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Aim: To evaluate the effect of bone morphogenetic protein 2 (BMP-2) incorporated biomimetic calcium phosphate (BMP-2/BioCaP) in conjunction with barrier membrane on periodontal regeneration in chronic periodontitis experimental model. Material and Methods: Chronic periodontitis experimental model with critical-sized supra-alveolar defects was created in 15 dogs’ mandibles. After the initial periodontal therapy, the defects were randomly assigned to the following groups: (a) control; (b) barrier membrane; (c) deproteinized bovine bone mineral + barrier membrane; (d) BioCaP + barrier membrane and (e) BMP-2/BioCaP + barrier membrane (6 quadrants with 18 teeth per group). Eight weeks later, clinical examinations, micro-CT, and histomorphometric analyses were performed. Results: Clinical examinations, including plaque index, bleeding index, and probing depth, were similar for all groups. In contrast, the clinical attachment loss was significantly lower in defects grafted with BMP-2/BioCaP and barrier membrane. The micro-CT results showed that the height of mineralized tissue in defects grafted with BMP-2/BioCaP and barrier membrane was significantly higher. For histometric analysis, the defects grafted with BMP-2/BioCaP and barrier membrane exhibited significantly more connective tissue height, new cementum height, new bone height and area, as well as less down-growth of junctional epithelium. Conclusion: BMP-2/BioCaP could be a promising bone substitute for periodontal regeneration.

The aim of the present systematic review was to answer the overall research question: “To what extent is bruxism associated with musculoskeletal signs and symptoms?”. The review was performed in accordance with the PRISMA guidelines. A PubMed search of articles published until 23 November 2017 was conducted. The search string included both MeSH terms and text words. Results were presented in categories according to study design, study population (eg, adults, children), bruxism sub-type (awake, sleep), assessment methods for bruxism and musculoskeletal symptoms (self-report, validated test) and type of outcome (pain, non-painful musculoskeletal symptoms). It could be concluded that bruxism is to some extent associated with musculoskeletal symptoms, even though the evidence is conflicting and seems to be dependent on many factors, such as age, whether the bruxism occurs during sleep or wakefulness, and also the quality of the diagnostic methodology regarding bruxism and musculoskeletal signs and symptoms. The literature does not support a direct linear causal relationship between bruxism and such symptoms, but points more in the direction of a multifaceted relationship dependent on the presence of other risk factors. Pain is by far the most commonly assessed symptom, whereas non-painful musculoskeletal symptoms have generally not been systematically evaluated. In the light of recent findings indicating that non-painful symptoms may precede TMD pain, it is suggested to increase the scientific focus on non-painful musculoskeletal symptoms in future studies. Also, future studies should use validated methods for case definition and outcome assessments.

Objectives: The aim of this investigation was to evaluate whether the use of a provisional implant‐supported crown improves the final esthetic outcome of implant crowns that are placed within esthetic sites.Materials and Methods: Twenty endosseous implants were inserted in sites 13 to 23 (FDI) in 20 patients. Following the reopening procedure, a randomization process assigned them to either cohort group 1: a provisional phase with soft tissue conditioning using the “dynamic compression technique” or cohort group 2: without a provisional phase. Screw‐retained all ceramic crowns were inserted. Clinical follow‐up appointments were completed at 36 months evaluating clinical, radiographic outcomes, and implant success and survival.Results: After 3 years, all implants survived; one implant‐supported crown was excluded from the study due to adjacent tooth failure replaced with a further implant supported crown. Modified pink esthetic score (ModPES) scores were significantly different between groups 1 and 2 (P = .018); white esthetic scores (WES) were not statistically different between both groups (P = .194). Mean values of combined modPES and WES were 15.6 for group 1, with a SD of 3.20. Group 2 had a mean combined modPES and WES of 12.2, with a SD of 3.86. Mean bone loss after 3 year was −0.05 and −0.04 mm for groups 1 and 2 respectively, without being statistically significant.Conclusion: Fixed implant‐supported provisionals improve the final esthetic outcome of the peri‐implant mucosa.

Objectives. Functional tooth replacement and bone regeneration are parts of the daily practice in modern dentistry, but well-reproducible and relatively inexpensive experimental models are still missing. We aimed to develop a new small animal model to monitor osseointegration utilizing the combination of multiple evaluation protocols.Material and methods. After cutting the tail between the C4 and C5 vertebrae in Wistar rats, costume made, parallel walled, non-threaded implants were placed into the center of the tail parallel with its longitudinal axis using a surgical guide. Osseointegration of the titanium implants was followed between 4 and 16 weeks after surgery applying axial extraction force, and resonance frequency analysis as functional tests, and histomorphometry and micro-CT as structural evaluations.Results. In functional tests, we observed that both methods are suitable for the detection of the time-dependent increase in osseointegration, but the sensitivity of the pull-out technique (an approximately five times increase with rather low standard error) was much higher than that of the resonance frequency analysis. In structural evaluations, changes in the detected bone implant contact values measured by histomorphometry (yielding 1.5 times increase, with low variations of data) were more reliable than micro-CT based evaluations to screen the developments of contact between bone and implant.Conclusion. Our results provide evidence that the caudal vertebrae osseointegration model is useful for the preclinical evaluation of implant integration into the bone.Clinical relevance. The combination of the biomechanical and structural tests offers a well-reproducible small animal system that can be suitable for studying the integration of various implant materials and surface treatments.

Infected bone defect healing is hindered by infection and compromised bone regenerative capacity. In this study, we designed a dual functional bone‐defect‐filling material with a sequential release system, that is, a burst release of a potent antibacterial agent, hydroxypropyltrimethyl ammonium chloride chitosan (HACC), followed by a controlled release of osteoinductive bone morphogenic protein (BMP2) to repair the infected bone defect. Minimum bactericidal concentration (MBC) of HACC against methicillin‐resistant Staphylococcus aureus was 40 μg/mL. HACC at 40 μg/mL did not affect preosteoblast proliferation and did not influence the BMP2‐induced alkaline phosphatase activity, osteocalcin expression, and matrix mineralization. in vitro release profile revealed burst release of HACC followed by a slow release of BMP2. in vivo bone formation was observed only in the BMP2‐containing groups. HACC did not influence of biomimetic calcium phosphate (BioCaP) resorption and BMP2‐induced bone formation. In conclusion, the optimized HACC/BMP2‐incorporated BioCaP complex showed strong antibacterial effect and robustly enhanced osteoinduction both in vitro and in vivo.

Background: The perfect position and axis of an implant is often limited by the morphology of the alveolar ridge, especially in Asians.Purpose: The aim of this study was to investigate the frequency at which ideal implant placement position in the anterior maxilla of Chinese Asians would require facial bone augmentation given by an initial facial bone profile.Materials and Methods: Implants were virtually placed in 303 sites without tooth loss in the anterior maxilla. The incidence and characters of implant facial plate fenestration were analyzed. If there was no facial fenestration, the thinnest buccal plate (TB) amount adjacent to the implant was measured and recorded.Results: A total of 79 (26.07%) sites showed fenestrations. The mean length, width, and area of exposure in the fenestration sites were 2.94 ± 1.67 mm, 1.52 ± 0.97 mm, and 2.84 ± 3.13 mm2, respectively. In the nonfenestrated sites, the TB of facial bone around the virtual implants was 1.10 ± 0.78 mm. Among the 224 nonfenestrated sites, 126 sites had a TB of less than 1 mm.Conclusions: It can be concluded that the initial facial bone profile should be considered when designing restorations and choosing an optimal implant position in the anterior maxilla.

