Manufacturing Resilience during the Coronavirus Pandemic: On the investigation Manufacturing Processes Agility

The unprecedented events that worldwide population experienced during year 2020 due to the COVID-19 pandemic, resulted in the formation of numerous challenges across the majority of aspects of every day life. Manufacturing industries and supply chain networks faced a unique decostruction during this period due to restrictions created by global or local lockdowns. Reduction of human resources availability and transportation restrictions linked with the extreme and rapid increase of demand for medical supplies led manufactring related activities to reach their limits. Moreover, the non flexible manufacturing methods that are employed for the production of this type of equipment as well as the delayed delivery of products that are used as raw material at the early production stages, resulted in market shortage of medical supplies while demand constantly growing. Additive Manufacturing was used for the immediate production of plastic/metal medical equipment, taking advantage of reverse engineering, process flexibility and commercialization of printing devices. Small and large enteprises in cooperation with individuals have been organized into Local Hubs in order to reduce the transportation time and accelerate the supply of the required equipment at local hopitals until the the non flexible production lines manage to produce the desired production volume under the required production rate. This study aims to identify reasons why traditional manufacturing facilies faced such difficulties in the production of medical equipment and to propose a framework where Additive Manufacturing methods can be used for the immediate, local and low volume production of the desired product, giving time to non easily adjustable industries to initiate the mass production

Mechanical and biological complications after implantoplasty:a systematic review

Objectives: Implantoplasty, i.e., the mechanical modification of the implant, including thread removal and surface smoothening, has been proposed during surgical peri-implantitis treatment. Currently, there is no information about any potential mechanical and/or biological complications after this approach. The aim of the current review was to systematically assess the literature to answer the focused question “Are there any mechanical and/or biological complications due to implantoplasty?”Materials and Methods: A systematic literature search was performed in 3 databases until 23/09/2018 to assess potential mechanical and/or biological complications after implantoplasty. All laboratory, preclinical in vivo, and clinical studies involving implantoplasty were included and any complication potentially related to implantoplasty was recorded and summarized.Results: Out of 386 titles, 26 publications were included in the present review (6 laboratory, 2 preclinical in vivo, and 18 clinical studies). Laboratory studies have shown that implantoplasty does not result in temperature increase, provided proper cooling is used, but leads in reduced implant strength in “standard” dimension implants; further, preclinical studies have shown titanium particle deposition in the surrounding tissues. Nevertheless, no clinical study has reported any remarkable complication due to implantoplasty; among 217 – 291 implants subjected to implantoplasty, no implant fracture was reported during a follow-up of 3 to 126 months, while only a single case of mucosal discoloration, likely due to titanium particle deposition, has been reported. Conclusions: Based on all currently available, yet limited, preclinical in vivo and clinical evidence, implantoplasty seems not associated with any remarkable mechanical or biological complications on the short- to medium-term

Efficacy of power-driven interdental cleaning tools: A systematic review and meta-analysis.

OBJECTIVES To summarize the available evidence on the efficacy of power-driven interdental cleaning tools (PDICTs) as an adjunct to tooth brushing compared to tooth brushing alone or tooth brushing combined with any other non-PDICT in terms of interproximal plaque and gingival bleeding reduction in gingivitis patients. MATERIAL AND METHODS A systematic literature search was performed in three databases until March 20, 2022 with the following main eligibility criteria: (1) randomized controlled clinical trials (RCTs) with (2) at least 28 days of follow-up in (3) gingivitis patients. Interproximal plaque and bleeding values were defined as the primary outcome variables and used for pair-wise meta-analyses. RESULTS Sixteen RCTs were identified including data from 1258 participants at the final evaluation. Eight studies each investigated the effect of either a liquid-based or mechanical PDICT; one of these studies tested additionally a combined liquid-based and mechanical PDICT. Tooth brushing combined with a liquid-based PDICT compared to tooth brushing alone did not result in better interproximal plaque values but in significantly lower interproximal bleeding values. Tooth brushing combined with either a liquid-based PDICT or with a mechanical PDICT compared to tooth brushing and flossing achieved comparable interproximal plaque and bleeding values. The majority of studies reporting on patient compliance/preference favored the use of a PDICT, and except for a single study, which was reporting soft tissue trauma in two subjects from improper use of a mechanical PDICT, none of the studies reported adverse events. CONCLUSIONS Daily use of PDICT as an adjunct to tooth brushing significantly reduces interproximal bleeding. This effect appears comparable to that of flossing, while PDICT may achieve higher patient acceptance/compliance

Radiographic bone level and soft tissue dimensional changes following explantation of implants affected by peri-implantitis: A retrospective exploratory evaluation.

