[Soft laser and its application areas in oral surgery and stomatology]. / Der Low-Level-Laser in der Oralchirurgie und Stomatologie.

Low-level lasers (LLL) are used in the stomatology and oral surgery field of dentistry. Due to the biostimulation or biomodulation and photodynamic effect, the healing process of soft-tissue and bone wounds can be accelerated. The indication in oral surgery is to achieve a faster bone healing after tooth extraction, but also to improve the osseointegration in implants. The advantage in stomatology is pain alleviation and improved healing in aphthae and cold sores as well as symptom relief in mucositis. Due to the use free of side effects and low time effort, the LLL offers high patients' comfort.

Evaluation of Preventive Treatment Protocols for Patients under Antiresorptive Therapy Undergoing Tooth Extraction at a Swiss University Clinic.

Antiresorptive agent-related osteonecrosis of the jaw (ARONJ) is a dreaded complication in patients with compromised bone metabolism. The purpose of the present study was to examine the occurrence of ARONJ and its related factors among patients with a history of antiresorptive therapy undergoing tooth extraction using preventive protocols at a Swiss university clinic. Data were retrospectively pooled from health records of patients having received a surgical tooth extraction between January 2015 and April 2020 in the Clinic of Cranio-Maxillofacial and Oral surgery, University of Zurich. A total of 970 patients received an extraction with flap elevation or wound closure during this period. A total of 104 patients could be included in the study. Furthermore, variables including age, gender, smoking, risk profile, choice, indication and duration of antiresorptive therapy, number of extractions, extraction site, surgical technique, choice and duration of antibiotics as well as the presence of postoperative inflammatory complications were assessed. Overall, 4 patients developed ARONJ (incidence of 3.8%) after tooth extraction at the same location, without previous signs of osteonecrosis. Preventive methods included predominantly primary wound closure using a full thickness mucoperiosteal flap and prolonged perioperative antibiotic prophylaxis. In accordance with current literature, the applied protocol showed a reliable outcome in preventing ARONJ when a tooth extraction is required.

[Lateral ridge augmentation with autologous dentin from the wisdom tooth - A case report]. / Laterale Alveolarkammaugmentation mit autologem Dentin aus dem Weisheitszahn.

Autologous dentin as a bone substitute can be used in regenerative dentistry. Extracted teeth are not discarded but recycled and used in block or particulate form for lateral ridge augmentation before implant insertion. Due to the growth factors contained in the dentin and the autologous origin, a stable and good osseointegration of the augmentation material can be expected. This case report demonstrates how the dentin of an autologous wisdom tooth is used for lateral ridge augmentation in area 15 in a 30-year old female patient. The patient was successfully rehabilitated with an implant afterwards. Even though the indication range is limited due to the availability of dentin and the size of the defect, the procedure represents a promising and comparatively minimally invasive autologous augmentation procedure to expand the oral surgical field in regenerative dentistry.

Autogenous bone augmentation from the zygomatic alveolar crest: a volumetric retrospective analysis in the maxilla.

BACKGROUND: Autogenous bone augmentation is the gold standard for the treatment of extended bone defects prior to implantation. Bone augmentation from the zygomatic crest is a valuable option with several advantages, but the current literature for this treatment is scant. The aim of this study was to evaluate the increase in bone volume after locoregional bone augmentation using autogenous bone from the zygomatic alveolar crest as well as the complications and success rate. RESULTS: Analysis of the augmented bone volume in seven patients showed a maximum volume gain of 0.97 cm3. An average of 0.54 cm3 of autogenous bone (SD 0.24 cm3; median: 0.54 cm3) was augmented. Implantation following bone augmentation was possible in all cases. Complications occurred in three patients. CONCLUSION: The zygomatic alveolar crest is a valuable donor site for autogenous alveolar onlay grafting in a locoregional area such as the maxillary front. Low donor site morbidity, good access, and its suitable convexity make it a beneficial choice for autogenous bone augmentation.

Erosive loss of tooth substance is dependent on enamel surface structure and presence of pellicle - An in vitro study.

