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To test the effect of membrane fixation on ridge volume stability and new bone formation using guided bone regeneration.In eight beagle dogs, after bilateral extraction of the maxillary pre-molars, a box-shaped defect was created on each side. All defect sites were augmented with a particulate bone substitute material, covered with either one of two non-cross-linked collagen membranes (CM1 or CM2) with or without fixation (-F or -UF). Samples were collected after 8 weeks. Histomorphometric and micro-computed tomography analyses were performed.Membrane fixation made no significant difference to the total augmented volume for both membranes (p .05). Histological data indicated that at the ridge crest the augmented tissue width amounted to 2.4 ± 0.4 mm in the group CM1-F and 2.4 ± 0.5 mm in the group CM1-UF, with no significant difference between the groups. Conversely, in CM2-F the augmented tissue width was significantly larger than in CM2-UF (2.3 ± 0.1 vs. 1.57 ± 0.27, p .05).Membrane fixation in contained defects failed to improve ridge volume stability regardless of the membrane type. However, it may enhance the width of the augmented ridge at the coronal portion depending on the type of membrane.

The fixture thread depth reportedly influences the primary stability of dental implant, but its effect on the positional accuracy in immediate implant placement has not been reported previously.Fifty-six single-rooted, anterior and premolar teeth were extracted from six human cadavers, followed by installing either regular-threaded implants (RT group, N = 30) or deep-threaded implants (DT group, N = 26) completely relying on the surgical guide. Optical impressions taken after osteotomy and fixture installation were superimposed with the preoperative virtual planning data to measure the vertical, angular, platform and apex deviations that occurred during osteotomy and installation.While the osteotomy deviations were similar between the two groups, the angular and apex deviation of the DT group (2.67 ± 2.56°; 1.04 ± 0.49 mm, respectively) were significantly larger than those of the RT group (1.61 ± 1.04°; 0.67 ± 0.41 mm, respectively) during installation (p .05). When the installation deviations were analysed in the anterior and premolar areas separately, the angular, platform and apex deviations of the DT group (3.05 ± 3.26°; 0.75 ± 0.32 mm; 1.08 ± 0.56 mm, respectively) were significantly larger than those of the RT group (1.56 ± 0.73°, 0.59 ± 0.28 mm; 0.62 ± 0.38 mm, respectively) in the anterior site (p .05), whereas there was no significant intergroup difference in the premolar site.In immediate-implant surgery, using an implant with a deeper thread might increase the deviations during installation, especially in the anterior area.

Aim To compare the 1-year outcomes of immediate loading (IL) and delayed loading (DL) protocols for implants placed by fully guided surgery in partially edentulous jaws. Materials and methods This study included 72 patients who received implant surgery with either IL (93 implants, 36 patients) or DL (94 implants, 26 patients). A prefabricated provisional prosthesis was delivered immediately for the IL group (86 implants, 32 patients) with the exception of 4 subjects in whom an initial torque of >20 Ncm and an implant stability quotient of >65 were not achieved, while all DL-group implants were loaded after 3 months. The 1-year implant survival rate estimated by intention-to-treat (ITT) and per-protocol (PP) analyses, and the marginal bone loss (MBL) estimated by cone-beam computed tomography were statistically evaluated (p Results The survival rate in the DL group was 100% at both patient and implant levels. With only 26 subjects with 78 implants surviving in the IL group, the survival rates were 69.4% and 83.4% at the patient and implant levels, respectively, in the ITT analysis, and 78.1% and 90.2% in the PP analysis. All intergroup differences in survival rates were statistically significant (p 0.05). Conclusions IL for implants placed by fully guided surgery in the partially edentulous jaws increased the probability of failure compared to 3-month DL. Regardless of when loading occurred, marginal bone levels remained stable.

The objective of this study was to investigate in vitro release kinetics and ossification patterns of bone morphogenetic protein-2-soaked collagenated porcine bone mineral (BMP-2/CPBM) in rabbit si...

Background Clinical benefits of local antibiotics as an adjunct to nonsurgical treatment of peri-implantitis have been widely reported, but most studies evaluated incipient peri-implantitis lesions, and showed incomplete treatment success rates. Purpose To assess the clinical and microbiological outcomes of administering metronidazole in combination with minocycline as a local adjunct to the nonsurgical treatment of peri-implantitis. Materials and methods One hundred and eighteen subjects with peri-implantitis were recruited in a four-center, three-arm, and 12-week randomized controlled trial. Subjects were randomly assigned to receive one of the following treatments: (a) MM-mechanical debridement + metronidazole-minocycline ointment, (b) MC-mechanical debridement + minocycline ointment, (c) NST-mechanical debridement only. Results Except for four subjects who was excluded during the trial, a total of 114 patients with 114 implants (one implant per each patient) finally completed the trial and were included in the analyses. Multivariate logistic regression analysis revealed that the treatment success rates (absence of bleeding or suppuration on probing, and sites showing pocket probing depth [PPD] ≥5 mm) on at 12 weeks were higher in MM-group patients (31.6%) and MC-group patients (20.5%) compared to NST-group patients (2.7%; p = 0.011 and 0.040, respectively). Subjects with deepest PPD ≥8 mm showed a significant difference in the PPD reduction between MM and MC groups at week 4 (p = 0.025) and week 12 (p = 0.047). Detection ratio of Tannerella forsythia was significantly lower for MM group than MC group (p = 0.038). Conclusions Additive use of either MM or MC results in significantly higher treatment success rates compared to sole mechanical debridement in nonsurgical treatment of peri-implantitis. Moreover, MM contributes to a significantly greater reduction in the PPD compared to MC in deep pockets (cris.nih.go.kr KCT0004557).

