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Cleeren G, Quirynen M, Ozcelik O, Teughels W. Role of 3D animation inperiodontal patient education: a randomized controlled trial. J Clin Periodontol2014; 41: 38–45. doi: 10.1111/jcpe.12170.AbstractAim: This randomized controlled parallel trial investigates the effect of 3Danimation on the increase and recall of knowledge on periodontitis by patientswith periodontitis. The effects of a 3D animation (3D animation group) werecompared with narration and drawing (control group) for periodontal patienteducation.Material and Methods: A total of 68 periodontitis patients were stratified accord-ing to educational level and then randomly allocated to control or 3D animationgroups. All patients received: (1) a pre-test (baseline knowledge), (2) a patienteducation video (3D animation or control video), (3) a post-test (knowledgeimmediately after looking at the video), and (4) a follow-up test (knowledge recallafter 2 weeks). Each test contained 10 multiple-choice questions.Results: There was no significant difference in baseline knowledge. Patientsreceiving the 3D animations had significantly higher scores for both the post-testand the follow-up test, when compared with patients receiving sketch animations.Conclusion: 3D animations are more effective than real-time drawings for peri-odontal patient education in terms of knowledge recall. 3D animations may be apowerful tool for assisting in the information process.

European Association of Osseointegration, EAO 22nd Annual Scientific Meeting, Dublin, Ireland 17-19 October 2013

BACKGROUND: There has been an explosion in research into possible associations between periodontitis and various systemic diseases and conditions.AIM: To review the evidence for associations between periodontitis and various systemic diseases and conditions, including chronic obstructive pulmonary disease (COPD), pneumonia, chronic kidney disease, rheumatoid arthritis, cognitive impairment, obesity, metabolic syndrome and cancer, and to document headline discussions of the state of each field. Periodontal associations with diabetes, cardiovascular disease and adverse pregnancy outcomes were not discussed by working group 4.RESULTS: Working group 4 recognized that the studies performed to date were largely cross-sectional or case-control with few prospective cohort studies and no randomized clinical trials. The best current evidence suggests that periodontitis is characterized by both infection and pro-inflammatory events, which variously manifest within the systemic diseases and disorders discussed. Diseases with at least minimal evidence of an association with periodontitis include COPD, pneumonia, chronic kidney disease, rheumatoid arthritis, cognitive impairment, obesity, metabolic syndrome and cancer. The working group agreed that there is insufficient evidence to date to infer causal relationships with the exception that organisms originating in the oral microbiome can cause lung infections.CONCLUSIONS: The group was unanimous in their opinion that the reported associations do not imply causality, and establishment of causality will require new studies that fulfil the Bradford Hill or equivalent criteria. Precise and community-agreed case definitions of periodontal disease states must be implemented systematically to enable consistent and clearer interpretations of studies of the relationship to systemic diseases. The members of the working group were unanimous in their opinion that to develop data that best inform clinicians, investigators and the public, studies should focus on robust disease outcomes and avoid surrogate endpoints. It was concluded that because of the relative immaturity of the body of evidence for each of the purported relationships, the field is wide open and the gaps in knowledge are large.

Aim To investigate the influence of the use L-PRF as a socket filling material and its ridge preservation properties. Materials and Methods Twenty-two patients in need of single bilateral and closely symmetrical tooth extractions in the maxilla or mandible were included in a split-mouth RCT. Treatments were randomly assigned (L-PRF socket filling versus natural healing). CBCT scans were obtained after tooth extraction and three months. Scans were evaluated by superimposition using the original DICOM data. Mean ridge width differences between timepoints were measured at three levels below the crest on both the buccal and lingual sides (crest −1 mm (primary outcome variable), −3 mm and −5 mm). Results Mean vertical height changes at the buccal were −1.5 mm (±1.3) for control sites and 0.5 mm (±2.3) for test sites (p

Introduction Universities are developing and implementing implant dentistry training to prepare dental professionals for the growing treatment needs. This study describes how implant dentistry is taught at the KU Leuven and focuses on implant-related clinical outcomes. Perspectives of participating undergraduate students are analysed with a view to improve oral implant dentistry training. Materials and methods Implant dentistry training at the KU Leuven consists of theoretical lectures, pre-clinical hands-on workshops and clinical (surgical/prosthetic) experience. Questionnaires were used to investigate the perceptions of students on the educational programme. Radiographs were taken at implant insertion, at healing abutment connection, at restoration/prosthesis insertion and after 1 and 2 years of functional loading. The marginal bone level was measured from the implant–abutment connection to the first visible bone-to-implant contact. Results One hundred and twelve implants were placed by 56 undergraduate students (61.5% of the total students) in 56 patients. After a follow-up time of 3 years, the cumulative implant survival rate, at implant level, was 97.1%. The mean marginal bone loss after 1 and 2 years in function was 0.35 mm and 0.39 mm, respectively. Eighty percentage of students were satisfied with the training, and they considered this sufficient preparation to perform implant placement under close supervision. Conclusions The clinical outcome of implant treatment performed by undergraduate students under close supervision is similar to that reported by experienced clinicians/research teams. Clinical, surgical as well as restorative experience in addition to theoretical and pre-clinical training seems beneficial when implementing implant dentistry in the undergraduate programmes.

Objectives This clinical trial explored the clinical and radiographic dimensional changes of the alveolar ridge in the first 4 months after tooth extraction in combination with the application of Leukocyte- and Platelet Rich Fibrin (L-PRF). Methods Eighteen single rooted maxillary and mandibular sockets were filled with L-PRF without soft tissue closure. Clinical measurements (bone sounding) were performed using a customized acrylic stent and radiographic measurements were accomplished using Cone Beam Computed Tomography (CBCT), immediately after tooth extraction and after 4 months. Results The clinical observations indicated a mean horizontal resorption of 1.18 ± 2.4 mm (p = 0.8) at the crest, 1.25 ± 2.0 mm (p = 0.57) and 0.83 ± 2.0 mm (p = 0.78) at 2 mm and 4 mm apical to the crest, respectively. The buccal plate demonstrated a mean vertical loss of 0.44 ± 3.5 mm (p = 0.9), the centre of the socket had a significant filling of 5.72 ± 3.6 mm (p = 0.0001) and the oral cortical plate had a mean vertical gain of 0.09 mm ± 1.57 mm (p = 0.9). The radiographic analysis demonstrated a mean vertical bone loss of 0.27 ± 2.5 mm (p = 0.9) on the buccal and of 0.03 ± 1.6 mm (p = 0.9) at the oral crest. The width of the alveolar ridge had a mean loss of 1.33 mm ± 1.43 mm. Conclusions Within the limitations of this pilot study, it can be concluded that L-PRF might show clinical benefits for ridge preservation.

