IL-6 between serum and GCF samples from healthy (r = 0.48, p = 0.03) and gingivitis (r = 0.79, p = 0.0001) sites. The correlation and agreement was strongest for IL-6 between serum and gingivitis GCF samples. CONCLUSION: The results of this pilot study suggest a lack of correlation and poor agreement between serum and GCF samples in obese subjects. Studies examining the link between periodontitis and obesity should consider collecting both serum and GCF.

Th2 cell regulatory and effector molecules single nucleotide polymorphisms and periodontitis.

To investigate the association between T helper 2 (Th2) cell regulatory and effector molecules' genetic polymorphisms and periodontitis. Single nucleotide polymorphisms (SNPs) of 11 Th2 cell regulatory or effector molecules genes (CD28, CTLA4, IL4, IL5, IL6, IL9, IL10, IL13, IL4R, GATA3, STAT6, and rs1537415; total 130 SNPs) were studied in Chinese nonsmokers (163 periodontitis-free controls, 141 periodontitis patients) using Sequenom iPlex assays. SNPs potentially associated with periodontitis (adjusted allelic P < 0.1) in this cross-sectional study were further investigated via meta-analysis. Allele G of rs4553808 in promoter of CTLA4 was more frequently detected in periodontitis than controls (P < 0.005), but did not remain significant after age and gender adjustment. Haplotype (GTT) in a block of three CTLA4 SNPs (rs4553808, rs16840252, rs5742909) was significantly associated with periodontitis. Meta-analysis of SNPs identified indicated allele T of CTLA4 rs5742909 (3 studies; 461 control, 369 periodontitis) and allele G of IL6 rs1800796 (18 studies; 2760 control, 2442 periodontitis) were significantly associated with periodontitis (OR = 1.44 and OR = 1.30, respectively). Within limitations of this study, a haplotype of CTLA4 concerning Th2 cell regulation, may be associated with periodontitis in Chinese nonsmokers followed. Meta-analysis indicated rs5742909 of CTLA4 and rs1800796 of IL6 appeared significantly associated with periodontitis.

B-spline interpolation for bend intra-oral radiographs.

Digital subtraction radiography (DSR) has been demonstrated to improve the detection of minute bone changes during the diagnosis of Periodontal diseases. However, during a dental X-ray session, it is not possible to control the bending of the X-ray film when installed in a patient's mouth. This leads to errors in the subsequent analysis. Error compensation can be done by a warping transformation, in conjunction with a reference wire grid attached to the X-ray film. However, the wire grid has to be attached to the film manually. The grid itself is a source of error in that it obscures the image and causes information loss. In this paper we propose a compensation method without the use of a reference grid. It is a simple algorithm based on B-spline interpolation and image scaling. No prior information about the bending is required. When compared with warping transformation, the method induces less disturbance to the pixel values during the compensation process. As a result, the proposed method produces more accurate image data for subsequent analysis.

Repeated oral hygiene instructions alone, or in combination with metronidazole dental gel with or without subgingival scaling in adult periodontitis patients: a one-year clinical study.

The aims of the present study were to evaluate the clinical efficacy of, and to monitor microbiologically, repeated oral hygiene instructions alone or in combination with metronidazole 25% gel or subgingival scaling with or without metronidazole gel in treatment of new, residual or recurrent periodontal pockets in previously treated adult periodontitis patients. Ten suitable patients were included in this randomized single-blind clinical study with an intra-individual design. Clinical parameters were measured before and at 1, 3, 6, 9 and 12 months after treatment. Subgingival plaque samples were taken at every examination from one selected site in each quadrant. Smears from plaque samples were silver-stained and differential counting was performed under light microscopy at 1000X magnification. Four treatment modalities: (i) oral hygiene instruction (OHI) alone; (ii) OHI and metronidazole dental gel; (iii) OHI and subgingival scaling; (iv) OHI and subgingival scaling plus metronidazole gel, were randomly assigned to one quadrant of each patient. At the 12-month examination, the mean reductions in probing pocket depth were 2.6 mm after OHI alone, 2.8 mm after OHI and metronidazole gel, 3.3 mm after OHI and subgingival scaling and 2.6 mm after oral OHI and subgingival scaling plus metronidazole gel. The mean gains in probing attachment level were 2.2 mm, 1.9 mm, 2.7 mm and 1.6 mm, respectively. Although there were statistically significant differences in treatment responses between some treatment modalities at some time points, these were not considered to be clinically significant. Differential counts showed a shift towards a healthy microflora in response to all treatment modalities. From the 12-month results, it was concluded that the metronidazole 25% gel produced positive effects on the clinical parameters and on the subgingival plaque microbiological composition in new, residual or recurrent pockets in previously treated chronic periodontitis patients. However, the metronidazole gel alone or in combination with scaling does not seem to have any additional clinically significant therapeutic effects over and above those derived from improved oral hygiene resulting from monthly recalls, with or without subgingival scaling.