OBJECTIVE To determine the positional accuracy of implants placed with a three-dimensionally printed template having nonmetal sleeves and to determine the contributing factors to observed deviations. MATERIALS AND METHODS One hundred and eighty-seven implants placed in 72 patients were analyzed. Presurgical intraoral scans and cone-beam computed tomography images obtained before and after surgery were superimposed, and vertical, angular, platform, and apex deviations were measured between the virtually planned and actually placed positions. A multiple linear regression model was designed for identifying the contributing factors. Statistical significance was set at p

OBJECTIVE To compare the efficacy of a collagenated synthetic bone substitute (C-SBS) to a particulated synthetic bone substitute (P-SBS) in volume maintenance and new bone formations in a rabbit sinus model. MATERIALS AND METHODS Either C-SBS or P-SBS was grafted in both sinuses of 16 rabbits. Four (N = 8) or 12 (N = 8) weeks after the surgery, total augmented volume (TAV) and area (TAA), as well as new bone volume (NBV) and area (NBA), were statistically compared by radiographic and histomorphometric analyses (p

Small molecules including sodium butyrate (SB) and dimethyloxalylglycine (DMOG) can promote bone regeneration via inhibitive effects eliciting cellular responses through signaling cascades. The purpose of this study was to determine the synergistic effects of SB and DMOG loaded on calcium sulfate (CaS) on bone regeneration in the challenging vertical augmentation model in the rabbit calvarium. Four plastic cylinders screwed on the calvarium of each of 10 rabbits were randomly grafted with CaS, CaS/SB, CaS/DMOG, or CaS/DMOG/SB. All specimens were assessed by radiographic, histologic, and histomorphometric analyses. In the radiographic analysis, three different layers (new bone, degraded CaS, and pristine CaS layers) could be distinguished within the cylinder in all groups at 2 weeks. Newly formed bone grew up from basal bone, and CaS in contact with newly formed bone was degraded into small particles to form a different layer. At 8 weeks, most of the pristine CaS had been absorbed and hardly seen within the cylinder. In the histomorphometric analysis, all groups showed comparable new bone areas and heights at 2 and 8 weeks. The DMOG group showed a significant increase in new bone area at 8 weeks compared with 2 weeks, but there was no significant difference among the groups at 8 weeks. The DMOG group showed significantly lower values for the residual material area than the control group at 2 weeks. Within the limitations of this study, SB and DMOG seem to exert smaller synergistic effects on bone regeneration compared to CaS alone in vertical bone augmentation.

To determine whether vertical ridge augmentation (VRA) can be obtained through guided bone regeneration (GBR) using exclusively resorbable collagen membranes and particulate bone substitutes without additional stabilization.This study retrospectively examined 22 participants who underwent VRA with staged or simultaneous implant placement. The vertical defects of all participants were filled with particulate bone substitutes and covered with resorbable collagen membranes. The augmented sites were stabilized with unfixed collagen membranes and the flap without any additional fixation. The augmented tissue height was assessed using cone-beam computed tomography at baseline, immediately after surgery, and at annual follow-ups.The vertical bone gain of the 22 augmented sites amounted to 6.48 ± 2.19 mm (mean ± SD) immediately after surgery and 5.78 ± 1.72 mm at 1- to 7-year follow-up. Of the 22 augmented sites, 18 exhibited changes of less than 1 mm, while the other 4 showed changes of greater than 1 mm. Histological observation of three representative cases revealed new bone apposition on the remaining material.The present findings indicate that GBR procedures using exclusively collagen membranes and particulate biomaterials without any additional fixation are feasible options for VRA.

To test whether soft-type block bone substitute used for guided bone regeneration (GBR) of peri-implant defects leads to a different dimension of the augmented hard tissue than particulate bone substitute.In 40 patients, 40 two-piece dental implants were placed2 months after tooth extraction. Following random allocation, 20 peri-implant bone dehiscences were grafted with a soft-type block made of synthetic biphasic calcium phosphate (BCP) + collagen and 20 bone dehiscences with particulate BCP. All the sites were covered with a collagen membrane stabilized with titanium pins. Immediately after wound closure and after 6 months, the horizontal dimension (HD) of the augmented hard tissue was measured at the level of implant shoulder using cone beam computed tomography. During re-entry at 6 months, the defect fill was clinically assessed.At 6 months, the median HD measured 1.15 mm (mean: 1.31 mm) in the soft-block group and 0.93 mm (mean: 1.05 mm) in the particulate group (p = .6). At 6 months, 7.1% of contained defects and 61.9% of non-contained defects showed an incomplete vertical defect fill.Soft-type block of BCP + collagen used for GBR of peri-implant defects did not differ from particulate BCP regarding the dimension of the augmented hard tissue after 6 months of healing.

