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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

Background: The innervation of skin and oral mucosa plays a major physiological role in exteroception. This innervation is also clinically relevant as sensory changes occur after neurosurgical procedures. Purpose: The goal of this study was to compare the perception of mechanical stimuli applied to the buccal mucosa in the vicinity of osseointegrated oral implants with that in the controlateral dentate side. The role of the previously reported increased innervation in the peri-implant soft tissues in the oral sensorimotor function was thus examined. Materials and Methods: Seventeen subjects with 20 implants were tested. Directional cutaneous kinaesthesia (DCK) and graphesthesia (G) were performed on the buccal side of the alveolar mucosa before and at planned intervals after implant placement. The observation was pursued until 6 months after the prosthetic rehabilitation. In each subject, the contralateral mucosa served as a control to the implant sites. Average percentages of correct responses in a four-choice task for DCK and a three-choice task for G were calculated. Results: Despite an intersubject variation in both the DCK and G, high intraindividual correlations were found (p < .005). The implant sites showed a significant difference toward the control sites at the four interval test for both tests. For DCK and G, the average of correct responses decreased after abutment connection (i.e., after the implant uncovering surgery) to increase afterwards to reach a level close to, but still lower than, the control sites 3 to 6 months after the prosthetic rehabilitation. Conclusion: The DCK and G are simple but reliable sensory tests that can be easily applied in the oral region. This prospective study indicates that tooth loss reduces tactile function compared with implant-supported prostheses. The peri-implant soft tissues could be partially involved in the osseoperception function.

The aim of this study was to evaluate longitudinally the bone-healing process by measuring volumetric changes of the extraction sockets in head and neck cancer patients undergoing radiotherapy after tooth extraction. A total group of 15 patients (nine males, six females) undergoing tooth extraction at the Department of Periodontology (University Hospital KULeuven) were enrolled after giving informed consent. In seven patients, teeth presenting a risk for complications and eventual radionecrosis were extracted prior to the radiotherapeutical procedure. Monitoring of bone healing was performed by evaluating the volumetric changes of the alveoli by cone beam CT scanning (CBCT) at extraction and after 3 and 6 months. In parallel, a similar longitudinal evaluation of extraction sites was done in a control group of eight patients. Within this pilot-study, a total of 15 healing extraction sockets were evaluated and followed up. There was a significant difference in volumetric fill up of extraction sockets in test group vs. control group at three (37.1 +/- 7.9%) vs. (54.6 +/- 4.0%) and 6 months (47.2 +/- 8.8%) vs. (70.0 +/- 7.3%), respectively. The present pilot study demonstrated the clinical usefulness of CBCT for evaluation of extraction socket healing. The study objectively demonstrates the delayed bone healing after tooth extraction in irradiated head and neck cancer patients. Considering the limitations of this pilot study, a potential effect of radiotherapy on further jaw bone healing after pre-therapeutic tooth extractions should be further explored.

Background: This study used a tissue-engineering approach, which combined autologous periosteal cells with a scaffold material, to promote bone augmentation under an occlusive titanium barrier that was placed on the skull of rabbits. Because the cell–matrix interaction is of key importance in tissue engineering, two different calcium phosphate–based scaffolds were seeded with autologous periosteal cells. One scaffold contained hydroxyapatite, tricalcium phosphate, and collagen; the other scaffold was a b-tricalcium phosphate structure. Methods: The experiment involved 38 rabbits divided into five groups: the two different scaffolds with and without cells and a blood clot only. Prior to implantation, autologous periosteal cells were harvested from the tibia by stripping the periosteum. Cells were cultured, and 1 day before the implantation ;20 million cells were collected and seeded onto the scaffolds. Two preformed dome–shaped full titanium barriers were placed subperiosteally onto the frontal and parietal bones of each rabbit. Before placement of the barriers, the different scaffolds, seeded with or without cells, were put on top of the skull. As a negative control, autologous blood was injected into the barriers. Histologic evaluation and histomorphometric analysis were performed after 12 weeks of undisturbed bone growth. Measurements involved the amounts of newly formed tissue and of new bone distinguishing between trabecular bone and osteoid. Results: No significant differences were found between the four treatment groups (scaffolds with or without cells). However, the amount of new bone tissue found underneath the titanium barriers with scaffolds was significantly higher (P

Aim: The aim of this study was to determine the accuracy of volumetric analysis of extraction sockets using cone beam computed tomography (CBCT). Material and Methods: The volume of 40 dental alveoli in nine dry skull specimens (four mandibles and five maxillae) was determined by measuring the volume of the tooth socket impression using the water displacement technique. This was considered as the gold standard. Then, the tooth socket was scanned with CBCT and data were uploaded in the semi-automated Livewire® segmentation software. The software segments the tooth socket in consecutive 1 mm-thick two-dimensional slices. After segmentation, the total volume of the delineated socket was computed. The statistical difference between direct volumetric measurements and those obtained with CBCT imaging was assessed using the Student paired t-test. Result: The mean socket volume of the skull specimens was 227±91 mm3 when obtained by direct measurement and 225±90 mm3 when obtained by CBCT imaging. Student paired t-test showed no significant differences between both volume measurements (p>0.1). Conclusions: CBCT permits imaging of anatomical structures in three planes and allows for reliable volume estimates. The results should be verified in clinical circumstances and might have potential applicability for evaluation of extraction socket healing under different conditions.

The objective of this research was to determine if the essence of expert performance could be captured on a virtual reality simulation system. Six experts in operative dentistry, six experts in periodontology, and six novice dental students performed a Class II tooth preparation task on the lower left second premolar. All subjects performed a pre-test to assess the basic skill level of each group. During the (limited) training component of the study, the three groups practiced three tooth preparations and received augmented feedback. At both a one-minute and one-day interval, subjects performed a final test in the absence of augmented feedback. All preparations were graded by the simulation system. The results showed at pre-test a significantly better performance of the experts in operative dentistry as compared to the novices. During the practice (acquisition) phase, the experts in operative dentistry outperformed both the periodontologists and novices, whereas the experts in periodontology performed more accurately than the novices. After one minute and one day following practice, similar results were obtained. Retention performance was most accurate after a one-day delay. Based on these results, the simulator appears to be a valid and reliable tool to capture expert performance. It is an effective screening device for assessing the level of expert performance.