Osteoporosis is a major skeletal disease affecting millions of people worldwide. Recent studies claim that patients with osteoporosis do not have a higher risk of early implant failure compared to non-osteoporotic patients. The aim of this study was to assess the effect of skeletal osteoporosis and local bone density on initial dental implant stability.Seventy-three patients were recruited and were assigned (based on a Dual-energy X-ray Absorptiometry scan) to either the osteoporosis (Opr), osteopenia (Opn), or control (C) group. Forty nine of the 73 patients received dental implants and had implant stability measured by means of resonance frequency analysis (RFA) at implant placement and at prosthetic abutment placement. On the computerized tomography scans, the cortical thickness and the bone density (Hounsfield Units) at the sites of implant placement were measured.At implant placement, primary stability was on average lower in group Opr (63.3 ± 10.3 ISQ) than in group Opn (65.3 ± 7.5 implant stability qutient (ISQ)), and group C (66.7 ± 8.7 ISQ). At abutment placement, a similar trend was observed: group Opr (66.4 ± 9.5 ISQ) scored lower than group Opn (70.7 ± 7.8 ISQ), while the highest average was for group C (72.2 ± 7.2 ISQ). The difference between groups Opr and C was significant. Implant length and diameter did not have a significant effect on implant stability as measured with RFA. A significant correlation was found between local bone density and implant stability for all regions of interest.Implant stability seems to be influenced by both local and skeletal bone densities. The lower stability scores in patient with skeletal osteoporosis reinforce the recommendations that safe protocols and longer healing times could be recommended when treating those patients with dental implants.

De zoektocht naar additieven die tijdens een heelkundige ingreep kunnen worden gebruikt, de noodzaak van biomaterialen beperken en tegelijkertijd de genezing bevorderen is nog steeds gaande. Momenteel kunnen we stellen dat de onderzoeken naar de tweede generatie plaatjesconcentraten (PRF) veelbelovende resultaten aangeven voor de chirurgische parodontale therapie en implantologie. Dit in tegenstelling tot de eerste generatie plaatjesconcentraten. Deze bestonden uit een zeer moeilijk bereidingsprotocol, met chemische toevoegingen. Hierdoor was hun gebruik in de algemene praktijk duur en omslachtig. De tweede generatie heeft geen van deze nadelen. In dit hoofdstuk wordt ingegaan op de geschiedenis van plaatjesconcentraten. Hun bereidingsprotocol wordt in detail beschreven en de verschillende chirurgische opties worden getoetst aan de recente literatuur.

OBJECTIVE: The predictability and simplicity of the Summers' technique for sinus floor elevation encouraged many clinicians to consider this new approach. The impact of such intervention on the sinus mucosa has, however, not been explored extensively. This pilot study followed the response of the Schneiderian membrane, longitudinally, via cone-beam CT images. MATERIAL AND METHODS: Ten consecutive patients (five women, mean age 58.7 years) referred for implant therapy in the posterior part of the maxilla, in combination with a trans-alveolar sinus floor elevation (13 sinuses involved), were enrolled. CBCT images were taken prior to and at 1 week and 1 month after surgery. The changes in thickness of the Schneiderian membrane were scored at nine standardized points per sinus using reformatted cross-sectional images. RESULTS: One week after sinus floor elevation, the Schneiderian membrane showed a significant swelling of 9.2 mm in the middle (SD 0.3; P

Aim To assess the accuracy of static computer-guided implant placement. Material and methods Electronic and manual literature searches were conducted to collect information on the accuracy of static computer-guided implant placement and meta-regression analyses were performed to summarize and analyse the overall accuracy. The latter included a search for correlations between factors such as: support (teeth/mucosa/bone), number of templates, use of fixation pins, jaw, template production, guiding system, guided implant placement. Results Nineteen accuracy studies met the inclusion criteria. Meta analysis revealed a mean error of 0.99 mm (ranging from 0 to 6.5 mm) at the entry point and of 1.24 mm (ranging from 0 to 6.9 mm) at the apex. The mean angular deviation was 3.81° (ranging from 0 to 24.9°). Significant differences for all deviation parameters was found for implant-guided placement compared to placement without guidance. Number of templates used was significant, influencing the apical and angular deviation in favour for the single template. Study design and jaw location had no significant effect. Less deviation was found when more fixation pins were used (significant for entry). Conclusion Computer-guided implant placement can be accurate, but significant deviations have to be taken into account. Randomized studies are needed to analyse the impact of individual parameters in order to allow optimization of this technique. Moreover, a clear overview on indications and benefits would help the clinicians to find the right candidates.

Objective: The objective of this study is to systematically review the literature regarding the impact of mouthrinses on oral malodor and present evidence for the treatment effects of mouthrinses on oral malodor. Material and methods: PubMed-MEDLINE, the Cochrane-CENTRAL and EMBASE were searched through February 10, 2012 to identify appropriate studies. Volatile sulphur compound measurements, organoleptic measurements and tongue coating were selected as outcome variables. Search results: The independent screenings of 333 unique titles and paper abstracts revealed 12 publications (12 experiments) that met the eligibility criteria. Means and standard deviations were extracted. The results were separated into short-term (

This 3-year prospective randomized controlled trial compared the clinical, microbiological and biochemical outcome of minimally (Turned, Tur) and moderately rough (TiUnite®, TiU) implant surfaces in a split-mouth design.The study population included 14 subjects: nine fully edentulous and five partially edentulous subjects with a history of periodontitis. Implants (n = 78, 39 Tur and 39 TiU) were installed randomly in each patient. Peri-implant clinical parameters and intra-oral radiographs were recorded after 3 years of loading. Subgingival plaque and peri-implant crevicular fluid samples were collected and analysed using culture and quantitative polymerase chain reaction for the biofilm, and enzyme-linked immunosorbent assay for the concentration of osteoprotegerin and receptor activator of nuclear factor kappa-B ligand, respectivelyNo statistically significant differences in clinical, microbiological and biochemical parameters could be observed when comparing the Tur and TiU implant surfaces.After 3 years of loading, in periodontitis susceptible patients, the moderately rough, TiU implants demonstrated a similar clinical outcome compared with the smoother, turned implants. Longer follow-up and studies using different implant types are needed to confirm the statement that minimally and moderately rough implant surfaces perform similar, both from a clinical and from a microbiological point of view.

