Platelet rich fibrin as a bioactive matrix with proosteogenic and proangiogenic properties on human healthy primary cells in vitro.

Blood concentrates like platelet rich fibrin (PRF) have been established as a potential autologous source of cells and growth factors with regenerative properties in the field of dentistry and regenerative medicine. To further analyze the effect of PRF on bone tissue regeneration, this study investigated the influence of liquid PRF matrices on human healthy primary osteoblasts (pOB) and co-cultures composed of pOB and human dermal vascular endothelial cells (HDMEC) as in vitro model for bone tissue regeneration. Special attention was paid to the PRF mediated influence on osteoblastic differentiation and angiogenesis. Based on the low-speed centrifugation concept, cells were treated indirectly with PRF prepared with a low (44 g) and high relative centrifugal force (710 g) before the PRF mediated effect on osteoblast proliferation and differentiation was assessed via gene and protein expression analyses and immunofluorescence. The results revealed a PRF-mediated positive effect on osteogenic proliferation and differentiation accompanied by increased concentration of osteogenic growth factors and upregulated expression of osteogenic differentiation factors. Furthermore, it could be shown that PRF treatment resulted in an increased formation of angiogenic structures in a bone tissue mimic co-culture of endothelial cells and osteoblasts induced by the PRF mediated increased release of proangiogenic growth factors. The effects on osteogenic proliferation, differentiation and vascularization were more evident when low RCF PRF was applied to the cells. In conclusion, PRF possess proosteogenic, potentially osteoconductive as well as proangiogenic properties, making it a beneficial tool for bone tissue regeneration.

What is the context?The treatment of bone defects is still a challenge in the field of regenerative medicine. In this context, researchers and clinicians are continuously focusing on developing new therapeutic strategies like the use of autologous blood concentrates like Platelet rich fibrin (PRF) to improve regeneration by directly delivering wound healing promoting cells and growth factors to the defect side in order to restore the structure and functional integrity of damaged hard tissue in combination with adequate tissue regeneration.What is new?Focus of the present in vitro study was to further evaluate the potential of PRF paying particular attention to the PRF-mediated effect on osteogenic differentiation and angiogenesis of human primary osteoblasts as well as on a more complex tissue like co-culture consisting of osteoblasts and microvascular endothelial cells. We could demonstrate that PRF is able to support and affect a variety of processes involved in bone tissue regeneration including osteogenic proliferation, osteogenic differentiation as well as angiogenic structure formation.Treatment of PRF resulted in:- increased cell viability*- higher expression of osteogenic differentiation factors*- higher release of osteogenic growth factors*- increased formation of microvessel-like structures*(*compared to untreated control)What is the impact?PRF represents a beneficial autologous tool for regenerative purposes combining proosteogenic and proangiogenic properties. Therefore, PRF might be used for applications in versatile fields of medicine in the context of improving bone tissue regeneration.

Horizontal Guided Bone Regeneration of the Posterior Mandible to Allow Implant Placement: 1-Year Prospective Study Results.

OBJECTIVE: Assess whether horizontal ridge augmentation with guided bone regeneration (GBR) using deproteinized bovine bone mineral (DBBM), autologous bone, and a resorbable collagen membrane supports successful implant placement. MATERIALS AND METHODS: This open, prospective, single-cohort, multicenter clinical study included patients with ridge defects that required GBR prior to implant insertion. The primary endpoint was radiologically assessed bone gain after 8 months post-GBR, measured at the center of planned implant sites. Secondary endpoints included implant survival and success, marginal bone levels (MBLs), MBL changes, and soft tissue health. RESULTS: Of 45 patients evaluated 8 months post-GBR, nine experienced dehiscence in the first 3 weeks of the healing period. GBR led to radiologically determined mean bone width gain of 4.0 ± 1.5 mm and 4.8 ± 1.7 mm, measured 1 and 3 mm from the top of the crest, respectively, allowing successful implant placement in 44 patients (97.8%). The cumulative implant survival and success rates were 98.9% and 95.5%, respectively. MBLs were stable: -1.18 ± 0.64 mm at definitive prosthesis placement (DPP) and - 1.07 ± 0.74 mm at 1 year. Soft tissue health and esthetics (plaque and bleeding indices, papilla, keratinized mucosa, and pink esthetic score) improved from DPP to 1 year. Patients were highly satisfied with implant function and esthetics, and their oral health-related quality of life improved. CONCLUSIONS: GBR using DBBM and a collagen membrane offered a safe and effective treatment option for horizontal ridge augmentation sufficient to support implant-based tooth rehabilitation. TRIAL REGISTRATION: Registered at ClinicalTrials.gov NCT03028922 (registrations sites, as above listed affiliations, first posted January 23, 2017).