Statement of problem Data available regarding the treatment outcome for completely edentulous jaws by means of a prefabricated fixed complete denture placed immediately after flapless implant insertion using a surgical guide are only short term. Purpose The purpose of this study was to follow the survival of implants inserted in completely edentulous jaws using a flapless procedure and immediately loaded with prefabricated fixed complete dentures for several years. A second purpose was to investigate whether there is a difference in marginal bone remodeling in smoking (S) and nonsmoking (NS) patients. Material and methods During a 5-year period (mean time of follow-up 2.2 years), 30 consecutive patients, 12 women, 38–74 years of age (average 56 years) were treated for complete edentulism in 1 arch in the Department of Periodontology at the University Hospitals in Leuven. The S group included 13 and the NS group 17 patients. Descriptive statistics were used to analyze the data. Two outcome parameters were analyzed: the cumulative survival rate (CSR) of individual implants and the marginal bone remodeling for up to 5 years in the 2 groups. Results Nine (4.9%) implants failed. Eight of the failures occurred in 3 smoking patients. The absolute survival rate for all patients was 95%, while the cumulative survival rate (CSR) after 5 years was 91.5%. For the NS group, the CSR was 98.9%, while for the S it was 81.2%. The mean marginal bone resorption was - 2.6 and - 1.2 mm in the S and NS groups, respectively. Conclusions The present findings indicate that the treatment protocol described results in good implant survival rate even after several years. Smoking may eventually compromise the efficacy of this treatment concept.

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

OBJECTIVES: The beneficial effects of the one-stage, full-mouth disinfection remain controversial in the scientific literature. This might be due to the fact that an entire mouth disinfection with the use of antiseptics has been confused with a full-mouth scaling and root planing. This parallel, single blind RCT study aimed to compare several full-mouth treatment strategies with each other. MATERIAL AND METHODS: Seventy-one patients with moderate periodontitis were randomly allocated to one of the following treatment strategies: scaling and root planing, quadrant by quadrant, at two-week intervals (negative control, NC), full-mouth scaling and root planing within 2 consecutive days (FRP), or three one-stage, full-mouth disinfection (FM) protocols within 2 consecutive days applying antiseptics to all intra-oral niches for periopathogens using as antiseptics: chlorhexidine (FMCHX) for 2 months, amine fluoride/stannous fluoride for 2 months (FMF), or chlorhexidine for 2 months followed by amine fluoride/stannous fluoride for another 6 months (FMCHX+F). At baseline and after 2, 4, and 8 a series of periodontal parameters were recorded. RESULTS: All treatment strategies resulted in significant (p

The impetus of the Bologna Process under the auspices of European Union governments has raised enormous expectations. It is the major educational change in Europe within the last 50 years and all the focus from university institutions, learned societies and thematic networks has shifted to this process, with the aim of developing consensus schemes in order to arrive at the expected European Convergence in Higher Education (to be completed by 2010). Dentistry as one of the health professions with clear Educational Standards, as defined by the European Dental Directives, is also reviewing its educational processes within this Bachelor-Master-Doctorate scheme and evaluating how the current and future dental specialities should be accommodated within this framework. Among these specialities, Periodontology is currently considered a formal dental speciality in 11 countries belonging to the EU however it lacks this legal status in the rest of the 14 EU countries. The purpose of this position paper is to provide evidence for the need for a recognized specialty in Periodontology at European level focusing on both the educational and professional perspective, with the hope of providing discussions that may contribute to facilitate its legal establishment as a new dental speciality in Europe.

Purpose: The aim of this report is to quantitatively and qualitatively describe the bone tissue response to Branemark implants retrieved from grafted sites in patients. Materials and Method: The material consists of consecutively received Branemark implants retrieved from grafted sites. Thirty-five of these implants, retrieved from 16 patients, were suitable for the histologic evaluation of undecalcified sections in the light microscope. Results: The unloaded implants were mainly lined with soft tissue, and sparse bone-implant contact was observed only in some sections. The loaded implants, with the exception of one implant removed due to mobility, had mature and new bone-implant contact. Resorption of graft through cutting cone structures was detected. Cement lines were found separating bone-like tissue albeit no cellular content and bone tissue with detectable osteocytes. Conclusion: In this heterogeneous group of implants from grafted sites, the unloaded implants showed limited bone-implant contact. The autografts showed seemingly mixed viability as judged by the cell content in the osteocyte lacunae and cement lines separating areas with filled and empty lacunae.

Item does not contain fulltext Orofacial diagnostic imaging has grown dramatically in recent years. As the use of endosseous implants has revolutionized oral rehabilitation, a specialized technique has become available for the preoperative planning of oral implant placement: cone beam computed tomography (CT). This imaging technology provides 3D and cross-sectional views of the jaws. It is obvious that this hardware is not in the same class as CT machines in cost, size, weight, complexity, and radiation dose. It is thus considered to be the examination of choice when making a risk-benefit assessment. The present review deals with imaging modalities available for preoperative planning purposes with a specific focus on the use of the cone beam CT and software for planning of oral implant surgery. It is apparent that cone beam CT is the medium of the future, thus, many changes will be performed to improve these. Any adaptation of the future systems should go hand in hand with a further dose optimalization.

Background: Periodontitis and peri-implantitis are linked to the presence of several key pathogens. The treatment of these infectious processes therefore involves the reduction/eradication of bacteria associated with periodontitis. Methods: This prospective, split-mouth, single-blind study followed the colonization of ‘pristine’ sulci created in 42 partially edentulous patients during implant surgery (e.g. abutment connection). The hypothesis was that the composition of the maturing subgingival plaque in these ‘fresh’ peri-implant pockets would soon (within 2 weeks) be comparable to the subgingival microbiota of teeth with similar clinical parameters (reference sites), including the presence of bacteria associated with periodontitis. Per patient, four subgingival plaque samples were taken from shallow and medium pockets around implants (test sites), and teeth within the same quadrant (undisturbed microbiota as control sites), 1, 2, 4, 13, 26 and 78 weeks after abutment connection, respectively. The samples were analysed by either checkerboard DNA–DNA hybridization, or cultural techniques, or real-time polymerase chain reaction (PCR) for intra-subject comparisons (teeth vs. implant, for comparable probing depths). Results: Checkerboard DNA–DNA hybridization and real-time PCR revealed a complex microbiota (including several pathogenic species) in the peri-implant pockets within 2 weeks after abutment connection. After 7 days, the detection frequency for most species (including the bacteria associated with periodontitis) was already nearly identical in samples from the fresh peri-implant pockets (5% and 20% of the microbiota belonging to red and orange complex, respectively) when compared with samples from the reference teeth. Afterwards (e.g. between weeks 2 and 13), the number of bacteria in peri-implant pockets only slightly increased (±0.1 log value), with minor changes in the relative proportions of bacteria associated with periodontitis (8% and 33% of the microbiota belonging to red and orange complex, respectively). Although small differences were seen between teeth and implants at week 2 with cultural techniques, a striking similarity in subgingival microbiota was found with this technique from month 3 on, with nearly identical detection frequencies for bacteria associated with periodontitis for both abutment types. Conclusions: This study indicates that the initial colonization of peri-implant pockets with bacteria associated with periodontitis occurs within 2 weeks.