The diversity and multi-disciplinary of the technical products introduces conflicts as not all of the requirements can be fulfilled to the satisfaction of the stakeholders. Here the knowledge on the interactions between technical requirements and the product characteristics can help to find solutions for the optimum trade-offs between the requirements. In this manuscript, the state space of the product concept with the integrated technical requirements is explored. The generated data set is analyzed by the sensitivity analysis and later trade-offs are evaluated. As an example, the application of the proposed method in the development of a self-balancing robot is studied.

The definition of initial requirements in the early phase of product development is characterised as a decision process under highest uncertainties. Studies show that projects often deviate from their planned goals or even fail due to ill-defined requirements. Despite the importance and criticality of this task, a detailed description and risk-oriented explanation is missing in the product development literature. The goal of this paper is to develop an explanation model/frame which establishes a link between the development context and an appropriate procedure for the initial requirements definition based on general risk treatment strategies. In a first step, risk-driving context factors with high influence on this task are identified. Then two case studies are compared to analyse the interrelations between their context factors and the applied risk treatment strategies that are implemented in their procedures for defining initial requirements.

Today, information and knowledge as competitive factors influence the success of companies as much as traditional production factors like human resources or physical capital. However, the reuse of design knowledge still represents a major challenge for engineering organizations. That is, because barriers exist hindering a successful knowledge reuse. On the basis of a literature review, the research depicted in this paper analyses the relation between single information conveying design knowledge and barriers hindering a successful knowledge reuse. Developing a model-based approach, we propose a micro logic containing three steps and underlying methods enabling practitioners to identify situation-specific barriers within their organization. We illustrate the industrial application of the approach in a case study at a mining machinery OEM.

AIM To assess the effect of Schneiderian membrane (SM) perforation on bone formation by applying a particulate deproteinized bovine bone mineral (PBBM). MATERIALS AND METHODS Bilateral sinus augmentation was performed in eight rabbits. The same amount of PBBM was placed at a sinus where the SM was intentionally perforated for the perforation group (standardized to 3 mm diameter) and the other sinus with an intact SM that served as the intact group. At 12 weeks, all animals were euthanized for radiographic and histomorphometric analyses. RESULTS The area of the newly formed bone in the perforation group was significantly less than that in the intact group (18.7% and 25.5%, respectively, p = .028). The newly formed bone in the area close to the perforated SM was significantly less than that in the intact group (18.7% and 26.1%, respectively, p

In immediately loaded implants within 72 h after the implant placement in the unilaterally and partially edentulous ridge, primary stability is considered critical, which can be influenced by the design of the implant fixture.To determine the outcomes at 1 year after the immediate loading of multiunit fixed partial prostheses over either tapered implants (TIs) or straight implants (SIs) in the posterior region.Forty-eight patients (24 patients, 52 implants in TI group; 24 patients, 50 implants in SI group) were included for the study. Except for the one SI group patient whose two implants showed the insertion torque less than 30 Ncm, provisional prostheses designed and fabricated from intraoral scan data obtained immediately after implant surgery were delivered to rest of the 47 subjects at 3-7 days. After a year, the survival rate was estimated by intention-to-treat (ITT) and per-protocol (PP) analyses, and marginal bone loss (MBL) and implant stability were also analyzed statistically (p 0.05).Survival rate at implant level in TI group was 96.2%, and that of SI group in the ITT analysis was 86.0%. Intergroup difference, however, was not statistically significant (p 0.05). Insertion torque was significantly higher in TI group than SI group (47.12 ± 6.37 Ncm vs. 41.60 ± 9.77 Ncm; p 0.05). MBLs of both groups were less than 0.1 mm at 1-year follow-up and was similar between two groups (p 0.05).Immediate loading of fixed partial prostheses after TI and SI placement showed reliable outcomes in the partially edentulous posterior ridge. In terms of the initial mechanical stability, the performance was superior for TIs than for SIs.