Pathological stimuli, such as bacterial activity, dental bleaching, and nonpolymerized resin monomers, can cause death of dental pulp cells (DPCs) through oxidative stress- (OS-) induced mitochondrial dysfunction. However, the crucial molecular mechanisms that mediate such a phenomenon remain largely unknown. OS is characterized by the overproduction of reactive oxygen species (ROS), e.g., H2O2, O2−, and ⋅OH. Mitochondria are a major source of ROS and the principal attack target of ROS. Cyclophilin D (CypD), as the only crucial protein for mitochondrial permeability transition pore (mPTP) induction, facilitates the opening of mPTP and causes mitochondrial dysfunction, leading to cell death. In the present study, we hypothesized that CypD-mediated mitochondrial molecular pathways were closely involved in the process of OS-induced death of human DPCs (HDPCs). We tested the phenotypic and molecular changes of HDPCs in a well-established OS model—H2O2 treatment. We showed that H2O2 dramatically reduced the viability and increased the death of HDPCs in a time- and dose-dependent manner by performing MTT, flow cytometry, and TUNEL assays and quantifying the expression changes of Bax and Bcl-2 proteins. H2O2 also induced mitochondrial dysfunction, as reflected by the increased mitochondrial ROS, reduced ATP production, and activation of mPTP (decreased mitochondrial membrane potential and enhanced intracellular Ca2+ level). An antioxidant (N-acetyl-L-cysteine) effectively preserved mitochondrial function and significantly attenuated H2O2-induced cytotoxicity and death. Moreover, H2O2 treatment markedly upregulated the CypD protein level in HDPCs. Notably, genetic or pharmacological blockade of CypD significantly attenuated H2O2-induced mitochondrial dysfunction and cell death. These findings provided novel insights into the role of a CypD-dependent mitochondrial pathway in the H2O2-induced death in HDPCs, indicating that CypD may be a potential therapeutic target to prevent OS-mediated injury in dental pulp.

Objectives: The effect of gingival retraction paste versus gingival retraction cord on periodontal tissue health is controversial. The aim of the present study was to evaluate the effect of gingival retraction paste versus gingival retraction cord on periodontal health by a systematic review and meta-analysis and to provide scientific guidelines for gingival retraction method selection in clinical work. Data Sources: The databases were systematically queried to collect studies exploring the effect of gingival retraction methods on periodontal tissue health in randomized controlled trials. Literature covering the period of January 1998 to April 2017 was extracted and the quality was assessed, followed by a random-effects meta-analysis with standardized mean differences and 95% confidence intervals. Eight studies met the inclusion criteria. The result of meta-analysis revealed that gingival retraction paste exhibited a less deleterious effect on the periodontal tissue compared with the gingival retraction cord technique measured by probing depth, Gingival Bleeding Index, and bleeding on probing (P < .05). However, no statistically significant differences were found in the measurements of Plaque Index, Gingival Index, and gingival recession between these two methods (P > .05). Conclusions: Gingival retraction paste can work better than the gingival retraction cord method in protecting periodontal tissue health.

Nanocrystalline hydroxyapatite (NHA) is a biocompatible, biodegradable, and osteoconductive bone graft material; however, it lacks osteoinductivity. The present study is aimed at investigating the feasibility of nanocrystalline hydroxyapatite (NHA) as an osteoinductive growth factor carrier. Bone morphogenic protein 2 (BMP2), an osteoinductive growth factor, was incorporated into NHA (BMP2-NHA) using a simple adsorption method. The growth factor loading and release kinetics were profiled using fluorescein-isothiocyanate-labeled bovine serum albumin (FITC-BSA) as a mimic of the osteoinductive growth factor BMP2. The effect of BMP2-NHA on the osteogenic differentiation of C2C12 cells and ectopic bone formation in mice were tested. Confocal laser-scanning microscopy showed that FITC-BSA was diffused throughout the porous structure of NHA. FITC-BSA was efficiently loaded in NHA and sustained release was observed up to 35 days in vitro. BMP2-NHA enhanced the expression of osteogenic markers Runx2, Osterix, Alp, and Col1α1 and ALP activity in C2C12 cells compared to NHA. Similarly, μ-CT and histological examinations showed that BMP2-NHA robustly induced ectopic bone formation in mice. This study suggests that NHA could be used as an effective carrier of osteoinductive growth factors, which ensures osteoinductivity of NHA via sustained release of the growth factor.

Bruxism may lead to negative health outcomes, such as musculoskeletal signs and symptoms and complications of oral implants. The exact association, however, is still not fully understood. Moreover, the diagnosis of both sleep and awake bruxism is challenging, with instrumental methods that can lead to a definite diagnosis not being widely available to both clinicians and researchers. The purpose of this thesis was to investigate the association between bruxism and musculoskeletal signs and symptoms (chapters 2 and 3), as well as the association between bruxism and oral implant complications (chapters 4, 5, and 6). Moreover, aspects related to the applicability of diagnostic methods for bruxism in the clinic were studied (chapters 6 and 7). To this end, a systematic review of the literature (chapter 2), two clinical studies (chapters 3, 5 and 6) and two qualitative studies (chapters 4 and 7) were performed. Results of these studies showed that bruxism may to some extent be considered a behaviour with negative implications, i.e., musculoskeletal signs and symptoms and a possible risk for oral implant complications. Linear associations are not likely. Adequate, i.e., pragmatic and accurate bruxism diagnostic methods are cornerstones for future relevant research and more predictable clinical treatment, and in this context, smartphone-based technologies are promising tools.

Implant surface modification that provides local sustained release of osteoinductive therapeutic agents enhances implant stability. We designed a mesoporous TiO2-layered titanium implant (MLT) by modified anodization technique that allowed local sustained release of zoledronic acid up to 21 days. Mesoporous layer has pore size 15 nm, depth ∼30 μm, volume 0.32 cm3/g, surface area 112.3 m2/g, surface roughness 20 nm and water contact angle 18.3°. Zoledronic acid-loaded MLT (MLT-Z) was biocompatible, showed anabolic effect on bone forming osteoblasts and catabolic effect on bone resorbing osteoclasts. MLT or MLT-Z implants were implanted in osteoporotic rat-tail vertebrae. Smooth implant in healthy rats were used as a positive control. Histomorphometric analysis showed that bone implant contact of smooth implant in osteoporotic rats was reduced by 4.1-fold compared to healthy rats and MLT-Z rescued the effect by 53%. Similar effect was observed in implant fixation, mechanical stability, BV/TV ratio, Tb.N, Tb.Th and OI% among the groups. Histological and μ-CT images strongly supported the above-mentioned findings. In conclusion, a novel surface-fabricated MLT-Z gives local sustained drug release, robustly enhances implant osseointegration and stability in osteoporotic condition, suggesting it as a promising implant model for patients with compromised bone quality.

Item does not contain fulltext Biomimetically deposited calcium phosphate-based coatings of prostheses can serve as a vehicle for the targeted delivery of growth factors to the local implant environment. Based on indirect evidence in previous studies we hypothesize that such agents are liberated gradually from the coating via a cell-mediated degradation. In the present study, we tested this hypothesis by investigating the release mechanism and its kinetics by use of a radiolabeled osteogenic agent ((131) I-BMP-2) under conditions in which native cell populations with a coating-degradative potential were either absent or present. The release of (131) I-BMP-2 was monitored for 5 weeks, either in vitro or after implantation at an ectopic (subcutaneous) site in rats in vivo. Only from implants that bore a coating-incorporated depot of bone morphogenetic protein 2 (BMP-2) was the agent released slowly and steadily over 5 weeks, that is, 50% of the loaded dose was liberated in vivo (5 to 10% weekly), as against 14.6% in vitro (less than 1% weekly). The coatings bearing an incorporated depot of BMP-2 underwent significant cell-mediated degradation, whereas under cell-free conditions no degradation occurred, and the spontaneous release of BMP-2 was negligible. Our findings confirm this carrier system to be a suitable vehicle for the sustained and cell-mediated delivery of BMP-2. (c) 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A:2363-2371, 2018. 01 september 2018

Advanced glycation end products (AGEs) can stimulate osteoblast apoptosis and have a critical role in the pathophysiology of diabetic osteoporosis. Mitochondrial abnormalities are closely related to osteoblast dysfunction. However, it remains unclear whether mitochondrial abnormalities are involved in AGE-induced osteoblastic cell apoptosis. Silibinin, a major flavonolignan compound of silimarin, has strong antioxidant and mitochondria-protective properties. In the present study, we explored the possible mitochondrial mechanisms underlying AGE-induced apoptosis of osteoblastic cells and the effect of silibinin on osteoblastic cell apoptosis. We demonstrated that mitochondrial abnormalities largely contributed to AGE-induced apoptosis of osteoblastic cells, as evidenced by enhanced mitochondrial oxidative stress, conspicuous reduction in mitochondrial membrane potential and adenosine triphosphate production, abnormal mitochondrial morphology, and altered mitochondrial dynamics. These AGE-induced mitochondrial abnormalities were mainly mediated by the receptor of AGEs (RAGE). In addition, we found that silibinin directly downregulated the expression of RAGE and modulated RAGE-mediated mitochondrial pathways, thereby preventing AGE-induced apoptosis of osteoblastic cells. This study not only provides a new insight into the mitochondrial mechanisms underlying AGE-induced osteoblastic cell apoptosis, but also lays a foundation for the clinical use of silibinin for the prevention or treatment of diabetic osteoporosis.