Objectives: Bone augmentation underneath an occlusive titanium membrane is evaluated in most cases by means of serial histological sections and histomorphometry. Micro-computed tomography (micro-CT) is a less invasive and dynamic technique to measure bone volume in animals of a size that fits into the gantry. The aim of the present study was to evaluate whether the latter approach could match histomorphometry to assess bone augmentation under a titanium membrane. Material and methods: Pre-formed titanium cups were placed on the skull of 16 rabbits. Bone formation underneath the cups was allowed to occur for 12 weeks. The amount of bone volume assessed by micro-CT was expressed as a numerical unit. One unit volume corresponds to 0.043 mm3. The measurements reveal the volume of bone-like tissue under the membrane, with the same density as that of the original rabbit skull bone. Histological sections were cut along the same plane as the one used for the micro-CT images. The total bone surface was assessed by a digital image system in double-stained undecalcified histological sections and related to the maximum available surface of the titanium cups, which was on average 1366 mm2. Results: The amount of total bone surface found under the titanium membrane varied between 40 and 163 mm2. Measured by micro-CT, the bone detected ranged from 3.7 to 396 numerical units. A highly significant (P

Background: Recent case reports introduced the term retrograde peri-implantitis as a lesion (radiolucency) around the most apical part of an osseointegrated implant. It develops within the first months after insertion. This retrospective study aimed to find predisposing conditions for such peri-apical lesions and to evaluate treatment strategies. Methods: All single implants (426 in the upper, 113 in the lower jaw, all Branemark system® type) placed at the department of Periodontology of the University Hospital (Catholic University Leuven) were included in this retrospective evaluation to check the incidence of retrograde peri-implantitis. Eventual predisposing factors such as patient characteristics (age, medical history), recipient site (local bone quality and quantity, cause of tooth loss), periodontal and endodontic conditions of neighboring teeth, implant characteristics (length, surface characteristics), and surgical aspects (guided bone regeneration, osseous fenestration, or dehiscency) were considered. Moreover, implants with retrograde peri-implantitis were followed longitudinally to verify their treatment outcome by means of different parameters (Periotest® values (PTV), marginal bone level, radiological size of peri-apical defect). Results: Seven implants in the upper (1.6%) and 3 in the lower jaw (2.7%) showed retrograde peri-implantitis, before or at abutment connection. In comparison with successful implants, such peri-apical lesions occurred preferably at sites with a history of an obvious endodontic pathology of the extracted tooth to be replaced. The incidence of retrograde peri-implantitis was significantly higher (P

Background: Based on three-dimensional implant planning software for computed tomographic (CT) scan data, customized surgical templates and final dental prostheses could be designed to ensure high precision transfer of the implant treatment planning to the operative field and an immediate rigid splinting of the installed implants, respectively. Purpose: The aim of the present study was to (1) evaluate a concept including a treatment planning procedure based on CT scan images and a prefabricated fixed prosthetic reconstruction for immediate function in upper jaws using a flapless surgical technique and (2) validate the universality of this concept in a prospective multicenter clinical study. Materials and Methods: Twenty-seven consecutive patients with edentulous maxillae were included. Treatments were performed according to the Teeth-in-an-Hour™ concept (Nobel Biocare AB, Goteborg, Sweden), which includes a CT scan-derived customized surgical template for flapless surgery and a prefabricated prosthetic suprastructure. Results: All patients received their final prosthetic restoration immediately after implant placement, that is, both the surgery and the prosthesis insertion were completed within approximately 1 hour. In the 24 patients followed for 1 year, all prostheses and individual implants were recorded as stable. Conclusion: The present prospective multicenter study indicates that the prefabrication, on the basis of models derived from three-dimensional oral implant planning software, of both surgical templates for flapless surgery and dental pros-theses for immediate loading is a very reliable treatment option. It is evident that the same approach could be used for staged surgery and in partial edentulism.

Background: Chlorhexidine (CHX) mouth rinse/spray can still be considered the gold standard in the chemical prevention of plaque formation and development of gingivitis. The product unfortunately has some side effects, such as extrinsic tooth staining, poor taste, taste disturbance, sensitivity changes in tongue, pain and irritation because of the alcohol content. These side effects led to the search of new formulations. Methods: In this double-blind, randomized, long-term, parallel study, 48 moderate periodontitis patients rinsed for 6 months (starting immediately after a “one-stage, full-mouth” disinfection) with one of the following products: CHX 0.2%+alcohol (Corsodyl®), CHX 0.05%+ cetyl pyridinium chloride (CPC) 0.05% and no alcohol (Perio-Aid Maintenance®, a new formulation), or the placebo of the latter. After 1, 3 and 6 months a series of clinical and microbiological parameters were recorded for the supra- and subgingival area as well as for saliva. Results: Although there was a significant treatment impact (mechanical debridement) in all groups, both CHX solutions further decreased both plaque and gingivitis indices (p

Little research has been published about the impact of simulation technology on the learning process of novel motor skills. Especially the role of augmented feedback (FB) on the quality of performance and the transfer of the acquired behaviour to a no-augmented FB condition require further investigation. Therefore, novice dental students were randomly assigned to one of three groups and given the task of drilling a geometrical class 1 cavity. The FB group trained under augmented visual FB conditions, provided by the virtual reality (VR) system (DentSim). The no-FB group practised under normal vision conditions, in the absence of augmented FB. A control group performed the test sessions without participating in any training programme. All preparations were evaluated by the VR grading system according to four traditional (outline shape, floor depth, floor smoothness and wall inclination), and two critical, criteria (pulp exposure and damage to adjacent teeth). Performance analyses revealed an overall trend towards significant improvement with training for the experimental groups. The FB group obtained the highest scores. It scored better for floor depth (P < 0.001), whilst the no-FB group was best for floor smoothness (P < 0.005). However, at the retention tests, the FB group demonstrated inferior performance in comparison with the no-FB group. The transfer test on a traditional unit revealed no significant differences between the training groups. Consequently, drilling experience on a VR system under the condition of frequently provided FB and lack of any tutorial input was considered to be not beneficial to learning. The present data are discussed in view of the guidance hypothesis of FB, which refers to the apprentice's dependence on FB.