Background: This in vitro study mainly aimed to compare VARO Guide® to the surgical guide fabricated by CAD/CAM (NAVI Guide®) in terms of accuracy and efficacy of the implant surgery held in the dentiform model. Methods: Twenty surgeons, 10 dentists in the beginner group and 10 dentists in the expert group, participated in the study. Each surgeon conducted fully guided surgery in dentiform models twice, once with VARO Guide® (VG surgery) and the other time with a conventional type of templates, NAVI Guide® (NG surgery). Based on the superimposition of presurgical and postsurgical STL files, the positional deviations between the virtually planned and actually placed implants and the time spent on presurgical preparation and surgical procedures were estimated and compared. Results: All dimensional deviations were similar between the two groups (p &gt, 0.05), and there was no significant difference between the expert and beginner groups regardless of the guide system. The total procedure time (mean (median)) of the VG surgery (26.33 (28.58) min) was significantly shorter than that of the NG surgery (378.83 (379.35) min, p &lt, 0.05). While the time spent only for the fully guided implant surgery (from the start of the surgical guide sitting onto the dentiform model to the final installation of the implant fixture) was comparable (p &gt, 0.05), the presurgical preparation time spent on virtual implant planning and surgical guide fabrication in the VG surgery (19.63 (20.93) min) was significantly shorter compared to the NG surgery (372.93 (372.95) min, 0.05). Conclusions: Regardless of experience, both VG and NG surgery showed reliable positional accuracy, however, the total procedure time and the preparation time were much shorter in the VG surgery compared to the NG surgery.

After tooth extraction, notable ridge alterations occur due to resorption of bundle bones during the healing process. In areas with thin or damaged socket walls and multiple adjacent tooth extraction, dimensional changes are more prominent in the marginal proportion. In addition to the marginal changes, upper molar teeth are also vulnerable to pneumatization of the maxillary sinus. To reduce dimensional changes in extraction sockets, alveolar ridge preservation (ARP) is favored by many clinicians in areas where a large amount of dimensional change is expected. This case report presents two cases of ARP using collagenated demineralized bovine bone mineral and demineralized porcine bone mineral in the apically involved upper premolar and molar, respectively. Implants were placed one and two years, respectively, after the ARP. Radiographic analyses of residual bone height and volume were measured using cone-beam-computed tomography (CBCT) and histologic analysis of newly formed mineralized bone and residual graft material percentages were measured from the collected tissue samples using a trephine bur. Implants were placed using a simple technique, without any additional bone grafts at the marginal proportion. The ARP technique could maintain the alveolar bone height and volume, as well as minimize the invasiveness of surgical procedures during implant surgery.

Background: This in vitro study mainly aimed to compare VARO Guide® to the surgical guide fabricated by CAD/CAM (NAVI Guide®) in terms of accuracy and efficacy of the implant surgery held in the dentiform model. Methods: Twenty surgeons, 10 dentists in the beginner group and 10 dentists in the expert group, participated in the study. Each surgeon conducted fully guided surgery in dentiform models twice, once with VARO Guide® (VG surgery) and the other time with a conventional type of templates, NAVI Guide® (NG surgery). Based on the superimposition of presurgical and postsurgical STL files, the positional deviations between the virtually planned and actually placed implants and the time spent on presurgical preparation and surgical procedures were estimated and compared. Results: All dimensional deviations were similar between the two groups (p > 0.05), and there was no significant difference between the expert and beginner groups regardless of the guide system. The total procedure time (mean (median)) of the VG surgery (26.33 (28.58) min) was significantly shorter than that of the NG surgery (378.83 (379.35) min; p < 0.05). While the time spent only for the fully guided implant surgery (from the start of the surgical guide sitting onto the dentiform model to the final installation of the implant fixture) was comparable (p > 0.05), the presurgical preparation time spent on virtual implant planning and surgical guide fabrication in the VG surgery (19.63 (20.93) min) was significantly shorter compared to the NG surgery (372.93 (372.95) min; p < 0.05). Conclusions: Regardless of experience, both VG and NG surgery showed reliable positional accuracy; however, the total procedure time and the preparation time were much shorter in the VG surgery compared to the NG surgery.

Objective To compare the outcome after extensive lateral guided bone regeneration using deproteinized bovine bone mineral (DBBM) with or without autogenous bone chips in a canine model of chronic horizontal alveolar ridge defect. Materials and methods The second, third and fourth lower premolars of both sides were extracted, and the buccal bone walls were completely removed in five beagle dogs. After 4 weeks, DBBM particles mixed with autogenous bone chips at a ratio of 1:1 were grafted at one side (DBBM/Auto group), while DBBM particles alone were grafted at the contralateral side (DBBM group). The graft materials on both sides were covered by a resorbable collagen membrane and fixation pins. Microcomputed tomographic volume and histomorphometric analyses were performed at 16 weeks post-surgery. Results The ridges of both groups were recovered horizontally, but new bone formation beyond the original ridge contour at the defect site was not found. The DBBM group exhibited a larger total radiographic augmented volume and new bone volume compared with the DBBM/Auto group, but the differences were minimal (p > 0.05). Histologically, the regenerated area and new bone area were also slightly larger without any statistical significance in the DBBM group than in the DBBM/Auto group (p > 0.05). Conclusion The addition of autogenous bone chips to DBBM for lateral ridge augmentation may confer no advantage over grafting DBBM alone with respect to both space maintenance and de novo bone formation in dogs.

