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Notes: Abstract. Several publications have reported an increased susceptibility for root caries after periodontal therapy. It has been suggested that newly exposed roots were less resistant to cariogenic species. This study examined the hypothesis that the increased susceptibility could also be related to an intra-oral microbial shift during the initial phase of the periodontal therapy from a perio-pathogenic to a more cariogenic flora. 10 patients with severe periodontitis were followed for 8 months after thorough scaling and root planing in combination with optimal plaque control. At baseline and after 4 and 8 months, samples were taken from the saliva, the tongue dorsum and the supragingival interdental spaces. These samples were cultured both aerobically and anaerobically in order to determine the total number of colony forming units (CFU) per sample as well as the number of CFU of Streptococcus mutans and Lactobacillus species. Oral hygiene parameters were recorded at the same visits. Finally, at baseline and at the 8 months follow-up, changes in caries activity and periodontal health were registered. Although the total number of aerobic and anaerobic CFU in samples from the tongue and the saliva remained nearly constant over the entire observation period (variations within 0.5 log), significant (p≤0.05) increases in the number of S. mutans could be detected, especially at month 8. The significant decrease in the total number of anaerobic CFU in samples from the teeth was not associated with a reduction in the number of S. mutans, so that also for this niche the relative proportion of the latter increased. The number of lactobacilli species for the different niches showed only negligible changes (within 0.5 log values), except for samples from the teeth for which a small (1 log), but statistically significant (p〈0.01), reduction could be detected. The periodontal conditions improved for all patients, but the caries activity could not be arrested. These findings seem to indicate that the increased caries susceptibility after periodontal therapy might partially be explained by a significant increase in the number of S. mutans due to ecological changes within the oral cavity. The clinical consequence of this observation would be to advocate a more strict caries preventive program during initial periodontal therapy.

Notes: Abstract. 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.

Notes: Background: Complete unilateral cleft lip and palate (UCLP) is a hereditary or multifactorial malformation that can be corrected successfully with a combined orthodontic, surgical and restorative treatment. Such multidisciplinary treatment takes many years and demands a lot of attention to both patients' teeth and periodontium.Objectives: This split-mouth study aimed to compare the periodontal health as well as the microbial parameters between cleft and non-cleft region.Material and methods:  75 patients (52 males, 23 females) between 8 and 20 years with a complete unilateral cleft lip and palate (before (n = 30), during (n = 34) and after (n = 11) the active orthodontic treatment) volunteered for this study. Four regions were defined for the split-mouth comparison: teeth neighbouring cleft (site 1), tooth in cleft (site 2), and the corresponding contra-lateral teeth, respectively, in the unaffected quadrants (sites 3 and 4). At all sites the following periodontal parameters were recorded: plaque and gingivitis indices, pocket depth, attachment loss, bleeding on probing, tooth mobility (visual and Periotest), radiographic bone loss and gingival width. In addition, three pooled subgingival plaque samples were taken (around tooth in cleft, teeth facing the cleft, and contra-lateral teeth of the latter).Results:  The differences between the teeth neighbouring the cleft and the corresponding contra-lateral opponents were of borderline significance (P ≤ 0.05) for the plaque index, the approximal probing depths and the attachment loss (teeth facing the cleft always had slightly higher parameters). When the tooth in the cleft was compared to the contra-lateral tooth, differences were only found for both the approximal probing depths, attachment loss and bone loss, which were significantly higher for the tooth in the cleft. The microbial analysis did not reveal differences between the different sites, neither in the proportion of aerobic and anaerobic bacteria (differences 〈 0.5 log), nor in the detection frequency of periopathogens.Conclusions:  These data indicate that the periodontium in UCLP patients can cope well with a long-term orthodontic treatment, even in unfavourable conditions (like absence of attached gingiva and poor oral hygiene).

Notes: The utility of a planimetric method for measuring in vivo plaque growth on teeth within 24 hours was tested. A reproducible photographic technique was developed. With this technique color slides were made after plaque disclosure with neutral red 0.5% and enlarged up to 25 times natural size for tracing on paper. The percentage of tooth surface covered by plaque was calculated with a planimeter. To obtain a stable and interpretable staining of the plaque three dye applications were applied. The interpretation of the slides was only reproducible when the slides were examined the same day and with the use of a tooth outline. Under these conditions an intra-examiner correlation coefficient of 0.999 was found. Furthermore, it was possible to detect significant differences in rate of plaque growth between two subjects within a time interval of four hours.

Notes: This study aimed to investigate the presence of microorganisms in the inner thread of the fixture (endosteal implant part) of the Brånemark™ system. In 9 volunteers the apical part of 2 abutment screws that had been in place for 3 months was examined by means of differential phase-contrast microscopy. All screws harboured a significant quantity of micro-organisms, mainly coccoid cells (86.2%) and nonmotile rods (12.3%). Motile organisms (1.3%) or spirochetes (0.1%) were only sporadically registered. A microbial leakage at the abutment/fixture interface probably is the most probable origin for this contamination.

