Soft Tissue Reactions Research Articles

Multivariate analysis of oral mucosal ulcers during orthodontic treatment.

Orthodontic treatment can easily cause local soft tissue reactions in the oral cavity of patients under mechanical stress, leading to oral mucosal ulcers and affecting their quality of life. At present, only limited literature has explored the factors leading to oral ulcers in orthodontic treatment, and these research results are still controversial. To investigate the current status and related factors of oral mucosal ulcers during orthodontic treatment, aiming to provide a valuable reference for preventing this disease in clinical practice. A total of 587 patients who underwent orthodontic treatment at the Peking University School of Stomatology and Hospital of Stomatology between 2020 and 2022 were selected and allocated to an observation or control group according to the incidence of oral mucosal ulcers during orthodontic therapy. A questionnaire survey was constructed to collect patient data, including basic information, lifestyle and eating habits, treatment details, mental factors, and trace element levels, and a comparative analysis of this data was performed between the two groups. A logistic regression model with oral ulcers as the dependent variable was established. The regression results showed that age (≥ 60 years: odds ratio [OR]: 6.820; 95% confidence interval [CI]: 2.226-20.893), smoking history (smoking: OR: 4.434; 95%CI: 2.527-7.782), toothbrush hardness (hard: OR: 2.804; 95%CI: 1.746-4.505), dietary temperature (hot diet: OR: 1.399; 95%CI: 1.220-1.722), treatment course (> 1 year: OR: 3.830; 95%CI: 2.203-6.659), and tooth brushing frequency (> 1 time per day: OR: 0.228; 95%CI: 0.138-0.377) were independent factors for oral mucosal ulcers (P < 0.05). Furthermore, Zn level (OR: 0.945; 95%CI: 0.927-0.964) was a protective factor against oral ulcers, while the SAS (OR: 1.284; 95%CI: 1.197-1.378) and SDS (OR: 1.322; 95%CI: 1.231-1.419) scores were risk factors. Age ≥ 60 years, smoking history, hard toothbrush, hot diet, treatment course for > 1 year, tooth brushing frequency of ≤ 1 time per day, and mental anxiety are independent risk factors for oral mucosal ulcers. Therefore, these factors should receive clinical attention and be incorporated into the development and optimization of preventive strategies for reducing oral ulcer incidence.

MRI-based radiomic analysis of soft tissue reactions near total hip arthroplasty.

This study applied radiomics to MRI data for automated classification of soft tissue abnormalities near total hip arthroplasty (THA). A total of 126 subjects with 1.5 T MRI of symptomatic THA were included in the analysis. Peri-prosthetic soft tissue regions of interest were manually segmented and classified by an expert radiologist. An established radiomics library was used to extract 96 features from 2D image patches across segmented regions. Logistic regression was employed as the primary radiomic classifier, achieving an average area under curve (AUC) of 0.71 in differentiating tissue classifications spanning normal, infected, and several inflammatory, noninfectious categories. Notably, infection cases were identified with the highest accuracy, attaining an AUC of 0.79. Statement of Clinical Significance: This study demonstrates that radiomics applied to MRI data can effectively automate the classification of soft tissue abnormalities in symptomatic total hip arthroplasty, particularly in differentiating periprosthetic infections.

Comparative Evaluation of Soft Tissue Reaction to Titanium and Polyetheretherketone Customized Healing Abutments: a Split-Mouth Randomised Clinical Trial

Aim. This study aimed to evaluate the peri-implant soft tissue response to customized healing abutments (CHAs) made of titanium and polyetheretherketone (PEEK). Methods. Titanium and PEEK CHAs were mounted on bone-level dental implants in bilateral edentulous patients in a randomized split-mouth study design. After a three-week healing period, the clinical parameters of the peri-implant soft tissues were assessed. The value of marginal bone resorption was measured by cone-beam computed tomography. In addition, peri-implant crevicular fluid samples were obtained to identify periodontal pathogenic bacteria, cytokine levels, and active neutrophil collagenase (aMMP-8) concentration. Microcirculation and oxygenation parameters were assessed using laser Doppler flowmetry and optical tissue oximetry. In addition, wavelet analysis was conducted to study blood flow control mechanisms. Results. Out of the 23 participants initially recruited, 20 were assessed after titanium and PEEK CHA installation due to losses to follow-up. The peri-implant soft tissue around 27 titanium and 25 PEEK CHAs was evaluated during follow-ups. No differences were found in the values of marginal bone resorption, cytokine levels, or total bacterial load (p&gt;0.05). PEEK CHAs demonstrated lower bleeding on probing values, less plaque accumulation, and faster relief of ischemia and hypoxia. Although aMMP-8 concentration was higher in the PEEK group, the values were within normal limits. Conclusions. The results of this comparative study showed a positive soft tissue response to PEEK CHAs. However, further studies comparing the effectiveness of different materials for CHAs should be carried out, considering their specific physical properties and processing protocols.

