Three-Dimensional Bioprinting Materials with Potential Application in Preprosthetic Surgery

Current methods in handling maxillofacial defects are not robust and are highly dependent on the surgeon’s skills and the inherent potential in the patients’ bodies for regenerating lost tissues. Employing custom-designed 3D printed scaffolds that securely and effectively reconstruct the defects by using tissue engineering and regenerative medicine techniques can revolutionize preprosthetic surgeries. Various polymers, ceramics, natural and synthetic bioplastics, proteins, biomolecules, living cells, and growth factors as well as their hybrid structures can be used in 3D printing of scaffolds, which are still under development by scientists. These scaffolds not only are beneficial due to their patient-specific design, but also may be able to prevent micromobility, make tension free soft tissue closure, and improve vascularity. In this manuscript, a review of materials employed in 3D bioprinting including bioceramics, biopolymers, composites, and metals is conducted. A discussion of the relevance of 3D bioprinting using these materials for craniofacial interventions is included as well as their potential to create analogs to craniofacial tissues, their benefits, limitations, and their application

Comparison of Gingival Retraction Materials Using a New Gingival Sulcus Model

Purpose To investigate the pressure generated by different retraction materials using a novel gingival sulcus model. Materials and Methods A gingival sulcus model was made using a polymer frame filled with silicon. A pressure sensor and a sulcus‐fluid simulation were embedded into the silicon chamber to evaluate the pressure generated by different retraction materials. Six sizes of Ultrapak retraction cords (Ultradent, sizes #000 ‐ 3), 4 retraction pastes (Expazen, Expasyl, Acteon, Access Edge, Traxodent) and 2 retraction gels (Sulcus Blue, Racegel) were analyzed. The mean and median pressure, interquartile range, and standard deviation (SD) of n = 10 repeated measurements were calculated. Statistical analysis was conducted by Kruskal‐Wallis test for differences between the main groups of retraction materials, and Mann‐Whitney U‐test was performed to analyze differences between the single retraction materials. Results Pressure (mean ± SD) generated by retraction cords increased with increasing size (48.26 ± 11.29 kPa, size #000 to 149.27 ± 28.75 kPa for #3). There was a significant difference between sizes (p \u3c 0.01), except in #0 versus #1, and #2 versus #3. Retraction pastes generated pressures that ranged from 82.74 ± 29.29 kPa (Traxodent) to 524.35 ± 113.88 kPa (Expasyl). Retraction gels generated pressures from 38.96 ± 14.68 kPa (Racegel) to 95.15 ± 24.18 kPa (Sulcus Blue). Pressure generated by Expasyl was significantly higher than pressure generated by all other tested materials (p \u3c 0.001). Conclusion Pressure generated by retraction pastes and gels depends on the consistency of the retraction material, while pressure generated by retraction cords increased with increasing size of cords. Expasyl was found to generate the highest pressure compared to all other retraction materials

Oral Health and Dental Anxiety in a German Practice-based Sample

Objective Does dental anxiety have an effect on dental and periodontal health? Methods Survey data was collected from n = 200 adults (53 % females, average age 49 years) in a cross-sectional study. Dental anxiety was measured with the modified dental anxiety scale (MDAS, score 1–5, the greater the score, the greater the anxiety). Clinical parameters including probing depth (PD), clinical attachment level (CAL), plaque index (SLI), and bleeding on probing (BoP) as well as the DMFT index were recorded and statistically analyzed. Results Rating of dental anxiety was higher in women than in men (65 vs 35 %). Subjects with higher MDAS values visited the dentist less frequently (p = 0.001) and had more decay (DT 6.7 ± 4.2 vs 1.7 ± 2.4; p \u3c 0.001) but fewer filled teeth than subjects with lower ratings of dental anxiety (FT 7.1 ± 4.5 vs 9.8 ± 5.7; p = 0.042). There were no differences in PD or CAL between subjects with or without dental anxiety, while patients with higher MDAS value showed significantly more BoP (50 ± 19 vs 34 ± 20 %; p = 0.002) than patients with low MDAS scores (no or low dental anxiety). Conclusions Patients with higher ratings of dental anxiety had significantly more caries experience and gingivitis. Therefore, dental anxiety is associated with negative effect on dental and periodontal health. Clinical relevance Identifying patients with high dental anxiety and helping to manage this anxiety has important implications to improve oral health in adults. The MDAS appears to be an easy and efficient tool that can be used to identify patients with dental anxiety in dental practices

