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Biomedical subjects

M Quirynen

Publications and source records attributed to M Quirynen.

118 records · Page 7Linked to original sources
PubMed1987

Plaque removing effect of a convex-shaped brush compared with a conventional flat brush.

The plaque-removing effect of a convex-shaped multitufted brush was compared with that of a conventional flat multitufted brush. Two group (five and seven dental students, respectively), well instructed in the modified Bass technique, participated in a blind, splitmouth, crossover study during two consecutive experimental periods of 96 hours of undisturbed plaque growth. After each of these periods, a supervised brushing session was performed, followed by toothpick utilization. Plaque removal was evaluated using the modified Navy Plaque Index (MNPI) and planimetry. A 4% erythrosin solution was used as a disclosing agent. Planimetrically, the flat Oral B brush appeared significantly more effective than the convex shaped Ph brush (P less than 0.001). This superiority was even enhanced after the use of toothpicks (P less than 0.0005). The differences between the brushes, however, were too small to be detected by the less discriminating MNPI. Although it has been claimed that the convex brush could assure approximal plaque control, the results indicate that for the convex-shaped, as well as for the flat brush, an approximal aid is essential for good plaque control. The hypothesis that the design of the convex-shaped brush could facilitate the modified Bass technique for the average patient could not be proven in this study.

Adult↗
PubMed1986

Double-blind comparison of the analgesic potency of ciramadol, codeine and placebo against postsurgical pain in ambulant patients.

The efficacy and safety of ciramadol (Cir) as an analgesic in relieving moderate to severe pain after oral surgery has been studied in 79 patients randomly assigned to receive single oral doses of Cir 15, 30 or 60 mg, codeine 60 mg or placebo. During the 6-hour observation period, the three ciramadol-treated groups indicated greater pain relief than the codeine 60 mg or placebo groups. In general, Cir 60 mg was significantly more effective than codeine 60 mg, and all doses of Cir were superior to placebo. The proportion of patients in each Cir group reporting adverse experiences was significantly higher than in either the placebo or codeine groups. The experimental system proved very effective in demonstrating analgesic potency of Cir. The very high incidence of side-effects in the three ciramadol-treated groups makes it unfit for further clinical use in ambulant patients.

Adult↗
PubMedDate not supplied

One-stage full-mouth disinfection to overcome intra-oral transmission of periodontopathogens.

The oral cavity offers a range of different niches where periodontopathogens can adhere and survive (e.g. the mucosa, the tongue, the tonsils, the saliva and all intra-oral hard surfaces such as teeth, dentures, oral implants). Transmission of bacteria from one niche to another is likely to occur. Recent studies, for example, illustrated that initially sterile abutments of oral implants were rapidly colonized by bacteria from the subgingival environment around teeth. This transmission of bacteria can occur spontaneously via the saliva, or by means of oral hygiene aids and/or dental instruments. Such an intra-oral transmission, if it occurs at a high speed, could jeopardize the outcome of periodontal therapy. To overcome a bacterial transmission, a 'one-stage full-mouth disinfection' was recently introduced for the treatment of periodontal infections. This new treatment strategy resulted in significant clinical and microbiological improvements when compared with the standard sequential treatment.

Journal Article↗
PubMedDate not supplied

Histo-pathologic characteristics of peri-implant soft tissues in Brånemark implants with 2 distinct clinical and radiological patterns.

This investigation is the result of a multicenter research project between the Catholic University of Leuven and the University of Madrid with the purpose of studying histometrically and ultrastructurally periimplant marginal tissue reactions in mendium-term Brånemark implants. 12 patients were selected and distributed according to predefined clinical and radiological parameters into a periimplant infection group (A) and a non-periimplant infection group (B). Biopsies were taken from these patients and analyzed by means of microscopy (LM), histometry (HM) and transmission electron microscopy (TEM). With LM group A showed pathological features consistent with an advanced gingivitis lesion, while group B showed signs of healthy gingiva in the connective tissue and vauolae formation in the epithelium. With HM, group A showed significantly higher transmigration of inflammatory cells in the epithelium than group B. In the connective tissue, group A showed a higher % of inflammatory infiltrate with significantly higher numbers of plasma cells and mononuclear cells than group B. With TEM, group A showed an ultrastructural picture consistent with plaque-induced periodontitis, while group B showed a rather healthy connective tissue and vacuolae formation in the epithelium. These results suggest that supracrestal marginal tissues around osseointegrated implants react to plaque bacteria similarly to periodontal tissues around teeth by chronic inflammation.

Bacterial Infections↗
PubMedDate not supplied

The reliability of pocket probing around screw-type implants.