The Biocompatibility and the Effect of Titanium and PEKK on the Osseointegration of Customized Facial Implants.

The purpose of this study was to investigate the optimization of computer-aided design/computer-aided manufacturing (CAD/CAM) patient-specific implants for mandibular facial bone defects and compare the biocompatibility and osseointegration of machined titanium (Ma), Sandblasted/Large-grit/Acid-etched (SLA) titanium, and polyetherketoneketone (PEKK) facial implants. We hypothesized that the facial implants made of SLA titanium had superior osseointegration when applied to the gonial angle defect and prevented the senile atrophy of the bone. Histologic findings of the soft-tissue reaction, hard-tissue reaction, and bone-implant contact (BIC (%) of 24 Ma, SLA, and PEKK facial implants at 8 and 12 weeks were investigated. There was no statistical difference in the soft tissue reaction. Bone was formed below the periosteum in all facial implants at 12 weeks and the BIC values were significantly different at both 8 and 12 weeks (p < 0.05). Ma, SLA, and PEKK facial implants are biocompatible with osseointegration properties. SLA can enhance osseointegration and provoke minimal soft tissue reactions, making them the most suitable choice. They provide an excellent environment for bone regeneration and, over the long term, may prevent atrophy caused by an aging mandible. The bone formation between the lateral surface of the facial implant and periosteum may assist in osseointegration and stabilization.

Evaluation of Clinical Performance of Ponto Implantation Using a Minimally Invasive Surgical Technique-A Prospective Multicenter Study.

To investigate the clinical outcomes of bone-anchored hearing implant surgery using the MONO procedure. Multicenter, multinational, single-arm, prospective trial with a 12-month follow-up. Seven European university hospitals from the United Kingdom, Sweden, Denmark, and The Netherlands. Fifty-one adult patients requiring surgical intervention for bone conduction hearing. Bone-anchored hearing implant surgery using the MONO procedure. The primary endpoint assessed implant usability 3 months after surgery. Implant status, soft tissue reactions, pain and numbness, postoperative events, and sound processor usage were assessed at all follow-up visits. Hearing-related quality of life was evaluated using the Glasgow Benefit Inventory (GBI). At 3 months, 94.2% of the implant/abutment complexes provided reliable anchorage for sound processor usage. No severe intraoperative complications occurred. Sixty-nine percent of surgeries were performed under local anesthesia, with surgery lasting 10 minutes on average. Four implants were lost due to trauma (n = 2), spontaneous loss of osseointegration (n = 1), or incomplete insertion (n = 1). Adverse soft tissue reactions occurred in 2.6% of visits, with a maximum Holgers grade of 3 (n = 1) and grade 2 (n = 5) across patients. Hearing-related quality of life at 3 months improved in 96% of patients. The MONO procedure provides a safe and efficient surgical technique for inserting bone-anchored hearing implants with few and minor intra- and postoperative complications.

Long-Term Outcomes of a Percutaneous Wide-Diameter Bone-Anchored Hearing Implant: A Clinical Evaluation of More than 800 Implants.

This study evaluates the clinical outcomes of 807 percutaneous wide-diameter bone-anchored hearing implants (BAHIs) in 701 patients. In addition, it compares patient groups and examines bone conduction device (BCD) usage. Retrospective cohort study. Mean follow-up period of 3.8 years. Tertiary referral center. All patients implanted with a percutaneous wide-diameter BAHI until December 2020 were included. Patients were divided into age groups, "loading-time" groups, and, if applicable, specific subgroups thought to be at risk for complications postsurgery, e.g., intellectual disability and comorbidities. Soft tissue reaction, implant survival, revision surgery, and BCD usage. In 9.1% of the 5,188 observations of 807 implants, an adverse soft tissue reaction was reported according to the Holgers' scale. Significantly more (adverse) soft tissue reactions were observed in children and intellectually disabled (ID) patients (p < 0.05). Comorbidity subgroups showed no significant differences in soft tissue reactions. Implant loss percentage, including explantations, was 6.2%. Implant survival was significantly worse in patients with ID (14.1%; p = 0.021). Pediatric age, early loading, or comorbidities did not significantly influence implant survival. At least 592 implants (73.4%) were used for bone conduction hearing, of which 65.4% were used daily. Both children and ID patients are more prone to (adverse) soft tissue reactions, ID patients only have a higher risk of implant loss. The rate of implant loss in children seemed to be reduced compared to previous studies and thus more comparable to adults since using wide-diameter implants.