Aan het eind van de negentiende eeuw werden was, stents of gips of een combinatie daarvan gebruikt om een (bijna) edentate kaak af te drukken. In een artikel uit 1894 werd een pleidooi gehouden om dat enkel met gips te doen. Tegenwoordig wordt bij voorkeur in 2 stappen afgedrukt, met uiteindelijk een mucostatische afdruk van de gebitsprothese. Of dit in toekomst ook met een digitale scan kan, zal de tijd leren.

To repair bone defects, we evaluate the in-vitro and in-vivo osteogenic activities of a novel tissue-engineered bone (TEB) by elaborately combining biomimetic calcium phosphate (BioCaP) granules with internally-incorporated simvastatin (SIM) and human adipose-derived stem cells (hASCs). First, we constructed BioCaP with SIM internally incorporated (SIM-BioCaP). Then we characterized the morphology and chemical composition of SIM-BioCaP. The release kinetics of SIM was monitored in vitro spectroscopically. Thereafter, we explored the in-vitro cellular responses of hASCs to SIM-BioCaP by performing scanning electron microscopy observation, proliferation assay, alkaline phosphatase (ALP) activity assay, alizarin red staining and real-time PCR. Finally, we investigated the in-vivo osteogenic activities of the novel TEB in a subcutaneous bone induction model in nude mice. We found that SIM was successfully incorporated internally in BioCaP and showed a slow release manner without significantly affecting the attachment and proliferation of hASCs. The released SIM from BioCaP could significantly enhance the proliferation, ALP activities, mineralized nodules formation and osteogenic genes of hASCs. The in-vivo tests showed this TEB could induce new bone formation while the other groups could not. Taken together, the present data show that this novel TEB represented a very promising construct to treat critical-volume bone defects.

Purpose: To evaluate the feasibility of a commercially available immediate root analog implant system Replicate (Natural Dental Implants). Materials and Methods: Five consecutive patients in need of an implant in the premolar region were recruited for this pilot study. Following clinical examination, a cone beam computed tomography scan was made and the dental impressions digitized. On the basis of the superimposition of these datasets, a three-dimensional (3D) envelope was created for the selected tooth. Subsequently, the tooth root at the prospective implant site was segmented to create a 3D surface, and the obtained mesh data were used as the basis for designing a single-piece root analog implant within the 3D envelope. The designed root analog implant was fabricated using a five-axis computer-aided manufacturing machine. The root analog implants were inserted following flapless minimally invasive root extraction. Following 3 months of uninterrupted healing, definitive restorations were fabricated. Peri-implant clinical and radiographic measurements were obtained up to 12 months follow-up. Results: All patients functioned well following 12 months of functional loading. Within one patient, one of the two root analog implants failed early. Peri-implant clinical and radiographic measurements demonstrated a stable situation after 12 months of functional loading. Conclusion: A novel digital approach for immediately restoring single teeth using root analog implants was introduced. In the future, long-term evaluation of the root analog implant technique is necessary to evaluate the success and survival of implants that were inserted using this technique.

The aim of this study is to test the cleaning effect and surface modification of a new implant surface treatment on explanted dental implants and titanium discs. It is a modified air powder abrasive (APA) treatment applied using osteoconductive powders. Twenty‐eight in vitro Ca‐precipitated organic film‐coated titanium discs and 13 explanted dental implants were treated. In a 2‐step approach, 3 powders were used: hydroxylapatite (HA) and biomimetic calcium phosphate (BioCaP), which are osteoconductive, and erythritol, which is not. APA treatment was applied. (Air pressure: 2.4 bar; water flow for cleaning: 41.5 ml/min, for Coating 1: 2.1 ml/min, and for Coating 2: 15.2 ml/min.) The test groups were as follows: Group 1: HA cleaning + BioCaP Coating 1; Group 2: HA cleaning + BioCaP Coating 2; Group 3: erythritol cleaning + BioCaP Coating 1; Group 4: erythritol cleaning + BioCaP Coating 2; Group 5: HA cleaning; Group 6: erythritol cleaning; and control: no powder. Cleaned areas were calculated by point counting method. Surface changes and chemical content were evaluated using light microscopy, scanning electron microscopy, and energy‐dispersive X‐ray spectroscopy. Cleaning effect between groups was compared by a pairwise Student's t test. The significance level was fixed at p

The objective of this study was to develop heparin-conjugated strontium-substituted hydroxyapatite/silk fibroin (Sr-nHAp/SF-Hep) scaffold loaded bone morphogenetic proteins-2 (BMP-2) with sustained release to improve bone regeneration. The average pore diameters and porosity of Sr-nHAp/SF scaffolds were respectively approximately 150 μm and 90%. The mechanical properties and thermostability of the Sr-nHAp/SF scaffolds were significantly stronger than those of the SF scaffold. The weight of composite scaffolds is higher than that of the SF scaffold in simulated body fluids. The Sr-nHAp/SF scaffold exhibited excellent biological function of bone marrow mesenchymal stem cell (BMSC) proliferation and adhesion. The expression of related osteogenic genes, including osteocalcin, osteopontion, and alkaline phosphatase activity was elevated by Sr-nHAp/SF-Hep-BMP-2 scaffold, which promoted the differentiation of BMSCs into osteoblasts. In vivo results showed that Sr-nHAp/SF-Hep-BMP-2 scaffolds enhanced bone mineral density and improved new bone regeneration, which was accomplished through microcomputed tomography (micro-CT) and histological and histochemical staining analysis. These results demonstrated Sr-nHAp/SF-Hep-BMP-2 scaffolds with favorable biocompatibility and good mechanical properties have great potential to repair bone defects.

Purpose: To evaluate the influence of fabrication method and finish line design on marginal and internal fit of full-coverage interim restorations. Methods: Four typodont models of maxillary central-incisor were prepared for full-coverage restorations. Four groups were defined; knife-edge (KE), chamfer (C), rounded-shoulder (RS), rounded-shoulder with bevel (RSB). All preparations were digitally scanned. A total of 80 restorations were fabricated; 20 per group (SLA/3D-printed n = 10, milled n = 10). All restorations were positioned on the master die and scanned using micro-computed tomography. The mean gaps were measured digitally (ImageJ). The results were compared using MANOVA (α =.05). Results: Internal and marginal gaps were significantly influenced by fabrication method (P =.000) and finish-line design (P =.000). 3D-Printed restorations showed statistically significant lower mean gap compared to milled restorations at all points (P =.000). The mean internal gap for 3D-printed restorations were 66, 149, 130, 95 μm and for milled restorations were 89, 177, 185, 154 μm for KE, C, RS, RSB respectively. The mean absolute marginal discrepancy in 3D-printed restorations were (30, 41, 30, 28 μm) and in milled restorations were (56, 54, 52, 38 μm) for KE, C, RS, RSB respectively. Conclusions: The fabrication methods showed more of an influence on the fit compared to the effect of the finish-line design in both milled and printed restorations. SLA-printed interim restorations exhibit lower marginal and internal gap than milled restorations. Nonetheless, for both techniques, all values were within the reported values for CAD/CAM restorations. Significance: 3D-printing can offer an alternative fabrication method comparable to those of milled restorations.