Leukocytes within Autologous Blood Concentrates Have No Impact on the Growth and Proliferation of Human Primary Osteoblasts: An In Vitro Study.

Platelet-rich fibrin (PRF) is a widely used autologous blood concentrate in regenerative medicine. This study aimed to characterize the cellular composition and distribution of different PRF matrices generated by high (710 g) and low (44 g) relative centrifugal forces (RCFs) and to analyze their bioactivity on human primary osteoblasts (pOBs). PRF was separated into upper layer (UL) and buffy coat (BC) fractions, and their cellular contents were assessed using histological and immunohistochemical staining. The release of platelet-derived growth factor (PDGF) and transforming growth factor (TGF-ß) was quantified using an ELISA. Indirect PRF treatment on pOBs was performed to evaluate cell viability and morphology. A histological analysis revealed higher quantities of leukocytes and platelets in the low-RCF PRF. TGF-ß release was significantly higher in the low-RCF PRF compared to the high-RCF PRF. All PRF fractions promoted pOB proliferation regardless of the centrifugation protocol used. The low-RCF PRF showed higher TGF-ß levels than the high-RCF PRF. These findings contribute to understanding the cellular mechanisms of PRF and provide insights into optimizing PRF protocols for bone regeneration, advancing regenerative medicine, and improving patient outcomes.

Effectiveness of Oroantral Communication Closure Using Solid Platelet-Rich Fibrin Compared to a Conventional Treatment Approach: A Randomized Clinical Trial.

This study aimed to compare the effectiveness of platelet-rich fibrin clot (PRF) and conventional oroantral communication (OAC) repair techniques following tooth extractions from the maxilla. The study involved 22 patients, divided into 2 groups: a study group treated with PRF and a control group undergoing conventional OAC repair. The primary outcome measured was the effectiveness of OAC closure, with pain intensity and postoperative complications as secondary outcomes. Cone-beam computed tomography (CBCT) was used to evaluate post-extraction bone regeneration. Pain was assessed using the Visual Analogue Scale (VAS) on days 0, 1, 7, and 14 postoperatively. The results showed that the PRF group experienced a significant decrease in pain within the first 24 hours and after 7 days (P < .0001; P < .05). In contrast, complications were reported in 45.45% of patients in the conventional repair group and 18.18% in the A-PRF group. Three months postsurgery, CBCT revealed appreciable bone healing in both groups, with no significant difference (P > .05). In conclusion, the study suggests that A-PRF treatment for OACs resulted in fewer complications and quicker pain reduction than traditional repair methods, making it a promising alternative for managing OACs. However, future studies are needed to confirm these findings and establish the full therapeutic potential of PRF.

The effect of antiresorptive therapy on the prevalence and severity of oral lichen planus: a retrospective study.