Objectives This study investigates the outcome of short implants additionally placed with longer implants to support a maxillary overdenture. Materials and methods Twelve patients received six implants to support a maxillary overdenture. Only one patient still had two molars in the maxilla, while the others had no remaining teeth. The status of the opposing arch was diverse. The distal implant in each quadrant was 6 mm in height (S) and the middle implants ranged between 10 and 14 mm (L). All implants were placed following a one-stage procedure and early loaded (6 weeks). Clinical and radiological parameters were assessed 6, 12 and 24 months after loading. Results One short implant failed 2 weeks after surgery, probably due to early mobilization by the provisional prosthesis. The mean bone loss on the rough part of the implant was 0.7 mm (S) vs. 1.3 mm (L) during the first year and 0.3 mm (S) vs. 0.2 mm (L) during the second year after loading. The mean implant stability quotient values were 67 (S) vs. 70 (L) at placement and 75 (S) vs. 78 (L) after 1 year. At the 2-year follow- up, all prostheses were still stable and comfortable. Conclusion An overdenture on six implants, of which two have a reduced length, might represent a successful treatment option. No significant difference could be found between both implant lengths at 2 years' follow-up. However, bone loss with short implants may increase the likelihood of failure.

Objective: The impact of the implant position on the restorative outcome could justify guided surgery even for the single implants particularly in the aesthetic zone and especially when a simplified concept is available. Material and methods: Based on a plaster model, on which the soft tissues were mimicked (according to the thickness measured on a Cone-Beam CT), a tooth-supported, surgical template was prepared. The latter guided all drills so that even flapless implant insertion became possible. All implants were placed by students of the master-after-master training program in Periodontology. Results: The prospective cohort included a total of 34 implants, all of AstraTech (Osteospeed®) type, which were successfully inserted in 29 patients, 16 flapless, 32 onestage. The marginal bone along the integrated implants remained stable over time, with 0.13 mm loss during the first year. The aesthetic parameters were reassuring. Conclusions: This simple model-based concept seems to be reliable for the guided placement of single implants and the pre-operative preparation of their restorations. To cite this article: Marcelis K, Vercruyssen M, Naert I, Teughels W, Quirynen M. Model-based guided implant insertion for solitary tooth replacement: a pilot study. Clin. Oral Impl. Res. 23, 2012; 999–1003 doi: 10.1111/j.1600-0501.2011.02242.x

DNA-based methodology for the identification and detection of specific bacteria in dental plaque offers advantages over culturing techniques. One drawback of current molecular techniques like real-time quantitative polymerase chain reaction (RT-QPCR) is that they are not able to distinguish between live or dead bacteria. To overcome this problem an assay was assessed to discriminate between viable or dead bacteria using DNA intercalating substances, propidium monoazide (PMA) and ethidium monoazide (EMA) in combination with RT-QPCR. The assay was tested on oral pathogens: Streptococcus mutans, Prevotella intermedia and Aggregatibacter actinomycetemcomitans. To determine the effectiveness of EMA and PMA, different concentrations (from 5 to 100 μg ml(-1)) of the substances were added to viable or heat-killed suspensions of both organisms (ranging from 10(8) to 10(4) colony-forming units ml(-1)). Afterwards, PMA was tested on mixtures of varying ratios of viable and dead cells. After DNA extraction, RT-QPCR was performed using species-specific primers. Both compounds inhibited PCR amplification from dead cells. The EMA treatment resulted in the largest signal decrease but EMA also inhibited DNA amplification from viable cells. For this reason, PMA was selected for use in further experiments. It was shown to be efficient in allowing selective PCR detection of only viable cells in mixtures containing both viable and dead cells. The amount of amplified DNA corresponded to the percentage of viable cells in the sample. The developed assay will potentially be useful for assessing bacterial loads remaining after disinfection protocols without interference by non-viable bacteria.

Quirynen M, Van Assche N. Microbial changes after full-mouth tooth extraction, followed by 2-stage implant placement. J Clin Peridontol 2011; doi: 10.1111/j.1600-051X.2011.01728.x. Abstract: Background: Recent studies showed that qPCR could detect bacteria related to periodontitis and peri-implantitis in a low concentration after full-mouth tooth extraction. This study monitored the microbiota from tooth extraction, over 9 months of full edentulism, up to 1 year after abutment connection. Material and methods: Ten patients with severe periodontitis were recruited. Six months after tooth extraction, implants were inserted. Three to 6 months later, they were connected to abutments. Plaque samples were collected from the tongue dorsum, saliva, and subgingival area (teeth/implants) before extraction up to 1 year after abutment connection, and analysed via culture, qPCR, and checkerboard technology. Results: A reduction in the total amount of aerobic and anaerobic CFU/ml was observed. The concentration of Porphyromonas gingivalis and Tannerella forsythia (qPCR and checkerboard) in the saliva and, to a lower extent, on the tongue dorsum reduced. For Prevotella intermedia, changes were negligible and no changes could be detected for Aggregatibacter actinomycetemcomitans. The pristine subgingival niches were quickly colonized by key pathogens. Their final concentration remained low, while the detection frequencies remained very high over time. Conclusion: Complete edentulation results in a significant reduction of bacteria related to periodontitis and peri-implantitis, with the exception of A. actinomycetemcomitans, which might indicate that key pathogens can survive without pockets.

