[Non-surgical peri-implantitis treatment with or without systemic antibiotics]. / Initiële behandeling van peri-implantitis met of zonder systemische antibiotica.

This study investigated the effect of initial nonsurgical treatment in patients with peri-implantitis with or without prescription of an antibiotic regimen consisting of amoxicillin and metronidazole. For this purpose, patients with peri-implantitis were randomized into a group of initial treatment with antibiotics and a group without antibiotics. They were re-evaluated 12 weeks after treatment. Analyses were performed at the patient level at 1 peri-implant pocket per patient. Both groups showed significant peri-implant pocket depth reductions after initial treatment. Treatment with antibiotics resulted in a higher mean reduction in peri-implant pocket depth than when no antibiotics were used, but this difference did not reach statistical significance. Only 2 implants, 1 in each group, showed a successful outcome of a peri-implant pocket depth ofunder ≤ 5 mm and with an absence of bleeding and pus after probing. Initial treatment with or without antibiotics is ultimately not sufficient to fully treat peri-implantitis; additional surgical procedures will often be required.

[Replacing heavily damaged molars with the use of 3D-techniques]. / Vervanging van ernstig beschadigde molaren met behulp van 3D-technieken.

Seriously damaged molars can be replaced by autotransplantation with the help of 3D techniques. In the present case, involving an 18-year old patient, 18, 38 and 48 were used to replace, respectively, 14, 36 and 37. Preoperatively, the width of the crowns and the root development of 18, 38 and 48 were analysed using 3D imaging. During the autotransplantation procedure, the new alveoli are formed with the help of replicas of the donor molars printed in 3D, in order to prevent iatrogenic damage to the actual donor molars.. The extra-alveolar time was less than 2 minutes for all donor molars. Postoperative follow-up showed physiologic integration of the transplanted molars. There was no ankylosis. Autotransplantation with the help of 3D techniques makes it possible to perform complex procedures with good results.

Bone regeneration in critical-sized bone defect enhanced by introducing osteoinductivity to biphasic calcium phosphate granules.

OBJECTIVES: Biphasic calcium phosphate (BCP) is frequently used as bone substitute and often needs to be combined with autologous bone to gain an osteoinductive property for guided bone regeneration in implant dentistry. Given the limitations of using autologous bone, bone morphogenetic protein-2 (BMP2)-coprecipitated, layer-by-layer assembled biomimetic calcium phosphate particles (BMP2-cop.BioCaP) have been developed as a potential osteoinducer. In this study, we hypothesized that BMP2-cop.BioCaP could introduce osteoinductivity to BCP and so could function as effectively as autologous bone for the repair of a critical-sized bone defect. MATERIALS AND METHODS: We prepared BMP2-cop.BioCaP and monitored the loading and release kinetics of BMP2 from it in vitro. Seven groups (n = 6 animals/group) were established: (i) Empty defect; (ii) BCP; (iii) BCP mixed with biomimetic calcium phosphate particles (BioCaP); (iv) BCP mixed with BMP2-cop.BioCaP; (v) BioCaP; (vi) BMP2-cop.BioCaP; (vii) BCP mixed with autologous bone. They were implanted into 8-mm-diameter rat cranial critical-sized bone defects for an in vivo evaluation. Autologous bone served as a positive control. The osteoinductive efficacy and degradability of materials were evaluated using micro-CT, histology and histomorphometry. RESULTS: The combined application of BCP and BMP2-cop.BioCaP resulted in significantly more new bone formation than BCP alone. The osteoinductive efficacy of BMP2-cop.BioCaP was comparable to the golden standard use of autologous bone. Compared with BCP alone, significantly more BCP degradation was found when mixed with BMP2-cop.BioCaP. CONCLUSION: The combination of BCP and BMP2-cop.BioCaP showed a promising potential for guided bone regeneration clinically in the future.

The effect of implant placement in patients with either Kennedy class II and III on oral health-related quality of life: a prospective clinical trial.