Very Early Loading of a Bone-Anchored Hearing System Is Safe.

To investigate the feasibility of early sound processor loading with two separate bone-anchored hearing aid implants 1 to 2 weeks after implantation. Secondary endpoints included registration of any postoperative complications, skin reactions, and any adverse events. Prospective, nonrandomized, noncontrolled, multicenter clinical trial. Tertiary referral center. Sixty adult patients, eligible for bone-anchored hearing aid surgery, were enrolled. Implantation of the bone-anchored hearing aid implants were done using minimally invasive surgery with tissue preservation. Implant stability quotient (ISQ) values were recorded using resonance frequency analysis. Follow-ups were scheduled 5 to 12 days, 4 to 8 weeks, 6 months, and 12 months postoperatively. Differences between the lowest ISQ values (ISQ low) over time were analyzed by paired-samples t test with a significance level of 0.05. Skin and soft tissue reactions were assessed according to Holger's classification. Loading time of the Ponto Wide implant was 11.6 ± 1.4 days (SD) in average (median, 12 d; range, 7-19 d). Loading of the Ponto BHX implant was done 9.7 ± 3.5 days (SD) postoperatively (median, 9 d; range, 5-19 d). The implant stability increased significantly during the 12-month study period with both implants. One Ponto BHX implant was lost. Skin and soft tissue reactions were few in both groups. Across all planned follow-up visits, no skin and soft tissue reactions were observed in 86% (Ponto BHX implant) and 85% (Ponto Wide implant). Very early loading of sound processors after percutaneous bone-anchored hearing system surgery is safe already 1 to 2 weeks postoperatively.

Achieving Complete Human Gingival Fibroblast Collagen Coverage on Implant Abutments through Vacuum Ultraviolet (VUV) Photofunctionalization.

The formation of a biological seal between implant abutments and the surrounding soft tissue is a preventive strategy against peri-implantitis. The aim of this study is to test the hypothesis that surfaces of prosthetic implant abutments treated with vacuum ultraviolet (VUV) light enhance the growth and function of human gingival fibroblasts. Implant abutments were treated with 172 nm VUV light for one minute. Untreated abutments were subjected as controls. Their surface properties were characterized using SEM, contact angle measurements, and chemical composition analysis. Human gingival fibroblasts were cultured on both untreated and VUV-treated abutments to evaluate cell attachment, proliferation, distribution, and collagen production. Cell detachment assays were also performed under various mechanical and chemical stimuli. After VUV treatment, implant abutments demonstrated a notable transition from hydrophobic to hydrophilic wettability. Surface element analysis revealed a considerable reduction in surface carbon and increases in oxygen and titanium elements on the VUV-treated surfaces. On day 1 of culture, 3.9 times more fibroblasts attached on VUV-treated abutments than on untreated control abutments. Fibroblastic proliferation increased 1.9-3.1 times on VUV-treated abutments, along with a significant improvement in the distribution of populating cells. Collagen production on VUV-treated abutments increased by 1.5-1.7 times. While untreated abutment surfaces showed voids and limited spread of collagen deposition, dense and full coverage of collagen was observed on VUV-treated abutments, with a great contrast in the challenging axial surface zone. Cell retention against mechanical and chemical detaching stimuli was increased 11.3 and 4.3 times, respectively, by VUV treatment. Treatment of implant abutments with VUV light for one minute resulted in a reduction of surface carbon and a transformation of the surface from hydrophobic to hydrophilic. This led to enhanced attachment, proliferation, and retention of human gingival fibroblasts, along with nearly complete collagen coverage on implant abutments. These in vitro results indicate the promising potential of utilizing VUV photofunctionalized implant abutments to enhance soft tissue reaction and sealing mechanisms.