Objectives: To investigate which opinions among dentists are associated with level of technology use, when characteristics of the dentist and dental practice, as well as motivating work aspects are taken into account. Methods: A total of 1000 general dental practitioners in the Netherlands received a questionnaire on digital technologies they use, opinions on using technologies and related motivating work aspects. Questions were derived from expert interviews, the Dentists’ Experienced Job Resources Scale and literature on technology implementation. Technology use was measured as the number of technologies used, and divided into three technology user groups: low (using 0-4 technologies, mostly administrative and radiographic technologies), intermediate (using 5-7, more varied technologies) and high technology users (using 8-12, including more innovative diagnostic technologies). Opinions on technology use and motivating work aspects were analysed using principal components analysis (PCA) and exploratory factor analysis. Scores on all components and factors were calculated for each respondent by computing the mean of all valid responses on the underlying items. Differences in these scale scores on opinions among the technology user groups were assessed using one-way analysis of variance and Kruskal–Wallis tests. A multiple linear regression analysis assessed the association of scale scores about opinions on technology use with the sum of technologies used, taking into account motivating work aspects and characteristics of the dentist and dental practice. Results: The response rate was 31%. Dentists who were high technology users perceived technologies as yielding more improvements in quality of care, adding more value to the dental practice and being easier to use, than low technology users. High technology users thought technologies added more value to their work and they reported higher skills and resources. They also focused more on technologies and thought these are more ready to use than low technology users. High technology users derived more motivation from “Immediate results” and “Craftsmanship” than low technology users. Personal and practice characteristics, motivating work aspects, and the opinion scales “Focus” and “Added value to dentist” explained 50% of the variance in the number of technologies a dentist uses. Conclusion: Opinions on digital technologies among dentists and motivating work aspects vary with level of technology use. Being more focused on technologies and perceiving a higher added value from using them are associated with using more digital dental technologies, when taking into account motivating work aspects and characteristics of the dentist and dental practice.

This systematic review provides an overview of studies on autotransplantation techniques using rapid prototyping for preoperative fabrication of donor tooth replicas for preparation of the neo-alveolus. Different three-dimensional autotransplantation techniques and their treatment outcomes are discussed. The systematic literature search yielded 19 articles that satisfied the criteria for inclusion. These papers described one case–control study, four clinical observational studies, one study with a clinical and in vitro part, four in vitro studies, and nine case reports. The in vitro studies reported high accuracy for the printing and planning processes. The case reports all reported successful transplantation without any pathological signs. The clinical studies reported a short extraoral time of the donor tooth, with subsequent success and survival rates of 80.0–91.1% and 95.5–100%, respectively. The case–control study reported a significant decrease in extraoral time and high success rates with the use of donor tooth replicas. In conclusion, the use of a preoperatively designed surgical guide for autotransplantation enables accurate positional planning, increases the ease of surgery, and decreases the extraoral time. However, the quality of the existing body of evidence is low. Further research is therefore required to investigate the clinical advantages of this innovative autotransplantation technique.

Purpose The aim of this study was to evaluate the dimensional accuracy, surface topography of a custom designed, 3D-printed zirconia dental implant and the mechanical properties of printed zirconia discs. Materials and methods A custom designed implant was 3D-printed in zirconia using digital light processing technique (DLP). The dimensional accuracy was assessed using the digital-subtraction technique. The mechanical properties were evaluated using biaxial flexure strength test. Three different build angles were adopted to print the specimens for the mechanical test; 0°( V ertical), 45° ( O blique) and 90°(Horizontal) angles. The surface topography, crystallographic phase structure and surface roughness were evaluated using scanning electron microscopy analysis (SEM), X-ray diffractometer and confocal microscopy respectively. Results The printed implant was dimensionally accurate with a root mean square (RMSE) value of 0.1 mm. The Weibull analysis revealed a statistically significant higher characteristic strength (1006.6 MPa) of 0° printed specimens compared to the other two groups and no significant difference between 45° (892.2 MPa) and 90° (866.7 MPa) build angles. SEM analysis revealed cracks, micro-porosities and interconnected pores ranging in size from 196 nm to 3.3 µm. The mean Ra (arithmetic mean roughness) value of 1.59 µm (±0.41) and Rq (root mean squared roughness) value of 1.94 µm (±0.47) was found. A crystallographic phase of primarily tetragonal zirconia typical of sintered Yttria tetragonal stabilized zirconia (Y-TZP) was detected. Conclusions DLP prove to be efficient for printing customized zirconia dental implants with sufficient dimensional accuracy. The mechanical properties showed flexure strength close to those of conventionally produced ceramics. Optimization of the 3D-printing process parameters is still needed to improve the microstructure of the printed objects.

The aim of this study was to evaluate the effect of maleic acid (MA) on both the bond strength of fibre post to root dentine and smear layer removal after post space preparation. Sixty, single-canal premolars were endodontically treated and randomly assigned to four groups: group 1 [0.9% saline solution (control]); group 2 [2.5% sodium hypochlorite (NaOCl)]; group 3 [17% ethylenediaminetetraacetic acid (EDTA) followed by 2.5% NaOCl]; and group 4 (7% MA followed by 2.5% NaOCl). Self-adhesive resin cement was used to test the adhesion of a glass-fibre post to the root dentine through a micropush-out test. Scanning electron microscopy was performed to examine and score the treated specimens for smear layer removal, and stereomicroscopy was applied to investigate the failure modes of fibre posts. Maleic acid exhibited the highest mean bond-strength values in the apical regions among all the groups. Most failure modes (31.9%) were adhesive-type failures between the dentine and luting materials. Maleic acid performed statistically significantly better than the other groups regarding smear layer removal, especially in the apical region. Maleic acid is an effective irrigant that can remove the smear layer, open dentinal tubules, and act as a high-efficiency final irrigant in activation protocols.

Peri-implant infection control is crucial for implant fixation and durability. Antimicrobial administration approaches to control peri-implant infection are far from satisfactory. During bacterial infection, pH level around the peri-implant surface decreases as low as pH 5.5. This change of pH can be used as a switch to control antimicrobial drug release from the implant surface. Silver nanoparticles (AgNPs) have broad-spectrum antimicrobial properties. In this study, we aimed to design a pH-dependent AgNPs releasing titania nanotube arrays (TNT) implant for peri-implant infection control. The nanotube arrays were fabricated on the surface of titanium implant as containers; AgNPs were grafted on TNT implant surface via a low pH-sensitive acetal linker (TNT-AL-AgNPs). SEM, TEM, AFM, FTIR as well as XPS data showed that AgNPs have been successfully linked to TNT via acetal linker without affecting the physicochemical characteristics of TNT. The pH 5.5 enhanced AgNPs release from TNT-AL-AgNPs implant compared with pH 7.4. AgNPs released at pH 5.5 robustly increased antimicrobial activities against gram-positive and gram-negative bacteria compared with AgNPs released at pH 7.4. TNT-AL-AgNPs implant enhanced osteoblast proliferation, differentiation, and did not affect osteoblast morphology in vitro. In conclusion, incorporation of AgNPs in TNT via acetal linker maintained the surface characteristics of TNT. TNT-AL-AgNPs implant was biocompatible to osteoblasts and showed osteoinductive properties. AgNPs were released from TNT-AL-AgNPs implant in high dose at pH 5.5, and this release showed strong antimicrobial properties in vitro. Therefore, this novel design of low pH-triggered AgNPs releasing TNT-AL-AgNPs could be an infection-triggered antimicrobial releasing implant model to control peri-implant infection.

Introduction: The study objective was to evaluate the effectiveness of cone-beam computed tomographic (CBCT) imaging for the detection of lateral canals (LCs) in endodontically treated premolars. Methods: Two evaluators classified 80 extracted premolars into 2 groups based on the absence (n = 40) or presence (n = 40) of LCs according to micro-computed tomographic analysis. The extracted teeth were fixated in a human mandible and scanned with CBCT imaging. Subsequently, each tooth was endodontically treated, and CBCT scans were repeated. Three experienced examiners evaluated all images randomly. Receiver operating characteristic curves were compared using the McNemar test, and sensitivity, specificity, positive predictive value, and negative predictive value (NPV) were obtained. Results: The area under the receiver operating characteristic curve values were 0.58 and 0.49 before and after root canal treatment, respectively. These values were statistically significantly different (P < .001). Before root canal treatment sensitivity, specificity, positive predictive value, and negative predictive value were 55%, 52%, 55%, and 56%, whereas after root canal treatment the values were 33%, 61%, 46%, and 48%, respectively. Conclusions: LC detection in nontreated teeth presented low accuracy, whereas among treated teeth CBCT imaging showed no efficacy. The results suggest that CBCT imaging is not an effective diagnostic tool for LC detection.