OBJECTIVES To assess the osseointegration of calcium-coated (CS) and chemically modified, sandblasted, large-grit, acid-etched (MS) dental implants with a lack of primary mechanical stability. MATERIALS AND METHODS Eighteen implants in CS and MS groups each were loosely placed in the mandible of six mongrel dogs and allowed to heal for 2, 4 and 8 weeks. Implant stability quotient (ISQ) and implant stability test (IST) values recorded periodically and bone-to-implant contact (BIC) and the number of Haversian canals per 1 mm2 measured histologically were statistically analysed (p

The aim of this study was to assess the internal fit accuracy of a three-dimensional (3D)-printed biphasic calcium phosphate (BCP) block compared with a 3D-milled poly methyl methacrylate (PMMA) block by scanning electron microscope (SEM) analysis. In a total of 20 porcine rib bones, two different types of defects having two adjacent walls and a floor were produced: a defect with a flat floor (flat defect, N = 10) and a defect with a concave floor (curved defect, N = 10). Each defect was grafted with either the 3D-printed BCP block or the 3D-milled PMMA block fabricated following the computer aided design. The defects were then cut cross-sectionally and evaluated under the SEM. The extents of internal contact and gap were measured and statistically analyzed (p &lt, 0.05). All blocks in both BCP and PMMA groups were successfully fit to the flat and curved defects. The internal contact ratio was significantly higher in the BCP group (flat defect: 0.47 ± 0.10, curved defect: 0.29 ± 0.05) compared with the PMMA group (flat defect: 0.21 ± 0.13, curved defect: 0.17 ± 0.04, p &lt, 0.05). The internal gap area was similar between the two groups regardless of the defect types ( p&gt, 0.05). The internal fit accuracy of the 3D-printed BCP block was reliable in both the flat and curved defects when compared with the accuracy of the 3D-milled PMMA block.

Background: Local delivery agents (LDA) have the advantage of delivering the antibiotics at high concentrations to the targeted sites. However, the constant flow of gingival crevicular fluids and saliva may restrict their efficacy. Therefore, the drug sustainability and pharmacodynamic properties of any proposed LDA should be evaluated. Methods: Four dental implants were placed unilaterally in the edentulous mandible of six beagle dogs. Peri-implantitis were experimentally induced using silk-ligatures. Each implant was randomly allocated to receive one of the following four treatments: (i) MC (Chitosan-alginate (CA) minocycline), (ii) MP (CA-without minocycline), (iii) PG (Polyacrylate-glycerin minocycline), and (iv) Control (mechanical debridement only). Mechanical therapies and LDAs were administered into the gingival sulcus two times at a 4-week interval. Drug sustainability as well as clinical, radiographical, and immunohistochemical (IHC) analyses were conducted to evaluate the efficacies of treatments. Results: Reduced mean probing depth was observed in all of the test groups after the second delivery. A minimal marginal bone level change was observed during the treatment period (MP (&minus, 0.06 &plusmn, 0.53 mm) to PG (&minus, 0.25 &plusmn, 0.42 mm)). The distribution of IHC cell marker analysis of all targeted antibodies ranged from 6.34% to 11.33%. All treatment outcomes between the test groups were comparable. A prolonged retention of LDA was observed from CA microspheres (MC and MP) at both administrations (p &lt, 0.017) and prolonged sustainability of bacteriostatic effect was observed from MC compared to PG after the second administration (p &lt, 0.05). Conclusions: Prolonged retention of CA microspheres was observed and the longer bacteriostatic effect was observed from the MC group. Mechanical debridement with adjunct LDA therapy may impede peri-implantitis progression, however, prolonged drug action did not lead to improved treatment outcome.

Background: The objective of this is preclinical investigation was to evaluate the differential drug sustainability and pharmacodynamic properties of two local minocycline microsphere carriers: chitosan-coated alginate (CA) and poly(meth)acrylate-glycerin (PG). Methods: Four dental implants were placed unilaterally in the edentulous mandible of six beagle dogs. Each implant was randomly assigned to receive one of the following four treatments: (i) CA (CA-based minocycline), (ii) placebo (CA substrate without minocycline), (iii) PG (PG-based minocycline) and (iv) control (mechanical debridement only). After inducing peri-implant mucositis, the randomly assigned treatments were administered into the gingival sulcus twice at a 4-week interval using a plastic-tipped syringe. Drug sustainability and pharmacodynamic (clinical, radiographical and cell marker intensity) evaluations were performed after each administration. Results: The CA microspheres remained longer around the healing abutment compared to the PG microspheres at both administrations and a longer bacteriostatic effect was observed from CA (7.0 &plusmn, 5.7 days) compared to PG (1.2 &plusmn, 2.6 days). The efficacy of the applied therapies based on clinical, radiographical and histological analyses were comparable across all treatment groups. Conclusions: CA microspheres showed longer carrier and bacteriostatic effect sustainability when compared to PG microspheres, however, longer drug sustainability did not lead to improved treatment outcomes.