Comparison of Time-Zero Primary Stability Between a Biodegradable Magnesium Bone Staple and Metal Bone Staples for Knee Ligament Fixation: A Biomechanical Study in a Porcine Model.

Bone staples have been shown previously to be a viable modality for cortical tendon graft fixation in ligament knee surgery. However, soft tissue reactions have been reported, making implant removal necessary. Magnesium alloys are a promising material for biodegradable orthopaedic implants, with mechanical properties closely resembling those of human bone. To compare the primary stability of a biodegradable bone staple prototype made from magnesium to bone staples made from metal in the cortical fixation of tendon grafts during knee surgery. Controlled laboratory study. Primary stability of peripheral tendon graft fixation was assessed in a porcine model of medial collateral ligament reconstruction. Two commercially available metal bone staples (Richards fixation staple with spikes [Me1] and spiked ligament staple [Me2]) were compared with a magnesium bone staple prototype for soft tissue fixation. Primary stability was assessed using a uniaxial materials testing machine. Cyclic loading at 50 and 100 N was applied for 500 cycles each, followed by load-to-failure testing. After 500 cycles at 50 N, elongation was 1.5 ± 0.5 mm in the Me1 group, 1.9 ± 0.5 mm in the Me2 group, and 1.8 ± 0.4 mm in the magnesium group. After 1000 cycles of loading (500 cycles at 50 N and 500 at 100 N), elongation was 3.6 ± 0.9 mm in the Me1 group, 3.5 ± 0.6 mm in the Me2 group, and 4.1 ± 1.0 mm in the magnesium group. No significant differences regarding elongation were found between the groups. Load to failure was 352 ± 115 N in the Me1 group, 373 ± 77 N in the Me2 group, and 449 ± 92 N in the magnesium group, with no significant difference between the groups. In this study, the magnesium bone staples provided appropriate time-zero biomechanical primary stability in comparison with metal bone staples and may therefore be a feasible alternative for cortical fixation of tendon grafts in knee surgery. The biodegradability of magnesium bone staples would eliminate the need for later implant removal.

Long-Term Results of the Linear Incision Technique With Tissue Reduction Versus Tissue Preservation for Inserting Bone-Anchored Hearing Implants: The Ongoing Optimization in Bone Implant Surgery.

To compare the long-term outcomes of the linear incision technique with tissue reduction (LIT-TR) and the linear incision technique with tissue preservation (LIT-TP) for inserting bone-anchored hearing implants (BAHIs). Single-center retrospective cohort study. Large general teaching hospital. A total of 231 adult patients were included between August 2005 and October 2020, with a minimum follow-up time of 6 months. The test group received a BAHI using the LIT-TP (N = 147). The control group underwent surgery using the LIT-TR (N = 84). Soft tissue reactions, skin thickening, postoperative complications (e.g., wound dehiscence), and implant loss were compared between the test and control group. Furthermore, Cochlear Bone Anchored Solutions AB (Mölnlycke, Sweden) and Oticon Medical AB (Askim, Sweden) implants/abutments within the LIT-TP cohort were compared. Validated questionnaires were used to quantify patients' health-related quality of life (HRQoL). Significantly more cases with wound dehiscence and adverse soft tissue reactions (Holgers ≥2) were observed in the LIT-TR cohort (p < 0.001). However, the LIT-TP cohort showed significantly more cases with skin thickening (requiring treatment) within the first 2 years after implantation. There were no differences in implant loss rates, overall soft tissue reactions (Holgers >1), and overall HRQoL between the two patient groups. Significant improvement in the patients' HRQoL after implementation of a BAHI was found in both techniques. The Ponto Wide implant/abutment showed less frequent skin thickening (requiring treatment) and fewer soft tissue reactions compared with the BIA400 implant/abutment. This large-scale study demonstrates that the LIT-TP shows excellent long-term outcomes, including a low incidence of implant failure.