Periodontal scaling procedures commonly require some kind of anesthesia. From the patient's perspective, the choice of anesthetic method is a trade-off between the degree of anesthesia and accepting the side effects. The present study evaluates the preferences for a novel non-injection anesthetic product (a gel, containing lidocaine 25 mg/g plus prilocaine 25 mg/g and thermosetting agents) versus injection anesthesia (lidocaine 2% adrenaline) in conjunction with scaling and/or root planing (SRP).In a multicenter, crossover, randomized, open study patients were asked, after they had experienced both products, if they preferred anesthetic gel or injection anesthesia. In addition, the adequacy of anesthesia and occurrence of post-procedure problems were assessed. The patients were also asked about their willingness to return if they were offered anesthetic gel at their next visit and their maximum willingness to pay (WTP) for this option.One-hundred seventy (170) patients at eight centers in Belgium were included in the study. There were 157 per protocol (PP) patients. A vast majority of the PP patients (70%) preferred the anesthetic gel to injection anesthesia (22%). The most common reason was less post-procedure numbness. Eighty percent (80%) of the patients expressed satisfactory anesthesia with the gel and 96% with injection anesthesia (P0.001). Post-procedure problems were significantly less with the gel than with injection (P0.001): numbness 15% versus 66%, unpleasant sensations such as soreness and pain 44% versus 63%, and problems connected with daily activities 19% versus 69%. The majority of patients (60%) who preferred gel were also willing to pay for it. A conservative estimate of the median WTP was $10.00. Furthermore, anesthetic gel would make almost every second patient (45%) more or much more willing to return for the next treatment.The data suggest that a somewhat less profound anesthesia with gel is clearly preferred by the patients because of the low incidence of post-procedure problems as compared to conventional injection anesthesia. The median WTP is likely in excess of the acquisition cost of the product, which indicates a favorable cost-benefit ratio for the individual patient.

Background: The anterior mandible is generally considered a rather safe surgical area, involving few risks of damage to vital anatomic structures. Nevertheless, both neurosensory disturbances and hemorrhages have been reported after implant surgery in that particular area. Purpose: With the increasing demand for oral implant placement, the anatomy of the anterior mandible should receive more attention. This review will focus on the anatomic peculiarities of the anterior mandible and the related clinical implications. Methods: The scientific evidence on the anatomic, histologic, physiologic, and clinical aspects of the neurovascularization of the anterior mandible will be reviewed. Results: Surgical complications may be attributed to the existence of a mandibular incisive canal with a true neurovascular supply. Potential risks may also be related to the presence of the lingual foramen and anatomic variations, such as an anterior looping of the mental nerve. Conclusions: Preoperative radiographic planning for oral implant placement in the anterior mandible should therefore not only consider all esthetic and functional demands but should also pay particular attention to the anatomic peculiarities of this region to avoid any neurovascular complications.

Background: During recent years a new treatment concept, Branemark Novum, has been developed in which implants are inserted in the edentulous lower jaw and immediately connected to a prefabricated titanium bar. A fixed prosthesis is then attached to the bar during or immediately following surgery. Purpose: The aim of the present study was to investigate the application of this concept under various settings, to determine technique sensitivity, and to evaluate the clinical outcome after 1 year of follow-up. Materials and Methods: Fifty-one patients were included in a prospective multicenter investigation and followed up for 1 year. Cumulative implant survival rates were evaluated by life table analysis. In addition, clinical comparisons were performed to evaluate implant loss in relation to patient characteristics. Questionnaires were used to evaluate the treatment protocols and to obtain patients' opinions. Results: The prosthetic treatment was completed on the same or the following day in 76% of the patients. The cumulative implant survival rates for implants and prostheses were 91% and 94%, respectively, after 12 months. Conclusions: The present study demonstrated that single-stage surgery and immediate loading of implants with prefabricated bridgework in the mandible can result in high implant success and significant reduction in treatment time, with patient satisfaction.

This study aimed to analyse variations in the mandibular interforaminal morphology in an attempt to identify potential risks or contraindications for surgery, especially implant installation, in this particular region. A total of 210 spiral computer tomography (CT) examinations of patients requiring endosseous implant installation in the lower jaw were re-evaluated to explore anatomical variations in bone morphology (shape and contour), and to measure parameters concerning height, width and inclination of the bone in the symphyseal atrea. All measurements were performed on the cross-sectional reformatted images mesial to the mental foramina. A lingual concavity (with a depth of 6 +/- 2.6 mm) was observed in 2.4% of the jaws, with a remaining bone height in that area ranging from 4.2 to 11.9 mm. A clearly lingual tilted/inclined morphology was seen in 28.1% of jaws with a mean angle of 67.6 +/- 6.5 degrees, but a relatively constant width (> 8.8 mm). The remaining jaws (69.5%) showed a slight broadening in the caudal direction. The morphologic parameters were influenced neither by age nor by gender. In conclusion, mandibles with a lingual concavity or a severe slope of the lingual cortex might confer increased risks of lingual perforations during trepanation surgery or graft harvesting as well as fenestrations during implant installation. The detection frequency of such variations within the lower jaw seems to advocate a profound dissection of the lingual site and, in the case of some special treatment strategies, additional cross-sectional radiography.

It has already been shown that occlusive titanium barriers have osteoconductive properties. These barriers, however, cover only a limited surface area and have only been used in animal experiments. The aim of this study was to evaluate bone neogenesis under a pre-shaped titanium barrier placed over the top of the rabbit skull and the top of highly resorbed edentulous upper-jaw bone in patients. Computed tomography (CT) scans made it possible to pre-shape the titanium barrier according to individual bone shape in human experiments. On the rabbit skull, tissue augmentation of up to 6 mm 1 year after barrier placement was observed, while the original thickness of skull bone was on average between 1.5 and 2.5 mm. The bone, which remained histologically immature for 1 year, grew systematically along the titanium surface, illustrating its osteoconductivity. Even after removal of the barrier, on average, 75.3 and 59.4% of the newly created tissue volume was maintained after 3 and 9 months, respectively. Clinical observations on 10 consecutive patients showed that, in those (5/10) in which the barrier remained unexposed for several months, an increase of the jawbone height and width of up to 16 mm could be observed when the barrier was removed after 12-18 months. As in the rabbits at barrier removal, the bone demonstrated a limited degree of mineralization as ascertained from biopsies. This newly formed osteoid tissue allowed the insertion of 33 screw-shaped titanium implants which in most cases (30/33) successfully osseointegrated to support a fixed prosthesis. The surrounding marginal bone level remained stable even up to 5 years after implant placement. Both animal and clinical data demonstrate that guided bone neogenesis under a subperiosteally placed titanium barrier can reach large volumes.

The aim of the present study was to assess the influence of endogenous and local factors on the occurrence of implant failure up to the abutment stage. The study comprised a group of 399 consecutive patients, which represented the total of patients who had been treated from 1995 to 1997 (with a total of 1263 Branemark Bran-system implants) at the Department of Periodontology of the University Hospital, Catholic University Leuven. For each patient, the medical history was carefully examined. Data collection and analysis were mainly focused on endogenous factors such as hypertension, osteoporosis, hypo- or hyperthyroid function, chemotherapy, diabetes type I or II, Crohn's disease, some local factors (e.g. bone quality, reason for tooth loss) and breach of sterility during surgery. The reason for tooth loss, smoking habits, radiotherapy and other local bone factors (bone quality and quantity) were also recorded. Implant failures were recorded up to the abutment connection. The present study indicated a success rate until this stage of 97.8%. General factors such as heavy smoking, chemotherapy plus poor bone quality increased implant failure rate. Radiotherapy, limited bone volume and claustrophobia, which led to breaching the strict preoperative rules of asepsis, appeared to be the most relevant local factors for early implant failures.