Teughels W, Loozen G, Quirynen M: Do probiotics offer opportunities to manipulate the periodontal oral microbiota? J Clin Periodontol 2011; 38 (Suppl. 11): 159–177. doi: 10.1111/j.1600-051X.2010.01665.x. Abstract Background: As in other fields of healthcare, probiotics have been introduced for prevention and treatment of periodontal diseases. Objective: This review was initiated to explore whether the use of probiotics can influence the periodontal microbiota and periodontal health. Materials and Methods: Literature on the mode of action of oral probiotics was reviewed and a systematic review was performed on the microbiological and clinical effects of oral probiotics on periodontal health. Results: Three animal and 11 in vivo human studies were retrieved. Six studies reported on microbiological effects whereas eight studies report on clinical effects. Seven studies were performed on healthy or gingivitis patients and four studies on periodontitis patients. Many of the retrieved studies are pilot in nature and with low quality. The high degree of heterogeneity between studies hampered analysis. Conclusion: Taking into consideration all limitations, the currently available data indicate an effect of probiotics on the oral microbiota and a more limited effect on clinical periodontal outcome measures. However, there is an urgent need for properly conducted clinical trials where probiotics are used as adjuncts to standard periodontal care, similar to antibiotics, using probiotic strains with, at least at an in vitro level, proven periodontal probiotic effects.

Objectives: The present study aims to identify radiographic methods revealing data that are most representative for the true peri-implant bone as assessed by histology. Materials and methods: Eighty implants were placed in 10 minipigs. To assess matching between different image modalities, measurements conducted on intra-oral digital radiographs (IO), cone beam computer tomography (CBCT) and histological images were correlated using Spearman's correlation. Paired tests (Wilcoxon test) were used to determine changes in the bone parameters after 2 and 3 months of healing. Results: Significant correlations between bone defect depth on IO and histological slices (r=+0.7, P

Recently, the predation of Bdellovibrio bacteriovorus on a periodontal pathogen has been described. The current study explores the potential antimicrobial activity of a range of predatory bacteria against key periodontal pathogens. A number of representatives from the Bdellovibrio, Bacteriovorax and Peredibacter lineages (called 'BALOs') were tested for their activity towards a group of key periodontal pathogens and an optimal multiplicity of infection was established. As the oral cavity contains a wide variety of bacteria that are not preyed upon, it was investigated if they can have an effect on the predation efficiency of BALOs. It was concluded that a number of important variables involved in bacterial predation are found to be compatible with the composition of the oral microbiota. This finding makes the case for continued study of the potential for BALOs to combat periodontal pathogens.

Jacobs R, Pittayapat P, van Steenberghe D, De Mars G, Gijbels F, Van Der Donck A, Li L, Liang X, Van Assche N, Quirynen M, Naert I. A split-mouth comparative study up to 16 years of two screw-shaped titanium implant systems. J Clin Periodontol 2010; doi: 10.1111/j.1600-051X.2010.01626.x. Abstract Introduction: Many studies have dealt with the clinical outcome of oral implants, yet none applied a randomized split-mouth design for a long-term follow-up of similar implant systems. Aim: To evaluate two oral implant systems with different surface characteristics in a randomized split-mouth design and to radiologically analyse peri-implant bone level and density over an up to 16-year period. Materials and Methods: The study comprised clinical and radiographic records of 18 partially edentulous patients treated with both implant types randomly placed in either left or right jaw sides. Outcome was evaluated over time. Results: Clinical and radiographic parameters showed no significant differences over time for both systems. Ten years after implant placement, a significantly increasing peri-implant bone density was noted, while Periotest values were found to be significantly decreasing. Fifteen years after implant loading, mean bone loss was 0.02 mm (range −1.15 to 1.51; SD 0.45) for Astra Tech® implants (n=24) and 0.31 mm (range −0.98 to 2.31; SD 0.69) for Branemark® implants (n=23). Conclusions: The study failed to demonstrate significant differences in the outcome of the peri-implant bone for two implant systems with different surface characteristics. The marginal bone level around oral implants changed

Objective: The inherent deformation and two-dimensional nature of panoramic radiographs jeopardise their interpretation and quantitative measurements. This study aims to estimate the degree of underestimation of available mesio-distal bone in the premolar area (comparing panoramic radiographs with multi-slice/cone-beam computer tomography [CT]) to determine the prevalence, width, length and position of the bony canal [artery] in the lateral sinus wall and to explore the prevalence, width and length of another (newly detected) bony canal at the palatal aspect of the upper canine. Material and methods: The distance between the distal side of the canine/first premolar and the mesial side of the first molar or the anterior wall of the maxillary sinus was measured on panoramic radiographs and corresponding multi-slice/cone-beam CT images (65 patients). Measurements were made at apical, mid-radicular and crestal regions, parallel to the occlusal plane. The presence and dimensions of the two above-mentioned intra-osseous canals were verified on multi-slice CT scans (144 patients) using reformatted cross-sectional images and/or axial slices. Results: For all 65 patients, panoramic radiographs underscored the mesio-distal distance of available bone in the upper premolar region (mean 2.9 mm, range 0.1–7.5 mm). An intra-osseous canal in the lateral maxillary sinus wall was clearly visible in 49.5% of the cases (mean diameter 1.4 mm). In the canine region, a bony canal was obvious in 32.9% of the cases, with a mean diameter of 1.23 mm. For both canals, there was no correlation between diameter and patient's age. Conclusions: Based on the present data, cone-beam CT imaging can be recommended for visualising anatomical structures during planning of sinus augmentation procedures. To cite this article: Temmerman A, Hertele S, Teughels W, Dekeyser C, Jacobs R, Quirynen M. Are panoramic images reliable in planning sinus augmentation procedures? Clin. Oral Impl. Res. 22, 2011; 189 –194. doi: 10.1111/j.1600-0501.2010.02000.x