Background: This study aims to reveal how air polishing behaves on a titanium surface by evaluating the size and shape of the cleaned area and the influence of different device settings, probing depths, and cleaning movements. Methods: Forty-eight titanium sandblasted large-grit acidetched surface film-coated disks were treated with an air abrasive system using a subgingival plastic nozzle. Two subgingival models were used: open-ended (step 1) and defined-size (step 2). In step 1, the most effective parameters were investigated by 5-second static applications under different settings. In step 2, the best settings were used for dynamic application to test influence of different movements (up-down, slowly up, rotation). For both steps, powder and water consumption and total cleaned area were calculated. Results: Air pressure was the main factor with the strongest effect on cleaning. Increasing air pressure extended cleaning area. Other factors, such as nozzle depth and excessive powder flow amount, had weak influence. Cleaning effect reached deeper than the nozzle physically reached. Step 2 showed that there was no significant difference between different nozzle movements; however, cleaning efficiency decreased significantly without movement. Conclusions: For the most effective clinical use of air polishing, it should be applied with high pressure, deep insertion of nozzle, and enough water flow. Additionally, the nozzle has to be moved to get the best cleaning effect.

Statement of problem: Complete-mouth implant-supported rehabilitations are challenging because of the multiple surgical and prosthetic steps involved in clinical evaluations to assure passive prosthesis fit and optimal esthetic and functional outcomes. As a result, these rehabilitations are usually associated with substantial clinical time, patient discomfort, and high treatment cost. Purpose: The purpose of this pilot clinical study was to evaluate a novel digital approach integrating digital intraoral dental and extraoral facial scanning information to design and mill a computer-aided design and computer-aided manufacturing (CAD-CAM) implant-retained prosthesis for patients with complete edentulism. Material and methods: Ten patients in need of complete-mouth rehabilitation were included in this pilot study. Digital intraoral records were obtained through optical scanning the duplicate interim prosthesis using a laboratory scanner, while digital extraoral records were obtained through facial scanning using an in-office scanner. The scanned impressions and occlusal records were used to create a virtual tooth arrangement, which was matched to the patient's 3-dimensional face scan to create a virtual clinical evaluation phase. After applying the necessary adjustments, the virtual arrangement was submitted to a CAM procedure where a 5-axis industrial milling machine was used to fabricate an interim prosthesis. Results: Digital intraoral and extraoral records were integrated and used to fabricate CAD-CAM milled interim prostheses, which were inserted and assessed for clinical fit, occlusion/articulation, and esthetics. The prostheses remained in function for at least 6 months with no notable technical or biological complications except for 1 prosthesis that fractured.Conclusions: A novel digital workflow incorporating facial scanning in a CAD-CAM workflow was used to fully digitally design and mill 10 implant-retained interim prostheses. More research is required to further develop and assess the accuracy and applicability of this approach.

Purpose: The aim of this 1-year randomized trial was to evaluate and compare the clinical and radiographic performance of four immediately loaded mini dental implants (MDIs) and two immediately loaded standard-sized tissue-level (STL) implants, placed in the interforaminal region of the mandible and used to retain mandibular overdentures (IODs) in completely edentulous patients. Materials and Methods: A total of 50 completely edentulous patients wearing conventional maxillary dentures and complaining about insufficient retention of their mandibular dentures were divided into two groups; 25 patients received four MDIs and 25 patients received two STL implants. The marginal bone loss (MBL) at the mesial and distal sides of each implant was assessed by means of standardized intraoral radiographs after a period of 1 year. Implant success and survival rates were also calculated. Results: Immediate loading was possible for all patients in the first group. In the second group, an immediate loading protocol could not be applied for 10 patients. These patients were treated with a delayed loading protocol. A mean MBL of 0.42 ± 0.56 mm for the MDIs and 0.54 ± 0.49 mm for the immediately loaded STL implants was recorded at the end of the evaluation period. There was no statistically significant difference between the MDIs and the immediately loaded STL implants. Two MDIs failed, resulting in a survival rate of 98%. The success rate was 91%. For the immediately loaded conventional implants, the survival rate was 100% and the success rate 96.7% after 1 year of function. However, in 10 patients, the immediate loading protocol could not be followed. Conclusion: Considering the limitations of this short-term clinical study, immediate loading of four unsplinted MDIs or two splinted STL implants to retain mandibular overdentures seems to be a feasible treatment option. The marginal bone level changes around the MDIs were well within the clinically acceptable range.

Purpose: The aim of this study was to evaluate the effect of the build orientation/build angle on the dimensional accuracy of full-coverage dental restorations manufactured using digital light-processing technology (DLP-AM). Materials and Methods: A full dental crown was digitally designed and 3D-printed using DLP-AM. Nine build angles were used: 90, 120, 135, 150, 180, 210, 225, 240, and 270 degrees. The specimens were digitally scanned using a highresolution optical surface scanner (IScan D104i, Imetric). Dimensional accuracy was evaluated using the digital subtraction technique. The 3D digital files of the scanned printed crowns (test model) were exported in standard tessellation language (STL) format and superimposed on the STL file of the designed crown [reference model] using Geomagic Studio 2014 (3D Systems). The root mean square estimate (RMSE) values were evaluated, and the deviation patterns on the color maps were further assessed. Results: The build angle influenced the dimensional accuracy of 3D-printed restorations. The lowest RMSE was recorded for the 135-degree and 210-degree build angles. However, the overall deviation pattern on the color map was more favorable with the 135-degree build angle in contrast with the 210-degree build angle where the deviation was observed around the critical marginal area. Conclusions: Within the limitations of this study, the recommended build angle using the current DLP system was 135 degrees. Among the selected build angles, it offers the highest dimensional accuracy and the most favorable deviation pattern. It also offers a self-supporting crown geometry throughout the building process.

The 6th ITI Consensus Conference was held in Amsterdam on 17-19 April 2018. In preparation for the conference, 21 systematic reviews were written. They were divided into five main topics in dental implantology-surgery, prosthodontics, patient-reported outcomes, complications/risk and digital technologies. Based on these review papers, the working groups prepared consensus statements, clinical guidelines and recommendations for future research.

Background: The healing of sockets following teeth extraction results in a marked reduction of the height and width of the ridge. This in vivo study aims to assess and compare the efficacy of calcium sulphate (CS) and sintered nano-hydroxyapatite (NHA) in postextraction sockets. Materials and Methods: 10 subjects were enrolled for single or multiple tooth extraction and implant placement. Each site was randomly assigned to one of four groups and filled with CS, NHA, a combination of CS and NHA, or left to normal healing. After five months tissue samples were harvested from the extraction sites and prepared for histological investigations. Results: Histomorphometric analysis showed that the average percentages of vital bone was 13.56% &plusmn, 13.08% for CS, 17.84% &plusmn, 7.32% for NHA, 58.72% &plusmn, 8.77% for CS + NHA%, and 80.68% &plusmn, 21.8% for the controls, for the connective tissue the results were 33.25% &plusmn, 35.75% for CS, 55.88% &plusmn, 21.86% for NHA, 17.34% &plusmn, 8.51% for CS + NHA, and 22.62% &plusmn, 0.52% for the controls, for residual biomaterial the results were 0.56% &plusmn, 0.52% for CS group, 21.97% &plusmn, 0.79% for NHA, and 47.54% &plusmn, 20.13% for CS + NHA. Conclusions: Both biomaterials led to bone tissue formation after five months of healing. The combination of the biomaterials presented a better behavior when compared to the individual application.