Background: To assess the soft tissue dimension following tooth extraction and alveolar ridge preservation in the posterior maxilla compared to spontaneous healing. Methods: Thirty-five patients randomly assigned to alveolar ridge preservation (ARP) and spontaneous healing (SH) after maxillary molar extraction. The crestal, buccal, and palatal gingival thickness at 6 months was measured around virtually placed implant fixtures using superimposed cone-beam computed tomography and intraoral scan taken at 6 months. Buccal mucogingival junction (MGJ) level change over 6 months was estimated using intraoral scans obtained at suture-removal and 6 months. Results: The crestal gingiva was significantly thinner in group ARP (&minus, 1.16 mm) compared to group SH (p &lt, 0.05). The buccal and palatal gingiva was significantly thinner at the implant shoulder (IS) level in group ARP (buccal: &minus, 0.75 mm, palatal: &minus, 0.85 mm) compared to group SH (p &lt, 0.05). The thickness at 2 mm below the IS of both sides and the buccal MGJ level change were similar in both groups (p &gt, 0.05). Conclusions: ARP in the posterior maxilla resulted in a thinner soft tissue on top of and at the prospective level of the implant shoulder at 6 months. The buccal MGJ level changed minimal for 6 months in both groups.

Diagnoses based on oral fluid biomarkers have been introduced to overcome limitations of periodontal probe-based diagnoses. Diagnostic ability of certain biomarkers for periodontitis have been identified and widely studied, however, such studies targeting gingivitis is scarce. The aims of this study were to determine and compare the efficacies and accuracies of eight biomarkers in diagnosing gingivitis with the aid of receiver operating characteristic (ROC) curves. The probing depth (PD), clinical attachment loss (CAL), bleeding on probing (BOP), gingival index (GI), and plaque index (PI) were examined in 100 participants. Gingival crevicular fluid was collected using paper points, and whole-saliva samples were collected using cotton roll. Samples were analyzed using enzyme-linked immunosorbent assay kits for the different biomarkers. The levels of matrix metalloproteinase (MMP)-8, MMP-9, lactoferrin, cystatin C, myeloperoxidase (MPO), platelet-activating factor, cathepsin B, and pyridinoline cross-linked carboxyterminal telopeptide of type I collagen were analyzed. MPO and MMP-8 levels in saliva were strongly correlated with gingivitis, with Pearson&rsquo, s correlation coefficients of 0.399 and 0.217, respectively. The area under the curve (AUC) was largest for MMP-8, at 0.814, followed by values of 0.793 and 0.777 for MPO and MMP-9, respectively. The clinical parameters of GI and PI showed strong correlations and large AUC values, whereas PD and CAL did not. MMP-8 and MPO were found to be effective for diagnosing gingivitis. Further investigations based on the results of this study may identify clinically useful biomarkers for the accurate and early detection of gingivitis.

To compare the clinical, radiographic, and histological healing patterns between the immediate and delayed applications of bone morphogenetic protein-2 (BMP-2) in damaged extraction sockets in dogs. The distal roots of the fourth premolars of the mandible were extracted bilaterally in five beagle dogs, and buccal bone defects (4 mm wide and 9 mm high) were surgically created. Collagenated biphasic calcium phosphate (CBCP) soaked for 10 min in 100 μL of BMP-2 solution was applied immediately to the defect site in the control group. In the test group, the BMP-2 solution of same dose was injected into the grafted site 2 weeks after grafting with a saline-soaked CBCP. The dogs were sacrificed 2 weeks later. Clinical, histological, and radiographic analyses were followed. Swelling and inflammatory reactions were predominantly observed in the control group at 2 weeks. The area of new bone formation was significantly larger in the control group compared with the test group (10.8 ± 7.0 mm2 [mean ± SD] and 6.3 ± 3.1 mm2, respectively; p = 0.043). No significant difference was found in ridge width at 2 mm, 4 mm and 6 mm below the lingual bone crest between the control (2.6 ± 1.0 mm, 3.2 ± 0.9 mm and 4.5 ± 0.5 mm, respectively) and test group (3.3 ± 1.0 mm, 3.7 ± 1.3 mm and 4.2 ± 1.0 mm; all p > 0.05). Delayed application of BMP-2 2 weeks after surgery did not show any advantage over immediate application of BMP-2 in terms of new bone formation. This study suggests that it might be better to apply BMP-2 immediately in alveolar ridge preservation, instead of delayed application, in order to enhance new bone formation.

OBJECTIVES To evaluate the histologic and volumetric changes of gingival tissues following grafting with collagen-based matrices at labial aspect of teeth in canines. MATERIALS AND METHODS Gingival augmentation was performed in the mandibular incisor area using two types of xenogeneic cross-linked collagen matrices (CCMs), bovine CCM for BCCM group and porcine CCM for PCCM group, whereas the contralateral sides remained untreated (B-control group and P-control group). Descriptive histology, histometric and volumetric analyses were performed after 12 weeks. For statistical comparison between each test group and respective control group, paired t test was used for histometric analysis, and repeated-measured analysis of variance was used for volumetric analysis (p < 0.05). RESULTS An increased number of rete pegs and an enhanced formation of new blood vessels were observed at both grafted sites compared to the corresponding control sites. There was statistically significant gain of horizontal thickness only in BCCM group (1.36 ± 0.27 mm vs. 1.26 ± 0.34 mm; p < 0.05) compared to the B-control groups. CONCLUSION BCCM was effective for gingival augmentation in terms of horizontal thickness at the labial aspect of teeth at 12 weeks post-surgery.