This study involved 108 patients (age 38-82 years) rehabilitated with overdentures in the lower jaw supported by 2 endosseous screw-shaped implants. At each follow-up visit, the clinical attachment level (PAL) around the implants was assessed with a Merrit-B probe or a constant force electronic probe, Peri-probe, and biannually parallel long-cone radiographs were taken to locate the marginal bone level. These data were used to examine the relationship between bone and attachment level estimations around implants. As a mean, bone level and PAL, for mesial and distal sites, was 0.67 and 0.61 for the Merrit-B probe, and 0.76 and 0.65, respectively for the Peri-probe. The highest correlations were obtained for sites with a healthy gingiva or in absence of intra-bony craters. Duplicate PAL registrations showed a standard deviation for the intra-examiner variability of 2.37 (Peri-probe) or 0.40 mm (Merrit-B probe) with more than 90% of the variation within 0.5 mm. The mean difference in PAL between Merrit-B probe or Peri-probe was 0.05 mm. It was concluded that the clinical attachment level determination is a reliable indicator for bone level around implants with a moderate healthy gingiva.

Adult↗
PubMedDate not supplied

Mechanical state assessment of the implant-bone continuum: a better understanding of the Periotest method.

The aim of this study was to obtain a better understanding of the Periotest method when used to detect subclinical mobility of osseointegrated implants. Four hundred two screw-shaped implants were tested with the Periotest device at the time of abutment connection. Several factors, including jaw location, implant and abutment length, and gender, were related to Periotest values (PTVs). Implants located in the anterior region of the mandible showed the lowest mean PTV (-3.2). The influence of abutment and implant length upon PTVs could be detected in the maxilla. In the mandible, only abutment length had influence on PTVs. Women showed higher mean Periotest scores in the maxilla compared with men. This difference was not found in the mandible. The Periotest method, its clinical limitations, and the meaning of a given PTV are also discussed.

Adult↗
PubMedDate not supplied

Comparison of surface characteristics of six commercially pure titanium abutments.

Clinical studies have reported a positive correlation between the surface roughness of teeth or implants and the rate of supragingival and subgingival plaque maturation. This study compared the surface characteristics of abutments from different implant systems (Astra Tech, Bonefit, Brånemark, Core-Vent, IMZ, and Steri-Oss). For each system, two abutments were examined for surface roughness and surface hardness. The latter served as an indicator for resistance against roughening during professional or habitual oral hygiene procedures. The Ra values (in microns) of the tested abutments were: Steri-Oss, 0.10; IMZ, 0.14; Brånemark, 0.21; Bonefit, 0.23; Astra Tech, 0.27; and Core-Vent, 0.30. The Vickers hardness scores (in VHN) were: Brånemark, 154; IMZ, 208; Astra Tech, 258; Bonefit, 292; Core-Vent, 304; and Steri-Oss, 340. In comparison to most metallographically polished composites, titanium abutments showed a higher initial surface roughness and a slightly higher surface hardness. This may explain, besides the known high surface free energy of titanium, rapid plaque growth on these abutments.

Dental Abutments↗
PubMedDate not supplied

The influence of titanium abutment surface roughness on plaque accumulation and gingivitis: short-term observations.

The roughness of intraoral hard surfaces plays an important role in bacterial adhesion and colonization. Earlier studies have shown that rough surfaces accumulate up to 25 times more subgingival plaque than do smooth sites. In the present study, the influence of surface smoothing was studied. In six partially edentulous patients waiting for a fixed prosthesis supported by endosseous titanium implants, four titanium abutments with different surface roughness were randomly placed. After 1 month of intraoral exposure, subgingival plaque samples from each abutment were compared within each patient by means of differential phase-contrast microscopy. After 3 months, supragingival and subgingival plaque samples were taken from all abutments for differential phase-contrast microscopy and culturing. Probing depth, recession, and bleeding upon probing were scored at the same visit. Differential phase-contrast microscopy showed that subgingivally, only the two roughest abutments harbored spirochetes after 1 month. After 3 months, subgingivally, the composition of the flora showed little variation on the different abutment types, although spirochetes were only noticed around the roughest abutments. Anaerobic culturing resulted in comparable amounts of colony-forming units for all abutment types, both supragingivally and subgingivally. Subgingivally, the microbiologic composition did not show major interabutment differences. Clinically, small differences in probing depth were observed. The roughest abutment showed some attachment gain (0.2 mm) during 3 months, whereas all other abutments had an attachment loss ranging from 0.8 to greater than 1 mm. The results indicate that a reduction in surface roughness (less than a roughness of 0.2 micron) had no major effect on the microbiologic composition, supragingivally or subgingivally. These observations indicate the existence of a threshold roughness below which no further impact on the bacterial adhesion and/or colonization should be expected. However, clinical evaluation seems to indicate that a certain surface roughness is necessary for increased resistance to clinical probing.

Bacteria, Anaerobic↗