This study evaluated the effect of build direction on the flexure strength of stereolithography (SLA), 3D-printed hybrid composite resin material. A total of 26 bar-shaped specimens were 3D-printed using SLA-based printer. The specimens were divided into two groups based on build direction (n = 13); vertically (V), horizontally (H) printed groups. The layer thickness was 0·05 mm. Three-point bending test was performed using a universal testing machine, with a load-cell of 250 N at 1 mm min−1 crosshead speed until failure of the specimens. The fractured surfaces were analyzed using scanning electron microscopy (SEM). The mean flexure strength for (V) and (H) printed specimens was 88.2 and 90.5 MPa respectively (P > .05). Fractographic analysis revealed brittle abrupt fracture pattern for (V) group and a ductile, slow pattern with layer delamination for H-group. Though there was no statistical difference in flexure strength between the test groups, the fractographic analysis revealed that the fracture mode was different.

Purpose: This cohort study evaluated patient satisfaction for maxillary implant-retained overdentures (IODs) on two implants up to 4 years and assessed the treatment effect over time. Materials and Methods: Patients encountering problems with their conventional dentures were included and received maxillary IODs on two titanium-zirconium implants and ball anchors in the canine area. Patient satisfaction was assessed using the oral health impact profile (OHIP-20E) questionnaires both for dentures and IODs. Two months after insertion of IODs (baseline), the patients chose the preferred overdenture design with full or reduced palatal coverage. OHIP-20E questionnaires were followed according to the individual choice at 1 and 4 years, and outcomes were compared with baseline. Results: Sixteen out of 21 patients were evaluated at a mean follow-up of 4 years (range: 2.4 to 4.8 years). There was no significant difference in the OHIP domains for IODs at 1 year (OHIP_total_1y: 9.5, SD: 13.0) and 4 years (OHIP_total_4y: 14.2, SD: 19.1) compared with baseline (OHIP_total_BL: 12.4, SD: 14.7). Patients were most satisfied with social disability both for IODs (OHIP_BL: 6.0, SD: 7.6; OHIP_1y: 3.4, SD: 5.4; OHIP_4y: 5.7, SD: 9.5) and dentures (OHIP_CD_old: 28, SD: 29.7; OHIP_CD_new: 25.4, SD: 28.67). Patients were least satisfied with functional limitation both for IODs (OHIP_BL: 6.0, SD: 7.6; OHIP_1y: 3.4, SD: 5.4; OHIP_4y: 5.7, SD: 9.5) and dentures (OHIP_CD_old: 28, SD: 29.7; OHIP_CD_new: 25.4, SD: 28.67). Conclusion: Patient satisfaction with maxillary IODs on two implants did not change from baseline to 4 years and was high at 4 years of function.

Notoginsenoside R1 (NGR1), one of the main effective components of Panax notoginseng, appears to be effective in promoting osteogenesis and treating osteoporosis. However, hitherto, whether NGR1 can directly promote osteoblastogenesis remains to be elucidated. In the present study, we hereby examined the effects of NGR1 on the osteoblastogenesis of a pre-osteoblast cell line (MC3T3-E1) in in vitro time-course and dose-dependent experiments. Its efficacy was evaluated by assessing cell viability (indicator of proliferation), alkaline phosphatase (ALP) activity (a marker of early osteoblastic differentiation), levels of osteocalcin (OCN; a marker of late osteoblastic differentiation), calcium deposition (a marker of final mineralization) and the expression of a series of osteoblastogenic marker genes (such as collagen Iα, Runx2, ALP and OCN) at different time points. When examining the proliferation of and ALP activity in the pre-osteoblasts, a bell-shaped dose-response pattern was observed when the cells were treated with various concentrations of NGR1, with a peak being observed at the concentration of 50 µg/ml. NGR1 markedly increased the expression of OCN at the concentration of 1,000 µg/ml in a dose‑dependent manner. Furthermore, treatment with 1,000 µg/ml NGR1 resulted in the highest mineralization by 4.3- and 5.9-fold on the 21st and 28th day, respectively compared with the control group (no treatment). On the whole, our findings indicate that NGR1 significantly promotes the osteoblastogenesis of pre-osteoblasts, which suggests that NGR1 has potential for use as a bone regeneration agent.

Objectives: Guided implant surgery (GIS) is performed with drilling guides that are produced on the virtual tooth model using CAD/CAM technology. The prerequisite for this workflow is the alignment of patients cone beam computed tomography CBCT and surface scan (registration). Dental restorations may cause deteriorating imaging artifacts in CBCT data, which in turn can have an impact on the registration process. The influence of the user and the preprocessing of data and of image artifacts on the registration accuracy were examined.Material and Methods: CBCT data and intraoral surface scans of 36 patients were used for virtual implant planning in coDiagnostiX (Dentalwings, Montreal, Canada). CBCT data were reconstructed to a three-dimensional anatomical model with the default settings provided by the software and also manually by four different examiners. Subsequently, the CBCT and intraoral surface models were registered by each examiner with the help of anatomical landmarks. Patients' data were subdivided into four groups (A-D) according to the number of metallic restorations: A = 0-2 restorations, B = 3-5 restorations, C = 6-8 restorations and D > 8 restorations. After registration, the distances between CBCT and dental surface models were measured. Linear regression models were used to assess the influence of the segmentation, the examiner and to the number of restorations (P < 0.05).Results: The deviations between surface scan and CBCT models accounted to 0.54 mm (mean). The mean deviations were 0.69 mm (max. 24.8 mm) and 0.4 mm (max. 9.1 mm) for default and manual segmentation, respectively. Mean deviations of 0.36 mm (Group A), 0.43 mm (Group B), 0.67 mm (Group C) and 1.01 mm (Group D) were recorded. The segmentation (P = 0.000), the user (P = 0.0052) and the number of restorations (P = 0.0337) had a significant influence on the registration accuracy.Conclusions: The deviation between CBCT and surface scan model resulting from inaccurate registration is transferred to the surgical field and results in a deviation between the planned and actual implant position. The registration accuracy in commercial virtual implant planning software is significantly influenced by the preprocessing of imported data, by the user and by the number of restorations resulting in clinically non-acceptable deviations encoded in drilling guides.

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.

Purpose: The aim of the present study was to evaluate the effect of the build angle and the support configuration (thick versus thin support) on the dimensional accuracy of 3D-printed full-coverage dental restorations. Materials and Methods: A full-coverage dental crown was digitally designed and 3D-printed using stereolithography-additive manufacturing (SLA-AM) technology. Nine different angles were used during the build process: 90, 120, 135, 150, 180, 210, 225, 240, and 270 degrees. In each angle, the crown was printed using a thin and a thick support type, resulting in 18 specimens. The specimens were digitally scanned using a highresolution optical surface scanner (IScan D104i; Imetric 3D). The dimensional accuracy was evaluated by digital subtraction technique. The 3D digital files of the scanned printed crowns (test model), exported in standard tessellation language (STL) format, were superimposed with the STL file of the designed crown (reference model) using Geomagic Studio 2014 (3D Systems). Results: The root mean square estimate value and color map results suggest that the build angle and support structure configuration have an influence on the dimensional accuracy of 3D-printed crown restorations. Among the tested angles, the 120-degree build angle showed a minimal deviation of 0.029 mm for thin support and 0.031 mm for thick support, indicating an accurate fit between the test and reference models. Furthermore, the deviation pattern observed in the color map was homogenously distributed and located further away from the critical marginal area. Conclusions: Within the limitations of this study, the selection of build angle should offer the crown the highest dimensional accuracy and self-supported geometry. This allows for the smallest necessary support surface area and decreases the time needed for finishing and polishing. These properties were mostly observed with a build angle of 120 degrees combined with a thin support type.