There is little evidence of the effect of implants restored with fixed partial dentures on oral health-related quality of life (OHRQoL) in partially edentulous Kennedy class II and III patients. The aim of this study was to determine the change in OHRQoL in Kennedy classification II and III patients treated with a two-implant-supported fixed dental prosthesis (FDP). Kennedy class II and III patients received dental implants and an FDP. Oral health-related quality of life was measured by administration of the Oral Health Impact Profile-14 (OHIP-14NL) questionnaire at intake (T1), 2 weeks after surgery (T2) and after 1 year of loading (T3). The mean OHIP score at T1 was 6·5 ± 1·2, 2·4 ± 1·0 at T2, and 0·9 ± 0·3 at T3. There was a statistically significant difference between T1 and T2 (P = 0·002) and T1 and T3 (P < 0·001) but not between T2 and T3 (P = 0·407). The OHIP score in Kennedy II patients decreased from 4·8 ± 3·2 at T1 to 1·5 ± 2·0 at T2 and 1·1 ± 1·8 at T3, and that in Kennedy III patients decreased from 8·9 ± 9·6 at T1 to 3·6 ± 8·9 at T2 and 0·8 ± 2·2 at T3. There were no statistically significant differences in the reductions in Kennedy II and III patients. Oral health-related quality of life changed positively in patients treated with implants and an FDP in both groups. There was no change in OHRQoL between the times of implant placement and FDP placement.

Evaluation of the implant-related restorative undergraduate programme at ACTA, the Netherlands. Part I: students' satisfaction.

INTRODUCTION: Due to the increasing use of dental implants, many future dentists will encounter implant-related procedures in general practice. Over the past decade, implant dentistry is more and more often included in undergraduate curricula. Very little is known about students' satisfaction regarding implant-related undergraduate programmes, as minimal analyses are performed. In particular, a lack of information exists regarding programmes where undergraduates restore implants. This study describes an evaluation of the students' satisfaction regarding the implant-related restorative undergraduate programme at ACTA, the Netherlands. MATERIAL AND METHODS: After clinical examination and establishment of the treatment plan, undergraduates were required to assist postgraduate implantology students during surgery. All patients received Straumann (Basel, Switzerland) implants. The restorative phase of the treatment was subsequently performed by the undergraduates. A students' questionnaire was developed. All questions were exclusively on the restorative part of the implant-related programme. RESULTS: In total, 90 patients were treated by 78 undergraduates. 146 Straumann implants were restored with 121 restorations. The most common restoration was a single crown (80.2%), followed by three-unit fixed partial dentures (12.4%). The questionnaires showed a high rate of students' satisfaction concerning the restorative implant programme. Students replied they think they can manufacture an implant-supported crown or FDP without supervision after following the programme. In their opinion, the existence of the restorative programme should definitely be continued. CONCLUSION: According to positive student perceptions, an implant-related restorative programme should be recommended for implementation in undergraduate dental curricula. The programme at ACTA could be used as a template for other universities.

[Autotransplantation 2.0. Considerations, results and the latest techniques]. / Autotransplantatie 2.0. Overwegingen, uitkomsten en nieuwste technieken.

Autotransplantation is a valuable technique offering a physiological type of tooth replacement to patients with missing teeth. Teeth with open apices (50-75% apical closure) will regenerate with vitality following autotransplantation. The success rate following an autotransplantation is 82%. The remaining 18% can usually still be treated successfully with a simple additional treatment. The tooth survival rate 10 years after autotransplantation is higher than 90%. The use of 3D techniques makes it possible to create a pre-operative replica of the donor tooth. With this, a new alveolus can be prepared at the transplant site even before extraction. This technique reduces the extra-alveolar time for the donor tooth and minimises the possibility of iatrogenic damage. This results in a streamlined procedure, enabling better planning with better results.

A retrospective analysis of the resorption rate of deproteinized bovine bone as maxillary sinus graft material on cone beam computed tomography.