BACKGROUND: Antiresorptive therapy (AR) disrupts osseous homeostasis and can induce direct irritation over the gastrointestinal mucosa; however, its possible erosive effects on the oral epithelium have not been totally described. Among the most frequent oral erosive lesions, oral lichen planus (OLP) frequently presents as painful mucosal ulcerations, arising from basal membrane inflammatory damage. Thus, the aim of this retrospective study was to describe the association between AR and the incidence of OLP. METHODS: This case-control study included data from 148 patients (17 patients undergoing AR therapy (AR group) / 131 without AR therapy (Control group)). Each patient record was systematically processed and the association between AR drugs and OLP clinical characteristics within both groups was assessed. RESULTS: The erosive form of OLP was significantly more frequent in the AR group than in the Control group (p = 0.029). Indeed, the AR treatment using alendronic acid (41.2%) was the most frequently reported. Additionally, the erosive form of OLP showed the strongest association with pain and burning sensation among the OLP types (p < 0.050). However, disease worsening and AR consumption were not significantly associated (p = 0.150). CONCLUSIONS: Patients under AR therapy show more clinical symptoms associated to the erosive type of OLP. Regardless of the AR therapy, the erosive type of OLP is associated with more severe symptoms.

FraMaDySc: dysphagia screening for patients after surgery for head and neck cancer.

PURPOSE: Oropharyngeal dysphagia is one of the most common postoperative consequences in head and neck cancer patients. Above all, these patients often suffer from aspiration and limitations of oral intake. However, no reliable dysphagia screening is available for this target group. This study aimed to develop and validate a screening, FraMaDySc, based on a water swallow test (WST) for the identification of postsurgical patients with a risk of aspiration, limitations of oral intake, and, as their derivate, a relevant oropharyngeal dysphagia in general (OD) that constituted the main reference standard. METHODS: A total of 184 postsurgical head and neck cancer patients were tested with a WST. The patients were, on average, 62 years old and predominantly male (71%). After WST, they underwent Fiberoptic Endoscopic Evaluation of Swallowing (FEES®). FEES® results were dichotomized by Penetration aspiration scale and Functional oral intake scale. Patients with a "fail" result on one of these two scales were classified as having OD. Quality criteria of WST were quantified by means of cross-tabulation with FEES® results. RESULTS: OD was found in 65% of patients, aspiration in 44%, limitations of oral intake in 56%. WST delivered a "fail" result in 65% of patients. WST showed sensitivity 91% and specificity 88% for OD. Quality criteria for aspiration (sensitivity 64%, specificity 93%) and limitations of oral intake (sensitivity 80%, specificity 87%) were lower. CONCLUSION: FraMaDySc is a standardized, quick, and valid WST and therefore an excellent screening tool for the identification of OD in postoperative head and neck cancer patients.

Influence of antiresorptive/antiangiogenic therapy on the extension of experimentally induced peri-implantitis lesions.

OBJECTIVES: To investigate the extension of experimentally induced peri-implantitis lesions under various antiresorptive and antiangiogenic medications. MATERIAL AND METHODS: Fourty-eight albino rats had randomly received the following medications (dual application, n = 8 each): (1) amino-bisphosphonate (zoledronate) (Zo), (2) RANKL inhibitor (denosumab) (De), (3) antiangiogenic (bevacizumab) (Be), (4) Zo+Be, (5) De+Be, or (6) no medication (Co). Ligature- and lipopolysaccharide-induced peri-implantitis lesions were established at 2 maxillary implants over a period of 16 weeks. Histological (e.g., apical extension and surface area of the inflammatory cell infiltrate-aICT, ICT; defect length; defect width; CD68 positive cells) and bone micromorphometric (µCT) outcomes were assessed. The animal was defined as a statistical unit. RESULTS: A total of n = 38 animals (Zo = 6, De = 6, Be = 8, Zo + Be = 6, De + Be = 5, Co = 7) were analyzed. ICT's were commonly marked by a positive CD68 antigen reactivity. Comparable median aICT (lowest-Zo: 0.53 mm; highest-Be: 1.22 mm), ICT (lowest-De + Be: 0.00 mm2; highest-Co: 0.49 mm2), defect length (lowest-Zo: 0.90 mm; highest-Co: 1.93 mm) and defect width (lowest-De+Be: 1.27 mm; highest-Be: 1.80 mm) values were noted in all test and control groups. Within an inner (diameter: 0.8 mm) cylindric volume of interest, the bone microstructure did not significantly differ between groups. CONCLUSIONS: The present analysis did not reveal any marked effects of various antiresorptive/ antiangiogenic medications on the extension of experimentally induced peri-implantitis lesions. CLINICAL RELEVANCE: The extension of peri-implantitis lesions may not be facilitated by the antiresorptive and antiangiogenic medications investigated.