Objective: This retrospective analysis evaluated the long-term outcome of two implants supporting an overdenture in the mandible, as well as the significance of some confounding factors (smoking, implant length, bone quality). Material and methods: All mandibular overdenture cases (n=495) treated during the past 25 years in our centre (with ≥5 years loading of the implants) were included in this study. General information (medical history, implant data, report on surgery) was retrieved from the patient's file. A large number of patients (n=248) were willing to visit the clinic for an additional follow-up visit. For the others, information on implant survival was collected by phone (n=121), or contact was impossible (57 had died, three were hospitalized and 66 could not be reached). In the latter group, information was used, up to their last visit to the clinic. An implant was considered as surviving if it was still in function in the mouth, without clear adverse effects (pain, swelling, mobility). A failure was defined as early if it occurred within the window, insertion-final prosthesis placement; afterwards, it was considered as late. Results: Most of the inserted implants (Branemark type) were of the turned (machined) type (95.5%), the remainder was anodized (TiUnite). The anchoring system was either a bar (86.3%), ball attachments (11.7%) or magnets (1.6%), and only some patients changed from one to the other (0.4%). Kaplan–Meier analyses showed a survival rate of 95.5% after 20 years of loading. Factors that influenced the outcome included smoking (90% rate for smokers) and the surgical protocol (reduced survival rate for one-stage-placed implants). Implant length and bone quality had no impact. Conclusions: These results fully support the two-implant overdenture concept in the mandible even in the long run. To cite this article: Vercruyssen M, Marcelis K, Coucke W, Naert I, Quirynen M. Long-term, retrospective evaluation (implant and patient-centred outcome) of the two-implants-supported overdenture in the mandible. Part 1: survival rate. Clin. Oral Impl. Res. 21, 2010; 357–365. doi: 10.1111/j.1600-0501.2009.01849.x

Van Assche N, van Steenberghe D, Quirynen M, Jacobs R. Accuracy assessment of computer-assisted flapless implant placement in partial edentulism. J Clin Periodontol 2010; 37: 398–403. doi: 10.1111/j.1600-051X.2010.01535.x Abstract Aim: To assess the accuracy of implants placed flapless by a stereolithographic template in partially edentulous patients. Material and Methods: Eight patients, requiring two to four implants (maxilla or mandible), were consecutively recruited. Radiographical data were obtained by means of a cone beam or a multi-slice CT scan and imported in a software program. Implants (n=21) were planned in a virtual environment, leading to the manufacture of one stereolithographic template per patient to guide the implant placement in a one-stage flapless procedure. A postoperative cone beam CT was performed to calculate the difference between virtual implant (n=21) positions in the preoperative planning and postoperative situation. Results: A mean angular deviation of 2.7° (range 0.4–8, SD 1.9), with a mean deviation at the apex of 1.0 mm (range 0.2–3.0, SD 0.7), was observed. If one patient, a dropout because of non-conformity with the protocol, was excluded, the angular deviation was reduced to 2.2° (range 0.6–3.9, SD 1.1), and the apical deviation to 0.9 mm (range 0.2–1.8). Conclusion: Based on this limited patient population, a flapless implant installation appears to be a useful procedure even when based on accurate and reliable 3D CT-based image data and a dedicated implant planning software.

Background Recently, guided surgery has been introduced and several papers verified its accuracy. Aim While those studies reported on the accuracy of the entire procedure, this experiment wanted to make clinicians aware of the amount of the deviation that can already occur during the drilling procedure alone, due to the tolerance of the drill in the drill key. Material and methods Drilling was executed in plexi-glass with a maximal inclination of the drills within the drill keys. Results A mean deviation in angulation of 4.7 degrees occurred with a mean horizontal deviation at the implant shoulder of 0.8 mm and 1.8 mm at the apex of 13 mm implant. The deviation was further dependent of the implant length, the distance of the sleeve above the bone and the respective guiding system. Discussion Increasing the height of the drill key will minimize the inaccuracy. Conclusions The results from this experiment showed the importance of keeping the drill parallel to the guide in a centric position.

Aims: To explore the relationship between primary implant stability and different parameters related to implant or bone properties. Materials and methods: Twenty-four patients received a total of 136 Straumann SLActive implants. Resonance frequency analysis (RFA) was performed at implant placement, and RFA and Periotest (PTV) were scored at loading. Bone density [Hounsfield (HU) scores] and coronal cortical thickness at osteotomy sites were measured from pre-operative computerized tomography scans. Results: Implant length, diameter or the presence of bony dehiscence did not have a significant effect on the mean RFA scores at implant insertion. Significant linear relations were found between RFA or PTV scores and HU values (P

Objectives: To evaluate the implant survival rate, periodontal and radiographic parameters of non-submerged screw implants with two different surfaces (TPS and SLA) in periodontally non-susceptible patients (NSP) and in patients with chronic adult periodontitis (CAP) or with generalized aggressive periodontitis (GAP). Material and methods: In 110 healthy partially edentulous subjects, 68 patients with CAP and 16 patients with GAP, a total of 513 implants were installed and followed for on average 48.1 +/- 25.9 months. Only fixed partial dentures were used as suprastructures. All patients were offered a supportive periodontal maintenance program. Smoking habits, health impairment, plaque score, bleeding on probing (BOP), type of surface, bone score, bone loss on radiographs and the number of failed implants were noted. Results: Implant survival in the NSP and CAP group was 98% and 96% after 140 months (NS), but only 80% after 100 months in the GAP group (P=0.0026). The overall rate of implant loss was 4.7%, but 15.25% in the GAP group (6/16 patients). The average marginal bone loss for all implants was 0.12 +/- 0.71 mm on the mesial side and 0.11 +/- 0.68 mm on the distal side. Bone loss/year was 0.08 +/- 0.31 and 0.07 +/- 0.3 mm in the NSP group, but 0.17 +/- 0.2 and 0.17 +/- 0.19 mm in the GAP group. Only in the GAP group, was bone loss significantly related to BOP, age, inflammation, presence of plaque, probing depth. Implants with a TPS surface had a lower survival than implants with an SLA surface (93% vs. 97%; P=0.06), especially in the GAP group (80% vs. 83%; P=0.005). Smoking habits had a significant influence on implant survival only in the GAP group (P=0.07), declining in current smokers to 63%, and to 78% in former smokers. Overall, impaired general health had no significant influence (P=0.85). However, impaired health further reduced implant survival in the GAP group (survival: 71%). In a statistical model to predict the chance for implant failing, only periodontal classification (P=0.012) and implant surface type (P=0.027) were significant. Conclusion: Periodontally healthy patients and patients with CAP show no difference in peri-implant variables and implant survival rate, but patients with GAP have more peri-implant pathology, more marginal bone loss and a lower implant survival implant rate. SLA surface had a better prognosis than the TPS surface.