Background: Breath odour is a complaint encountered worldwide, often linked to microbial overload in the oral cavity. This double blind, crossover, randomised study assessed the efficacy of several antiseptic mouthrinses or slurry vs. a control solution in the prevention of morning bad breath during an experimental period of 7 days without mechanical plaque control. Methods: Sixteen dental students with a healthy periodontium abolished, after a thorough professional cleaning, all means of mechanical plaque control during five experimental periods of 7 days, interleaved by washout periods of at least 3 weeks. During each experimental period, as the only oral hygiene measure, the students rinsed twice a day with one of the following formulations (in a randomised order): a 0.2% chlorhexidine-alcohol mouthrinse (CHX-Alc), a 0.05% CHX + 0.05% cetylpyridinium chloride + 0.14% zinc lactate mouthrinse (CHX-CPC-Zn), an amine fluoride/stannous fluoride (125 ppm F–/125 ppm F–) containing mouthrinse (AmF/SnF2Mr), a slurry of a tooth paste (AmF/SnF2Sl) containing amine fluoride (350 ppm F–) and stannous fluoride (1050 ppm F–) and a placebo solution (placebo). At days 0, 3 and 7, morning breath was scored via VSC level measurements of the mouth air, and organoleptic ratings of the mouth air and tongue coating. At the same visits both the degree of gingival inflammation and the de novo plaque formation were rated. At the end of each period a questionnaire for subjective ratings was completed and microbiological samples were taken from the tongue dorsum, the saliva and the supragingival plaque for anaerobic and aerobic culturing. Results: Although oral hygiene during the experimental periods was limited to rinsing, bad breath parameters systematically improved (P

Background: As the use of oral implants for the treatment of partially as well as fully edentulous patients has increased the past two decades, more specialized radiographie techniques have become available for the preoperative planning of oral implant placement. Purpose: The goal of this article was to enable clinicians to select the appropriate imaging techniques when planning for oral implants. Materials and Methods: This article reviews the available literature about various imaging techniques and their indication for the preoperative planning of oral implants. The advantages and drawbacks of each technique are described. A dosimet-ric overview is given relative to different radiologie techniques used in various clinical situations. Results: For preoperative planning of implant placement, advantages and drawbacks of the available imaging techniques have been considered, which allows guidelines for image technique selection to be formulated based on the clinical situation provided, considering the diagnostic yield of each technique and the radiation doses involved. Conclusions: From the available literature, it can be stated that many clinical situations demand the use of cross-sectional imaging techniques for optimal preoperative planning of implant placement. Nevertheless, such techniques are not required in cases in which the clinical examination reveals sufficient bone width and where standard radiographie examinations, such as intraoral and panoramic radiography, reveal adequate bone height and space for implant placement.

The purpose of this study was to evaluate over time the marginal bone level changes around implants installed to treat partial edentulism and to investigate the possible effect of several confounding variables. Consecutive intraoral radiographs taken with the paralleling technique were used. In all, 660 partially edentulous patients ever treated in the departments (248 males; 15-83 years of age) with 1655 implants, which were successfully integrated at abutment connection, were loaded by means of fixed partial prostheses. The observation period starting at abutment connection reached 16 years (mean 5.1). Implants were divided into three groups: 235 implants supported single-tooth crowns, 398 supported implant-tooth connected and 1022 free-standing fixed partial prostheses. Implants were placed in maxilla and mandible, both anteriorly and posteriorly. No significant difference in bone level evolution was predicted between the three groups of implants, either for posterior or for anterior sites. The estimated marginal bone loss for the first 6 months is 0.31 mm/year and after that 0.015 mm/year higher in the maxilla than in the mandible. More bone loss was predicted for the first 6 months when dehiscences existed, when a membrane or a bone graft were used, or when metal/ceramic prosthesis material was applied. Age and gender did not affect the change in bone level. The use of subsequently situated single-implant crowns to restore an edentulous space did not lead to more marginal bone loss than around splinted implants. Based on marginal bone height maintenance, the excellent prognosis of the presently used implants to support restorations in the treatment of partial edentulism was confirmed.

The purpose of this study was to predict the outcome of implant restorations in the treatment of partial edentulism, taking into account implant interdependency and the effect of several confounding variables. Between December 1982 and June 1998, 1956 Branemark system implants (1212 and 744 in the maxilla and mandible, respectively, 846 distal to first premolars) were installed in 660 patients (248 males) at the Department of Periodontology of the University Hospitals of the Catholic University of Leuven. Of the 810 restorations installed at the Department of Prosthetic Dentistry of the same hospital, 235 were single crowns, 166 were supported by implants and teeth and 409 were free-standing fixed partial prostheses. An additional 87 restorations was placed in private dental offices and were not included. The patients were followed from implant installation until June 1999. The estimated cumulative survival rates were 91.4% for all implants and 95.8% for all restorations over a period of 16 years. Estimated cumulative survival rates from loading for implant-tooth connected and free-standing implants were, respectively, 93.6% and 97.2%. Neither jaw site nor implant position (anterior-posterior) had any significant effect on the outcome. Short implant length, high number of implants per patient, low number of implants per prosthesis, implants loaded by acrylic-veneered restorations and implants combined with bone grafting present a higher risk hazard for implant failure. The idea of not splinting the implants in a fixed partial prosthesis is promising but needs replication before accepting it.

Breath malodour, a significant social and/or psychological handicap, may be caused by several intra- and extraoral factors. Malodour of intraoral origin is the result of microbial putrefaction, during which volatile sulphur compounds (VSC) and other volatile compounds are produced. The treatment of oral malodour can therefore be focused on the reduction of the intraoral bacterial load and/or the conversion of VSC to nonvolatile substrates. This article outlines the efficacy and mechanisms of different antimalodour approaches. Most approaches were found to be inefficient and/or short lasting. The most successful treatment involves mechanical debridement (including toothbrushing, flossing, and tongue cleaning), possibly combined with the use of an antimicrobial mouthrinse.

The use of oral implants in the rehabilitation of partially and fully edentulous patients is widely accepted even though failures do occur. The chance for implants to integrate can for example be jeopardised by the intra-oral presence of bacteria and concomitant inflammatory reactions. The longevity of osseointegrated implants can be compromised by occlusal overload and/or plaque-induced peri-implantitis, depending on the implant geometry and surface characteristics. Animal studies, cross-sectional and longitudinal observations in man, as well as association studies indicate that peri-implantitis is characterised by a microbiota comparable to that of periodontitis (high proportion of anaerobic Gram-negative rods, motile organisms and spirochetes), but this does not necessarily prove a causal relationship. However, in order to prevent such a bacterial shift, the following measures can be considered: periodontal health in the remaining dentition (to prevent bacterial translocation), the avoidance of deepened peri-implant pockets, and the use of a relatively smooth abutment and implant surface. Finally, periodontitis enhancing factors such as smoking and poor oral hygiene also increase the risk for peri-implantitis. Whether the susceptibility for periodontitis is related to that for peri-implantitis may vary according to the implant type and especially its surface topography.