OBJECTIVES: Graft resorption remains a major disadvantage of the various employed materials in maxillary sinus augmentation. Our aim was to assess the percentage of graft volume reduction in deproteinized bovine bone (DBB) using cone beam computed tomography (CBCT). MATERIALS AND METHODS: A retrospective analysis of 29 augmented sinuses in 19 patients was conducted. The graft material was either DBB alone or DBB mixed with autologous bone chips (80% DBB/20% bone chips). CBCT scans of the augmented sinuses were obtained pre- and post-operatively up to 2-year follow-up. RESULTS: In total, 55 dental implants were placed in the posterior maxillary region following sinus augmentation. The mean height of the alveolar ridge pre-operative was 2.7 ± 1.2 mm and post-operative was 14.13 ± 4.6 mm. The mean percentages of alveolar ridge height reduction were 18.58% (SD14.23%) and 27.62% (SD12.70%), and the mean percentages of graft volume reduction were 19.30% (SD9.19%) and 19.85% (SD9.61%) for DBB and DBB + bone chips, respectively. CONCLUSIONS: The results indicate that DBB graft volume resorption is approximately (20 ± 10%) following 2-year follow-up. CBCT is a useful radiographic tool to follow-up changes in sinus graft volumes.

Implant dentistry in postgraduate university education. Present conditions, potential, limitations and future trends.

INTRODUCTION: In recent years, opportunities for postgraduate university education in implant dentistry have increased significantly, with an increase in both the number but also the complexity of available postgraduate programmes. However, there appears to be a lack of standards directing the learning outcomes of such programmes. METHODS: A scientific literature search was conducted for publications reporting on university programmes within implant dentistry, including description of programmes and evaluation of learning outcomes. A separate Internet search was conducted to collect information on existing university programmes as presented on university websites. RESULTS: Implant dentistry has reached a critical mass of an independent, multidisciplinary and vibrant domain of science, which combines knowledge and discovery from many clinical and basic sciences. Many university programmes conclude with a master's or equivalent degree, but there appears to be a great diversity with regard to duration and learning objectives, as well as targeted skills and competences. The importance of implant dentistry has also increased within established specialist training programmes. There was little indication, however, that the comprehensive aspects of implant dentistry are present in all specialist training programmes where implants are being covered. CONCLUSIONS: Although universities should maintain the options of designing academic programmes as they best see fit, it is imperative for them to introduce some form of transparent and comparable criteria, which will allow the profession and the public to relate the degree and academic credentials to the actual skills and competences of the degree holder. With regard to established specialist training programmes, the interdisciplinary and comprehensive nature of implant dentistry needs to be emphasised, covering both surgical and restorative aspects. Finally, implant dentistry is not, at present, a dental specialty. The profession has not reached a consensus as to whether the introduction of a new recognised specialist field is either necessary or desired.

Cytokine and matrix metalloproteinase expression in fibroblasts from peri-implantitis lesions in response to viable Porphyromonas gingivalis.

BACKGROUND AND OBJECTIVE: To assess inflammatory reactions of fibroblasts in the pathophysiology of peri-implantitis, we compared the pro-inflammatory and matrix-degrading responses of gingival and granulation tissue fibroblasts from periodontally healthy controls, peri-implantitis, and periodontitis lesions to an in vitro challenge with Porphyromonas gingivalis. METHODS: Fibroblasts from periodontally healthy, peri-implantitis and periodontitis donors were challenged with viable P. gingivalis. The inflammatory reactions of fibroblasts were analyzed before and after 6 h P. gingivalis challenge, and 2.5 and 18 h after removal of the challenge. Gene expression and induction of pro-inflammatory mediators, and matrix metalloproteinases (MMPs) were assessed by real-time polymerase chain reaction. Protein expression was measured by enzyme-linked immunosorbent assay. RESULTS: Non-challenged fibroblasts from peri-implantitis and periodontitis lesions expressed higher levels of interleukin (IL)-1ß, IL-8, and monocyte chemotactic protein (MCP)-1 than fibroblasts from periodontally healthy individuals. The P. gingivalis challenge induced expression of IL-1ß, IL-8, IL-6, MCP-1, and MMP-1 in periodontitis and peri-implantitis fibroblasts, but not in fibroblasts from periodontally healthy individuals. MMP-8 expression was higher in non-challenged peri-implantitis fibroblasts than in fibroblasts from periodontally healthy individuals. However, the P. gingivalis challenge downregulated MMP-8 gene expression in peri-implantitis fibroblasts. After removal of the P. gingivalis challenge, peri-implantitis fibroblasts sustained higher induction of IL-1ß, MCP-1, and MMP-1 compared to periodontitis fibroblasts. CONCLUSIONS: Fibroblasts from peri-implantitis and periodontitis lesions gave a more pronounced inflammatory response to the P. gingivalis challenge than fibroblasts from healthy donors. They may therefore be involved in the development of inflammation in peri-implantitis and periodontitis. Moreover, the sustained upregulation of inflammatory mediators and MMP-1 in peri-implantitis fibroblasts may play a role in the pathogenesis of peri-implantitis.