Purpose: The aim of this study was to introduce a novel method for accurate autotransplantation with computer-assisted guided templates and assembled custom-designed surgical tooling and to test the feasibility and accuracy of this method ex vivo.Materials and Methods: A partially edentulous human mandibular cadaver was scanned with a cone-beam computed tomography (CBCT) system and an intraoral scan system. The 3-dimensional (3D) data of this cadaver were imported into specialized software and used to analyze the region of the recipient site and the donor tooth was selected. Subsequently, congruent to the donor tooth, custom surgical tools and a surgical guided template were designed and 3D printed. The guided osteotomy was performed and the donor tooth was transplanted. To evaluate the planned position of the donor tooth in relation to the position of the transplanted donor tooth, the mandible with the transplanted donor tooth was rescanned with the CBCT system and software matching was applied to measure the accuracy of the procedure.Results: The angular deflection of the transplanted donor tooth in relation to the planned donor tooth position was 3.1°. When comparing the 3D positions of the shoulder, there was a deviation of 1.25 mm and an apical deviation of 0.89 mm.Conclusion: With the use of currently available technology, it is feasible to accurately plan and create in a virtual simulation a donor tooth position with congruent custom surgical tools and to transfer this to a clinical setting with 3D printing. However, further research on multiple levels is needed to explore this novel approach.

Purpose: The aim of this systematic review and meta-analysis was to evaluate crestal bone changes around implants when placing the implant-abutment connection at the crestal bone level or above. Materials and Methods: Medline (Pubmed), EMBASE, and Cochrane Library up to January 2014 were electronically and hand searched for any publications that evaluated radiographic crestal bone changes around nonsubmerged, rough-surfaced implants placed in healed sites in humans and loaded for a minimum of 1 year. Results: The search yielded 1,122 publications; 1,106 could not be included. After 16 full-text articles were read and subjected to inclusion and exclusion criteria, four were included. The mean difference was -0.29 mm (95% CI, -0.58 mm to -0.01 mm). Heterogeneity between studies was observed (I2 = 95%). Significantly more crestal bone change was seen in the epicrestal implant-abutment (bone level) connection group when compared to implants with the prosthetic connection above the crestal bone level (tissue level) (P < .00001). Conclusion: Dental implants at bone level show significantly less crestal bone change after 1 year of loading than tissue-level implants.

There is a paucity of data for the effectiveness of reconstructive procedures in the treatment of peri-implantitis. The objective of this study was to compare reconstruction of peri-implant osseous defects with open flap debridement (OFD) plus porous titanium granules (PTGs) compared with OFD alone. Sixty-three patients (36 female, 27 male; mean age 58.4 y [SD 12.3]), contributing one circumferential peri-implant intraosseous defect, were included in a multinational, multicenter randomized trial using a parallel-group design. After OFD and surface decontamination using titanium brushes and hydrogen peroxide, 33 defects received PTGs. The implants were not submerged. All patients received adjunctive perioperative systemic antibiotics. The primary outcome variable (defect fill) was assessed on digitalized radiographs. Clinical measurements of probing depth (PPD), bleeding on probing (BoP), suppuration, and plaque were taken by blinded examiners. After 12 mo, the test group (OFD plus PTG) showed a mean radiographic defect fill (mesial/distal) of 3.6/3.6 mm compared with 1.1/1.0 in the control group (OFD). Differences were statistically significant in favor of the test group ( P < 0.0001). The OFD plus PTG group showed a mean reduction in PPD of 2.8 mm compared with 2.6 mm in the OFD group. BoP was reduced from 89.4% to 33.3% and from 85.8% to 40.4% for the test and control groups, respectively. There was no significant difference in complete resolution of peri-implantitis (PPD ≤4 mm and no BoP at six implant sites and no further bone loss), because this finding was accomplished at 30% of implants in the test group and 23% of implants in the control group. Reconstructive surgery using PTGs resulted in significantly enhanced radiographic defect fill compared with OFD. However, limitations in the lack of ability to discern biomaterial from osseous tissue could not be verified to determine new bone formation. Similar improvements according to clinical measures were obtained after both surgical treatment modalities (ClinicalTrials.gov NCT02406001).

Purpose: Autotransplantation of premolars is a good treatment option for young patients who have missing teeth. This study evaluated the use of a preoperatively 3-dimensional (3D)-printed replica of the donor tooth that functions as a surgical guide during autotransplantation.Materials and Methods: Five consecutive procedures were prospectively observed. Transplantations of maxillary premolars with optimal root development were included in this study. A 3D-printed replica of the donor tooth was used to prepare a precisely fitting new alveolus at the recipient site before extracting the donor tooth. Procedure time, extra-alveolar time, and number of attempts needed to achieve a good fit of the donor tooth in the new alveolus were recorded.Results: For each transplantation procedure, the surgical time was shorter than 30 minutes. An immediate good fit of the donor tooth in the new alveolus was achieved with an extra-alveolar time shorter than 1 minute for all transplantations.Conclusion: These results show that the extra-alveolar time is very short when the surgical guide is used; therefore, the chance of iatrogenic damage to the donor tooth is minimized. The use of a replica of the donor tooth makes the autotransplantation procedure easier for the surgeon and facilitates optimal placement of the transplant. (C) 2016 American Association of Oral and Maxillofacial Surgeons

Objectives: This study aimed to explore the feasibility of fabrication of three-dimensional (3D)-printed zirconia root analogue implant (RAI) through digital light processing (DLP) technology.Material and methods: One partially edentulous mandibular human cadaver was scanned with a cone-beam computed tomography (CBCT) system. The scan volumes and data sets were used to create computer-aided design (CAD) model of the RAI. A high-end DLP 3D printing technology was used to fabricate the RAI from the CAD model. Within this approach, solid 3D objects are built using a DLP projector to translate voxel data so it is reproduced in liquid photopolymer dispersed with a commercial ceramic, thereby light polymerizing the resin to solid. Optical scanning technology was used to measure the tooth and 3D-printed RAI. To validate the accuracy of the printed zirconia RAI, the optical surface model of the original tooth and CAD model were superimposed.Results: The differences between the optical scans of the RAI and original tooth are most noticeable towards the apical foramen, showing a disparity for the RAI with a maximum deviation of 0.86 mm. When setting a maximum threshold of 0.5 mm for the 3D-printed RAI surface to be deviating from the original tooth model and CAD model, measurements show 1.55% and 4.86% of the surface areas are exceeding the threshold distance, respectively. Conclusion: With the use of currently available technology, it is well feasible to 3D print in zirconia a custom RAI.

Diabetes mellitus is a well-recognized risk factor for periodontitis. The goal of the present study was to elucidate whether oxidative stress and nuclear factor erythroid 2-related factor 2 (Nrf2) participate in the aggravation of periodontitis by diabetes. For this purpose, we assigned Wistar rats to control, periodontitis, diabetes, and diabetic periodontitis groups. Two weeks after induction of diabetes by streptozotocin, periodontitis was induced by ligation. Two weeks later, periodontal tissues and blood were harvested and analyzed by stereomicroscopy, immunohistochemistry, and real-time polymerase chain reaction. We found that ligation induced more severe bone loss and periodontal cell apoptosis in diabetic rats than in normal rats (p<0.05). Compared with the control group, periodontitis significantly enhanced local oxidative damage (elevated expression of 3-nitrotyrosine, 4-hydroxy-2-nonenal, and 8-hydroxy-deoxyguanosine), whereas diabetes significantly increased systemic oxidative damage and suppressed antioxidant capacity (increased malondialdehyde expression and decreased superoxide dismutase activity) (p<0.05). Simultaneous periodontitis and diabetes synergistically aggravated both local and systemic oxidative damage (p<0.05); this finding was strongly correlated with the more severe periodontal destruction in diabetic periodontitis. Furthermore, gene and protein expression of Nrf2 was significantly downregulated in diabetic periodontitis (p<0.05). Multiple regression analysis indicated that the reduced Nrf2 expression was strongly correlated with the aggravated periodontal destruction and oxidative damage in diabetic periodontitis. We conclude that enhanced local and systemic oxidative damage and Nrf2 downregulation contribute to the development and progression of diabetic periodontitis.

