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D van Steenberghe

Publications and source records attributed to D van Steenberghe.

At least 73 records · Page 4Linked to original sources
PubMed1999

Multi-layered periodontal pocket epithelium reconstituted in vitro: histology and cytokeratin profiles.

BACKGROUND: In order to study inter-individual differences in bacterial adhesion/invasion of periodontal tissues, an in vitro model for culturing multi-layered pocket epithelium without feeder layers or stromal equivalents (including the evaluation of their cytokeratin profiles) was developed. METHODS: Pocket epithelium was collected and grown until confluent in Falcon flasks using keratinocyte-serum free medium (KSFM), without a feeder layer. In the second passage, oral keratinocytes were re-grown in a 2 compartment system using either a clear polyester (transwell-clear [TCL]) or a collagen (transwell-col [TCO]) membrane as culture surface. After the first week, the calcium concentration was raised to 1.2 mM and in half the wells, the KSFM was supplemented with 10% fetal calf serum (FCS). Histology and immunohistochemistry were performed after 1, 2, and 3 weeks of additional growth. RESULTS: In general, all conditions resulted in a structured epithelium consisting of 3 to 5 layers, but important differences were observed between the membrane types and between the media. CK4 was rarely and only lightly expressed while CK18 and 19 (characteristic of junctional epithelium) were very strongly expressed in the older (2 and 3 weeks) cultures. CK13 and 14 (characteristic of any stratifiable epithelial cell) also tended to increase over time; CK13 seemed to be stronger in KSFM with FCS while the contrary was true for CK14. The multi-layer created by the combination TCL/KSFM + 10% FCS resembled a junctional epithelium most, while that grown on TCO without FCS mimicked the sulcular epithelium. CONCLUSIONS: It seems possible to create a histiotypic culture resembling either periodontal pocket or junctional epithelium without the use of stromal equivalents or feeder layers which make this approach more cumbersome. This multi-layered culture offers a model to investigate the permeability of pocket epithelium and the adhesion and penetration of bacteria under well-defined environmental conditions.

Animals↗
PubMed1999

An inventory of patients' response to treatment at a multidisciplinary breath odor clinic.

OBJECTIVE: This study was undertaken to assess patients' response to their treatment at a multidisciplinary oral malodor clinic. METHOD AND MATERIALS: In 4 years, a multidisciplinary breath odor clinic in Belgium examined 406 patients. The team consisted of an ear, nose, and throat specialist, a periodontologist, occasionally a specialist in internal medicine, and, more recently, a psychiatrist. After the initial visit, each patient was scheduled for a follow-up appointment 2 to 6 months later; however, only 143 patients (35%) showed up for this control visit. The remaining 65% of the patients answered a mailed questionnaire. RESULTS: About half of the patients who returned no longer had complaints, while 17% reported no improvement. This group was characterized by imaginary bad breath and manifest psychologic problems. There was also disbelief of their cure, although clinical examination (organoleptic evaluation and volatile sulfide measurement by means of a portable monitor) did not reveal any oral malodor. Some also insufficiently performed the recommended oral hygiene measures (tongue brushing and interdental cleaning). Most of the patients who returned the questionnaire were disappointed by the suggestion that their halitosis was the result of insufficient oral hygiene. CONCLUSION: Better education of both the public and dental professionals as to the most frequent cause of halitosis, insufficient oral hygiene, might elevate the level of compliance by patients.

Adolescent↗
PubMed1999

In vitro volatile sulfur compound production of oral bacteria in different culture media.