BACKGROUND While the dimensional alteration of alveolar bone following tooth extraction have been extensively descripted in the literature, no information is available regarding potential hard and soft tissues changes following implant explantation. AIM To evaluate the radiographic bone healing and the horizontal and vertical soft tissue dimensional alterations at implant extraction alveoli, 6 months following implant explantation. MATERIAL AND METHODS Data from 31 patients scheduled for extraction of one implant with persisting peri-implantitis despite treatment were analysed. Bone crest level changes and the extent of bone healing at the apical aspect of the implant socket were assessed on the radiographs prior and 6 months following explantation. Regression analyses assessed the impact of various predictors (e.g., bone crest level, presence/absence of buccal bone) on bone level changes. Fisher's exact probability test was applied to assess the difference in probability to have mucosa recession of ≥2 mm in the presence or absence of alveolar buccal bone. RESULTS A vertical bone loss of 0.8 mm (standard deviation [SD] = 1.3) of the peri-implant bone crest and a gain of 0.8 mm (SD = 1.1) from the bottom of the peri-implant defect were recorded. Complete healing was noted in the intact implant extraction socket (i.e., the part of the implant not affected by peri-implantitis). A reduction of 0.4 mm (SD = 0.7) of the alveolar mucosa height was recorded in concomitant with a decrease of 0.7 mm (SD = 0.8) of the mucosa width. These alterations were more pronounced in the absence of the alveolar buccal bone. CONCLUSION The results of the present explorative study indicated a decrease in the height and width of the alveolar soft and hard tissues following explantation of peri-implantitis affected implants, and these changes were more pronounced in the absence of the buccal bone wall. Nevertheless, the apical portion of the implant alveolus (the intact implant socket) tend to heal with no further bone loss

Two- and three-piece implants to boost data generation in preclinical in vivo research-A short technical report.

The purpose of this technical report is to present two novel experimental implant designs to boost data generation in preclinical in vivo research. Specifically, the report describes the rationale and the components of (1) a two-piece experimental implant suitable for a small animal platform (e.g., the rabbit femur/tibial epiphysis model), consisting of a threaded apical- and a coronal cylindrical piece, which is intended for collecting two types of biomechanical data, and (2) a three-piece experimental implant suitable for a large animal platform (e.g., the mini-pig mandible model), consisting of an apical "wound chamber", which allows the collection of histological/histomorphometrical data, and a middle threaded and coronal cylindrical piece, which also allow the collection of two types of biomechanical data. The increased volume of information generated from a single experiment in a small animal platform, using the proposed two-piece implant design, may assist in a more qualified decision-making process, on whether it is relevant to proceed to further assessment using a large animal platform. Furthermore, the increased volume of information generated in a single animal experiment either in a small or large animal platform, using the proposed two- and three-piece implants, respectively, likely decreases the number of animals otherwise needed for collecting the same information with standard one-piece implants and, thus, contributes to the reduction/refinement elements of the 3R principle

Histological evaluation of human intrabony periodontal defects treated with an unsintered nanocrystalline hydroxyapatite paste

