[Effect of Neodymium-Doped Yttrium Aluminum Garnet Laser Combined With Desensitizing Toothpaste on Dentinal Tubule Occlusion Against Acid Challenge].

Objective To assess the effects of different application sequences of neodymium-doped yttrium aluminum garnet(Nd∶YAG)laser and the desensitizing toothpaste containing stannous fluoride on dentinal tubule occlusion.Methods Twelve intact third molars freshly extracted from human were selected and prepared into dentin slices with a thickness of 0.8 mm.Each dentin slice was subdivided into four small slices,three of which were etched with 6% citric acid and randomly assigned to the following three groups(n=12):(1)control group:no treatment;(2)Nd∶YAG+toothbrushing(TB)group:first irradiated with Nd∶YAG laser and then brushed with desensitizing toothpaste;(3)TB+Nd∶YAG group:first brushed with desensitizing toothpaste and then irradiated with Nd∶YAG laser.The Nd∶YAG laser irradiation were carried out at 1 W,15 pulses/s,and the pulse width of 150 µs for 10 s(for a total of 6 cycles).After the above treatment,the 12 dentin slices from the Nd∶YAG+TB and TB+Nd∶YAG groups were randomly assigned to four subgroups(n=3)and subjected to acid etching in the Coca-Cola solution for 0,5,10,and 15 min.A scanning electron microscope was used to observe and photograph the dentin slices in each group,and eight single-blinded examiners scored the slices according to uniform criteria.The analysis of variance was carried out to compared the scores between groups.Results Before acid etching,the dentin tubule occlusion scores of the Nd∶YAG+TB and TB+Nd∶YAG groups were(4.83±0.09) scores and(3.85±0.66) scores,respectively,which had no significant difference between each other(P=0.0590)and were higher than that[(0.10±0.07)scores]of the control group(both P<0.0001).The dentin tubule occlusion scores of the Nd∶YAG+TB group after acid etching for 5,10,and 15 min were(4.33±0.60)scores,(4.27±0.24)scores,and(3.63±0.07)scores,respectively,which were not significantly different from those[(4.04±0.10)scores,(3.76±0.59)scores,and(3.17±0.29)scores,respectively]of the TB+Nd∶YAG group(all P>0.05).In the Nd∶YAG+TB subgroup,the dentin tubule occlusion score after acid etching for 15 min was significantly lower than that before acid etching(P=0.0011).In the TB+Nd∶YAG group,there was no statistically significant difference in the score between before and after acid etching(P>0.05).Conclusions Nd∶YAG laser irradiation with appropriate parameters combined with the use of desensitizing toothpaste could produce an excellent occluding effect on dentinal tubules regardless of the sequence.However,brushing with desensitizing toothpaste followed by Nd∶YAG laser irradiation produced more consistent dentin sealing after acid etching.

The Use of 810 and 1064 nm Lasers on Dental Implants: In Vitro Analysis of Temperature, Surface Alterations, and Biological Behavior in Human Gingival Fibroblasts.

Objective: The primary objective of this study was to evaluate the safety of 810 and 1064 nm laser treatment on dental implants. Background: Peri-implantitis is a challenge for clinicians and researchers. Methods: A pig mandible model was used to evaluate temperature increases during laser irradiation. Surface alterations on processed pure titanium discs were analyzed via scanning electron microscopy and measurement of surface contact angles. Processed titanium discs were cocultured in vitro with human gingival fibroblasts; subsequently, cell proliferation was measured. Results: The maximum temperature and time to reach each threshold were comparable. No surface alterations were detected after 810 nm laser irradiation, whereas surface cracks were observed after 1064 nm laser irradiation under the parameter setting of 31.84 W/cm2. Compared with unaltered processed pure titanium discs, the proliferation of human gingival fibroblasts was significantly greater on altered processed pure titanium discs. Conclusions: The use of either 810 or 1064 nm laser treatments may increase the risk of thermal damage in terms of increased temperature if the parameter setting is not warranted. In addition, the use of 1064 nm laser treatment could lead to changes in pure titanium discs that do not negatively affect cell proliferation. Further investigations of laser-assisted therapy are necessary to improve guidelines concerning the treatment of peri-implantitis. Clinical trial registration number: 2021-P2-098-01.