OBJECTIVE: The purpose of this study was to detect the relative contribution of Porphyromonas gingivalis, Fusobacterium nucleatum, and Prevotella intermedia in the production of oral malodor. METHOD AND MATERIALS: The volatile sulfur compounds produced by these bacteria in vitro were measured semiquantitatively by a portable sulfide monitor. RESULTS: Samples from the tongue, tonsils, and pharynx showed a significantly higher production (550 ppb) of volatile sulfur compounds during the first 6 hours after anaerobic incubation in broths (brain-heart infusion, Columbia, and Trypticase Soy) than after incubation in agar media (300 ppb) (P < 0.001). After 24 hours, values in broths and agars leveled off at 350 ppb (P = 0.3) and remained constant during the next 6 days. Measurement of separate pure cultures showed that maximal volatile sulfur compound production was reached 6 hours after incubation (450 ppb for the 3 bacteria). Higher volatile sulfur compound values were measured in brain-heart infusion. When measurements of mixed cultures of the 3 pathogens were performed every 15 minutes, the maximal value was reached after only 30 minutes of incubation (nearly 500 ppb). CONCLUSION: The in vitro volatile sulfur compound production of oral samples is preferably measured in broths. Maximal sulfur production from mixed cultures is reached after 30 minutes of incubation. Samples should always be inoculated at the same dilution.

Culture Media↗
PubMed1998

Oral stereognosis: a review of the literature.

Stereognosis is the ability to recognise and discriminate forms. Oral stereognostic ability has been studied in different reports. The experimental design of the test is of primary importance as both the method used and the material applied may influence the results dramatically. The form, size and surface characteristics of the test piece, the presentation order, subject-related factors and the method of scoring all have their effect on the results. With regard to subject-related factors, ageing has a negative influence on stereognostic ability; gender is considered of no importance. Another influencing factor is dental status. A healthy natural dentition offers a very good oral stereognostic ability. Edentulous subjects usually show a decreased oral stereognostic ability, depending on the rehabilitation form. A number of questions have been addressed, especially with regard to the perception itself. Receptors mainly involved in oral stereognostic ability are located in various oral structures and form perception results from an association of more than one group of receptors. The following review tries to deal with these questions and attempts to provide clear guidelines for further research on oral stereognosis.

Humans↗
PubMed1998

Rigidly splinted implants in the resorbed maxilla to retain a hinging overdenture: a series of clinical reports for up to 4 years.

STATEMENT OF PROBLEM: The results of the implant overdenture treatment in the maxilla remains inferior to those in the mandible. Different reasons have been alluded to, such as bone quality and quantity, number of implants, as well as the prosthesis design. PURPOSE: To investigate the latter, a new design for the rehabilitation of the resorbed maxillae was set up. MATERIAL AND METHODS: Thirteen patients were selected and provided with four endosseous maxillary implants, splinted with a rigid-cast bar. RESULTS: After a mean loading time of 3 years, six implants were lost; three at abutment and another three shortly after abutment connection, resulting in a cumulative success rate of 88.6% at year 4. A mean marginal bone loss of 0.3 mm was observed within the first year. After the first year, the marginal bone level, the attachment level, and the Periotest scores hardly changed. The main prosthetic complication was the frequent need to renew or to activate the attachments. A strong improvement in patient satisfaction was observed when compared with the old conventional denture. CONCLUSIONS: Within the limits of this study, the outcome confirmed that, on a medium-term base, implant-retained hinging overdentures on four implants were promising.

Adult↗
PubMed1998

A 5-year randomized clinical trial on the influence of splinted and unsplinted oral implants in the mandibular overdenture therapy. Part I: Peri-implant outcome.

Thirty-six completely edentulous patients were enrolled for a 5-year prospective study testing the treatment outcome between splinted and unsplinted implants retaining a mandibular hinging overdenture. The patients were randomized into 3 groups of equal size depending on the attachment system used such as: magnets, ball attachments or bars (reference group). Only 1 implant out of the 72 had failed at the abutment stage. Not a single implant failed during the 5-year loading period. The accumulation of plaque was significantly higher for the Magnet than for the Ball group. Bleeding on probing, as well as marginal bone level, attachment level and Periotest values did not statistically differ among the groups, neither at year 1 nor at year 5. However, the Periotest values were significantly lower at year 5 compared to year 1 for all groups, which indicates a higher rigidity at the bone-implant interface. No correlation was found between bleeding on probing and marginal bone loss. We conclude that the connection state of 2 implants retaining a hinging overdenture did not influence the peri-implant outcome.