Quality of Postoperative Pain Management After Maxillofacial Fracture Repair

Background: Effective pain management is an essential component in the perioperative care of surgical patients. However, post-operative pain after maxillofacial fracture repair and its optimal therapy has not been described in detail. Materials and Methods: In a prospective cohort study, 95 adults rated their pain on the first postoperative day after maxillofacial fracture repair using the questionnaire of the Quality Improvement in Postoperative Pain Management (QUIPS) project. Quality Improvement in Postoperative Pain Management allowed for a standardized assessment of patients’ characteristics and pain- related parameters. Results: Overall, the mean maximal pain and pain on activity (numeric rating scales) were significantly higher in patients with mandibular fractures than in patients with midface fractures (P = 0.002 and P = 0.045, respectively). In patients with mandibular fractures, a longer duration of surgery was significantly associated with higher satisfaction with pain intensity (P = 0.015), but was more frequently associated with postoperative vomiting (P = 0.023). A shorter duration of surgery and an absence of preoperative pain counseling in these patients were significantly correlated to desire for more pain medication (P = 0.049 and P = 0.004, respectively). Patients with mandibular fractures that received opioids in the recovery room had significantly higher strain-related pain (P = 0.017). In patients with midface fractures, a longer duration of surgery showed significantly higher levels of decreased mobility (P = 0.003). Patients receiving midazolam for premedication had significantly less minimal pain (P = 0.021). Conclusions: Patients with mandibular fractures seem to have more postoperative pain than patients with midface fractures. Monitoring of postsurgical pain and a procedure-specific pain-treatment protocol should be performed in clinical routine

Salivary MMP-9 in the detection of oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is the most common malignant tumour of the oral cavity. Detection of OSCC is currently based on clinical oral examination combined with histopathological evaluation of a biopsy sample. Direct contact between saliva and the oral cancer makes measurement of salivary metalloproteinase- 9 (MMP-9) an attractive alternative. In total, 30 OSCC patients and 30 healthy controls were included in this prospective study. Saliva samples from both groups were collected, centrifuged and supernatant fluid was subjected to ELISA for assessment of MMP-9. The median salivary MMP-9 values with interquartile range (IQR) of OSCC patients and the control group were statistically analysed using the Mann-Whitney U-test. The receiver operating characteristic (ROC) curve was constructed and the area under curve (AUC) was computed. The median absorbance MMP-9 value of the OSCC group was 0.186 (IQR=0.158) and that of control group was 0.156 (IQR=0.102). MMP-9 was significantly increased in the OSCC patients than in the controls by +19.2% (p=0.008). Median values in patients with recurrence and in patients with primary event were 0.233 (IQR=0.299) and 0.186 (IQR=0.134) respectively. MMP-9 was significantly increased in patients with primary event (p=0.017) compared to controls by +19.2%. No significant increase of MMP-9 level was detected when comparing patients with recurrence and healthy controls (+49.4%; p=0.074). The sensitivity value of MMP-9 was 100% whereas the specificity value was 26.7% with AUC of 0.698. The present data indicates that the elevation of salivary levels of MMP-9 may be a useful adjunctive diagnostic tool for detection of OSCC. However, further studies are necessary to provide scientific and clinical validation

Effect of Biomimetic Mineralization on Enamel and Dentin: A Raman and EDX Analysis