The relationship between periodontitis and peri-implantitis remains a matter of debate. The present study compared, "within" randomly chosen partially edentulous patients (n=84 subjects, 97 jaws), the marginal bone loss around teeth and implants during 5 years (range 3 to 11 years) following the first year of bone remodelling. The patients had all been rehabilitated by means of screw-shape c.p. titanium implants with a machined surface (Branemark system). During the 5 years observation interval, periodontal parameters (marginal bone and attachment loss, the latter for teeth only) were collected together with data on confounding factors (smoking, oral hygiene, tooth loss). Marginal bone loss was measured through long-cone intra-oral radiographs. The mean "interval" bone loss was significantly (P=0.0001) higher around teeth (0.48+/-0.95 mm) than around implants (0.09+/-0.28 mm). The corresponding data for the "worst" performing tooth (0.99+/-1.25 mm) and implant (0.19+/-0.32 mm) per subject showed the same tendency. Neither attachment nor bone loss around teeth correlated with marginal bone loss around implants. This study indicated that the rate of bone loss around screw-shape c.p. titanium implants with a machined surface (Branemark system implants) was not influenced by the progression rate of periodontal destruction around the remaining teeth within the same jaw.

BACKGROUND, AIMS: Previous studies indicated that oral hygiene aids can play a rôle in the intra-oral translocation of pathogens. The survival rate of cariogenic and periodontopathogenic species on toothbrushes, with and without toothpaste, and interdental brushes was presently investigated. MATERIAL AND METHODS: 12 periodontitis patients had their interdental spaces professionally cleaned with interdental brushes and their teeth with new toothbrushes with or without different dentifrices. Each time brushes were rinsed with tap water and stored dry at room temperature. At different time intervals an interdental brush or 4 tufts from a toothbrush were processed for vitality staining and selective and non-selective culturing procedures. RESULTS: Immediately after rinsing, a toothbrush without toothpaste harboured 10(7), 10(8) and 10(7) colony forming units (CFU) of respectively aerobic, anaerobic and black pigmented species. An insignificant decrease occurred the first 24 hours and after 48 hours still 10(4) CFU of aerobic and anaerobic species could be cultured. No periodontopathogen remained detectable at 8 hours, except for Fusobacterium nucleatum. The proportion of vital bacteria decreased in 48 hours from 50% to 30%. Comparable results were obtained for interdental brushes. The bacterial survival rate on toothbrushes was significantly reduced by the use of a detergent containing toothpaste by 2 log at baseline, another 2 log at 4 hours and an extra log more at 8 hours for aerobic and anaerobic species. A toothpaste without detergent only had an insignificant bactericidal effect. CONCLUSION: Toothpaste detergents decrease the survival rate of pathogenic species on a toothbrush and can thus limit the risk for bacterial translocation. ispartof: Journal of clinical periodontology vol:28 issue:12 pages:1106-14 ispartof: location:United States status: published

Morning breath odor is an often-encountered complaint. This double-blind, crossover, randomized study aimed to examine the bad breath-inhibiting effect of 3 commercially available mouthrinses on morning halitosis during an experimental period of 12 days without mechanical plaque control.Twelve medical students with a healthy periodontium refrained from all means of mechanical plaque control during 3 experimental periods of 12 days (with intervening washout periods of at least 3 weeks). A professional oral cleaning preceded each period. During each experimental period, as the only oral hygiene measure allowed, the students rinsed twice a day with one of the following formulations in a randomized order: CHX-Alc (a 0.2% chlorhexidine [CHX] solution); CHX-NaF (CHX 0.12% plus sodium fluoride 0.05%); or CHX-CPC-Zn (CHX 0.05% plus cetylpyridinium chloride 0.05% plus zinc lactate 0.14%). After 12 days, morning breath was scored via volatile sulfur compound (VSC) level measurements of the mouth air and organoleptic ratings of the mouth air, the expired air, and a scraping of the tongue coating. At the 12-day visit, a questionnaire (subjective ratings) was completed and samples taken from both the tongue coating and the saliva for anaerobic and aerobic culturing and vitality staining. The de novo supragingival plaque formation was also recorded. All parameters were correlated with the baseline registrations.Although oral hygiene during the 3 experimental periods was limited to oral rinses, bad breath parameters systematically improved, with the exception of a slight increase in VSC levels while using CHX-Alc, a finding which was associated with the direct influence of the CHX on the sulfide monitor. The oral microbial load after the use of CHX-NaF remained unchanged, while for the CHX-Alc and CHX-CPC-Zn, significant reductions in both aerobic and anaerobic colony forming units (CFU)/ml were noticed in comparison with baseline data for both tongue coating and saliva samples. The composition of microflora, on the other hand, did not reveal significant changes. The supragingival plaque formation was inhibited, in descending order, by CHX-Alc, CHX-CPC-Zn, and CHX-NaF. The subjective scores for the rinses indicated a higher appreciation for CHX-CPC-Alc and CHX-NaF because of a better taste and fewer side effects.The results of this study demonstrate that morning halitosis can be successfully reduced via daily use of mouthrinses. CHX-Alc and CHX-CPC-Zn mouthrinses result in a significant reduction of the microbial load of tongue and saliva.

Summary Although the available literature with its large variation in quality and criteria does not easily allow one to draw many firm conclusions, some common findings can be traced. The use of autogenous onlay blocks placed together with self-tapping implants can achieve an excellent long-term success rate of individual implants. Autogenous bone chips can be used to deal with fenestration and dehiscence defects when used in combination with e-PTFE membranes. (D)FDBA has been used as particulate material and in conjunction with barrier membranes. Although these allografts do not compare favorably with autogenous bone chips, their role as space maintainers under barrier membranes cannot be ignored. Demineralized bovine bone offers excellent osseoconductive properties. It can secure a predictable fill of intrabony defects on its own, whereas for bone augmentation in dehiscence and fenestration defects it should be used in combination with a membrane. Its slow resorption makes it more favorable for use with rather than before implant placement. Thus far the e-PTFE membranes, GTAM and TR-GTAM, are best documented. They offer reliable results, except for vertical augmentation procedures, in which exposure is regularly encountered (approximately 15%). The use of a collagen membrane when supported by a bone substitute to maintain the space gives good results, although the clinical data are still limited. The clinician should evaluate the eventual benefit of GBA, namely to be able to harbor longer implants with a better prognosis, versus the drawbacks and risks involved with the use of either bone substitutes or membranes.