Adult↗
PubMed1998

An image-guided planning system for endosseous oral implants.

A preoperative planning system for oral implant surgery was developed which takes as input computed tomographies (CT's) of the jaws. Two-dimensional (2-D) reslices of these axial CT slices orthogonal to a curve following the jaw arch are computed and shown together with three-dimensional (3-D) surface rendered models of the bone and computer-aided design (CAD)-like implant models. A technique is developed for scanning and visualizing an eventual existing removable prosthesis together with the bone structures. Evaluation of the planning done with the system shows a difference between 2-D and 3-D planning methods. Validation studies measure the benefits of the 3-D approach by comparing plans made in 2-D mode only with those further adjusted using the full 3-D visualization capabilities of the system. The benefits of a 3-D approach are then evident where a prosthesis is involved in the planning. For the majority of the patients, clinically important adjustments and optimizations to the 2-D plans are made once the 3-D visualization is enabled, effectively resulting in a better plan. The alterations are related to bone quality and quantity (p < 0.05), biomechanics (p < 0.005), and esthetics (p < 0.005), and are so obvious that the 3-D plan stands out clearly (p < 0.005). The improvements often avoid complications such as mandibular nerve damage, sinus perforations, fenestrations, or dehiscences.

Dental Implantation, Endosseous↗
PubMed1998

The use of locally delivered minocycline in the treatment of chronic periodontitis. A review of the literature.

Tetracyclines are frequently used in the treatment of periodontitis; however, emergence of resistant bacterial strains has decreased the utility of these drugs. At present, there are a lot of data in the literature from which one can draw conclusions regarding the use of local drug delivery. This paper reviews the utility and different systems of local delivery of minocycline, a semisynthetic tetracycline, in the treatment of periodontitis.

Administration, Topical↗
PubMed1998

The effect of a 1-stage full-mouth disinfection on oral malodor and microbial colonization of the tongue in periodontitis. A pilot study.

Oral malodor affects a large proportion of the population and may be the cause of a significant social and psychological handicap. This pilot study aimed to examine whether a 1-stage full-mouth disinfection in periodontitis patients (scaling and root planing of all pockets within 24 hours together with the application of chlorhexidine to all intra-oral niches followed by chlorhexidine mouth rinsing for 2 months) resulted in a significant improvement in malodor when compared to a fractionated periodontal therapy (consecutive root planings per quadrant, at a 1 to 2 week interval). The baseline and outcome data concerning oral malodor were linked to the presence of tongue coating and to its roughness (fissures). Twenty-four patients with severe periodontitis were randomly allocated to test and control groups. At baseline and after 1 and 2 months, the concentration of volatile sulfur compounds (VSC) in the mouth was measured and organoleptic ratings (expired air and total mouth air) were given. Plaque samples were collected from the dorsum of the tongue to calculate the number of colony forming units (CFU) per ml (anaerobic culturing) as well as the number of pigmented CFU/ml. Both the baseline organoleptic ratings and the VSC scores correlated well with the presence of tongue coating but not with the tongue roughness. Because a correlation between tongue coating and its microbial load could not be detected, it was hypothesized that the tongue coating per se, and not the bacteria, might be responsible for the malodor. The 1-stage full-mouth disinfection resulted in a faster and additional reduction in the organoleptic ratings of the oral malodor, even after 2 months. This might be explained by the improved periodontal outcome and/or the more significant reduction in the CFU/ml of pigmented species. In contrast to the organoleptic ratings, which were significantly reduced in both treatment groups (when compared to baseline), the VSC levels remained unchanged. This pilot study indicates that a 1-stage full-mouth disinfection has, in comparison to a standard periodontal therapy, additional beneficial effects in the treatment of oral malodor.