Hyperspectral Imaging Allows Evaluation of Free Flaps in Craniomaxillofacial Reconstruction.

INTRODUCTION: Treatment of extended defects after tumor resection in oral, maxillofacial, and facial surgery (craniomaxillofacial) is usually performed by free microvascular flaps. Evaluation of flap survival is crucial, especially in the first hours after insertion and connection. For flap evaluation various invasive and noninvasive methods have been developed. This retrospective clinical study examined the ability of a hyperspectral imaging (HSI) camera (Tivita, Diaspective Vision, Germany) to assess postoperative flap properties in comparison to established clinical parameters. MATERIALS AND METHODS: Thirteen patients with tumor resection and free flap reconstruction were included for camera analysis and another 10 patients as control group. For this purpose, at defined time intervals and under standardized conditions, recordings of transplants 3 to 100 hours postoperatively were performed. Images were used to examine oxygenation (StO 2 %), tissue hemoglobin index, tissue water index, near infrared range perfusion index of free flaps quantitatively and qualitatively. RESULTS: HSI provides values differing between patients observed with no intraindividual significant difference. After 24 hours a mean reduction of 16.77% for StO 2 %, 9.16% for tissue hemoglobin index and 8.46% was observed, going in line with no loss of flap was noted in the observation period. CONCLUSION: HSI is suitable as a noninvasive measure for the evaluation of free flaps in craniomaxillofacial surgery in case of stable imaging conditions with respect to light, surrounding and position of the camera. However, clinical measurements are still the method of choice.

Esthetic complications in implant dentistry.

Esthetic complications in implant dentistry have become a significant consideration for patients and practitioners. This review presents an appraisal on the current knowledge of the physiological peri-implant soft-tissue dimensions and factors that may compromise peri-implant tissue esthetics. Factors such as papilla fill adjacent to the implant and midfacial mucosal height are critical parameters that determine the esthetic success of implant-supported restorations. Papilla fill adjacent to a single dental implant appears to depend upon the clinical attachment level of the neighboring tooth. A horizontal inter-implant distance of at least 3 mm is necessary to ensure optimal interproximal mucosal embrasure between two adjacent implants in the anterior maxilla. In cases where implants cannot be placed at least 3 mm apart, a single implant with a cantilever bridge should be considered. Buccolingual implant positioning plays a major role in midfacial mucosal height. Soft-tissue volume grafting following immediate implant placement in the presence of a thin soft-tissue phenotype or simultaneous to surgical peri-implantitis therapy might help to overcome facial mucosa recession.

Efficacy of autogenous tooth roots for a combined vertical and horizontal alveolar ridge augmentation and staged implant placement. A prospective controlled clinical study.

OBJECTIVES: To assess and compare the efficacy and safety of autogenous tooth roots (TRs) and autogenous bone blocks (ABs) for combined vertical and horizontal alveolar ridge augmentation and two-stage implant placement. MATERIALS AND METHODS: A total of 28 patients in need of implant therapy and vertical ridge augmentation were allocated to parallel groups receiving either healthy autogenous tooth roots (e.g., retained wisdom teeth) (n = 14, n = 15 defects) or cortical autogenous bone blocks harvested from the retromolar area (n = 14, n = 17 defects). After 26 weeks of submerged healing, the clinical reduction in ridge height (RH) deficiency was defined as the primary outcome. RESULTS: Both surgical procedures were associated with a similar mean reduction in RH deficiency values, amounting to 4.48 ± 2.42 mm (median: 4.25; 95% CI: 3.08-5.88) in the TR group and 4.46 ± 3.31 mm (median: 3.00; 95% CI: 2.54-6.38) in the AB group (p = .60, Mann-Whitney U-test). In all patients investigated, the reduction in RH deficiency values allowed for an adequate implant placement at the respective sites. The frequency of complications (e.g., soft tissue dehiscences) was low (TR: n = 4; AB: n = 0). CONCLUSIONS: Up to staged-implant placement, both TR and AB grafts appeared to be associated with comparable efficacy and safety for combined vertical and horizontal alveolar ridge augmentation.