Association of Total Hip Arthroplasty Flexural Rigidity With Magnetic Resonance Imaging and Histological Findings

BackgroundModular connections in total hip arthroplasty (THA) offer surgical advantages, but can contribute to implant fretting and corrosion due to micromotion at the head–stem interface. Previous studies implicated lower flexural rigidity as a key contributing factor to THA corrosion and fretting, but none associated flexural rigidity with direct histological evaluation or magnetic resonance imaging (MRI) outcomes. The purpose of this study was to determine how implant flexural rigidity is associated with MRI imaging metrics and histopathological outcomes in patients who have a failed THA. MethodsPatients requiring revision THA surgery underwent preoperative MRIs with 3-dimensional multispectral imaging techniques to suppress metal artifacts. The MRI images were graded for adverse local tissue reactions. For each hip, trunnion flexural rigidity was measured from the retrieved femoral stem, and a periprosthetic tissue sample was retrieved and evaluated using semiquantitative histology. Generalized linear models and analyses of variance were used to assess associations between flexural rigidity and MRI and histology outcomes. ResultsA total of 106 THA stems were retrieved (46 women and 60 men, age: 68 years (range, 60 to 73 years). After adjustment for length of implantation, flexural rigidity was negatively correlated with histologic aseptic lymphocyte-dominant vasculitis-associated lesion severity (β = −26.27, P = .018), Fujishiro lymphocyte grading (β = −13.4, P = .039), perivascular lymphocyte layers (β = −17.8, P = .022), the grade of tissue organization (β = −22.5, P = .009), the presence of diffuse synovitis (β = −66.5, P = .003), and the presence of lymphoid aggregates (β = −75.9, P = .022). No association was found between MRI metrics and flexural rigidity. ConclusionsAmong these implants, decreased trunnion stiffness was associated with increased histologic features of adverse host-mediated soft tissue reactions.

Influence of Physical Activity and Cup Orientation on Metal Ion Release and Oxidative Stress in Metal-on-Metal and Ceramic-on-Metal Total Hip Arthroplasty.

Metal-on-metal (M-M) total hip arthroplasty (THA) has shown adverse reactions to metal debris, abnormal soft-tissue reactions, and high blood metal ion levels. This study aims to: (1) assess whether the toxicity of high levels of ions is related to altered oxidative stress and (2) evaluate tribological factors related to increased blood levels of chromium (Cr) and cobalt (Co) ions. A cross-sectional analytical descriptive study was conducted on 75 patients. A total of 25 underwent M-M THA, 25 ceramic-on-metal (C-M) THA, and 25 were on the THA waiting list. Ion metallic levels in blood, oxidative stress, physical activity, and implant position were compared. In the M-M group, Co and Cr levels were significantly higher than those found in the C-M group and the control group (p < 0.01). We found no differences in terms of oxidative stress between the groups. Also, we did not find a correlation between metal blood levels and oxidative stress indicators, the physical activity of the patients or the position of the implants between groups. The use of M-M bearing surfaces in THA raises the levels of metals in the blood without modifying oxidative stress regardless of the physical activity levels of the patients. Therefore, although patients with M-M bearings require close monitoring, it does not seem necessary to recommend the restriction of physical activity in patients with M-M or C-M arthroplasties.

SAT245 Hips Don’t Lie: A Case Of Peri-Prosthetic Pseudotumor Leading To Hypercalcemia After Total Hip Replacement.