Comparing culture, real-time PCR and fluorescence resonance energy transfer technology for detection of Porphyromonas gingivalis in patients with or without peri-implant infections.

BACKGROUND AND OBJECTIVE: The aim of the study was to compare the detection of Porphyromonas gingivalis using a fluorescence resonance energy transfer (FRET) technology with commonly used diagnostic methods in salivary and subgingival plaque samples from subjects with dental implants. P. gingivalis was considered as a marker for a pathogenic microbiota. MATERIAL AND METHODS: Ninety-seven adult subjects were recruited, including periodontally healthy controls with no dental implants, implant controls with no peri-implant disease and patients with peri-implant disease. Saliva and subgingival/submucosal plaque samples were collected from all subjects and were analyzed using culture, real-time PCR and FRET technology employing P. gingivalis-specific substrates. RESULTS: It was found that the P. gingivalis-specific substrates were highly suitable for detecting the presence of P. gingivalis in saliva and in subgingival plaque samples, showing comparable specificity to culture and real-time PCR. CONCLUSION: We applied the FRET technology to detect P. gingivalis in implant patients with or without an implant condition and in controls without implants. The technique seems suitable for detection of P. gingivalis in both plaque and saliva samples. However, with all three techniques, P. gingivalis was not very specific for peri-implantitis cases. Future work includes fine-tuning the FRET technology and also includes the development of a chair-side application.

[Radiographs for the assessment of bone loss around implants. Exploring the potential]. / Röntgenopnamen voor het vaststellen van botverlies rond implantaten. Een exploratie van de mogelijkheden.

Twelve per cent of oral implants fail due to the loss of bone within 15 years after implantation. If bone loss is detected early, measures can be taken which increase the success rate of implants. To monitor implants, radiographs are made regularly. Generally, the loss of marginal bone level is measured on the radiographs. An alternative method is based on the subtraction ofradiographs. The authors applied subtraction to non-standardized panoramic radiographs of patients with implants. Bone loss around the implants could be rendered visible, at least on the level of patient groups. For individuals, no accurate method exists to render bone loss around implants visible. For the early recognition of bone loss around implants, intra-oral radiographs are preferred above panoramic radiographs. It is also important to maintain the same exposure time and projection geometry.

[Considerations with respect to the use of corticosteroids in dentoalveolar surgical treatments]. / Beschouwingen over het gebruik van corticosteroïden in de dentoalveolaire chirurgie.

Corticosteroids are used incidentally in dentoalveolar surgical treatments to reduce possible postsurgical problems. Natural corticosteroids are produced in the adrenal cortex. Synthetic corticosteroids are known to have anti-inflammatory effects when they are administered in doses exceeding the normal physiological amounts which the body produces. Several contraindications and side effects are known. Administration of corticosteroids for dentoalveolar surgical treatments shows a reduction of edema and pain. When using corticosteroids, the risk of infections is not known to be higher than usual and the risk of adverse effects is minimal. According to the literature, there is no clear recommendation to use corticosteroids as a standard for dentoalveolar surgical treatments.

The effectiveness of 2-implant overdentures - a pragmatic international multicentre study.

The purpose of this multicentre observational study was to determine patient satisfaction with either conventional dentures or mandibular 2-implant overdentures in a 'real world' setting. Two hundred and three edentulous patients (mean age 68·8 ± 10·4 years) were recruited at eight centres located in North America, South America and Europe. The patients were provided with new mandibular conventional dentures or implant overdentures supported by two implants and ball attachments. At baseline and at 6 months post-treatment, they rated their satisfaction with their mandibular prostheses on 100-mm visual analogue scale questionnaires. One hundred and two (50·2%) participants had valid baseline and 6-month satisfaction data. Although both groups reported improvements, the implant overdenture group reported significantly higher ratings of overall satisfaction, comfort, stability, ability to speak and ability to chew. These results suggest that edentulous patients who choose mandibular implant overdentures have significantly greater improvements in satisfaction, despite their relatively higher cost, than those who choose new conventional dentures.