Notes: Abstract This clinical investigation examined the effect of a sanguinarine extract on bacterial plaque growth in man. Three different mouthrinses were examined: (i) Veadent® containing 0.03% sanguinarine and 0.2% zinc chloride (test rinse); (ii) a vehicle solution containing all the excipients of Veadent® except the 0.03% sanguinarine (control rinse); (iii) Hibident® a 0.2% chlorhexidine digluconate formulation (positive control rinse). The trial in which 12 dental students participated, was designed as a single-blind, cross-over study. During 3 experimental periods of 18 days, the participants refrained from mechanical oral hygiene and rinsed twice a day with one of the above mentioned solutions. Between experimental phases, a wash-out period of 11 days was instituted. In each subject, 4 teeth were randomly selected for assessment. Clinical evaluations were performed at days 1 (0, 4, 8, 12 hours), 2, 4, 11 and 18. The plaque on the buccal surfaces of the selected teeth was disclosed with neutral red 0.5% and colour slides taken. The % of the tooth surface covered with plaque was calculated planimetrically from these colour slides. The present results show an excellent anti-plaque effect with Hibident®, a very small effect with Veadent® and a negligible effect with the vehicle solution without the sanguinarine. These findings would suggest that the Veadent® mouthrinse would have at most only a limited role as a plaque inhibitor.

Notes: Abstract Previous in vivo studies suggested that a high substratum surface free energy (s.f.e.) and an increased surface roughness facilitate the supragingival plaque accumulation. It is the aim of this clinical trial to explore the “relative” effect of a combination of these surface characteristics on plaque growth. 2 strips, one made of fluorethylenepropylene (FEP) and the other made of cellulose acetate (CA) (polymers with surface free energies of 20 and 58 erg/cm2, respectively) were stuck to the labial surface of the central incisors of 16 volunteers. Half the surface of each strip was smooth (Ra ± 0.1 μm) and the other half was rough (Ra ± 2.2 μm). The undisturbed plaque formation on these strips was followed over a period of 6 days. The plaque extension at day 3 and 6 was scored planimetrically from color slides. Finally, of 6 subjects samples were taken from the strips as well as from a neighbouring smooth tooth surface (s.f.e. 88 erg/cm2; Ra ± 0.14 μm). These samples were analysed with a light microscope to score the proportion of coccoid cells, and small, medium, and large rods or fusiform bacteria. At day 3, a significant difference in plaque accumulation was only obtained when a rough surface was compared with a smooth surface. However, at day 6, significantly less plaque was recorded on FEP smooth (19.4%) when compared with CA smooth (39.5%). Between FEP rough (96.8%) and CA rough (98.2%), no significant difference appeared. The latter were of course significantly higher than the scores of the smooth surfaces. Small differences in bacterial composition appeared: the highest % of coccoid cells was observed on FEP smooth (86.2%) and the lowest % on FEP rough (78.5%) and CA rough (82.8%). The results of this study suggested that the influence of the surface roughness on plaque accumulation and plaque composition is more prominent than the influence of the surface free energy.

Notes: This study examined in vitro the existence of microbial leakage along the components of the Brånemark® implant system. Thirty-two implant/abutment assemblies were installed in a liquid blood medium previously inoculated with oral micro-organisms. To examine the leakage at the implant abutment interface, 16 assemblies were partially immersed. The remaining 16 were completely immersed to observe the leakage at both the implant abutment and abutment-prosthesis interface. After 7 days of an-aerobic incubation, the micro-organisms in the internal part of the implants were collected and incubated on blood agar plates in anaerobic conditions. Micro-organisms were found in the completely immersed assemblies and at lower numbers in the partially immersed implants, indicating that bacterial leakage at both levels seems to exist. Several penetrating bacteria have been associated with peri-implantitis. The clinical importance of this bacterial leakage is not yet well understood. Although the longevity of the Brånemark® implants is well documented, this bacterial leakage might play a role in peri-implantitis. both in the etiology as well as in the treatment.

Notes: For several years, osseointegrated implant-supported overdentures have been used in the rehabilitation of full edentulism with excellent results, at least in the lower jaw. This study involved 3 groups of patients with different prosthetic reconstructions:(1) mandibular overdentures supported by 2 implants connected by a bar (30 patients), (2) mandibular fixed prostheses supported by 4–6 implants (25 patients) and (3) mandibular complete dentures without implant support as controls (85 patients). The primary aim of this study was to examine on orthopantomograms (by means of the area index to minimize distortion and magnification errors), posterior mandibular ridge resorption in the 3 treatment groups. The present data demonstrated a minimal posterior mandibular ridge resorption in patients with fixed implant-supported prostheses. A more considerableposterior ridge resorption was observed in the complete denture group and especially in the overdenture wearers. For the latter, the annual posterior jaw bone resorption after the post-extraction remodeling period of 6 months, was 2- to 3-fold that of full denture wearers. When patients were edentulous for more than 10 years, the difference between the 2 latter groups disappeared. It is suggested that although the overdenture design on 2 implants offers advantages from a financial and failure rate point of view, its indications in younger patients should cautiously be evaluated in a long-term perspective concerning posterior mandibular bone resorption.

Notes: 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 medium-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 transmision 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 supra-crestal marginal tissues around osseointegrated implants react to plaque bacteria similarly to periodontal tissues around teeth by chronic inflammation.