Ahmed Khocht

Effect of Implant Design on Initial Stability of Tapered Implants

Implant design is one of the parameters for achieving successful primary stability. This study aims to examine the effect of a self-tapping blades implant design on initial stability in tapered implants. Polyurethane blocks of different densities were used to simulate different bone densities. The two different implant designs included one with self-tapping blades and one without self-tapping blades. Implants were placed at 3 different depths: apical third, middle third, and fully inserted at 3 different densities of polyurethane blocks. A resonance frequency (RF) analyzer was then used to measure stability of the implants. Repeated-measures analysis of variance was used to examine the effect of implant design, insertion depth, and block density on RF. Analysis of covariance was used to examine the strength of association between RF and the aforementioned factors. In both medium-density (P = .017) and high-density (P = .002) blocks, fully inserted non-self-tapping implants showed higher initial stability than self-tapping implants. No differences were noted between the 2 implant designs that were not fully inserted. The highest strength of association was with insertion depth (standardized beta [std beta] = -0.60, P = .0001), followed by block density (std beta = -0.15, P = .0002). Implant design showed a weak association (std beta = -0.07, P = .09). In conclusion, fully inserted implants without self-tapping blades have higher initial stability than implants with self-tapping blades. However, the association strength between implant design and initial stability is less relevant than other factors, such as insertion depth and block density. Thus, if bone quality and quantity are optimal, they may compensate for design inadequacy.

Periodontal health in Down syndrome: Contributions of mental disability, personal, and professional dental care

Fifty-five dentate patients with Down syndrome (DS) and 74 with mental disability non-Down (MR) were compared to 88 control subjects. Subjects in the MR and Control groups were matched by gender and ethnicity to subjects with DS. All subjects were nonsmokers. Periodontal evaluation included plaque index (PI), gingival index (GI), bleeding on probing (BOP), and clinical periodontal attachment levels. Caries and missing teeth were recorded. Measures of personal dental hygiene and the frequency of professional dental care were also recorded. Most subjects brushed their teeth at least once per day, but did not floss. Both groups with DS and MR had significantly more missing teeth, more BOP, and higher GI and PI levels than the control group. Patients with DS had more attachment loss (AL) than the other two groups (p < .001). Increased AL in patients with DS was not associated with differences in socioeconomic status, personal/professional dental care, or mental disability.

Subgingival microbiota in adult Down syndrome periodontitis.

BACKGROUND AND OBJECTIVE The subgingival microbiota in Down syndrome and non-Down syndrome adults receiving periodic dental care was examined for 40 bacterial species using checkerboard DNA-DNA hybridization and the results were related to clinical periodontal attachment loss. MATERIAL AND METHODS A total of 44 Down syndrome, 66 non-Down syndrome mentally retarded and 83 mentally normal adults were clinically evaluated. This involved, for each subject, the removal of subgingival specimens from three interproximal sites on different teeth; all subgingival samples per subject were then pooled and assessed for the presence and levels of 40 bacterial species using species-specific whole-genomic DNA probes and checkerboard DNA-DNA hybridization. Significant group differences in species proportions averaged across subjects were evaluated using the Kruskal-Wallis test, and associations between subgingival species and mean subject attachment loss within Down syndrome and non-Down syndrome subject groups were quantified using Pearson correlation and multiple linear regression analysis. RESULTS Down syndrome subjects exhibited greater attachment loss than non-Down syndrome subjects (p=0.05). Most microbial species were present in Down syndrome subjects at levels similar to non-Down syndrome subjects, except for higher proportions of Selenomonas noxia, Propionibacterium acnes, Streptococcus gordonii, Streptococcus mitis and Streptococcus oralis in Down syndrome subjects compared with non-Down syndrome study subjects, higher proportions of Treponema socranskii in Down syndrome subjects compared with non-Down syndrome mentally retarded subjects, and higher proportions of Streptococcus constellatus in Down syndrome subjects compared with mentally normal subjects. Down syndrome adults classified with periodontitis revealed higher subgingival levels of T. socranskii than Down syndrome subjects with no periodontitis (p=0.02). Higher subgingival proportions of S. constellatus, Fusobacterium nucleatum ssp. nucleatum, S. noxia and Prevotella nigrescens showed significant positive correlations (r=0.35-0.42) and higher proportions of Actinomyces naeslundii II and Actinomyces odontolyticus showed negative correlations (r=-0.36 to -0.40), with increasing mean subject attachment loss in Down syndrome adults. CONCLUSION Individuals with Down syndrome show higher levels of some subgingival bacterial species and specific associations between certain subgingival bacterial species and loss of periodontal attachment. These findings are consistent with the notion that certain subgingival bacteria may contribute to the increased level of periodontal disease seen in Down syndrome individuals and raise the question as to the reason for increased colonization in Down syndrome.