[Notes concerning an overdenture on 2 implants as the standard for treating an edentulous mandible]. / Kanttekeningen bij een overkappingsprothese op 2 implantaten als gouden standaard voor de behandeling van een edentate onderkaak.

Patients with an edentulous mandible often have difficulty retaining conventional dentures. It was formerly the case that, as a rule, 4 implants were placed in the interforaminal area of the mandible in order to provide retention for the mandibular denture. A large body of research, however, revealed good results with 2 implants with various mesostructures. The 2 implant overdenture in the mandible has since become standard for edentulous patients. Research results indicate that this treatment should be the primary option under certain conditions. The appropriate types of care which are indicated by these conditions should, however, be carefully distinguished. Under certain anatomical conditions, such as a low and narrow alveolar ridge, exposed mandibular nerves, very low density alveolar bone (Class IV bone) and very sensitive mucous membranes, 4 implants are indicated. Patients who are less manually dextrous might be better served with 2 implants and a single mesostructure.

VEGF incorporated into calcium phosphate ceramics promotes vascularisation and bone formation in vivo.

Bone formation and osseointegration of biomaterials are dependent on angiogenesis and vascularization. Angiogenic growth factors such as vascular endothelial growth factor (VEGF) were shown to promote biomaterial vascularization and enhance bone formation. However, high local concentrations of VEGF induce the formation of malformed, nonfunctional vessels. We hypothesized that a continuous delivery of low concentrations of VEGF from calcium phosphate ceramics may increase the efficacy of VEGF administration.VEGF was co-precipitated onto biphasic calcium phosphate (BCP) ceramics to achieve a sustained release of the growth factor. The co-precipitation efficacy and the release kinetics of the protein were investigated in vitro. For in vivo investigations BCP ceramics were implanted into critical size cranial defects in Balb/c mice. Angiogenesis and microvascularization were investigated over 28 days by means of intravital microscopy. The formation of new bone was determined histomorphometrically. Co-precipitation reduced the burst release of VEGF. Furthermore, a sustained, cell-mediated release of low concentrations of VEGF from BCP ceramics was mediated by resorbing osteoclasts. In vivo, sustained delivery of VEGF achieved by protein co-precipitation promoted biomaterial vascularization, osseointegration, and bone formation. Short-term release of VEGF following superficial adsorption resulted in a temporally restricted promotion of angiogenesis and did not enhance bone formation. The release kinetics of VEGF appears to be an important factor in the promotion of biomaterial vascularization and bone formation. Sustained release of VEGF increased the efficacy of VEGF delivery demonstrating that a prolonged bioavailability of low concentrations of VEGF is beneficial for bone regeneration.

Depth cue combination in spontaneous eye movements.

Where we look when we scan visual scenes is an old question that continues to inspire both fundamental and applied research. Recently, it has been reported that depth is an important variable in driving eye movements: the directions of spontaneous saccades tend to follow depth gradients, or, equivalently, surface tilts (L. Jansen, S. Onat, & P. König, 2009; M. Wexler & N. Ouarti, 2008). This has been found to hold for both simple and complex scenes and for a variety of depth cues. However, it is not known whether saccades are aligned with individual depth cues, or with a combination of depth cues. If saccades do follow a combination of depth cues, then it is interesting to ask whether this combination follows the same rules as the well-studied case of depth cue combination in conscious perception. We showed subjects surfaces inclined in depth, in which perspective and binocular disparity cues specified different plane orientations, with different degrees of both small and large conflict between the two sets of cues. We recorded subjects' spontaneous saccades while they scanned the scene, as well as their reports of perceived plane orientation. We found that distributions of spontaneous saccade directions followed the same pattern of depth cue combination as perceived surface orientation: a weighted linear combination of cues for small conflicts, and cue dominance for large conflicts. The weights assigned to the cues varied considerably from one subject to the next but were strongly correlated for saccades and perception; moreover, for both perception and saccades, cue weights could be modified by manipulating cue reliability in a way compatible with Bayesian theories of optimal cue combination. We also measured vergence, which allowed us to calculate the orientation of the plane fitted to points scanned in depth. Contrary to perception and saccades, vergence was dominated by a single cue, binocular disparity.