Influence of width of keratinized tissue on the prevalence of peri-implant diseases: A systematic review and meta-analysis.

AIM: To evaluate the influence of the width of keratinized tissue (KT) on the prevalence of peri-implant diseases, and soft- and hard-tissue stability. MATERIALS AND METHODS: Clinical studies reporting on the prevalence of peri-implant diseases (primary outcome), plaque index (PI), modified plaque index (mPI), bleeding index (mBI), bleeding on probing (BOP), probing pocket depths (PD), mucosal recession (MR), and marginal bone loss (MBL) and/or patient-reported outcomes (PROMs; secondary outcomes) were searched. The weighted mean differences (WMD) were estimated for the assessed clinical and radiographic parameters by employing a random-effect model that considered different KT widths (i.e., <2 and ≥2 mm). RESULTS: Twenty-two articles describing 21 studies (15 cross-sectional, five longitudinal comparative studies, and one case series with pre-post design) with an overall high to low risk of bias were included. Peri-implant mucositis and peri-implantitis affected 20.8% to 42% and at 10.5% to 44% of the implants with reduced or absent KT (i.e., <2 mm or 0 mm). The corresponding values at the implant sites with KT width of ≥2 mm or >0 mm were 20.5% to 53% and 5.1% to 8%, respectively. Significant differences between implants with KT < 2 mm and those with KT ≥ 2 mm were revealed for WMD for BOP, mPI, PI, MBL, and MR all favoring implants with KT ≥ 2 mm. CONCLUSION: Reduced KT width is associated with an increased prevalence of peri-implantitis, plaque accumulation, soft-tissue inflammation, mucosal recession, marginal bone loss, and greater patient discomfort.

Importance of keratinized mucosa around dental implants: Consensus report of group 1 of the DGI/SEPA/Osteology Workshop.

OBJECTIVES: To assess the literature on (i) the relevance of the presence of a minimum dimension of keratinized peri-implant mucosa (KPIM) to maintain the health and stability of peri-implant tissues, and; (ii) the surgical interventions and grafting materials used for augmenting the dimensions of the KPIM when there is a minimal amount or absence of it. MATERIAL & METHODS: Two systematic reviews complemented by expert opinion from workshop group participants served as the basis of the consensus statements, implications for clinical practice and future research, and were approved in plenary session by all workshop participants. RESULTS: Thirty-four consensus statements, eight implications for clinical practice, and 13 implications for future research were discussed and agreed upon. There is no consistent data on the incidence of peri-implant mucositis relative to the presence or absence of KPIM. However, reduced KPIM width is associated with increased biofilm accumulation, soft-tissue inflammation, greater patient discomfort, mucosal recession, marginal bone loss and an increased prevalence of peri-implantitis. Free gingival autogenous grafts were considered the standard of care surgical intervention to effectively increase the width of KPIM. However, substitutes of xenogeneic origin may be an alternative to autogenous tissues, since similar results when compared to connective tissue grafts were reported. CONCLUSION: Presence of a minimum width of KPIM should be assessed routinely in patients with implant supported restorations, and when associated with pathological changes in the peri-implant mucosa, its dimensions may be surgically increased using autogenous grafts or soft-tissue substitutes with evidence of proven efficacy.

Crestal bone loss and implant failure of prefabricated versus customized abutments: a 10-year retrospective radiological study.