Aggressive forms of periodontitis secondary to systemic disorders.

A number of systemic disorders increase a patients susceptibility to destructive periodontitis and have impacts on periodontal disease progression and severity. The underlying factors are usually genetic and are mainly related to alterations in the immune response and in certain endocrine functions, leading to various syndromes in which periodontitis and/or early tooth loss are secondary manifestations. Neutrophils are important immune defense cells that play a significant role in controlling the spread of microbial plaque infections in the dentogingival region. This review focuses on a selected group of systemic disorders that are associated with alterations in either neutrophil counts (quantitative disorders) or function (qualitative disorders), and defects in the mineralization of bone and dental tissues. In most of these diseases controlling the periodontal disease progression is very challenging. Proper diagnosis is a prerequisite for proper management of the periodontal problem. Future advances in research, including gene targeting and the resolution of enzyme deficiencies, may bring about remedies of the underlying systemic disorders and may significantly improve the outcome of periodontal treatment in these patients.

Dental Care and Oral Disease in Alcohol Dependent Persons

Dental/Oral health of alcohol-dependent persons and substance abusers is often neglected. It is not clear that alcohol dependence has effects on oral health beyond those expected in nonalcoholic persons of similar socioeconomic status (SES). Study objectives were to examine the personal dental care habits, ability to access professional dental care, and the types of services received and to examine their effect on the oral health of alcohol-dependent persons and substance abusers. Forty Diagnostic and Statistical Manual of Mental Disorders, Third Edition Revised-diagnosed alcohol-dependent persons and a comparison group of 25 non-alcohol-dependent subjects matched for race, age, gender, and SES were recruited. Subjects were medically healthy. Each subject received a comprehensive oral/dental examination, and an interview was conducted to record personal dental hygiene habits, ability to access professional dental care, and types of dental services provided. No statistical differences were found between the oral care habits of the groups. Forty-four percent of all subjects had access to charity professional dental care. Tooth extraction was the main dental service they received. Seventy-five percent of subjects brushed their teeth once or more per day. In the non-alcohol-dependent group, brushing frequency was inversely associated with plaque levels (p < .05); in the alcohol-dependent group, brushing frequency showed no statistical effect on plaque levels. Access to professional dental care was inversely associated with periodontitis in the alcohol-dependent group (p < .05). Alcohol dependence may increase plaque levels above that seen in race, gender, age, and SES-matched controls, but professional dental care can limit the subsequent development of periodontal disease in these people.

Phagocytic cell activity and periodontitis in Down syndrome.

BACKGROUND This study investigated the phagocytic function of peripheral granulocytes and monocytes from adult individuals with Down syndrome (DS) and assessed the relation between phagocytic function and periodontal status. METHODS Fifty-five DS individuals (18-56 years old), 74 mentally retarded individuals, and 88 medically healthy controls (HC) participated in the study. Gingival inflammation index, plaque index, probing depth, periodontal attachment level (AL), and bleeding on probing were taken for each subject. Whole blood was collected for granulocyte/monocyte phagocytosis tests. Phagocytic function was determined by flow cytometry in terms of percentage of cells actively involved in phagocytosis, and phagocytic intensity (magnitude of the bacterial staining per cell). RESULTS Phagocytic intensity of both granulocytes and monocytes was comparable in HC and DS subjects. While AL was directly related to phagocytic intensity of both granulocytes (r = 0.14, P = 0.03) and monocytes (r = 0.2, P = 0.003) in all subjects, this relationship was stronger in DS than in other subjects, even after controlling for known risk factors for periodontitis (P < 0.05). Monocyte phagocytic intensity was the only necessary predictor of AL (P = 0.003), indicating a similar relationship between AL and phagocytic activity in either cell type. CONCLUSIONS While granulocyte and monocyte phagocytic intensities are similar in Down and non-DS individuals, phagocytic intensity was associated with more AL in DS than non-DS individuals.

Probing and scaling instrumentation on implant abutment surfaces: an in vitro study.