[Severe periodontal disease as the cause of a fever of unknown origin]. / Ernstige paradontitis als oorzaak voor onbegrepen koorts.

A 41-year old man was admitted to a university medical centre with a belly ache, bloody diarrhoea and fever with peaks rising up to 39 degrees C. The differential diagnosis included among others infectious bowel disease, tuberculosis and amoeba-infection. After the exclusion of other pathologies the diagnosis morbus Crohn was given. A few days later the patient complained about toothache and severe periodontal disease was diagnosed. Instantly after extraction of the entire dentition the fever disappeared.

Reliability and validity of the instrumental assessment of implant stability in dry human mandibles.

The aim of this study was to determine the intra- and interobserver reliability and validity of the instrumental assessment of primary dental implant stability, using resonance frequency analysis (RFA). Sixteen tapered implants and 16 cylindrical implants were installed in eight unfixed dry human mandibles (Cawood classification IV/V). Implant stability quotients (ISQ; the outcome variable of RFA) and peak removal torque were determined. Both the intra-observer reliability and the interobserver reliability of the RFA measurements were fair-to-good, while no significant correlations between the ISQ values and removal torque were found. The removal torque of the cylindrical implants was higher than that of the tapered implants. The smallest detectable difference was almost nine ISQ units. Within the limitations of the present dry cadaver study, it was concluded that (i) primary dental implant stability can be assessed reliably with RFA measurements, (ii) the concurrent validity between RFA measurements and removal torque is poor, (iii) cylindrical implants may be more stable than tapered ones and (iv) two subsequent readings of RFA measurements need to differ at least nine ISQ units before the difference between the two measurements can be considered statistically significant. More research is needed to see whether these conclusions can be extrapolated to the clinical situation, including the assessment of implants during function (secondary stability).

[Infectious complications with dental implants]. / Infectieuze complicaties bij implantaten.

Dental implantology represents an essential step in the rehabilitation of function, stability and aesthetics of the human dentition.The introduction of dental implantology has at the same time created a problem: peri-implant infections. Putative risk factors for this disorder are, among others, smoking, a history of periodontitis, genetic traits, and uncontrolled diabetes mellitus. Since no validated protocol for the treatment of peri-implantitis exists, clinicians have to rely on their own experience and knowledge and on the experience of others.

Augmented and virtual reality in dental medicine: A systematic review.

BACKGROUND: The aim of this systematic review was to provide an update on the contemporary knowledge and scientific development of augmented reality (AR) and virtual reality (VR) in dental medicine, and to identify future research needs to accomplish its clinical translation. METHOD: A modified PICO-strategy was performed using an electronic (MEDLINE, EMBASE, CENTRAL) plus manual search up to 12/2018 exploring AR/VR in dentistry in the last 5 years. Inclusion criteria were limited to human studies focusing on the clinical application of AR/VR and associated field of interest in dental medicine. RESULTS: The systematic search identified 315 titles, whereas 87 abstracts and successively 32 full-texts were selected for review, resulting in 16 studies for final inclusion. AR/VR-technologies were predominantly used for educational motor skill training (n = 9 studies), clinical testing of maxillofacial surgical protocols (n = 5), investigation of human anatomy (n = 1), and the treatment of patients with dental phobia (n = 1). Due to the heterogeneity of the included studies, meta-analyses could not be performed. CONCLUSIONS: The overall number of includable studies was low; and scientifically proven recommendations for clinical protocols could not be given at this time. However, AR/VR-applications are of increasing interest and importance in dental under- and postgraduate education offering interactive learning concepts with 24/7-access and objective evaluation. In maxillofacial surgery, AR/VR-technology is a promising tool for complex procedures and can help to deliver predictable and safe therapy outcomes. Future research should focus on establishing technological standards with high data quality and developing approved applications for dental AR/VR-devices for clinical routine.