OBJECTIVES: There is no information today about the impact of abutment type on the crestal bone stability. This retrospective study was aimed to evaluate the crestal bone levels (CBL) and failures of implants with prefabricated and customized abutments after the long term. MATERIALS AND METHODS: The mesial and distal CBL around dental implants with prefabricated and custom abutments were recorded. Measures were completed at 5- and 10-year endpoints. RESULTS: Sixty-three patients with 249 implants were included. One hundred twenty-seven implants (51%) were restored with prefabricated and 122 implants (49%) with customized abutments. All the patients received fixed restorations. The results showed that the CBL was higher in patients with custom abutments than the CBL of patients with prefabricated abutments. The mean bone loss around implants with prefabricated abutments was 0.29 mm mesial/0.45 mm distal after 10 years. Meanwhile, the mean bone loss at implants with custom abutments was 1.19 mm mesial/1.27 mm distal (p < 0.05) after 10 years. None of the implants with prefabricated abutments failed up to 10-year follow-up, whereas 4.1% of implants with customized abutments failed. CONCLUSION: Implants with prefabricated abutments present less crestal bone loss compared to customized abutments. CLINICAL RELEVANCE: The selection of abutment type is associated with the crestal bone stability or marginal bone loss.

Bacterial translocation and microgap formation at a novel conical indexed implant abutment system for single crowns.

OBJECTIVES: A conometric concept was recently introduced in which conical implant abutments hold the matching crown copings by friction alone, eliminating the need for cement or screws. The aim of this in vitro study was to assess the presence of microgap formation and bacterial leakage at the Acuris conometric restorative interface of three different implant abutment systems. MATERIAL AND METHODS: A total of 75 Acuris samples of three implant-abutment systems (Ankylos, Astra Tech EV, Xive) were subjected to microbiological (n = 60) and scanning electron microscopic (SEM) investigation (n = 15). Bacterial migration into and out of the conical coupling system were analyzed in an anaerobic workstation for 48, 96, 144, and 192 h. Bacterial DNA quantification using qrt-PCR was performed at each time point. The precision of the conometric coupling and internal fit of cemented CAD/CAM crowns on corresponding Acuris TiN copings were determined by means of SEM. RESULTS: qrt-PCR results failed to demonstrate microbial leakage from or into the Acuris system. SEM analysis revealed minute punctate microgaps at the apical aspect of the conometric junction (2.04 to 2.64 µm), while mean cement gaps of 12 to 145 µm were observed at the crown-coping interface. CONCLUSIONS: The prosthetic morse taper connection of all systems examined does not allow bacterial passage. Marginal integrity and internal luting gap between the ceramic crown and the coping remained within the clinically acceptable limits. CLINICAL RELEVANCE: Conometrically seated single crowns provide sufficient sealing efficiency, relocating potential misfits from the crown-abutment interface to the crown-coping interface.

Image Fusion Improves Interdisciplinary Communication in the Treatment of Head and Neck Cancer.

INTRODUCTION: The diagnosis and therapy of oral squamous cell carcinoma (Osee) in Germany is according to guidelines and relies on interdisciplinary board meetings. Standard examination techniques are computed tomography (CT) and magnet resonance imaging (MRI). These technologies are used as objective tools for serial presentation in an oncologic board meeting. The presentation of multiple series at different time points can be time consuming and might not often depict a patients case clearly for all involved disciplinaries. A conclusive image fusion could improve the communication. Thus, this study aims to introduce a novel idea of image fusion into the field of craniomaxillofacial surgery in order to ease understanding and improve therapy in complex Osee patients' cases. MATERIALS AND METHODS: Three key data sets of a patient with OSCC at the right tongue have been merged by image fusion of 3 MRi of head and neck with 3 CT thorax and abdomen using Syngo via (Siemens). Fused images were used as at a glance picture for presenting and discussion a patients case. Focus was on presenting a case of a primary manifestation of OSCC with the potential of a local relapse and distant metastases in an interdisciplinary oncol-ogic board meeting. RESULTS: Image fusion enabled to visualize the primary tumor, local relapse as well as distant pulmonary metastasis and within the suprarenal gland, which have been occurred in a linear time line of 13 months. DISCUSSION: Image fusion of different modalities that is CT and MRi, which were gathered at different time points, presents a new approach within the field of craniomaxillofacial surgery and helped to understand cancer localization and relapse at 1 glance. This new approach will enable a compact data set of patients oncological history as a more decisive tool for all involved disciplinaries. CONCLUSIONS: Image fusion might have the potential to become a standard approach in order to ease multiple therapists to make therapy decisions in oncologic board meetings on basis of current three-dimensional ready CT imaging and MRI.