Objective To investigate the effect of an experimental biomimetic mineralization kit (BIMIN) on the chemical composition and crystallinity of caries-free enamel and dentin samples in vitro. Methods Enamel and dentin samples from 20 human teeth (10 for enamel; 10 for dentin) were divided into a control group without treatment and test samples with BIMIN treatment. Quantitative analysis of tissue penetration of fluoride, phosphate, and calcium was performed using energy-dispersive X-ray spectroscopy (EDX). Mineralization depth was measured by Raman spectroscopy probing the symmetric valence vibration near 960 cm−1 as a marker for crystallinity. EDX data was statistically analyzed using a paired t-test and Raman data was analyzed using the Student’s t-test. Results EDX analysis demonstrated a penetration depth of fluoride of 4.10 ± 3.32 μm in enamel and 4.31 ± 2.67 μm in dentin. Calcium infiltrated into enamel 2.65 ± 0.64 μm and into dentin 5.58 ± 1.63 μm, while the penetration depths for phosphate were 4.83 ± 2.81 μm for enamel and 6.75 ± 3.25 μm for dentin. Further, up to 25 μm of a newly mineralized enamel-like layer was observed on the surface of the samples. Raman concentration curves demonstrated an increased degree of mineralization up to 5–10 μm into the dentin and enamel samples. Significance Biomimetic mineralization of enamel and dentin samples resulted in an increase of mineralization and a penetration of fluoride into enamel and dentin

Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

Dental Applications of Natural-Origin Polymers in Hard and Soft Tissue Engineering

Clinical advances in the treatment of dentoalveolar defects continue to evolve with the introduction of new innovations in regenerative medicine and tissue bioengineering. Recent developments in tissue engineering are aimed at safely and effectively regenerating a damaged or necrotic area by replenishing its cells and increasing surrounding gene expression. Various techniques have successfully given rise to porous scaffolds being used by clinicians to treat the defect and initiate the repair process. Tissue reconstruction using bioengineered scaffolds is advantageous over traditional autografting, since it prevents the instigation of pain and donor site morbidity while ultimately creating both the environment and machinery needed to induce cell proliferation, migration, and reattachment within the affected area. This review article aims to describe and review the available literature regarding the regenerative capacity of natural polymers used for the treatment of dentoalveolar defects. The repair mechanisms, advantages of protein and polysaccharide derivatives, and the potential of stem cell therapy are discussed

Treatment of a Periodontic-Endodontic Lesion in a Patient with Aggressive Periodontitis

Case Description. This case report describes the successful management of a left mandibular first molar with a combined periodontic-endodontic lesion in a 35-year-old Caucasian woman with aggressive periodontitis using a concerted approach including endodontic treatment, periodontal therapy, and a periodontal regenerative procedure using an enamel matrix derivate. In spite of anticipated poor prognosis, the tooth lesion healed. This case report also discusses the rationale behind different treatment interventions. Practical Implication. Periodontic-endodontic lesions can be successfully treated if dental professionals follow a concerted treatment protocol that integrates endodontic and periodontic specialties. General dentists can be the gatekeepers in managing these cases

Cross-Sectional Study of Four Serological Bone Turnover Markers for the Risk Assessment of Medication-Related Osteonecrosis of the Jaw

Background: Despite the benefits related to the use of bisphosphonates and denosumab, medication-related osteonecrosis of the jaw (MRONJ) is a serious complication. The purpose of this study was to investigate the utility of 4 biochemical markers including serum c-terminal telopeptide cross-link of type I collagen (s-CTX), serum osteocalcin (s-OC), serum parathormon (s-PTH), and serum bone-specific alkaline phosphatase (s-BAP) as useful clinical tools to help assess the risk for MRONJ prior to invasive oral surgery. Materials and Methods: Twenty patients diagnosed with MRONJ and 20 controls who have been on antiresorptive therapies with no occurrence of MRONJ were included in this 2-arm cross-sectional study. The s-CTX, s-OC, s-PTH, and s-BAP values were measured. Mann–Whitney U test compared the s-CTX, s-OC, s-PTH, and s-BAP values of the MRONJ group and the controls (P \u3c 0.05). Results: Lower values were observed in the MRONJ group compared with the control group for s-CTX (130.00 pg/mL versus 230.0 pg/mL; P = 0.12) and for s-OC (10.6 ng/mL versus 14.80 ng/mL; P = 0.051) both without significance and for s-BAP (0.23 μkat/L versus 0.31 μkat/L; P = 0.002) with significance. By contrast, the median s-PTH value of the MRONJ group was higher (30.65 ng/L versus 25.50 ng/L; P = 0.89), but without significance. Conclusions: The evaluation of the 4 biochemical markers showed that only the value of s-BAP was significantly decreased in the MRONJ patients compared with the controls. Presently, because of the lack of evidence, a routine check prior to oral surgery for the risk assessment of MRONJ cannot be recommended