[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.

[A Sampling Survey of the Oral Health Status and Awareness among Primary School Students in Lhasa].

Objective To investigate the oral health status and awareness of urban children in Lhasa,aiming to provide a data basis for the prevention and treatment of children's caries and the promotion of oral health education. Methods A total of 504 Tibetan students were selected by cluster sampling from 2 primary schools in Chengguan District of Lhasa.All the participants were required to take oral health examination and complete a questionnaire about oral health awareness and behavior. Results The caries prevalence rate and mean decayed-missing-filled tooth(DMFT)of permanent teeth were 75.00% and 2.18±1.91,respectively.The rates of pit and fissure sealant and filling of permanent teeth were 3.77% and 6.81%,respectively.The caries prevalence rate of first permanent molars was 47.62%.The mean DMFT of permanent teeth and caries prevalence rate of first permanent molar were significantly higher in female group(P=0.001 and P=0.007,respectively).The prevalence rate of dental fluorosis was 61.51%,and the detection rate of dental calculus was 71.83%.Multivariate logistic regression analysis showed that prevalence of caries was influenced by many independent factors including gender,oral health awareness,intention of dental intervention,and dental experience. Conclusion High caries prevalence rate,low filling rate,and poor oral hygiene and health awareness were found among the primary school students in Lhasa,which require continuous dentistry investment and oral health education for the local students and their parents.

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.

Types of Organ Involvement in Patients with Immunoglobulin G4-related Disease.

BACKGROUND: Immunoglobulin G4-related disease (IgG4-RD) is a newly recognized systemic disease that can involve multiple organs and various clinical phenotypes. The purpose of this study was to analyze different types of organ involvement in IgG4-RD patients in China. METHODS: We conducted a prospective cohort study on IgG4-RD patients to analyze the clinical manifestations and rare features of IgG4-RD. Patients were grouped into different types according to organ involvement regarding organ number and organ site. The constituent ratio in different types was also analyzed. RESULTS: A total of 200 IgG4-RD patients, with a male:female ratio of 2.08:1, were grouped into different types. Cases having involvement of two or three organs were the most common whereas the fewest number of patients had multi-organ (≥4) involvement. Serum IgG4 and IgE levels, IgG4/IgG ratio, and percentage of eosinophils increased as the number of involved organs increased. In addition, constituent ratio analysis revealed that patients with salivary gland/lacrimal gland swelling, who also constituted the largest number of IgG4-RD patients, had higher serum IgG4 concentrations and IgG4/IgG values, had higher percentage of Eos, and were more likely to have had a history of allergies relative to patients with internal organ involvement. CONCLUSIONS: The characteristic feature of IgG4-RD is multiple organ involvement with various clinical manifestations and different types. Although serum IgG4 levels increased with the number of involved organs, serum IgG4 levels were higher for those patients with salivary gland/lacrimal gland swelling compared with those with internal organ involvement. Thus, valuable clues to the differential diagnosis of IgG4-RD could be obtained by examining the clinical patterns of organ involvement.

Efficacy of Topical Tacrolimus for Erosive Oral Lichen Planus: A Meta-analysis.

OBJECTIVE: To assess the efficacy and safety of topical tacrolimus for erosive oral lichen planus (EOLP). METHODS: Literatures published up to December 2013 were searched from PubMed, Embase, CENTRAL, Chinese BioMedical Literature Database (CBM), and System for Information on Grey Literature in Europe (SIGLE). All randomized controlled trials (RCTs) of topical tacrolimus for EOLP which compared with other interventions or a placebo were considered in this Meta-analysis. Two researchers collected data independently. The assessment of methodological quality was based on Cochrane Handbook and the materials were analyzed with the software Revman 5.2.5. The primary outcome measures were the symptoms (e.g. pain, discomfort) complained by patients. The secondary outcome measures included the improvement rate of clinical signs assessed by the investigators and the incidence of adverse effects (e.g. clinical candidiasis). RESULTS: A total of 9 RCTs involving 476 patients were finally included. The pooled odds ratio (OR) of clinical improvement for topical tacrolimus vs. topical corticosteroids was 1.19 [95% confidence interval (CI): 0.64-2.22, I2: 44%]. Regarding to 0.1% tacrolimus and 0.03% tacrolimus, the pooled OR were 1.87 (95% CI: 0.60-5.82) and 1.47 (95% CI: 0.14-16.04) respectively in subgroup analysis. No serious adverse events were reported in topical tacrolimus group. CONCLUSIONS: There was no evidence to support that topical tacrolimus for EOLP was more effective and safer than topical corticosteroids in this Meta-analysis. Clinical assessment criteria should be established and accepted by clinicians and researchers before further RCTs are undertaken.

[Advances in Oral Venous Lakes].

New advances have been pioneered in the pathogenesis,clinicopathological features,and treatment of oral venous lakes. It is concluded that oral venous lakes can be classified as a venous malformation,and multidisciplinary approaches (in particular the involvement of department of dermatology and department of ear,nose and throat) may be adopted to achieve better management of this disease.