Aims: The aim of this paper was to analyse the aetiology and characteristics of 2000 patients who visited a multidisciplinary bad breath clinic in Leuven, Belgium and to correlate organoleptic ratings with portable device measurements. Materials and Methods: The characteristics and aetiology of breath malodour of two thousand consecutive patients who visited a halitosis consultation were explored by means of a standard questionnaire and a clinical examination, including organoleptic scores provided by a trained and calibrated judge, and a portable bad breath detector (Halimeter®). Results: Most patients came without referral and had complaints for several years (mean: 7 years, SD: 8 years). For 76% of the patients, an oral cause was found [tongue coating (43%), gingivitis/periodontitis (11%) or a combination of the two (18%)]. Pseudo-halitosis/halitophobia was diagnosed in 16% of the cases; and ear, nose and throat/extra-oral causes were found in 4% of the patients. Most patients had an organoleptic score

The inflammatory response plays an important role in the tissue destruction associated with periodontitis. Bacterial species can regulate the inflammatory response of host cells, triggered by pathogens. It was hypothesized that also in the field of oral microbiology/immunology such effects of bacterial interactions on inflammatory host cell responses might be present. In this study the effect of beneficial, commensal and pathogenic species on Aggregatibacter actinomycetemcomitans-induced interleukin-8 (IL-8) production by human cells was investigated. The beneficial species, Streptococcus mitis, Streptococcus salivarius and Streptococcus sanguinis, were able to lower the IL-8 production triggered by A. actinomycetemcomitans. The inhibitory effect was also achieved by the application of streptococcal supernatants. In contrast, the commensal Streptococcus gordonii caused no reduction, and the pathogen Fusobacterium nucleatum increased the IL-8 production by the host cells. These results show that bacterial species can influence the inflammatory response of host cells triggered by infection with A. actinomycetemcomitans. ispartof: Journal of Dental Research vol:88 issue:11 pages:1026-1030 ispartof: location:United States status: published

Objective: To test the hypothesis that there are differences in total bacterial counts and capacity for biofilm formation between seven different bracket types. Material and Methods: By means of an in vitro experiment, seven commercially available bracket systems (Damon [A], Clarity [B], Mystique [C], Speed [D], Victory MBT [E], Micro-loc [F], and Generus [G]) were compared. A total of 25 premolar brackets of each bracket system were incubated in brain heart infusion medium containing the saliva and bacteria of two orthodontic patients. After 72 hours, the amounts of aerobe and anaerobe bacteria were determined by counting the colony-forming units (CFU). The CFU ratio (aerobe/anaerobe) also was calculated, and the black pigmented bacteria were analyzed. Results: Significant differences between the different bracket types in terms of biofilm formation were found. Bracket types can be arbitrarily divided into low, intermediate, and high plaque-retaining brackets. The group with low adhesion consists of bracket types E, F, and G; the group with high adhesion of bracket types A, B, and C; and type D exhibits intermediate adhesion. The group with high microbial adhesion (A, B, and C) did present significantly lower CFU ratios (aerobe/anaerobe) than were exhibited by the other bracket systems (P < .05). Conclusion: The hypothesis is accepted. Orthodontic brackets serve as different loci for biofilm formation; in this in vitro study, significant differences were noted between the different types of brackets.

Quantification of Bdellovibrio-and-like organisms (BALOs) by microbial culturing has a number of substantial drawbacks. Therefore a quantitative PCR (qPCR) assay was designed for the culture-independent enumeration of the Bdellovibrionaceae. After optimization, the dynamic range of the qPCR assay was assessed, the specificity was evaluated and a comparison with quantitative microbial culturing was made. To evaluate the suitability of the qPCR assay for analysing environmental samples, fresh water samples were investigated by microbial culturing and by the qPCR assay. The results revealed a substantial difference between the two techniques and indicate that most Bdellovibrionaceae cells are left undetected in environmental samples when only current microbial culturing techniques are used. The application of this new technique is therefore likely to confirm the hitherto underestimated sizes and roles of predatory bacterial populations in nature. ispartof: Environmental microbiology reports vol:1 issue:4 pages:228-233 ispartof: location:United States status: published

Introduction: Knowledge of the early oral colonization patterns could provide a better understanding of oral biofilm development and disease initiation that in turn could be the basis for early preventive programmes. Methods: Microbial samples were collected from five different oral habitats from a total of 93 children (age 3–12 years), attending the Dental School of the University of Athens, who were split into three age groups. A total of 38 microbial species were sought out by the checkerboard DNA–DNA hybridization technique. Results: All of the test species, except Parvimonas micra and Porphyromonas gingivalis, differed significantly among sample locations providing quite distinct microbial profiles for the different oral surfaces. Supragingival and subgingival plaque had similar profiles and exhibited higher proportions of Actinomyces species and Green complex while soft tissue samples were dominated by streptococci of the Yellow complex. The profiles of the tongue dorsum and saliva were also similar. Many of the species were in similar proportions in all three age groups for a given location. Periodontal pathogens showed increases in proportions with increasing age. Specifically, the Red complex species (Tannerella forsythia, P. gingivalis, Treponema denticola) showed a significant increase in proportion with age (P

Background: Since intra-bony pathologies might jeopardize implant outcome, their preoperative detection is crucial. Material and methods: In sixteen human cadaver bloc sections from upper and lower jaws, artificial defects with progressively increasing size (n=7) have been created. From each respective defect, analogue and digital intra-oral radiographs were taken, the latter processed via a periodontal filter and afterwards presented in black-white as well as in colour, resulting in three sets of 7 images per bloc section. Eight observers were asked to diagnosis an eventual defect on randomly presented radiographs, and at another occasion to rank each set based on the defect size. Results: The clinicians were only able to identify a defect, when the junctional area was involved, except for bony pieces with a very homogeneous structure. Conclusion: For longitudinal evaluation of healing bone (e.g. after tooth extraction), colour digital images can be recommended. These observations indicate that intra-oral radiographs are not always reliable for the detection of any intra-bony defect.