[Pre-treatment dysphagia in head-and-neck cancer patients]. / Prätherapeutische Dysphagie bei Kopf-Hals-Tumor-Patienten.

BACKGROUND: The swallowing and nutritional status of head-and-neck cancer patients after oncological therapy have been extensively researched. However, the same topics are seldom scrutinized before the onset of oncological therapy, although they can influence treatment success in the long term. OBJECTIVE: This study focusses on a systematic assessment of swallowing function and nutritional status in head-and-neck cancer patients prior to oncological therapy. MATERIALS AND METHODS: In 102 patients, penetration/aspiration (PA scale), limitations of oral intake (Functional Oral Intake Scale, FOIS), and the need for further intervention (NFI) were endoscopically assessed to objectively quantify swallowing function. The subjective evaluation of swallowing function was carried out with the gEAT-10 (German EAT-10) questionnaire, nutritional status was assessed by body mass index (BMI). Possible impact factors for swallowing function and BMI were analyzed by univariate and multivariate methods. RESULTS: PAS, FOIS, and NFI values were abnormal in ≤ 15% of patients. BMI was more often too high than too low. Objectively assessed swallowing functions depended predominantly on tumor stage and showed moderate correlations with gEAT-10. The latter mostly yielded a "fail" result. The nutritional status depended on the patients' biological sex and NFI. CONCLUSION: In the pre-treatment setting, neither dysphagia nor malnutrition were found in most patients. Impaired swallowing was associated with higher tumor stages, malnutrition with female sex and NFI. A systematic pre-treatment assessment of swallowing and nutritional status in head-and-neck cancer patients appears necessary for modern oncological therapy and optimal patient outcome.

3D printed versus commercial models in undergraduate conservative dentistry training.

INTRODUCTION: The treatment of carious lesions is one of the most fundamental competencies in daily dental practice. However, many commercially available training models lack in reality regarding the simulation of pathologies such as carious lesions. 3D printed models could provide a more realistic simulation. This study provides an exemplary description of the fabrication of 3D printed dental models with carious lesions and assesses their educational value compared to commercially available models in conservative dentistry. MATERIALS AND METHODS: A single-stage, controlled cohort study was conducted within the context of a curricular course. A stereolithographic model was obtained from an intraoral scan and then printed using fused deposition modelling. These models were first piloted by experts and then implemented and compared against commercial models in a conservative dentistry course. Experts and students evaluated both models using a validated questionnaire. Additionally, a cost analysis for both models was carried out. RESULTS: Thirteen dentists and twenty-seven 5th year dental students participated in the study. The 3D printed models were rated significantly more realistic in many test areas. In particular, the different tactility and the distinction in colour was rated positively in the 3D printed models. At 28.29€ (compared to 112.36€), the 3D printed models were exceptionally cost-efficient. CONCLUSIONS: 3D printed dental models present a more realistic and cost-efficient alternative to commercial models in the undergraduate training of conservative dentistry.

[Nutritional Risk Screening in head-and-neck cancer patients prior to oncological therapy]. / Screening auf Mangelernährung bei Kopf-Hals-Tumor-Patienten vor onkologischer Therapie.