Aim: The aim of the present study was to study the effect of occlusal factors, oral hygiene, gender and age on the long-term maintenance of alveolar bone height around screw-shaped machined surface commercially pure (c.p.) titanium implants retaining hinging mandibular overdentures. Method: In this retrospective study a long-term (4-, 8-, up to 12-years) follow-up of such implant-retained overdentures was performed. From the population of patients so treated at the University Hospital of the Catholic University Leuven, Department of Periodontology and Department of Prosthetic Dentistry, 158 patients were selected on the basis of being treated before March 1994, and the availability of intra-oral radiographs (paralleling technique) present at abutment connection (baseline) and at years 4, 8, and 12. For each patient, all relevant clinical data were recorded, and measurements of marginal bone height around the implants were performed on intra-oral radiographs by means of a digital sliding calliper. Results: Results indicated that only the factor “time” had a significant influence on marginal bone loss. The age and gender of the patients, dental/prosthetic status in the antagonistic jaw, oral hygiene variables, and location of the implants had no significant effect. Conclusion: The very high cumulative success rate (97.2%) and limited marginal bone loss (on average 1.7 mm) after 12-years, encourage this kind of treatment using this type of implants.

The head of a human cadaver was positioned in a Cranex TOME® multifunctional unit (Orion Corporation Soredex, Helsinki, Finland) to measure the organ radiation doses after tomographic examinations of the upper and lower edentulous jaw bone. Five consecutive examinations were carried out in the upper and lower anterior jaw regions to cover the entire frontal area, 2 in the upper and lower left premolar regions, and 3 and 4 in the upper and lower left molar regions, respectively. Each examination consisted of 4 slices with a 2 mm slice thickness. Thermoluminescent dosimeter chips were placed in the thyroid gland and bilaterally in the parotid and submandibular glands. Dosimetric measurements were repeated for the different tomographic examinations mentioned above. For spiral tomography in the maxilla, organ doses for both parotid glands were most elevated, while those for the thyroid glands were the lowest. Average doses per examination reached levels of 0.27 mGy for the right (OS) parotid gland with frontal tomography, and 3.89 mGy and 1.67 mGy for the parotid gland at tube-side (TS) for premolar and molar tomography. For the thyroid gland, a minimal dose of ≤0.004 mGy was noticed for all examinations. For spiral tomography of the frontal area in the mandible, the OS parotid gland received the highest dose (0.77 mGy), while for an analysis of the premolar and molar areas, doses were more elevated for the TS parotid gland (1.22 mGy and 1.72 mGy, respectively). For the TS submandibular gland, organ doses were also raised, with values of 0.39 mGy for frontal, 1.31 mGy for premolar and 1.61 mGy for molar tomography. This study thus indicates that for conventional spiral tomographic examinations in the maxilla and the mandible, radiation doses for the TS submandibular and parotid glands were significantly more elevated than those to the thyroid gland. These values remain however below the organ doses previously reported for spiral CT involving both a full upper or lower jaw.

Periodontology has broadened its scope by the research and clinical use of osseointegrated implants. Since tactile and reflex functions have been associated with periodontal ligament neural receptors, osseoperception could be associated with endosseous and/or periosteal innervation.

Impaction of front teeth (often upper canines) can result in esthetic, functional, and phonetic problems, in addition to root resorption and chronic or acute infections. Most impacted front teeth can be extruded orthodontically after minor periodontal surgery. The purpose of this retrospective study was to examine the periodontal outcome of surgically exposed and orthodontically extruded impacted teeth compared with the spontaneously erupted contralateral teeth.A total of 38 patients, who had been treated by a combined surgical and orthodontic approach (closed eruption technique by same periodontist and 2 associated orthodontists), underwent a periodontal re-examination after 4 to 10 years. Periodontal parameters (plaque and gingivitis indices, probing depth, bleeding on probing, gingival recession and width, bone level, and root resorption) of the orthodontically extruded teeth (test) were scored and compared with those of the contralateral naturally erupted teeth (control) in a masked set-up.No significant differences could be detected between test and control teeth, except for the gingival width, which was 1 mm larger for the spontaneously erupted teeth.The data indicate that orthodontic extrusion of impacted front teeth does not jeopardize their periodontal health. This procedure appears to be a satisfactory alternative to extraction and/or transplantation.

Background/aims Recent studies reported significant additional clinical and microbiological improvements when severe adult periodontitis was treated by means of a "one-stage full-mouth" disinfection instead of a standard treatment strategy with consecutive root planings quadrant per quadrant. The one stage full-mouth disinfection procedure involves scaling and root planing of all pockets within 24 h in combination with an extensive application of chlorhexidine to all intra-oral niches such as periodontal pockets, tongue dorsum, tonsils (chairside, and at home for 2 months). This study aims to examine the relative importance of the use of chlorhexidine in the one stage full-mouth disinfection protocol. Methods Therefore, 3 groups of 12 patients each with advanced periodontitis were followed, both from a clinical and microbiological point of view, over a period of 8 months. The patients from the control group were scaled and root planed, quadrant per quadrant. at two-week intervals. The 2 other groups underwent a one stage full-mouth scaling and root planing (all pockets within 24 h) with (Fdis) or without (FRp=full-mouth root planing) the adjunctive use of chlorhexidine. At baseline and after 1, 2, 4 and 8 months, the following clinical parameters were recorded: plaque and gingivitis indices, probing depth, bleeding on probing and clinical attachment level. Microbiological samples were taken from different intra-oral niches (tongue, mucosa, saliva and pooled samples from single- and multi-rooted teeth). The samples were cultured on selective and non-selective media in order to evaluate the number of CFU/ml for the key-periodontopathogens. At baseline, an anonymous questionnaire was given to the patients to record the perception of each treatment (post operative pain, fever, swelling etc.). Results All 3 treatment strategies resulted in significant improvements for all clinical parameters, but the Fdis and FRp patients reacted always significantly more favourably than the control group, with an additional probing depth reduction of +/- 1.5 mm and an additional gain in attachment of +/- 2 mm (for pockets > or = 7 mm). Also from a microbiological point of view both the FRp and Fdis patients showed additional improvements when compared to the control group, as well in the reduction of spirochetes and motile organisms as in the number of CFU/ml of the key-pathogens, especially when the subgingival plaque samples were considered. The differences between FRp and Fdis patients were negligible. Conclusions These findings suggest that the benefits of a "one-stage full-mouth disinfection" in the treatment of patients suffering from severe adult periodontitis probably results from the full-mouth scaling and root planing within 24 h rather than the beneficial effect of chlorhexidine. The raise in body temperature the second day after the full-mouth scaling and root planing seems to indicate a Shwartzman reaction.