Abstract Disclosure: F. Sotomayor: None. H. Whitlatch: None. Background: Peri-prosthetic pseudotumors are well described, yet rare complications of total hip replacement. They can present as destructive or granulomatous lesions. We present the first documented case of 1,25 vitamin D-mediated severe hypercalcemia caused by a periprosthetic granuloma. Case: A 62-year-old man with a history of osteoporosis, ankylosing spondylitis presented with hypercalcemia (calcium 12.2 mg/dL) on routine laboratory testing. He had a history of bilateral cement hip arthroplasty in 1981 followed by multiple bilateral revisions - three revisions of left hip arthroplasty, one revision of right hip arthropasty. Biochemical evaluation included PTH 5 pg/mL (8 - 54 pg/mL), PTHrP 2.7 pmol/L (0.0 - 2.3 pmol/L), vitamin D-25 59 ng/mL (20-80 ng/mL), a negative Quantiferon TB Gold, and normal serum protein electrophoresis. 1,25 Vitamin D was elevated at 280.5 pg/mL (19.9-79.3 pg/mL). During investigation of 1,25 vitamin D-mediated hypercalcemia, he received a dose of zoledronic acid with transient improvement in hypercalcemia. ACE was negative and CT chest and abdomen was without evidence of granulomatous disease. A whole-body PET scan showed increased metabolic activity surrounding the right femoral and acetabular components with a broad zone of osteolysis in the proximal femur and increased metabolic activity surrounding the left greater trochanter. These findings were concerning for inflammatory granuloma formation. He was prescribed prednisone 30 mg daily with rapid normalization of serum calcium. Prednisone was gradually tapered to 10 mg daily with maintenance of normocalcemia. Discussion: Pseudotumors are an uncommon complication of total hip arthroplasty. These are described as non-infectious and non-neoplastic adverse soft tissue reactions to implants. They manifest as destructive or granulomatous periprosthetic lesion. They cause osteolysis, erosions, pathological fractures, and dislocations. Their formation is due to foreign body reaction to polyethylene, methylmethacrylate, cement or metal adjacent to the joint implant. Associated inflammation leads to macrophage activation, prostaglandin release, and osteolysis. Histologically, they are characterized by the presence of macrophages, extensive coagulation necrosis, lymphocytes, eosinophilic infiltration and granulomatous reaction. While non-malignant, they can cause extensive bony destruction and may require complex revision surgery. To date, this is the first reported case of hypercalcemia due to excess 1,25 vitamin D caused by a periprosthetic granuloma. Conclusion: Hypercalcemia is a well-described complication of granulomatous diseases, including sarcoidosis, mycobacterium infection, and lymphoma. In patients with a history of arthroplasty, we recommend adding peri-prosthetic pseudotumors to the differential diagnosis of 1,25 vitamin D mediated hypercalcemia. Presentation: Saturday, June 17, 2023

Medium-term outcome of medial patellofemoral ligament reconstruction using synthetic graft

BackgroundRecurrent patella instability is a common and debilitating condition which affects mainly adolescents and young adults. Medial patellofemoral ligament (MPFL) reconstruction is the most popular surgical treatment for recurrent patella instability. The most common graft choice in the literature is ipsilateral hamstring tendon (gracilis or semitendinosis) but the complication rate remains high (11–26%). Conversely, there are very few papers on the use of modern, synthetic grafts. MethodsA total of 85 patients who underwent MPFL reconstruction using a modern, synthetic graft (Xiros, UK) from 2014 to 2022 were retrospectively reviewed. Exclusion criteria were patella alta, malalignment, trochlea dysplasia and significant pain between episodes of instability. The author has developed an operative technique which is anatomic, minimally invasive and reproducible. Pre- and post-operative Kujala and Oxford knee scores were collected and analysed. ResultsThe male to female ratio was 27:58, the average age was 28 years, and the follow up range was 1–9 years (mean follow up 4.84 years). We found a statistically significant improvement in mean Kujala and Oxford knee scores (P < 0.001) postoperatively. No major complications such as knee stiffness, soft tissue reaction, re-dislocation, patella fracture were identified in the series. There were nine minor complications (10.6%): five cases of medial knee pain, two cases of residual instability and two of superficial infection. ConclusionThis study demonstrates that modern, synthetic graft is a viable option for MPFL reconstruction. The technique described, achieves good clinical outcomes with low complication rates when compared with the published literature.

Evaluation of different designs for posterior cantilever zirconia inlay-retained fixed dental prostheses in missing tooth replacement: Stage one results with 18-month follow-up assessment

ObjectivesThis clinical study aimed to investigate the outcomes and survival rates of different variations of inlay-retained fixed dental prostheses (IR-FDPs) composed of monolithic zirconia ceramic. The IR-FDPs with a single-retainer design were used for replacing missing mandibular second premolars. The research evaluated the effectiveness and longevity of these prostheses in clinical settings. MethodsA total of 30 IR-FDPs (n = 30) were placed for 27 female patients who presented with missing mandibular second premolar teeth. For this study, the mandibular first molar was chosen as a retainer for the cantilever IR-FDPs and the study involved a random assignment of participants into three distinct groups, each comprising 10 individuals (n = 10). The criterion for the grouping was the retainer design: inlay ring (IR), lingual coverage (LC), and occlusal coverage (OC). The three groups included mesial inlay box with the same dimensions (3 mm height, 3 mm width and 2 mm depth). All IR-FDPs were manufactured using monolithic high translucent 3Y zirconia and the connector area to the cantilever pontic was adjusted to dimensions of 3 × 3 mm for all designs. The restorations were bonded using adhesive resin cement. The clinical and radiographic evaluations of the restorations were conducted for a duration of 18 months, following the modified FDI (World Dental Federation) criteria. ResultsThe restorations were observed in stage one for a period of 18 months. Only one restoration in group LC was debonded after 10 months and re-bonded. The clinical quality of all crowns and the patient's satisfaction were high. No adverse soft tissue reactions around the crowns were observed and only one abutment in group IR was endodontically treated after 12 months. ConclusionsZirconia cantilever IR-FDPs offer a viable short-term treatment option for replacing missing posterior teeth, providing esthetic and functional benefits while minimizing invasiveness. Over an 18-month observation period, these prostheses have demonstrated a remarkable survival rate of 100% and a success rate of 96.6%. These findings suggest the effectiveness and reliability of zirconia cantilever IR-FDPs as a short-term solution for replacing missing posterior teeth. Clinical significanceZirconia cantilever IR-FDPs could present a practical solution for addressing posterior tooth loss, especially in cases where implant placement is not recommended and conventional fixed dental prostheses entail excessive invasiveness.