Adult↗
PubMed1998

[Halitosis, foetor ex ore].

OBJECTIVE: To review the results of a multidisciplinary approach on halitosis. DESIGN: Descriptive. SETTING: University Hospital Leuven, Belgium. METHODS: Review of the data on etiology, diagnosis and therapy of halitosis, obtained by a multidisciplinary team consisting of ENT specialists, periodontologists and a psychiatrist. Malodour was confirmed by a halimeter. RESULTS: 491 patients, equally males and females, with a concentration between 20-50 years of age were seen. Oral causes (87%) were due to tongue coating (51%), gingivitis (17%), periodontitis (15%) or combinations 17%). The other 13% causes were due to ENT-related problems (4%), both ENT and oral (3%), digestive tract (1%) and presumed psychic (5%). CONCLUSION: Halitosis is a rather unknown medical problem that often can be solved by a multidisciplinary approach.

Adult↗
PubMed1997

A randomised clinical trial on the influence of splinted and unsplinted oral implants in mandibular overdenture therapy. A 3-year report.

A randomised clinical trial was performed to investigate whether there is a need or advantage to splint two implants in the mandible retaining a hinging overdenture. Furthermore, patient satisfaction was evaluated for different attachment systems retaining the overdenture. Thirty-six edentulous patients were randomised into three groups of equal size and treated with either magnets, ball attachments or straight bars (reference group). After 3 years of observation no implants were lost in any of the groups. Besides, no statistically significant differences were noted for the peri-implant outcome. Although the bar group presented the highest retention force, the general satisfaction of the patients in the three groups did not differ. The patients with bar retentions showed less prosthetic complications of the retention elements but more at the level of the denture-supporting mucosa. Finally, the clinical outcome of all groups confirms that overdenture treatment demands regular controls with limited time intervals.

Adult↗
PubMed1997

The stereognostic ability of natural dentitions versus implant-supported fixed prostheses or overdentures.

A stereognostic ability test was performed in 60 patients. Forty patients were rehabilitated by means of osseointegrated implants. One group consisted of 20 patients with fixed prostheses on implants in both the upper and lower jaws. The other 20 patients had a maxillary denture while in the mandible an overdenture was retained by means of two implants connected by a bar. They were compared to a group of 20 subjects (controls) with a non-restored natural dentition. For the stereognostic ability test, subjects had to recognise ten different test pieces by manipulating them with two antagonistic incisor teeth, avoiding any contact with other oral structures. Both response time and percentage accuracy of recognition were evaluated. The present findings indicated that subjects with an overdenture on implants did not score significantly different from those with an implant-supported fixed prosthesis. In contrast, subjects with teeth had a significantly better stereognostic ability. The percentage of correct responses was 52% for overdentures, 56% for fixed prostheses on implants and 75% for natural dentitions. From these results, it could be concluded that the stereognostic ability is impaired in subjects rehabilitated with osseointegrated implants by about one-third to one-quarter compared to subjects with natural teeth.

Adult↗
PubMed1997

The rehabilitation of the severely resorbed maxilla by simultaneous placement of autogenous bone grafts and implants: a 10-year evaluation.

The long-term success of Brånemark implants has been previously reported. The success rate of the same implants, when associated with autologous grafts, seemed much less predictable. In the present study it is demonstrated that when these implants are installed in conjunction with an autologous corticocancellous hip graft, either onlay or inlay, the cumulative success rate remains at 95% for individual implants in non-smokers. The short extracorporal time might be an explanation. On the other hand, the same approach in patients with congenital defects or who underwent radiotherapy is deceptive. The use of hyperbaric oxygen may dramatically improve these results.

Adult↗
PubMed1997

The reliability of implant-retained hinging overdentures for the fully edentulous mandible. An up to 9-year longitudinal study.