Objectives: The aim of the study was to clinically and histologically evaluate the healing of human intrabony defects treated with open flap surgery (OFD) and application of a new, resorbable, fully synthetic, unsintered, nanocrystalline, phase-pure hydroxyapatite (nano-HA). Materials and methods: Six patients, each of them displaying very advanced intrabony defects around teeth scheduled for extraction due to advanced chronic periodontitis and further prosthodontic considerations, were included in the study. Following local anaesthesia, mucoperiosteal flaps were reflected; the granulation tissue was removed, and the roots were meticulously debrided by hand and ultrasonic instruments. A notch was placed at the most apical extent of the calculus present on the root surface or at the most apical part of the defect (if no calculus was present) in order to serve as a reference for the histological evaluation. Following defect fill with nano-HA, the flaps were sutured by means of mattress sutures to allow primary intention healing. At 7months after regenerative surgery, the teeth were extracted together with some of their surrounding soft and hard tissues and processed for histological analysis. Results: The postoperative healing was uneventful in all cases. At 7months following surgery, mean PPD reduction and mean CAL gain measured 4.0 ± 0.8 and 2.5 ± 0.8mm, respectively. The histological analysis revealed a healing predominantly characterized by epithelial downgrowth. Limited formation of new cementum with inserting connective tissue fibers and bone regeneration occurred in three out of the six biopsies (i.e. 0-0.86 and 0-1.33mm, respectively). Complete resorption of the nano-HA was found in four out of the six biopsies. A few remnants of the graft particles (either surrounded by newly formed mineralized tissue or encapsulated in connective tissue) were found in two out of the six biopsies. Conclusion: Within their limits, the present results indicate that nano-HA has limited potential to promote periodontal regeneration in human intrabony defects. Clinical relevance: The clinical outcomes obtained following surgery with OFD + nano-HA may not reflect true periodontal regeneratio

Impact of Orthodontic Forces on Plasma Levels of Markers of Bone Turnover and Inflammation in a Rat Model of Buccal Expansion.

Plasma levels of protein analytes might be markers to predict and monitor the kinetics of bone and tissue remodeling, including maximization of orthodontic treatment stability. They could help predict/prevent and/or diagnose possible adverse effects such as bone dehiscences, gingival recession, or root resorption. The objective of this study was to measure plasma levels of markers of bone turnover and inflammation during orthodontic force application in a rat model of orthodontic expansion. Two different orthodontic forces for bilateral buccal expansion of the maxillary arches around second and third molars were applied in 10 rats equally distributed in low-force (LF) or conventional force (CF) groups. Four rats served as the control group. Blood samples were collected at days 0, 1, 2, 3, 6, 13, 21, and 58. Longitudinal concentrations of osteoprotegerin (OPG), soluble receptor activator of nuclear factor kappaB ligand (sRANKL), interleukin-4 (IL-4), interleukin-6 (IL-6), interleukin-10 (IL-10), tumor necrosis factor α (TNF), and parathyroid hormone (PTH) were determined in blood samples by a multiplex immunoassay. CF and LF resulted in a significantly maxillary skeletal expansion while the CF group demonstrated significantly higher expansion than the LF group in the long term. Bone turnover demonstrated a two-phase response. During the "early phase" (up to 6 days of force application), LF resulted in more sRANKL expression and increased sRANKL/OPG ratio than the CF and control animals. There was a parallel increase in PTH levels in the early phase in response to LF. During the "late phase" (6-58 days), the markers of bone turnover were stable in both groups. IL-4, IL-6, and IL-10 levels did not significantly change the test groups throughout the study. These results suggest that maxillary expansion in response to different orthodontic forces follows different phases of bone turnover that may be force specific

Impact of fixed orthodontic appliances on blood count and high-sensitivity C-reactive protein levels: A prospective cohort study.

INTRODUCTION The aim was to elucidate the magnitude of alterations in systemic blood counts in healthy patients during the first 14 days after fixed orthodontic appliance placement. METHODS This prospective cohort study consecutively included 35 White Caucasian patients starting orthodontic treatment with fixed appliances. The mean age was 24.48 ± 6.68 years. All patients were physically and periodontally healthy. Blood samples were collected at 3 time points: (1) baseline (exactly before the placement of appliances), (2) 5 days after bonding, and (3) 14 days after baseline. Whole blood and erythrocyte sedimentation rates were analyzed in automated hematology and erythrocyte sedimentation rate analyzer. Serum high-sensitivity C-reactive protein levels were measured by the nephelometric method. Standardized sample handling and patient preparation procedures were adopted to reduce preanalytical variability. RESULTS A total of 105 samples were analyzed. All clinical and orthodontic procedures were performed without complications or side effects during the study period. All laboratory procedures were performed per protocol. Significantly lower white blood cell counts were detected 5 days after bracket bonding, compared with baseline (P <0.05). Hemoglobin levels were lower at 14 days than baseline (P <0.05). No other significant shifts or alteration patterns were observed over time. CONCLUSIONS Orthodontic fixed appliances led to a limited and transient change in white blood cell counts and hemoglobin levels during the first days after bracket placement. The fluctuation of high-sensitivity C-reactive protein levels was not significant, demonstrating a lack of association between systemic inflammation and orthodontic treatment