Introduction: Microbial interactions are considered important in the adhesion process of pathogenic bacteria in the oral cavity. This study addressed the hypothesis that a streptococcal biofilm influences the hard tissue colonization by the periodontopathogen Aggregatibacter actinomycetemcomitans under hydrodynamic conditions. Methods: The colonization of a green-fluorescent-protein-labelled A. actinomycetemcomitans strain on surfaces coated with a streptococcal biofilm, was monitored in real time using a confocal laser scanning microscope-mounted flow cell. Culture and quantitative polymerase chain reaction data were obtained in parallel from a Modified Robbins Device. Results: Colonization of A. actinomycetemcomitans was inhibited by the four tested streptococci (Streptococcus sanguinis, Streptococcus cristatus, Streptococcus salivarius, and Streptococcus mitis). The most inhibiting species was S. sanguinis. Conclusion: These results confirmed the hypothesis that some bacterial species influence A. actinomycetemcomitans colonization of hard surfaces in vitro under hydrodynamic conditions.

In the past few decades, more patients have been treated orthodontically, but no longitudinal study has compared orthodontic bands and brackets microbiologically and clinically.This longitudinal trial (split-mouth design) included 24 patients. Microbiology (sub- and supragingival), probing depth (PD), bleeding on probing (BOP), and gingival crevicular fluid flow (GCF) were assessed at baseline (band placement) and at weeks 18 (bracket bonding) 20, 24, and 36. A statistical comparison was made over time and among the banded, bonded, and control sites.The aerobe/anaerobe ratio of sub- and supragingival colony forming units decreased significantly (relatively more anaerobes) over the study period for the banded and bonded sites (P0.001). This decrease was accompanied by significant elevations in PD, BOP, and GCF. These changes occurred faster after bonding compared to banding. No significant changes were observed 18 weeks after banding with the exception of increased PD (P0.001). At week 36, all microbial and clinical variables at the bonded site had changed significantly in the negative direction (P0.001) compared to week 18. The control sites did not show any significant changes over time, indicating that the effects were localized.The placement of fixed orthodontic appliances had a significant impact on microbial and clinical variables. The changes occurred faster at the bonded sites compared to the banded sites, probably because wire insertion caused difficulties in approximal cleaning. Over the long term, banding did not lead to more adverse microbial and periodontal effects than bonding.

ispartof: Periodontology 2000 vol:48 issue:1 pages:111-147 ispartof: location:Denmark status: published

Some investigators suggest a similarity between the oral microbiota of dogs and humans. The in vivo assessment of ecologic relationships among bacterial species and between bacterial species and their habitat is difficult to carry out. Consequently, this aspect is often neglected in animal oral microbiological studies. This study aimed to examine the proportions of 40 bacterial species in samples from five intra-oral habitats in beagle dogs using checkerboard DNA-DNA hybridization. Microbial samples were taken from subgingival and supra-gingival plaque, the tongue, tonsils and cheek mucosa in seven beagle dogs. Samples were individually evaluated for their content of 40 bacterial species and the percentage of total DNA probe count was determined for each species, at each habitat. All tested species could be detected in all sampled habitats but each habitat had a distinct community structure. The microbiotas colonizing the hard surfaces in the oral cavity were quite different from the microbiotas colonizing the soft tissues. Bacterial species that are in humans considered to be periodontopathogens are present in high proportions. This study underlines the importance of the habitat and the host on the local microbial profile. (c) 2007 Elsevier B.V. All rights reserved. ispartof: Veterinary microbiology vol:127 issue:1 pages:79-88 ispartof: location:Netherlands status: published

Introduction: Periodontitis results from a shift in the subgingival micro. ora into a more pathogenic direction with Porphyromonas gingivalis, Prevotella intermedia, and Actinobacillus actinomycetemcomitans considered as periodontopathogens. In many cases, treatment procures only a temporary shift towards a less pathogenic microflora. An alternative treatment could be the deliberate colonization of pockets with antagonistic microorganisms to control the adhesion of periodontopathogens. The aim of this study was to identify bacterial strains that reduce adhesion of periodontopathogens to surfaces. Methods: Streptococcus sanguinis, Streptococcus crista, Streptococcus salivarius, Streptococcus mitis, Actinomyces naeslundii, and Haemophilus parainfluenzae were evaluated as potential antagonists against P. gingivalis ATCC 33277, P. intermedia ATCC 49046, and A. actinomycetemcomitans ATCC 43718 as periodontopathogens. Adhesion of periodontopathogens to the bottom plate of a parallel plate flow chamber was studied in the absence (control) and the presence of pre-adhering antagonistic strains up to a surface coverage of 5%. Results: The largest reduction caused by antagonistic strains was observed for P. gingivalis. All antagonistic strains except S. crista ATCC 49999 inhibited the adhesion of P. gingivalis by at least 1.6 cells per adhering antagonist, with the largest significant reduction observed for A. naeslundii ATCC 51655 (3.8 cells per adhering antagonist). Adhering antagonists had a minimal effect on the adhesion of A. actinomycetemcomitans ATCC 43718. Intermediate but significant reductions were perceived for P. intermedia, most notably caused by S. mitis BMS. Conclusion: The adhesion of P. gingivalis was inhibited best by antagonistic strains, while S. mitis BMS appeared to be the most successful antagonist.