Purpose:To investigate surface roughness on the apical collar of implant abutments caused by probing and scaling instruments. Materials and Methods:Fourteen transmucosal abutments (BioHorizons, Atlanta, GA) and 4 instruments: UNC-15 metal probe, Periowise plastic probe, McCall SM 17/18 metal scaler, and universal plastic scaler were used to conduct the study. Four abutments were used for nontreated measures, and 10 abutments were treated with the 4 indicated instruments. Surface roughness was assessed with a contact profilometer. Results:Analysis of variance showed significant differences in surface roughness between the treated and untreated surfaces (P < 0.0001). Add hoc analysis using Tukey-Kramer honestly significant difference test showed no statistical differences between untreated measures and metal probe measures. On the other hand, statistical differences were noted between untreated measures with plastic probe measures (P = 0.05), plastic scaler measures (P = 0.05), and metal scaler measures (P = 0.05). The metal scaler measures were higher than plastic probe measures (P = 0.05) and plastic scaler measures (P = 0.05). Conclusions:Probing around implant abutments with a metal probe seems to have no effect on abutment surfaces. In contrast, instrumentation with scalers (metal and plastic) and plastic probe may cause surface roughness.

Gingival Fluid Inflammatory Biomarkers and Hypertension in African Americans

Hypertension and periodontitis are highly prevalent among African Americans. This cross-sectional study investigated the relationships among inflammatory biomarkers in the gingival fluid, periodontitis, and blood pressure in these individuals. Twenty-one subjects who reported a diagnosis of hypertension and a comparison group of 26 nonhypertensive participants were enrolled. All were African Americans, non–cigarette smoking, and free from other systemic illness. Blood pressure and body mass index were assessed. A comprehensive periodontal examination was performed. Gingival fluid was collected from 3 healthy sites and 3 diseased sites when available. Samples were assessed for 8-isoprostane, interleukin 1β, monocyte chemoattractant protein 1, tumor necrosis factor-alpha (TNFα), C-reactive protein (CRP), and matrix metalloproteinase 8. Regardless of hypertension status, diseased sites were associated with increased levels of these biomarkers. CRP and TNFα levels were also significantly higher in hypertensive than nonhypertensive individuals without diseased sites. After adjusting for demographics and body mass index, periodontal attachment loss was higher among hypertensive than nonhypertensive subjects. TNFα and CRP levels and hypertension were in the same association pathway with attachment loss. Elevated blood pressure may increase the risk of periodontitis through a localized inflammatory mechanism. Knowledge Transfer Statement: The results of this study can be used by clinicians to better understand the etiology and pathogenesis of periodontitis in hypertensive individuals in general and African Americans in particular. The information could lead to better management of periodontal disease.

A comparison of computed tomography scans and digital periapical radiographs ridge height measurements.

To investigate the agreement between computerized tomography scans (CT) and intraoral periapical digital radiographs (PA) alveolar ridge height measurements in maxillary and mandibular posterior regions. We reviewed 100 implant patient radiographic records and identified 27 mandibular sites in 19 patients and 23 maxillary sites in 13 patients with available CT scans and matching PA radiographs. The distance from the crest of the ridge to the floor of the maxillary sinus or to the superior border of the inferior alveolar canal was measured. PAs were measured with Dexis software v. 8.0 and CTs were measured with Simplant software v. 11.02. Two examiners (RJ and MM) recorded the measurements separately; each examiner recorded two readings. The average of the 4 readings was used for data analysis. Absolute agreement: Paired t test comparing ridge-height measurements between the two imaging methods showed no differences for maxillary sites (P > 0.2) and significant differences for the mandibular sites (CT > PA, P = 0.0009). Relative agreement: Kendall rank correlation analysis of ridge-height measurements between the 2 imaging methods showed a high positive correlation for maxillary sites (Kendalls tau = 0.76, P = 0.0001) and moderate correlation for the mandibular sites (Kendalls tau = 0.46, P = 0.001). Maxillary PAs tend to approximate CT ridge-height measurements. By contrast mandibular PAs tend to underestimate the distance from the crest of the ridge to the inferior alveolar canal.

Re: The influence of gingival margin recession on loss of clinical attachment in alcohol-dependent patients without medical disorders. Khocht A, Janal M, Schleifer S, Keller S (2003;74:485-493).

may have early complications as transposed colon ischemia and anastomotic fistula. Late complications as anastomotic stricture “redundant graft”, ulceration, colitis, perforation, diverticulitis, or tumor in the colonic segment are reported4,5. Must be remembered that colorectal cancer has a high incidence; is the third leading cause of cancer diagnosed in men and second among women in the world12 and this colonic segment has a risk for malignancy too. There are 21 cases of adenoma/adenocarcinoma in transposed colon described in literature1,3-7. This case shows that all patient underwent to esophagocoloplasty and develops dysphagia during late follow-up should be investigated for malignancy and the initial diagnosis of stenosis of the esophagocolic anastomosis without biopsy should be evoid.