When planning to place implants in the posterior region of the maxilla, the location of the maxillary sinus floor is influencing the available bone height and the implant length chosen. The aim of the present study was to evaluate in vitro the spiral tomographic technique that could be used for pre-operative implant planning. Tomographs were taken of 6 dry human skulls using the Cranex Tome multifunctional unit (Orion Corporation Soredex, Helsinki, Finland). Three sites were selected in the left posterior maxilla and marked with gutta percha meaning a total of 18 sites (6 x 3 = 18) for interpretation. Bone height and width were measured on the tomographs and after sectioning also on the skulls. The values obtained from the measurements on tomographs were divided by an enlargement factor of 1.5 (as defined by the manufacturer) and then compared with those from the real measurements on the skulls. Real measurements were on average 0.24 mm (SD 0.19) lower than the tomographic measurements (P < 0.05). From the present results it could be concluded that spiral tomography using the recently developed Cranex Tome reveals sufficient information and detail for pre-operative planning of a limited edentulous region.

Background: Barrier membranes have been used to promote bone ingrowth on implants with dehiscences and fenestrations. Membranes also have been used to protect defects adjacent to implants placed at the time of extraction. The concept of guided bone regeneration relates to preferentially allowing cells from bone to migrate into various defects while excluding fibrous tissue and epithelium. The purpose of these procedures is to enhance bone-to-implant contact at the treated sites and to prevent mucosal complications. Purpose: The purpose of this article is to report clinical outcomes for implants placed at the time of extraction and augmented with expanded polytetrafluoroethylene (ePTFE) and followed for 5 years. The outcomes for implants with dehiscences and fenestrations augmented with ePTFE barriers and followed up to 5 years also are reported. Methods and Materials: Four treatment centers participated in this study (Tucson, Gothenburg, Spokane, and Leuven). In the extraction group, teeth were removed for varying reasons, and Branemark implants were placed and stabilized within the host bone. Defects present at the coronal implant aspect were covered with ePTFE barrier membranes. Flaps were rotated to cover the membrane-treated sites. If exposure of the material occurred prior to second-stage surgery, the membranes were removed. Barriers remaining unexposed were removed at second-stage surgery. The implants were followed up to 5 years. In the fenestration and dehiscence group, implants with exposed threads were augmented with ePTFE barrier membranes. The barriers were removed at appropriate intervals, and the patients were followed up to 5 years. Radiographic measurements were made from nonstandardized periapical radiographs at abutment connection and 1, 3, and 5-year follow-up visits. Results: Forty patients participated in the extraction group. They received a total of 49 implants. Three implants failed prior to loading. The 5-year cumulative survival rates for implants placed at the time of extraction were 93.9% and 93.8%, respectively, for maxillary and mandibular implants. The average maxillary mesial and distal marginal bone loss (1–5 yr) was 0.3 mm (standard deviation [SD] = 1.5) and 0.3 mm (SD = 1.0). In mandibles, the average mesial and distal bone loss (1–5 yr) was -0.2 mm (SD = 0.5) and -0.05 mm (SD = 0.6), respectively. The dehiscence and fenestration group included 44 patients. Twenty-six were followed for up to 5 years. Eight patients experienced total implant failure. For dehiscences and fenestrations, the cumulative survival rates were 76.8% and 83.8% for maxillary and mandibular implants, respectively. The average maxillary mesial and distal bone loss (1–5 yr) was 0.4 mm (SD = 0.8) and 0.2 mm (SD = 0.9), respectively. In mandibles, the average mesial and distal marginal bone loss was 0.3 mm (SD = 0.9) and 0.3 mm (SD = 0.8), respectively. Conclusions: Implants placed at the time of extraction and augmented with ePTFE barrier membranes have favorable long-term predictability. On the other hand, long-term evaluation of implant dehiscences and fenestrations augmented with barrier membranes indicates that they have less favorable 5-year survival rates. Membrane augmentation of these may be questioned.

The present study compared 2 different methods (direct versus indirect evaluation) for the quantification of the adhesion of Porphyromonas gingivalis strains to in vitro cultured mono-layers of pocket epithelium.The indirect culture viability assay (calculation of colony forming units) was compared to a direct microscopic evaluation using a novel fluorescent stain. The fluorescent kit was found to stain both bacteria and epithelial cells and enabled a differentiation between dead and living cells.Comparing the visual to the culture data, a high and significant correlation was found (Pearson's correlation = 0.75; P0.001). The adhesion capacity was in general higher for dead epithelial cells than for living cells (P0.01). Although comparable numbers of bacteria of 2 P. gingivalis strains (Pg 4 and Pg 5) were applied, Pg 4 showed a significantly lower adhesion capacity. This intra-strain variability was observed by the culture assay (2.3 x 10(6) versus 7.8 x 10(6)+/-2.7 x 10(6); P0.01) and by the direct microscopy (P0.01) for both live and dead epithelial cells. A second goal was to see whether there was a difference in the amount of bacterial adherence to mono- and multi-layers of in vitro cultured epithelium. No significant differences were found for the 5 examined P. gingivalis strains. However, interstrain differences in adhesion capacity were evident for both tissues.This study highlights the reproducibility of a direct microscopic evaluation of bacterial adhesion to in vitro cultured epithelial cells, and suggests both intrastrain (P. gingivalis) and inter-cell (live versus dead) variation in adhesion capacity. Studies are needed to determine the extent to which P. gingivalis strain variation is reflected in variation of other strains in humans.

Recent studies showed the clinical benefits of a one stage full-mouth disinfection, when compared to the worldwide standard treatment strategy of consecutive root planings per quadrant without proper disinfection of the remaining intraoral niches. The purpose of this study was to investigate the microbiological benefits of such a one stage full-mouth disinfection with special attention to all intraoral niches for periodontopathogens and to evaluate the perception by the patients of the new treatment strategy.Sixteen patients with early-onset periodontitis and 24 patients with severe adult periodontitis were randomly assigned to test and control groups. The control group was scaled and root planed, per quadrant, at 2-week intervals and given oral hygiene instructions. The test group received the one stage full-mouth disinfection treatment. At baseline and after 1, 2, 4, and 8 months, microbiological samples were taken from all niches (tongue, mucosa, saliva, and pooled samples from single- and multi-rooted teeth). The samples were cultured on selective and non-selective media. Patient perception of the treatment was evaluated using a questionnaire.In comparison to the standard therapy, the one stage full-mouth disinfection resulted in significant additional microbial improvements. The test group showed larger reductions in the proportions of spirochetes and motile organisms in the subgingival flora, and more significant reductions in the density of key pathogens, with even the eradication of P. gingivalis. The beneficial effects in the other niches were primarily restricted to the number of colony-forming units/ml of black-pigmented bacteria, especially on the mucosa and in the saliva and to a lesser extent on the tongue. Both treatments were well tolerated by the patients and the overall severity rating for both therapies was comparable, although 4 quadrants were treated within 24 hours in the test group versus only 1 in the control group. The full-mouth disinfection approach resulted more frequently in a slight increase of body temperature, especially after the second day.These findings support the benefit of a one stage full-mouth disinfection in the treatment of patients with either chronic adult or early-onset periodontitis.