Adjunctive use of modified Yunu-Jian in the non-surgical treatment of male smokers with chronic periodontitis: a randomized double-blind, placebo-controlled clinical trial.

BACKGROUND: Yunu-Jian (YJ) is a Chinese medicine (CM) heat purging formula, which is used to reduce wei huo (stomach-heat, SH) and enrich shen yin (kidney-yin, KY). This formula is also commonly used to manage diabetes mellitus and gum/oral inflammation. The activity of YJ can be modified or refined by the addition of other CM herbs and/or minor changes to one of its five key ingredients. The aim of this study was to evaluate the adjunctive use of modified YJ (mYJ) or YJ containing additional osteoblast-stimulating and inflammation-modulating CM herbs in the non-surgical periodontal treatment of smokers with chronic periodontitis in a randomized, double-blind, prospective, placebo-controlled study. METHODS: Healthy adult male smokers with untreated chronic periodontitis who showed CM syndrome of SH and KY deficiency (KYD) whilst attending a dental teaching hospital from October to December, 2005, were invited to participate in a randomized double-blind, placebo-controlled clinical trial. The trial itself involved the once-daily oral administration of a placebo or mYJ for 3 months as an adjunct to non-surgical periodontal therapy. Several periodontal parameters, including radiographic alveolar bone density, were measured by computer-assisted densitometric image analysis (CADIA) on selected sites, and CM signs of SH and KYD were followed from their baseline values to various time points up to 12 months or the end of study. RESULTS: Twenty-five smokers (consumed 25.0 ± 15.3 smoking-pack years, ranged 7.5-80; aged 46.3 ± 6.8 years) with periodontitis and SH and KYD were recruited (Placebo, n = 14; mYJ, n = 11). All of the participants showed good tolerance towards the CM recipe. All of the periodontal parameters had improved after 12-month follow-up, and no statistically significant differences were detected between the control group and test group, except for the higher CADIA values observed compared with the baseline at 12 months for test sites (P = 0.025). 4/3/3 test vs 14/13/13 control participants had persisting SH and KYD at 6, 9 and 12 months (P < 0.001), respectively. CONCLUSIONS: The adjunctive use of mYJ preserved the post-treatment increases in the radiographic alveolar bone density at the study sites and led to an overall improvement in SH and KYD compared with the controls. Trial registration HKU Clinical Trial Register, HKCTR-1848 (www.hkuctr.com/Study/Show/3acbf983831244d29d50b543540bf6e9).

Clinical responses to mechanical periodontal treatment in Chinese chronic periodontitis patients with and without Actinobacillus actinomycetemcomitans.

BACKGROUND: The purpose of this study was to compare 12-month clinical responses to mechanical periodontal treatment in Chinese chronic periodontitis patients at sites with and without Actinobacillus actinomycetemcomitans at baseline, and to investigate the ability of mechanical periodontal treatment to eliminate A. actinomycetemcomitans. METHODS: Nineteen patients and a total of 76 selected sites with a mean probing depth (PD) of > or = 7 mm were studied. Whole mouth presence or absence of supragingival plaque (PI%), bleeding on probing (BOP%), probing depth (PD), and probing attachment level (PAL) were recorded at six sites per tooth at baseline and after 3, 9, and 12 months. Baseline subgingival plaque samples were taken from the deepest PD site in each quadrant using sterile paper points and were cultured on TSBV plates for 5 days in a 5% CO2-air incubator. All sites received mechanical periodontal treatment, which included oral hygiene instructions and supragingival and subgingival instrumentation with or without surgical access, with maintenance care being provided once every 3 months thereafter. RESULTS: At baseline, A. actinomycetemcomitans was isolated in 13 of the 19 subjects (68%) and in 29 out of the 76 sampled sites (38%). At the end of 12 months, in three of the initially A. actinomycetemcomitans-positive subjects, A. actinomycetemcomitans was not detected in the sampled sites, while one subject, in whom A. actinomycetemcomitans was not initially found at the sampled sites was A. actinomycetemcomitans-positive at 12 months. Multi-level variance component models showed there was no statistically significant difference in all clinical parameters between A. actinomycetemcomitans-positive and -negative subjects (P > 0.05). In the sampled sites of the initially A. actinomycetemcomitans-positive subjects, the mean PD was reduced from 7.6 +/- 1.6 mm to 3.2 +/- 1.8 mm, the mean PAL gain was 1.4 +/- 2.0 mm, and the mean recession was 3.0 +/- 2.3 mm. The corresponding figures in the sampled sites of the initially A. actinomycetemcomitans-negative subjects were 7.5 +/- 1.6 mm to 2.7 +/- 1.0 mm, 2.3 +/- 2.6 mm and 2.4 +/- 2.2 mm for mean PD changes, PAL gain, and mean recession, respectively. CONCLUSIONS: Favorable clinical responses to mechanical periodontal therapy may occur in Chinese chronic periodontitis patients at sites infected with A. actinomycetemcomitans. The mere detection of subgignival A. actinomycetemcomitans does not necessarily imply poorer treatment outcomes in the control of chronic periodontitis.