Advance in Functional Restoration of Injured Nerve with Low Level Laser and its Utilization in the Dental and Maxillofacial Region.

The inferior alveolar nerve and facial nerve are the two most important nerves in the dental and maxillofacial region. The injury to them is one of the major postoperative complications after alveolar surgery and orthognathic surgery. However, recovering the nerve function after injury takes a long time and the recovery effect tends to be unsatisfactory. In recent years, an intensively investigated technique, low level laser which has been applying in assisting the recovery of nerve function, has been gradually proved to be effective in clinically treating postoperative nerve injury. In this article we review in terms of the mechanisms involved in low level laser-assisted functional restoration of nerve injury and its clinical application in the recovery of nerve function in the dental and maxillofacial area as well.

Medical Emergencies in Dental Clinics: A Survey of 2013 Dentists in China.

Objective To investigate the feature and frequency of medical emergencies in dental clinics in China and the associated factors for Chinese dentists experiencing medical emergencies.Methods A survey study was conducted among 2408 dentists who attended continuing educational courses held by Society of Sedation and Analgesia of Chinese Stomatological Association in 18 cities from December 2015 to December 2018. Demographic information of the dentists and the characteristics of medical emergencies they encountered were collected and analyzed. The associated demographic features for dentist experiencing medical emergencies were analyzed by logistic regression model.Results A total of 2013 dentists provided valid responses and reported 2923 events of medical emergencies in dental clinics. Among them, 85.0% reported that they had encountered medical emergencies, and 35.5% had encountered at least twice. Syncope (35.9%) and hypoglycemia (30.3%) were the most common reported medical emergencies. Medical emergencies were most likely to occur during local anesthesia (49.9%), out-patient oral surgery (25.9%), and root canal treatment (11.3%). There were 6 patients (0.2%) died in emergencies. 84.0% dentists reported that they had never received training courses about medical emergency management in dentistry other than Basic Life Support. Longer practicing time (10-15 years) (OR=0.59, 95% CI: 0.41-0.85, P=0.004), working in private dental facilities (OR=1.69, 95% CI: 1.20-2.38, P=0.003) were associated with an increased risk of experiencing medical emergencies.Conclusion More efforts are needed in prevention, early identification, and timely management of medical emergencies in dental clinics in order to prevent fatal outcomes. The results of this survey are useful information for re-designing emergency training courses for Chinese dentists.

Combined overexpression of cadherin 6, cadherin 11 and cluster of differentiation 44 is associated with lymph node metastasis and poor prognosis in oral squamous cell carcinoma.

Oral squamous cell carcinoma (OSCC) is a highly invasive lesion that frequently metastasizes to the cervical lymph nodes and is associated with a poor prognosis. Several adhesion factors, including cadherin 6 (CDH6), cadherin 11 (CDH11) and cluster of differentiation 44 (CD44), have been reported to be involved in the invasion and metastasis of multiple types of cancer. Therefore, the aim of the present study was to determine the expression of CDH6, CDH11 and CD44 in tumor tissues from patients with OSCC, and whether this was associated with the metastasis and survival of OSCC. The mRNA expression of the human tumor metastasis-related cytokines was examined by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) in OSCC tumors with or without lymph node metastasis (n=10/group). The expression of CDH6, CDH11 and CD44 in 101 OSCC and 10 normal oral mucosa samples was examined by immunohistochemical staining. The association between overall and disease-specific survival times of patients with OSCC and the expression of these three proteins was evaluated using Kaplan-Meier curves and the log-rank test. RT-qPCR results indicated that the mRNA expression of CDH6, CDH11 and CD44 was increased in OSCC patients with lymph node metastasis (2.93-, 2.01- and 1.92-fold; P<0.05). Overexpression of CDH6, CDH11 and CD44 was observed in 31/35 (89%), 25/35 (71%) and 31/35 (89%) patients, respectively. The number of OSCC patients with lymph node metastasis exhibiting CDH6, CDH11 and CD44 overexpression was significantly higher than the number of patients without lymph node metastasis exhibiting overexpression of these proteins (P=0.017, P=0.038 and P=0.007, respectively). OSCC patients with high co-expression of CDH6, CDH11 and CD44 exhibited lower disease-specific survival times (P=0.047; χ2=3.933) when compared with OSCC patients with low co-expression of these adhesion factors. CDH6, CDH11 and CD44 serve important roles in OSCC metastasis and the combined use of these factors as biomarkers may improve the accuracy of the prediction of cancer metastases and prognosis.