Assessing the osseointegration potential of a strontium releasing nanostructured titanium oxide surface: A biomechanical study in the rabbit tibia plateau model.

OBJECTIVES To investigate the impact of a Ti-Sr-O technology, applied to either a turned surface or an SLA surface, on the mechanical robustness of osseointegration, benchmarked against the SLActive surface. MATERIAL AND METHODS Ti discs (6.25-mm-diameter and 2-mm-thick) with three different surfaces were inserted on the proximal-anterior part of the tibial plateau of adult Swedish loop rabbits: (I) turned surface modified with Ti-Sr-O (turned + Ti-Sr-O), (II) SLA surface modified with Ti-Sr-O (SLA + Ti-Sr-O), and (III) SLActive surface (SLActive). Following a healing period of 2 weeks and 4 weeks, the pull-out (PO) force needed to detach the discs from the bone was assessed, as a surrogate of osseointegration. RESULTS The SLActive surface exhibited statistically significant higher median PO forces, compared with the SLA + Ti-Sr-O surfaces at both 2- and 4 weeks post-op (p > .05). In this study, no single turned + Ti-Sr-O surface disk was integrated. CONCLUSIONS The tested Ti-Sr-O technology failed to enhance osseointegration; however, this finding may be related to the inappropriateness of the rabbit tibia plateau model for assessing third-generation implant surface technologies, due to the limited diffusion and clearance at the disk-bone interface

The effect of connective tissue graft or a collagen matrix on epithelial differentiation around teeth and implants: a preclinical study in minipigs.

OBJECTIVES This study aimed to histologically evaluate the healing at 8 weeks after coronally advanced flap (CAF) with either a superficial (SCTG) or deep palatal connective tissue graft (DCTG), or a collagen matrix (CM) to cover recession defects at teeth and implants. MATERIAL AND METHODS One mandibular side of 6 miniature pigs received each 3 titanium implants 12 weeks after extraction. Eight weeks later, recession defects were created around implants and contralateral premolars and 4 weeks later randomly subjected to CAF + SCTG, CAF + DCTG, or CAF + CM. After 8 weeks, block biopsies were histologically analyzed. RESULTS For the primary outcome, i.e., keratinization of the epithelium, all teeth and implants exhibited a keratinized epithelium with no histological differences among them also not in terms of statistically significant differences in length (SCTG 0.86 ± 0.92 mm, DCTG 1.13 ± 0.62 mm, and Cm, 1.44 ± 0.76 mm). Pocket formation was histologically seen at all teeth, around most implants with SCTG and DCTG, however not in the CM implant group. The connective tissue grafts showed hardly signs of degradation, whereas the CM was partly degraded and integrated in connective tissue. The mean gain in gingival height was similar in all experimental groups (SCTG 3.89 ± 0.80 mm, DCTG 4.01 ± 1.40 mm, CM 4.21 ± 0.64 mm). Statistically significant differences were found in the height of the junctional epithelium between the control teeth and the connective tissue groups (p = 0.009 and 0.044). CONCLUSIONS In this animal model, the use of either a superficial or deep connective tissue graft or a collagen membrane did not seem to have any impact on the epithelial keratinization around both teeth and implants. All procedures (CAF + SCTG/DCTG/CM) resulted in a long JE that was even longer at implants. CLINICAL RELEVANCE Deep/superficial palatal connective tissue graft yielded similar keratinization around teeth/implants. Given the absence of pocket formation and inflammatory processes at implants when using a CM, CAF + CM might bear potential clinical benefits