Drug extravasation with Enfortumab vedotin.

Enfortumab vedotin is an antibody drug conjugate approved for management of pretreated locally advanced or metastatic urothelial carcinoma, which is associated with a rare risk of drug extravasation and soft tissue reactions. We report two cases of EV extravasation with subsequent development of bullae and cellulitis. They were both treated for cellulitis and had conservative management without surgical intervention and were able to resume treatment with Enfortumab vedotin without subsequent adverse events. We propose that EV acts as a vesicant upon extravasation, highlight measures to prevent extravasation events, and encourage appropriate measures when dealing such as attempt of aspiration, removal of catheter, application of compresses, and thorough documentation with photographic evidence.

Bone and Soft Tissue Reaction to Co(II)/Cr(III) Ions Stimulation in a Murine Calvaria Model: A Pioneering in vivo Study.

Metal ions released during wear and corrosion of the artificial knee/hip joints are considered to contribute to aseptic implant failure. However, there are few convincing in vivo studies that demonstrate the effects of metal ions on bone and soft tissue. This study examined the in vivo effects of Co(II)/Cr(III) ions on mouse calvaria and the supra-calvaria soft tissue in an original mouse model. With the implantation of a helmet-like structure, we set up a subcutaneous cavity on the calvaria in which Co(II) Chloride or Cr(III) Chloride solutions were administered respectively. A layer of interface membrane formed on the calvaria along with the implantation of the helmet. The administered Cr(III) ions accumulated in the interface membranes while Co(II) disseminated into the circulation. Accumulated Cr(III) and related products induced local massive macrophage infiltration and skewed the bone metabolic balance. At last, we revealed that lymphocyte aggregates, which are the pathologic hallmark of human periprosthetic tissue, could be caused by either Co(II) or Cr(III) stimulation. These in vivo results may shed light on the effects and pathogenic mechanism of the Co(II)/Cr(III) ions released from the joint prosthesis. STATEMENT OF SIGNIFICANCE: Macrophage infiltration and lymphocyte aggregates are hallmarks of human joint periprosthetic tissue. We chronically administered Co(II)/Cr(III) ions on mouse calvaria and reproduced these two histopathologic hallmarks on mouse tissue based on an implanted helmet-like structure. Our results reveal that Cr(III) ions are locally accumulated and are effective in inducing macrophage infiltration and they can be phagocytosed and stored. However, the lymphocytes aggregates could be induced by both Co(II), Cr(III) and other unspecific inflammatory stimuli.

WATER SORPTION AND WATER SOLUBILITY OF 3D PRINTED AND CONVENTIONAL PMMA DENTURE BASE POLYMERS

Background: Patients who cannot afford more expensive prosthetic restorations, such as implant-supported fixed prostheses, prefer removable dentures. Removable dentures have been manufactured with different types of acrylics, including conventional polymer polymethyl methacrylate (PMMA) and the popular nowadays three–dimensional(3D) printed resins. Water sorption and water solubility often occur because these prosthetic restorations are constantly immersed in saliva and always have interactions with oral fluids. Review results: Alternating processes of imbibition and drying of acrylics lead to internal stresses and fatigue. As a result, dental resins undergo significant dimensional changes. The water diffuses into the dental resin and inflicts a gradual expansion and volume increase, which may cause aging of the material and discomfort during masticatory function. Denture base resins have low water solubility, which results from the leaching out of unreacted monomer and soluble additives into the oral cavity. This is an undesired property and may cause soft tissue reactions. Conclusion: The affinity of dental resins for water degrades their mechanical and physical properties and causes dimensional changes in the denture base, which results in internal stresses that have a negative impact on the denture's long-term success.