Additive Fertigungsverfahren bieten im Vergleich zu konventionellen Fertigungsverfahren konstruktive Freiheiten. Aufgrund der vielen Freiheitsgrade werden bei der Entwicklung von Produktkonzepten neue Anforderungen an Produktentwickler und den Produktentwicklungsprozess gestellt. Am Beispiel eines konkreten Anwendungsfalls, der Erstellung einer Leitlinie zur Berucksichtigung additiver Fertigungsverfahren in der Produktentwicklung bei der Firma thyssenkrupp, werden einhergehende Herausforderungen genauer untersucht. Basierend auf einer Literaturrecherche werden vorhandene Ansatze zur Unterstutzung von Design fur die additive Fertigung systematisch zur unternehmensspezifischen Anwendung angepasst. Dazu werden sie zunachst Produktentwicklungsphasen zugeordnet. Im folgenden Schritt werden allgemeine Gestaltungsrichtlinien an den konkreten Unternehmenskontext durch den unternehmensspezifischen Produktentwicklungsprozess, die Fertigungsmoglichkeiten und die Produktpalette angepasst. Abschliesend wird die Verallgemeinerbarkeit des vorgeschlagenen Vorgehens zur Entwicklung der unternehmensspezifischen Leitlinie diskutiert.

Product development projects are bound by objectives of various stake-holders. In early planning and design phases. these objectives can be very vague due to uncertainties with regard to knowledge and information about potential solutions as well as the design process. Moreover. time and cost requirments interact with product related requirements. Still. from the beginning of any design activity objectives must be translated into requirements to serve as a common information basis for the design process and to allow for the verification of the design solution. This paper presents a case study to exemplify typical problems in the development process caused by ill-defined requirements. In addition. approaches for a methodical procedure to address these problems are presented.

Purpose The purpose of this study was to evaluate the effectiveness of conventional sandblasted, large-grit, acid-etched (SLA) surface coated with a pH buffering solution based on surface wettability, blood protein adhesion, osteoblast affinity, and platelet adhesion and activation. Methods Titanium discs and implants with conventional SLA surface (SA), SLA surface in an aqueous calcium chloride solution (CA), and SLA surface with a pH buffering agent (SOI) were prepared. The wetting velocity was measured by the number of threads wetted by blood over an interval of time. Serum albumin adsorption was tested using the bicinchoninic acid assay and by measuring fluorescence intensity. Osteoblast activity assays (osteoblast adhesion, proliferation, differentiation, mineralization, and migration) were also performed, and platelet adhesion and activation assays were conducted. Results In both the wetting velocity test and the serum albumin adsorption assay, the SOI surface displayed a significantly higher wetting velocity than the SA surface (P=0.000 and P=0.000, respectively). In the osteoblast adhesion, proliferation, differentiation, and mineralization tests, the mean values for SOI were all higher than those for SA and CA. On the osteoblast migration, platelet adhesion, and activation tests, SOI also showed significantly higher values than SA (P=0.040, P=0.000, and P=0.000, respectively). Conclusions SOI exhibited higher hydrophilicity and affinity for proteins, cells, and platelets than SA. Within the limits of this study, it may be concluded that coating an implant with a pH buffering agent can induce the attachment of platelets, proteins, and cells to the implant surface. Further studies should be conducted to directly compare SOI with other conventional surfaces with regard to its safety and effectiveness in clinical settings., Graphical Abstract

Objectives This study histologically analyzed biopsy samples obtained from sites of damaged extraction socket grafting using deproteinized bovine bone mineral (DBBM) or deproteinized porcine bone mineral (DPBM) with coverage by a collagen membrane. Material and methods One hundred patients participated in this randomized controlled clinical trial of extraction socket grafts performed in cases of periodontally compromised teeth. All participants were blinded to their group allocations, and each material was grafted with coverage by collagen membranes after extraction of the tooth and removal of granulation tissue. At implant placement at 4 months, a biopsy was harvested at the implant site using a trephine was analyzed histologically. Results Eighty-five biopsy samples were acquired, of which 81 were finally included in the histologic analysis (42 in DBBM and 39 in DPBM group). Both DBBM and DPBM groups showed comparable proportions of residual biomaterial (12.37 ± 5.67% and 12.21 ± 5.75%, respectively), newly formed bone (15.07 ± 10.52% and 18.47 ± 11.47%, respectively), and nonmineralized tissue (72.56 ± 10.07% and 71.55 ± 15.47%, respectively). There were no significant differences in these histologic parameters between the two groups with different biomaterials. Conclusion Comparable histologic bone formation was found in both socket grafted groups with DBBM or DPBM covered by collagen membranes in periodontally damaged extraction sockets. However, a wide variation in new bone formation was found after 4 months of postsurgical healing and a tendency of higher new bone formation was shown at damaged sockets that had an intact unilateral residual wall regardless of buccal or lingual side.