Application of a peripheral nerve block technique in laser treatment of the entire facial skin and evaluation of its analgesic effect.

BACKGROUND: The aim was to develop a technique for peripheral nerve block anesthesia (PNB) for the skin of the entire face and neck, considering the nerves anesthetized, injection sites, use of an injection method assisted by computer-controlled local anesthetic delivery (CCLAD), and to evaluate the analgesic effects of the PNB technique. METHODS: 50 patients who suffered from large nevus of Ota lesions or port-wine stains on their facial and neck skin and who required laser treatment were included. This study was designed as a non-randomized self-control trial. All the patients received the laser treatment under topical anesthesia in the first phase and three to six months later, they received the same treatment under the PNB using CCLAD. The differences in scores from the visual analogue scale of pain for the two phases were analyzed by the t-test. P values <0.05 were considered to be statistically significant. RESULTS: The peripheral nerve block technique was simple to execute and easy to learn, the anesthetic injection site was generally located at a subcutaneous depth of 0.5-1.0 cm. The analgesic effect of PNB was significant, the mean pain score (2.8 ± 2.2) was significantly lower than that with topical anesthesia (P<0.0001). Patients during the PNB phase did not experience injection pain following CCLAD. CONCLUSION: The peripheral nerve block technique can greatly ease the pain that occurs during laser treatment, especially for patients with larger lesions. CCLAD will allow PNB to be broadly applied in laser treatments.

[The application of free tissue flap in simultaneous reconstruction of defects after tongue cancer].

OBJECTIVE: To discuss the feasibility of using free tissue flap for simultaneous tongue reconstruction after tongue cancer resection. METHOD: Radial forearm flaps and anterolateral thigh flaps were used for simultaneous reconstruction of different defects after tongue cancer resection in 47 cases. The functional evaluation was assessed during the follow-up period of 3 months to 9 years. RESULTS: Only one flap failed,giving a success rate of 97.7%. The 36 patient available for postoperative follow-up were all able to communicate in basic languages and eat normally. Among them, normal speech was found in 34, while slurred speech was found in two. 31 patients could eat normal diet ,while eight could eat soft diet and two could eat liquid diet. CONCLUSIONS: Simultaneous tongue reconstruction with free tissue flap is a reliable method with high successful rate. Flaps selection based on different tongue defects is the key point to achieve good functional and cosmetic results for the reconstruction tongue.

An extraoral nasoalveolar molding technique in complete unilateral cleft lip and palate.

SUMMARY: Although nasoalveolar molding is commonly performed before cleft lip surgery, customized palatal plate availability is limited for patients far from a hospital. This case report describes a preformed extraoral nasoalveolar molding (PENAM) appliance and treatment approach for presurgical nasoalveolar molding in newborns with complete unilateral cleft lip and palate. A 12-day-old boy presented with complete unilateral cleft lip and palate. The PENAM device was supported by an adhesive-taped upper lip, which consisted of a lip nasal stent made from a 0.5-mm stainless steel wire. The spring was activated monthly. The shape of the cartilaginous septum, alar cartilage tip, medial crus, lateral crus, and alveolar segments was molded to resemble the normal shape of these structures. The 9.3-mm alveolar gaps were reduced and approximated. The approximation mostly came from the major alveolus segment with approximately 6.4-mm movement. Cleft side nostril height increased 5.5 mm and deviation of the columella was corrected by 42°. PENAM can be helpful in infants with unilateral cleft lip and palate because it has benefits for long-term forced delivery, requires less frequent activations, and is suitable for patients who live far from a hospital.

[Expression of MICA/B protein in esophageal cancer and its clinical significance].