166P A mono-institutional experience of field-in-field 3D-CRT planning in breast radiotherapy with FAST and FAST-forward protocols

The benefits of hypofractionated radiotherapy with FAST and FAST-forward protocols could be compromised by soft tissue reactions and cardiac toxicity caused by dose inhomogeneity and inaccurate heart sparing. This study aims to evaluate the dosimetric results of whole-breast hypofractionated radiotherapy with the field-in-field 3D conformal radiotherapy (3D-CRT) technique. A mono-institutional consecutive cohort of 122 early-stage invasive breast cancer patients was treated using field-in-field 3D-CRT. Thirty-nine patients were treated with 28.5 Gy in 5 fractions once a week (FAST protocol) and eighty-three patients with 26 Gy in 5 consecutive fractions (FAST-forward protocol). Different parameters were evaluated to assess target coverage, dose conformity and homogeneity and hot spots in unspecified tissues. To assess breast dimensions, nipple-to-pectoral muscle distance (NPD) and maximum mediolateral thickness (MLT) along tangential fields were measured. Evaluated OARs were ipsilateral lung and heart with their respective dose constraints as required by the clinical protocols. The median NPD and MLT were 4.65 cm [1.70-9.30] and 21.55 cm [11.26-32.30] respectively, with a median CTV of 380.50 cm3 [60.29-1255.13]. The median V95% was 99.45% [95.19-100], and the median 105% isodose volume was 0.74 cm3 [0.00-48.02] of whom 0.07 cm3 [0.00-5.22] in the first skin centimetre. This led to a median CI of 0.53 [0.33-1.00] and a median HI of 0.07 [0.03-0.19]. OARs dose-volume constraints were always respected. The median ipsilateral lung V8Gy was 7.32% [0.31-25.15]; as for the heart (left breast only), the median V1.5Gy was 6.45% [0.00-25.12] and median V7Gy was 0.34% [0.00-4.50]. Each plan achieved a clinically acceptable target coverage and homogeneity, with reduced superficial hot spots. These results suggested that field-in-field 3D-CRT can provide good quality FAST and FAST-forward breast RT plans, with the advantages of an efficient and cost-effective delivery technique. The clinical follow-up will give further critical feedback on treatment outcomes and toxicities.

Complications and Practice Variation in the Use of Peripherally Inserted Central Venous Catheters in People With Cystic Fibrosis: The Prospective Study of Peripherally Inserted Venous Catheters in People With Cystic Fibrosis Study

Peripherally inserted central catheters (PICCs) are used commonly to administer antibiotics to people with cystic fibrosis (CF), but their use can be complicated by venous thrombosis and catheter occlusion. Which participant-, catheter-, and catheter management-level attributes are associated with increased risk of complications of PICCs among people with CF? This was a prospective observational study of adults and children with CF who received PICCs at 10 CF care centers in the United States. The primary end point was defined as occlusion of the catheter resulting in unplanned removal, symptomatic venous thrombosis in the extremity containing the catheter, or both. Three categories of composite secondary outcomes were identified: difficult line placement, local soft tissue or skin reactions, and catheter malfunction. Data specific to the participant, catheter placement, and catheter management were collected in a centralized database. Risk factors for primary and secondary outcomes were analyzed by multivariate logistic regression. Between June 2018 and July 2021, 157 adults and 103 children older than 6 years with CF had 375 PICCs placed. Patients underwent 4,828 catheter-days of observation. Of the 375 PICCs, 334 (89%) were≤ 4.5 F, 342 (91%) were single lumen, and 366 (98%) were placed using ultrasound guidance. The primary outcome occurred in 15 PICCs for an event rate of 3.11 per 1,000 catheter-days. No cases of catheter-related bloodstream infection occurred. Other secondary outcomes developed in 147 of 375 catheters (39%). Despite evidence of practice variation, no risk factors for the primary outcome and few risk factors for secondary outcomes were identified. This study affirmed the safety of contemporary approaches to inserting and using PICCs in people with CF. Given the low rate of complications in this study, observations may reflect a widespread shift to selecting smaller-diameter PICCs and using ultrasound to guide their placement.