OBJECTIVES To test whether or not alveolar ridge preservation reduces vertical changes in the posterior maxilla compared to spontaneous healing following tooth extraction. MATERIALS AND METHODS Forty subjects requiring extraction of maxillary posterior teeth with root apices protruding into the maxillary sinus floor were consecutively enrolled. Patients were randomly assigned to either one of two surgical interventions: an alveolar ridge preservation procedure using collagenated bovine bone mineral and a resorbable collagen membrane (test) or no grafting (control). Cone-beam computed tomographies were taken immediately and at 6 months after surgery, prior to dental implant placement. RESULTS Based on radiographic data, the level of the sinus floor remained stable over time (baseline to 6 months) in the test group (-0.14 mm [-0.31, -0.02]). In the control group, the sinus floor level shifted more coronally (-1.16 mm [-1.73, -0.61]) than the test group (p

Purpose Various crosslinking methods have been introduced to increase the longevity of collagen membranes. The aim of this study was to compare and evaluate the degradation and bone regeneration patterns of 3 collagen membranes. Methods Four 8-mm-diameter circular bone defects were created in the calvaria of 10 rabbits. In each rabbit, each defect was randomly allocated to 1) the sham control group, 2) the non-crosslinked collagen sponge (NS) group, 3) the chemically crosslinked collagen membrane (CCM) group, or 4) the biphasic calcium phosphate (BCP)-supplemented ultraviolet (UV)-crosslinked collagen membrane (UVM) group. Each defect was covered with the allocated membrane without any graft material. Rabbits were sacrificed at either 2 or 8 weeks post-surgery, and radiographic and histologic analyses were done. Results New bone formed underneath the membrane in defects in the CCM and UVM groups, with a distinctive new bone formation pattern, while new bone formed from the base of the defect in the NS and control groups. The CCM maintained its shape until 8 weeks, while the UVM and NS were fully degraded at 8 weeks; simultaneously, sustained inflammatory infiltration was found in the margin of the CCM, while it was absent in the UVM. In conclusion, the CCM showed longer longevity than the UVM, but was accompanied by higher levels of inflammation. Conclusions Both the CCM and UVM showed distinctive patterns of enhancement in new bone formation in the early phase. UV crosslinking can be a biocompatible alternative to chemical crosslinking., Graphical Abstract

A big challenge in the definition and prioritisation of requirements for a new product is to find compromises when conflicts arise. What is the best compromise depends on the objectives of the specific development context. After developing an explanation based on literary theory, the here presented case study describes an exemplary development context to better understand the correlating influencing factors in this decision process in real development projects. Based on the findings, three hypotheses are developed and requirements for a methodical support are derived.

Purpose This study was conducted to assess the efficacy of prophylactic gingival grafting in the mandibular anterior labial area for preventing orthodontically induced gingival recession. Methods Eight mongrel dogs received gingival graft surgery at the first (I1) and third (I3) mandibular incisors on both sides based on the following group allocation: AT group (autogenous connective tissue graft on I1), AT-control group (contralateral side in the AT group), CM group (xenogeneic cross-linked collagen matrix graft on I3) and CM-control group (contralateral side in the CM group). At 4 weeks after surgery, 6 incisors were splinted and proclined for 4 weeks, followed by 16 weeks of retention. At 24 weeks after surgery, casts were made and compared with those made before surgery, and radiographic and histomorphometric analyses were performed. Results Despite the proclination of the incisal tip (by approximately 3 mm), labial gingival recession did not occur. The labial gingiva was thicker in the AT group (1.85±0.50 mm vs. 1.76±0.45 mm, P>0.05) and CM group (1.90±0.33 mm vs. 1.79±0.20 mm, P>0.05) than in their respective control groups. Conclusions The level of the labial gingival margin did not change following labial proclination of incisors in dogs. Both the AT and CM groups showed enhanced gingival thickness., Graphical Abstract

The purpose of this study is to promote utilization of paper mill sludge as an adsorbent for stabilizing heavy metals in contaminated water by measuring the adsorption capacity of paper mill sludge for cadmium and arsenic. To measure adsorption capacity of paper mill sludge, sorption isotherm experiments were analyzed by Langmuir and Freundlich isotherm models. Also, two methods of chemical modifications were applied to improve the adsorption capacities of paper-mill-sludge: the first method used sodium hydroxide (NaOH), called PMS-1, and the second method used the NaOH and tartaric acid (C4H6O6) together, called PMS-2. For Cd adsorption, PMS-1 presented the increase of reactivity while PMS-2 presented the decline of reactivity compared to that of untreated paper-mill-sludge. In case of As adsorption, both PMS-1 and PMS-2 showed the decrease of adsorption capacities. This is because zeta-potential of paper mill sludge was changed to more negative values during chemical modification process due to the hydroxyl group in NaOH and the carboxyl group in C4H6O6, respectively. Therefore, we may conclude that the chemical treatment process increases adsorption capacity of paper mill sludge for cation heavy metals such as Cd but not for As.