OBJECTIVE: To explore the expression of MICA/B in human esophageal cancer, and to analyze its correlation with clinicopathological features. METHODS: The expression of MICA/B in 40 cases of esophagus carcinoma and corresponding normal esophageal mucosa tissues were examined by immunohistochemistry. RESULTS: The positive rate of expression of MICA/B protein in the esophageal carcinoma was 75.0% (30/40), and that in the corresponding normal esophageal mucosa was 0 (0/40). Up-regulation of MICA/B expression was found in the esophageal carcinomas. The expression of MICA/B was related with histological grade of the esophageal carcinoma (P = 0.012). CONCLUSION: MICA/B protein plays an important role in the esophageal carcinogenesis, and my become a useful molecular marker for the diagnosis of esophageal carcinoma.

[Mutation and expression of tumor suppressor gene phosphatase and tensin homolog deleted in chromosome 10 in oral squamous cell carcinoma].

OBJECTIVE: To investigate the role of mutation and mRNA expression of tumor suppressor gene phosphatase and tensin homolog deleted in chromosome 10 (PTEN) in tumorigenesis and progression of oral squamous cell carcinoma (OSCC). METHODS: The mutation of exon 3, 5, 6 and exon 8 of PTEN gene in 42 oral squamous cell carcinoma tissue and paired normal tissue were detected by polymerase chain reaction (PCR) and DNA sequencing methods. The levels of PTEN mRNA expression in these tissues were assayed using semi-quantitative RT-PCR. Data was analyzed with SPSS 14.0 software package. RESULTS: Mutated exon 5 of PTEN gene was found in 2 cases of advanced OSCC. The expression of PTEN mRNA was detected in all OSCC and paired normal tissue. The level of PTEN mRNA in OSCC tissue (0.36 +/- 0.12) was significantly lower than that of paired normal tissue (0.64 +/- 0.09, P < 0.01). CONCLUSIONS: The decreased expression of PTEN mRNA contributes to tumorigenesis of OSCC.

[Reconstruction of large through-and-through palate defects with folded free forearm flap].

OBJECTIVE: To explore the reconstruction method of large through-and-through palate defects. METHODS: From 2003 to 2006, 7 cases of large through-and-through palate defects were reconstructed with vascularized folded free forearm flap. 8 flaps were used, including 7 free forearm flaps and 1 pectoralis major myocutaneous flap. RESULTS: All the tissue flaps survived well except one flap necrosis because of arterial thrombosis. The appearance of reconstructed palate was acceptable, and the functions of swallowing and speech were normal or almost normal. CONCLUSIONS: It is feasible and effective to repair large through-and-through palate defects with folded free forearm flap.

[Evaluation of midazolam intravenous sedated patient's comfort degree in mandibular third molar surgery].

OBJECTIVE: To evaluate the clinical efficacy and safety of continuous low-flow intravenous infusion of midazolam sedation in mandibular third molar surgery. METHODS: Fifty healthy patients with symmetrically placed impacted bilateral mandibular third molars were included in this self controlled, randomized clinical study. Degree of comfort (their actual current anxiety level) was assessed using a visual analogue scale (VAS) of pain and anxiety. Patients' satisfaction and degree of amnesia were also evaluated. Vital signs and oxygen saturation were recorded. RESULTS: Low dose midazolam sedation obviously increased the degree of patients' comfort and satisfaction. Vital signs and oxygen saturation levels did not differ significantly between the two groups. CONCLUSIONS: Midazolam as an intravenous sedation agent in mandibular third molar surgery showed satisfactory effect on patients with mild dental fear.

[Application of CTA and CAD\CAM techniques in mandible reconstruction with free fibula flap].

OBJECTIVE: To explore the application of computed tomographic angiography (CTA) and computer aided design\manufacture (CAD\CAM) techniques in mandible reconstruction with free fibula flap. METHODS: 7 cases of complex mandible defect were reconstructed with free fibula flap. Patients' lower extremity vasculature was evaluated by preoperative CTA examination; mandible tumor resection and reconstruction were simulated by CAD technique, the surgical template was manufactured with CAM technique preoperatively; and fibula flap was shaped according to surgical template during mandible reconstruction operation. RESULTS: Preoperative CTA examination performed without complication, the desired anatomy was adequately demonstrated in all patients. All of flaps survived, patients' facial contour are symmetry approximately. CONCLUSIONS: CTA and CAD\CAM techniques have important value for complex mandible reconstruction in selection of donor site, planning of operation and shaping of fibula flap.