The treatment of fully edentulous mandibles by means of implant-supported hinging overdentures has become a routine therapy, although long-term data on the success rate of implants and prostheses are lacking. This longitudinal study examined 207 consecutively treated patients who received, during the past 10 years, 449 Brånemark implants to retain a mandibular hinging overdenture, mainly on a Dolder bar. Clinical parameters and standardized radiographs taken at every recall visit with an interval of 6-12 months were used to judge the implant rigidity in the jawbone, the marginal bone level, and attachment level changes. The cumulative implant failure rate at 9 years was 3%. After loading, implant loss was concentrated during the first 12 months, with only one failure observed at 22 months. A radiographically determined bone loss of 0.7 mm was observed during the first year. From the second year, a mean annual bone loss of 0.05 mm occurred. The attachment loss, calculated as the sum of probing pocket depth plus the recession, was 0.07 mm/year and paralleled the changes in marginal bone level over time. The rigidity of the implant-bone interface revealed an increase over time, as shown by a decrease in Periotest values. The bar-overdenture complications were related to relining (23%), untightening of the retention clip (10%), and renewal of the prosthesis (7%). When magnets or ball attachments were used, more aftercare was needed. Fracture of the antagonistic full denture occurred in 7% of patients. The present data indicate that the mandibular overdenture therapy on two (Brånemark) implants is a very reliable and cost-effective treatment, even in a long-term perspective for the fixed full mandibular prosthesis and especially in elderly patients.

Adult↗
PubMed1997

Control of a trackball by the chin for communication applications, with and without neck movements.

The overall aim was to evaluate whether a trackball could be used for communication by people who cannot speak due to severe motor impairment. The precision of trackball control by isolated jaw movements or a combination of jaw and head movements was evaluated in 18 healthy physical-education students, free of overt symptoms of craniomandibular dysfunction. The participants were asked to operate a trackball using the chin to type a standard text of four short sentences. There were two experimental situations: nine participants performed the typewriting task with their heads fixed; the other nine performed this task with free head movements. Trackball operation moved to the cursor over an alphabetical keyboard displayed on a computer screen and character selection was made by depression of the left-hand click button using the chin. Participants were asked to perform the task as quickly and accurately as possible. Result showed that those with free head movement typed the test significantly faster than those restricted to using only their jaw muscles. The mean time per character selection was 2.4 s (SD 0.3) for the group with free head movement and 2.7 s (SD 0.3) for the group using only jaw muscles. Group scores were not significantly different with regard to accuracy. It is suggested that a chin-operated trackball could be used for communication applications both with and without neck movements.

Adult↗
PubMed1997

Complete nose coverage to prevent airborne contamination via nostrils is unnecessary.

Besides an atraumatic procedure, aseptic techniques during surgery have been suggested to have a positive impact on the predictability of osseointegration. To avoid an infection of the surgical field, coverage of the face of the patient (drapes) and nose (surgical mask, drape and plastic film) were advocated in order to reduce airborne infections and to prevent a contact contamination of instruments and gloves. Such a coverage, however, increases the feeling of claustrophobia when local anaesthesia is used and can lead to hypoxemia. The aim of the present study was to investigate whether the expired air via the nostrils could contribute to the contamination of the oral surgical field. Test blood agar plates were installed for 30 min under the nose of volunteers lying on a surgical table; once with full coverage of their nostrils, as indicated above, and once without. Simultaneously, control plates were installed on a table besides the patient to measure the basic contamination from the environment. All plates were incubated both aerobically and anaerobically. The number of colony forming units (c.f.u.) recorded on test plates after aerobic and anaerobic incubation were surprisingly low, with a mean score of 2.7 and 5.0 c.f.u. for the uncovered situation, and 2.5 and 3.3 c.f.u. for the covered situation, respectively. The control plates were infected by a nearly comparable number of bacteria (means ranging from 2.2 to 3.2). These findings indicate that covering nostrils by a mask and sterile adhesive plastic film is not essential in avoiding airborne microbial contamination. However, the use of a meshed nose guard to prevent contact with the highly contaminated nasal skin is highly recommended.

Adult↗