Prevalence of cervical enamel projection and its correlation with furcation involvement in eskimos dry skulls.

The objectives of this study were to investigate the prevalence of cervical enamel projection (CEP) in molars of Eskimo dry skulls and to study the correlation of CEP with furcation involvement (FI). The material consisted of 834 upper and lower first and second permanent molars from 133 Eskimo dry skulls. CEPs were investigated from the buccal aspect of the tooth and classified according to a system modified from Masters & Hoskins (12). FI was measured horizontally from the buccal aspect into the furcation with a graduated probe to the nearest mm. Any measurement > or = 2 mm was considered to have positive FI. The result showed a presence of 72% of CEPs among the examined molars. Grade III was found in 53%, Grade II in 9% and Grade I in 11% of the 834 molars. Lower molars had a higher prevalence of CEPs (78%) than upper molars (67%). With the individual skull used as the unit for analysis, a statistically significant correlation of CEP with FI was found in upper right 2nd molar, upper left 1st molar, lower left 1st and 2nd molars and lower right 1st molar. These results may be of clinical importance since the impact of CEPs to periodontal treatment of FIs has been discussed.

Implication of cervical enamel projection to furcation involvement in molars. A pilot clinical study.

The aim of this study was to investigate the correlation of cervical enamel projection (CEP) with furcation involvement (FI) and compare the healing response of molars with or without CEP after surgery. A total of 30 patients contributing 78 maxillary and mandibular first or second molars were included. Plaque Index (PII), Gingival Index (GI), probing pocket depth (PPD) and probing attachment level (PAL) were measured before surgery and 1 and 3 or 6 months postoperatively. During surgery, CEPs were identified and classified with a modified grading system from Masters & Hoskins (24). FI was measured horizontally from the buccal aspect into the furcation with a graduated probe to the nearest mm. Any measurement > or = 1 mm was considered as FI. CEPs were found in 33 molars (42%). Grade III CEPs were found in 14 teeth, Grade IIIb in 4 teeth, Grade II in 1 tooth and Grade I in 14 teeth. The results showed no significant correlation of CEP with FI. Nor was CEP significantly affecting the PPD and PAL 3 or 6 months after surgery. However, FI was a significant factor in the further loss of PAL after surgery. Further studies, involving larger sample size may be necessary in order to give more conclusive results.

Ultramicroscopy of bone at oral implant sites: a comparison of ED and control patients. Part 1-defining the protocol.

PURPOSE: The aim of this study was to develop a protocol to analyze the microstructure of mandibular and maxillary bone in association with implant placement in ectodermal dysplasia (ED) and anodontia conditions compared to patients not suffering from such conditions. MATERIALS AND METHODS: This study was not additionally invasive, since the bone harvesting was completed at the time and site of implant placement. Bone samples were allocated into two groups (ED and control patients) and specified by the site of bone harvesting. Microcomputed tomography (micro-CT) analysis at 5-Μm resolution was conducted on each bone sample. Computer analysis applying specialized CT analysis and software allowed evaluation of the three-dimensional microstructure of alveolar and basal bone samples for comparison of structural parameters. RESULTS: Ten bone samples (five alveolar and five basal) were harvested. Preliminary data confirmed the structural features and significant differences between alveolar and basal bone. Basal bone had greater absolute and percent bone volume, greater bone surface, and a lower trabecular bone pattern factor than alveolar bone. CONCLUSION: Preliminary data were derived from bone harvested from both the maxilla and mandible of control patients, while bone samples from ED patients were harvested from only the anterior mandible. Further bone samples will provide more data on whether broader areas of bone harvesting, age, or sex affect the quality and quantity of the bone and influence implant treatment outcomes.