OBJECTIVE: Aim of this in vitro study was to investigate erosive tooth loss in dependence of the enamel surface structure and presence of an acquired pellicle. METHODS: Enamel specimens from 19 bovine incisors (4 specimens/incisor) were allocated to four experimental groups (n = 19). The surfaces of half of the specimens were polished (two groups), while the other half was left native (two groups). Specimens of one polished and one native group were placed in pooled human saliva (30 min) for the formation of an acquired pellicle. Thereafter, all specimens were demineralized by superfusion with hydrochloric acid (17 min, pH 2.3) with collection of the superfluent. Erosive substance loss was determined by measuring the dissolved calcium content using a colorimetric assay with Arsenazo III reagent. Differences in erosive substance loss were statistically analyzed with respect to enamel surface and pellicle. A linear mixed effects model was fitted to the data and pairwise differences between groups were evaluated (significance level α= 0.05). RESULTS: Enamel surface structure (p < 0.001) and presence of pellicle (p = 0.01) had a significant effect on erosive substance loss. Polished surfaces with pellicle showed the lowest cumulative calcium release [nmol Ca/mm2] (means ± standard deviation: 48+/-5), followed by polished specimens without (51+/-9) and native specimens with pellicle (54+/-10). No significant differences were found between these groups. Highest cumulative calcium release was found for native specimens without pellicle (61+/-9; p < 0.05). CONCLUSIONS: Both enamel surface structure and the acquired pellicle are important determinants of the susceptibility to erosive tooth loss.

Use of a xenogeneic collagen matrix on extraction sockets: a new approach in ARONJ prevention (in german) / Plastische Deckung von Extraktionsalveolen mit einem xenogenen Bindegewebstransplantat

Antiresorptive drugs are increasingly used for the treatment of osteoporosis, various bone pathologies and malignant tumors. Antiresorptive agent-related osteonecrosis of the jaw (ARONJ) is a relevant complication, especially in nonhealing extraction sockets. Prescription of antibiotics in combination with a safely guaranteed closure of the extraction socket is considerably reducing the risk of ARONJ development. Full mucosal coverage usually requires the formation of a full thickness flap, which involves periosteal disclosure of the remodeled bone. In this new approach, primary wound closure is performed by covering the extraction socket with a xenogeneic collagen matrix. Ultimately, elevation of a periosteal flap and additional exposure of the surrounding alveolar bone is avoidable. The technique is exemplified on a patient case with a perennial anti resorptive medication history.

A volumetric assessment and follow-up of a granuloma gravidarum in the anterior maxilla.

AIM: Granuloma gravidarum (GG) is a benign lesion of the soft tissue. The aim of this technical note is the volumetric assessment and follow-up 3D measurement of a GG in the anterior maxilla. MATERIALS AND METHODS: A 35-year-old female patient who was 7 months pregnant was referred due to a soft tissue tumor in the papilla of tooth 21. A biopsy verified a pyogenic granuloma gravidarum. Initial and consecutive volumeatric measurements were made with an intraoral scanner during the patient's pregnancy and until 16 months postpartum. RESULTS: The volumetric assessment showed a continuous growth of the tumor and a consecutive volume reduction 16 months postpartum. In comparison with the level of the papilla of the contralateral incisor, there was an almost complete remission at the last follow-up. CONCLUSION: Intraoral scans can serve for the volumetric assessment of soft tissue tumors of the alveolar crest. Image superimposition enables the quantification of changes in morphology. This supports clinical follow-ups and enables the quantification of clinical observations.

The Effects of Preoperative Radiotherapy on Head and Neck Free Flap Anastomosis Success.

PURPOSE: The long-term survival benefit of neoadjuvant radiotherapy for oropharyngeal tumors is controversially discussed in the literature. To bring more light into this important debate, we evaluated our cases. PATIENTS AND METHODS: In this retrospective study the main focus was the relationship between neoadjuvant irradiation and anastomosis failure. Other influencing factors including previous operative treatment and tumor stage and type also were studied. RESULTS: In total, 7 anastomoses failed (total failure rate, 8.4%; n = 83); 1 of the 7 underwent neoadjuvant irradiation (failure rate, 3.1%; n = 32). All 7 anastomosis failures were in squamous cell carcinoma cases, with 5 of them staged as T4. CONCLUSION: Our data suggest that neoadjuvant radiotherapy for oropharyngeal carcinoma does not increase the risk of postoperative anastomosis failure compared with surgical reconstruction alone. Furthermore, the data suggest a correlation between the stage and type of tumor.