OBJECTIVE: Head-and-neck cancer patients run a high risk of peri- or post-treatment malnutrition that can severely affect the therapy outcome. However, little is known about malnutrition under the pre-treatment condition. Therefore, this study aimed to provide a systematic description of the pre-treatment nutritional status and risk of malnutrition in this population. MATERIAL AND METHODS: Before the onset of the oncological therapy, nutritional status of 102 head-and-neck cancer patients was assessed by body mass index (BMI), their risk of malnutrition by "Nutritional Risk Screening" (NRS). Tumour stage and site, patients' age and sex as well as oropharyngeal dysphagia were analysed as possible influence factors. The latter was quantified by the Flexible Endoscopic Evaluation of Swallowing (FEES). RESULTS: According to BMI, malnutrition (undernutrition) was found in 6% of patients, a risk of malnutrition (NRS) in 27% of patients, and oropharyngeal dysphagia in 15%. In a linear regression, only oropharyngeal dysphagia was identified as a significant influence factor for the risk of malnutrition (ß = 0.380/3.776; p < .001). CONCLUSIONS: Pre-treatment risk of malnutrition was found in a quarter of head-and-neck cancer patients. For the early identification of this risk and for the introduction of measures that would help to avoid it, a pre-treatment examination of swallowing functions and a systematic malnutrition screening by means of NRS are recommended.

[Post-operative prevalence of dysphagia in head-and-neck cancer patients in the acute care units]. / Postoperative Dysphagieprävalenz bei Kopf-Hals-Tumorpatienten im akutstationären Setting.

OBJECTIVE: Dysphagia constitutes a frequent post-operative functional impairment in head-and-neck cancer patients. This impairment can result in aspiration/penetration and limitations of oral intake. Therefore, often it requires a therapeutic intervention. In this study, prevalence of post-operative dysphagia and its associations with the tumour stage, localisation, patients' age, and biological sex were analysed for the inpatient treatment setting. MATERIAL AND METHODS: A total of 201 adult head-and-neck cancer patients (mean age 63 years) were analysed prospectively by FEES in two university hospitals in regard to their penetration/aspiration, limitations of oral intake, and need for therapeutic interventions directly after the operative tumour treatment. Additionally, the influence of the same patients' characteristics on these three parameters were analysed by means of univariate and multivariate statistical methods. RESULTS: Out of 201 patients, 66.7 % needed a therapeutic intervention because of their dysphagia, 57.2 % needed a nasogastral or PEG tube due to limitations of oral intake, 45.3 % had an aspiration. In the latter subgroup, 38.5 % had a silent aspiration. Higher tumour stage, patients' higher age and male sex were shown to be significant influence factors for dysphagia, tumour localisation showed only a marginally significant result. CONCLUSIONS: The study demonstrated a clinical importance and relevance of the consequent and systematic treatment of post-operative dysphagia in head-and-neck cancer patients in the acute care units as a constituent of a modern oncological therapy.

Assessment of soft and hard tissue dimensions following different treatment approaches of ligature-induced peri-implantitis defects.

OBJECTIVES: To evaluate peri-implant tissue dimensions following nonsurgical (NS) and surgical therapy (S) employing different decontamination protocols of advanced ligature-induced peri-implantitis in dogs. MATERIAL & METHODS: Peri-implantitis defects (n = 5 dogs, n = 30 implants) were randomly and equally allocated in a split-mouth design to NS or S treatment using either an Er:YAG laser (ERL), an ultrasonic device (VUS), or plastic curettes + local application of metronidazole gel (PCM), respectively. Horizontal bone thickness (hBT) and soft tissue thickness (hMT) were measured at different reference points: (v0) at the marginal portion of the peri-implant mucosa (PM); (v1) at 50% of the distance from PM to bone crest (BC); (v2) at the BC; (v3) at the most coronal extension of the bone-to-implant contact. Vertical peri-implant tissue height was calculated from PM to BC. RESULTS: All of the treatment groups showed a gradual hMT increase from v0 to the v2 reference point, followed by a reduction from v2 to the v3 region. The S-VUS subgroup tended to be associated with higher hMT values at the v0 region than the NS-VUS subgroup (0.44 mm versus 0.31 mm). PM-BC distance varied from 2.22 to 2.83 mm in the NS group, and from 2.07 to 2.38 in the S group. CONCLUSION: Vertical and horizontal peri-implant tissue dimensions were similar in different treatment groups.