Aim: This retrospective study aimed to determine the consequence of early cover screw exposure on peri-implant marginal bone level. Material and Methods: Sixty Astra Tech® MicroThread implants installed in partially edentulous jaws were compared: 20 implants were placed following a two-stage procedure and were unintentionally exposed to the oral cavity (two-stage exposed), 20 implants were placed following a two-stage procedure and were surgically exposed after a subgingival healing time of 3–6 months (two-stage submerged), and 20 implants were placed following a one-stage surgical protocol (one-stage). Digital radiographs were taken at implant placement for all implants, and after abutment surgery for the two-stage exposed and two-stage submerged groups or after 3 months for the one-stage group. Bone loss mesially and distally was measured with an on-screen cursor after calibration. Results: Mean bone re-modelling was 1.96 mm (range: 0.2–3.2 mm) around the two-stage exposed implants, 0.01 mm (range: 0.0–0.3 mm) around the two-stage submerged implants and 0.14 mm (range: 0.0–1.2 mm) around the one-stage implants. Conclusion: The unintentional perforation of two-stage implants resulted in significant bone destruction, probably because the biological width was not considered.

The complexity of the periodontal microbiota resembles that of the gastro-intestinal tract, where infectious diseases are treatable via probiotics. In the oro-pharyngeal region, probiotic or replacement therapies have shown some benefit in the prevention of dental caries, otitis media, and pharyngitis, but their effectiveness in the treatment of periodontitis is unknown. Therefore, this study addressed the hypothesis that the application of selected beneficial bacteria, as an adjunct to scaling and root planing, would inhibit the periodontopathogen recolonization of periodontal pockets. Analysis of the data showed, in a beagle dog model, that when beneficial bacteria were applied in periodontal pockets adjunctively after root planing, subgingival recolonization of periodontopathogens was delayed and reduced, as was the degree of inflammation, at a clinically significant level. The study confirmed the hypothesis and provides a proof of concept for a guided pocket recolonization (GPR) approach in the treatment of periodontitis. ispartof: Journal of Dental Research vol:86 issue:11 pages:1078-1082 ispartof: location:United States status: published

Item does not contain fulltext AIM: To evaluate the precision of transfer of a computer-based three-dimensional (3D) planning, using re-formatted cone-beam images, for oral implant placement in partially edentulous jaws. MATERIAL AND METHODS: Four formalin-fixed cadaver jaws were imaged in a 3D Accuitomo FPD cone-beam computed tomography (CT). Data were used to produce an accurate implant planning with a transfer to surgery by means of stereolithographic drill guides. Pre-operative cone-beam CT images were subsequently matched with post-operative ones to calculate the deviation between planned and installed implants. RESULTS: Placed implants (length: 10-15 mm) showed an average angular deviation of 2 degrees (SD: 0.8, range: 0.7-4.0 degrees ) as compared with the planning, while the mean linear deviation was 1.1 mm (SD: 0.7 mm, range 0.3-2.3 mm) at the hex and 2.0 mm (SD: 0.7 mm, range 0.7-2.4 mm) at the tip. CONCLUSIONS: Cone-beam images could be used for implant planning, taking into account a maximal 4 degrees angular and 2.4 mm linear deviation at the apical tip.

AIM: To compare undisturbed plaque formation on teeth bonded with different types of orthodontic brackets with non-bonded control teeth, via a de novo plaque growth experiment over a 7-day period. MATERIAL AND METHODS: A randomized controlled trial with split-mouth design was set up enroling 16 dental students. Within each subject sites with Speed(S) and GAC(G), brackets and control sites were followed. Clinical periodontal parameters were recorded at baseline, on days 3 and 7. Microbiological samples were taken from the brackets and the teeth on days 3 and 7. RESULTS: Both anaerobe and aerobe colony-forming units (CFU) were significantly higher in S-sites than in G-sites (p=0.0002, p=0.02). The shift from aerobic to anaerobic species was observed earlier in S-sites than in G-sites. The aerobe/anaerobe CFU ratio was significantly lower in S-sites than in G-sites (p=0.01). On day 3, the crevicular fluid flow was significantly higher in S-sites than in control sites (p=0.01). On day 7, S-sites and G-sites showed a significantly higher crevicular flow than control sites (both p

AIM: The study was set to evaluate the validity of subjective jaw bone quality assessment. MATERIALS AND METHODS: A total of 298 patients (198 females, mean age 56.4) were treated with oral implants at the Periodontology Department at the University Hospital of KUL. A total of 761 TiUnite implants have been installed. Subjective bone quality assessment was performed on radiographs and by the surgeon's tactile sensation and was compared with torque measurements. In a subset of patients, implant stability was also assessed by implant stability quotient and/or periotest values. RESULTS: Subjective assessment of bone quality was related to the PTV, ISQ and placement torque [in the crestal, the second and the apical third (N cm)], respectively; in grade 1: -5.3, 73.3 (4.2, 9.6, 15.2), and grade 3 or 4: -1.6, 55 (3.3, 5.5, 8.4). For the surgeon's tactile sensation, a good correlation was noted for the presence of a thick cortex: -4.6, 70.3 (4.2, 9.7, 15.1), or a thin one: -0.3, 65.9 (3.6, 6.9, 10.1). For dense trabecular bone, the values were -2.8, 69.4 (4.4, 9.7,14.8), while for poor trabecular bone, the values were-1.7, 66.4 (3.6, 6.4, 9.8). CONCLUSIONS: Subjective assessment of bone quality is related to PTV, ISQ and placement torque measurements at implant insertion. ispartof: Journal of clinical periodontology vol:34 issue:4 pages:359-366 ispartof: location:United States status: published

Adherence of Actinobacillus actinomycetemcomitans to epithelial cells is an important step in periodontal disease pathogenesis. Recent publications describe the subgingival presence of a wide array of viruses [e.g., human cytomegalo-virus (hCMV)]. Since viruses can increase cellular susceptibility for bacterial adherence, we investigated whether hCMV renders epithelial cells more prone to adherence by Actinobacillus actinomycetemcomitans. Cultivated HeLa and primary epithelial cells were shown to be semi-permissive for hCMV infection, which resulted in increased bacterial adherence. This increase correlated with viral concentrations, was evident in all Actinobacillus actinomycetemcomitans strains examined, and increased during the first 24 hrs, followed by a slight decrease. Immediate early antigen expression was not correlated with the increased adherence of Actinobacillus actinomycetemcomitans. The results confirmed our hypothesis that the adherence of Actinobacillus actinomycetemcomitans is influenced by hCMV in vitro. ispartof: Journal of Dental Research vol:86 issue:2 pages:175-180 ispartof: location:United States status: published