Om het gebruik en het gemak van een vrij-eindigende frameprothese te vergroten, kunnen implantaten van toegevoegde waarde zijn. Implantaatondersteuning blijkt de functionaliteit en de tevredenheid te doen toenemen. Bij een (extreem) verkorte restdentitie met een resterend front heeft de molaarregio als locatie voor ondersteuning en retentie de voorkeur boven de premolaarregio. Het aanbrengen van een retentiesysteem of mesostructuur vergroot de functionaliteit en de tevredenheid verder. Vooral negatieve krachten worden hiermee opgevangen. Het type mesostructuur, knop- of balanker, Dolder Bar® of Locator®, maakt niet veel uit. Het aantal vrijheidsgraden is het grootst bij een knop- of balanker, waarmee dan kan worden gecompenseerd voor een eventueel afwijkende stand van het implantaat. De kosten van het frame stijgen aanzienlijk door het aanbrengen van implantaten, maar het zorgt wel voor een significante verbetering van kauwvermogen, gebruik en tevredenheid. Goed onderhoud is essentieel voor de duurzaamheid; dit vergt regelmatige controle.

Objective To explore how bruxism is dealt with by accredited oral implantologists within daily clinical practice. Materials and methods Nine semi-structured interviews of oral implantologists practicing in non-academic clinical practices in the Netherlands were performed, and thematic analysis was conducted using a framework-based approach. Results Oral implant treatments in bruxing patients were a generally well-accepted practice. Complications were often expected, with most being of minor impact. Contradictive attitudes emerged on the topic of bruxism being an etiologic factor for peri-implant bone loss and loss of osseointegration. Views on the ideal treatment plan varied, though the importance of the superstructure’s occlusion and articulation features was repeatedly pointed at. Similarly, views on protective splints varied, regarding their necessity and material choice. Bruxism was diagnosed mainly by clinical examination, alongside with patient anamnesis and clinician’s intuition. There was little attention for awake bruxism. Discussion Bruxism was generally not considered a contraindication for implantological treatments by accredited oral implantologists. Views on the interaction between bruxism and bone loss/loss of osseointegration varied, as did views on the ideal treatment plan. Conclusions There is a need for better understanding of the extent to which, and under which circumstances, sleep and/or awake bruxism can be seen as causal factors for the occurrence of oral implant complications.

Critical-size bone defects are a common clinical problem. The golden standard to treat these defects is autologous bone grafting. Besides the limitations of availability and co-morbidity, autografts have to be manually adapted to fit in the defect, which might result in a sub-optimal fit and impaired healing. Scaffolds with precise dimensions can be created using 3-dimensional (3D) printing, enabling the production of patient-specific, ‘tailor-made’ bone substitutes with an exact fit. Calcium phosphate (CaP) is a popular material for bone tissue engineering due to its biocompatibility, osteoconductivity, and biodegradable properties. To enhance bone formation, a bioactive 3D-printed CaP scaffold can be created by combining the printed CaP scaffold with biological components such as growth factors and cytokines, e.g., vascular endothelial growth factor (VEGF), bone morphogenetic protein-2 (BMP-2), and interleukin-6 (IL-6). However, the 3D-printing of CaP with a biological component is challenging since production techniques often use high temperatures or aggressive chemicals, which hinders/inactivates the bioactivity of the incorporated biological components. Therefore, in our laboratory, we routinely perform extrusion-based 3D-printing with a biological binder at room temperature to create porous scaffolds for bone healing. In this method paper, we describe in detail a 3D-printing procedure for CaP paste with K-carrageenan as a biological binder.

Steeds meer van de hedendaagse tandtechniek wordt – tenminste gedeeltelijk – digitaal verricht. De snelle opkomst van intraorale scanners in de algemene praktijk zorgt ervoor dat ontwikkelingen elkaar in sneltreinvaart opvolgen. Het is voor tandtechnici efficiënt dat gegevens digitaal worden aangeleverd, maar hoe wordt de clinicus daar zelf beter van? En welke ‘tools’ zijn inmiddels beschikbaar om een gedeelte van het tandtechnisch werk weer zelf te doen?

Background Bone regenerative heterodimeric bone morphogenetic protein 2/7 (BMP2/7) enhances but all-trans retinoic acid (ATRA) inhibits osteoclastogenesis. However, the effect of ATRA on physiological and/or BMP2/7-induced osteoclastogenesis in still unclear. In this study, we aimed to test the effect of combined treatment of BMP2/7 and ATRA on osteoclastogenesis, and resorption activity. Results All-trans retinoic acid (1 µM) ± BMP2/7 (5 or 50 ng/ml) was added in murine pre-osteoclasts cell line RAW264.7 or mouse bone marrow derived macrophages (BMM) cultures. Osteoclast marker gene expression, osteoclastogenesis, and resorption activity were analyzed. BMP2/7 robustly enhanced osteoclast maker gene expression, osteoclastogenesis, and resorption activity. Interestingly, ATRA completely inhibited osteoclast formation in presence or absence of BMP2/7. Pan-antagonist of retinoic acid receptors (RARs) and antagonist of RARα, β or γ failed to reverse the inhibitory effect of ATRA on osteoclastogenesis. ATRA strongly inhibited Rank and Nfatc1 expression. Conclusions All-trans retinoic acid inhibits BMP2/7-induced osteoclastogenesis, and resorption activity possibly via RANKL–RANK pathway. Our findings from previous and current study suggest that combination of ATRA and BMP2/7 could be a novel approach to treat hyperactive osteoclast-induced bone loss such as in inflammation-induced severe osteoporosis and bone loss caused by cancer metastasis to bone. Electronic supplementary material The online version of this article (10.1186/s13578-018-0246-y) contains supplementary material, which is available to authorized users.

Voor de mondzorg komen steeds meer digitale technologieën beschikbaar. Digitale radiologie, maar ook digitale afsprakensystemen voor patiënten hebben in veel praktijken toepassing gevonden. Een belangrijke vraag hierbij is welke nieuwe technieken de mondzorg daadwerkelijk verbeteren of het werk in tandartspraktijken vergemakkelijken. Technische kenmerken van digitale technologieën zijn vaak onderzocht, maar de effecten van het werken ermee op de mondzorg en op het werk in de praktijk zijn vaak onbekend. Marieke van der Zande onderzocht de invloed van digitale technologieën op het werken in tandartspraktijken, en welke afwegingen tandartsen maken bij het gebruik ervan.

Background: In implant dentistry, three-dimensional (3D) imaging can be realised by dental cone beam computed tomography (CBCT), offering volumetric data on jaw bones and teeth with relatively low radiation doses and costs. The latter may explain why the market has been steadily growing since the first dental CBCT system appeared two decades ago. More than 85 different CBCT devices are currently available and this exponential growth has created a gap between scientific evidence and existing CBCT machines. Indeed, research for one CBCT machine cannot be automatically applied to other systems. Methods: Supported by a narrative review, recommendations for justified and optimized CBCT imaging in oral implant dentistry are provided. Results: The huge range in dose and diagnostic image quality requires further optimization and justification prior to clinical use. Yet, indications in implant dentistry may go beyond diagnostics. In fact, the inherent 3D datasets may further allow surgical planning and transfer to surgery via 3D printing or navigation. Nonetheless, effective radiation doses of distinct dental CBCT machines and protocols may largely vary with equivalent doses ranging between 2 to 200 panoramic radiographs, even for similar indications. Likewise, such variation is also noticed for diagnostic image quality, which reveals a massive variability amongst CBCT technologies and exposure protocols. For anatomical model making, the so-called segmentation accuracy may reach up to 200 μm, but considering wide variations in machine performance, larger inaccuracies may apply. This also holds true for linear measures, with accuracies of 200 μm being feasible, while sometimes fivefold inaccuracy levels may be reached. Diagnostic image quality may also be dramatically hampered by patient factors, such as motion and metal artefacts. Apart from radiodiagnostic possibilities, CBCT may offer a huge therapeutic potential, related to surgical guides and further prosthetic rehabilitation. Those additional opportunities may surely clarify part of the success of using CBCT for presurgical implant planning and its transfer to surgery and prosthetic solutions. Conclusions: Hence, dental CBCT could be justified for presurgical diagnosis, preoperative planning and peroperative transfer for oral implant rehabilitation, whilst striving for optimisation of CBCT based machine-dependent, patient-specific and indication-oriented variables.