[Applications of lasers in dental implantology].

With the constant progress of laser physics, medical laser technology has been widely applied in clinical practices and basic researches. In this article, we reviewed the relevant articles on the laser applications in dental implantology and concluded that lasers provides promising solutions in the treatment technology of dental implants and in the treatment of soft and hard tissue conditions.

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.

Multiple coatings can improve the bond durability of one-step self-etching adhesive to primary dentin.

OBJECTIVE: To investigate whether multiple coatings can improve the bond durability of one-step self-etching adhesive to primary dentin. METHODS: Twelve caries-free human primary molars were randomly divided into 2 groups. In group 1, each tooth was hemisected into 2 halves. One half was assigned to the control subgroup 1, which was bonded with a commercially available one-step self-etching adhesive according to the manufacturer's instructions; the other half was assigned to experimental subgroup 1, in which the adhesive was applied three times before light curing. In group 2, one split half tooth was bonded with a commercially available one-step self-etching adhesive according to the manufacturer's instructions; for the other half, three layers of adhesive were applied with each successive layer of light curing. Specimens were stored in 0.9% NaCl containing 0.02% sodium azide at 37℃ for 18 months and then were subjected to microtensile bond strength test and the fracture mode analysis. RESULTS: When the adhesive was applied three times before light curing, the bond strength of the experimental subgroup 1 was significantly higher than that of the control subgroup 1 (47.46∓13.91 vs. 38.12∓11.21 MPa, P<0.05). When using the technique of applying multiple layers of adhesive with each successive layer of light curing, no difference was observed in bond strength between the control subgroup and the experimental subgroup (39.40±8.87 vs. 40.87±9.33 MPa, P>0.05). CONCLUSION: Multiple coatings can improve the bond durability of one-step self-etching adhesive to primary dentin when using the technique of light-curing after applying 3 layers of adhesive.

[Effect of Yunnan Baiyao capsules on the socket healing of impacted mandibular third molar extraction].

OBJECTIVE: To investigate the effect of the traditional Chinese medicine Yunan Baiyao on the socket healing of impacted mandibular third molar extraction. METHODS: A total of 200 patients requiring extractions of impacted mandibular wisdom teeth were randomized into the treatment group and the control group in a double-blinded manner, and Yunan Baiyao capsules or placebo capsules (2 g/d) were orally administered for 28 days after the operation. Dental quantitative CT scan was performed, and the volume and density of new bone at the extraction site were measured two month after operation. RESULTS: A total of 188 patients completed the study. No adverse events related to the medication occurred. The volume of new bone was (477.39 ± 166.47) mm(3) in the treatment group and (442.65 ± 143.58) mm(3) in the control group, which was not significantly different between the two groups. The density of new bone was (296.90 ± 37.94) mg/cm(3) in the treatment group and (298.54 ± 40.21) mg/cm(3) in the control group, which was not significantly different between the two groups. The number of the teeth root, the impacted conditions, whether or not retainning the alveolar septum, suturing soft tissues of the extraction site and blood clot formation within 1 week after operation were significantly correlated with the volume of new bone. CONCLUSIONS: Yunnan Baiyao capsules has no effect on the volume and density of new bone at the extraction site two months after operation following extractions of impacted mandibular third molars.

[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.

Effect of multiple coatings of one-step self-etching adhesive on microtensile bond strength to primary dentin.

OBJECTIVE: To investigate the effect of multiple coatings of the one-step self-etching adhesive on immediate microtensile bond strength to primary dentin. METHODS: Twelve caries-free human primary molars were randomly divided into 2 groups with 6 teeth each. In group 1, each tooth was hemisected into two halves. One half was assigned to control subgroup 1, which was bonded with a single-step self-etching adhesive according to the manufacturer's instructions; the other half was assigned to experimental subgroup 1 in which the adhesive was applied three times before light curing. In group 2, the teeth were also hemisected into two halves. One half was assigned to control subgroup 2, which was bonded with the single-step self-etching adhesive according to the manufacturer's instructions; the other half was assigned to experimental subgroup 2 in which three layers of adhesive were applied with light curing each successive layer. Microtensile bond strength was immediately tested after specimen preparation. RESULTS: When the adhesive was applied three times before light curing, the bond strength of the experimental subgroup 1 (n=33, 57.49 +/-11.61 MPa) was higher than that of the control subgroup 1 (n=31, 49.71 +/-11.43 MPa, P<0.05). When using the technique of applying multiple layers of adhesive with light curing each successive layer, no difference of immediate bond strength was observed between the control subgroup 2 and the experimental subgroup 2 (P>0.05). CONCLUSION: strength to primary dentin when using the technique of light-curing after applying three layers of adhesive.

[Effect of combination of pulsed CO2 laser irradiation and diammine silver fluoride treatment on ultrastructure of dentine].

OBJECTIVE: To explore the effect of combination of pulsed CO2 laser irradiation and diammine silver fluoride treatment on the ultrastructure of dentine. METHODS: Each extracted molars was made into four identical dentinal specimens, which were randomly divided into 4 groups according to the treatment methods: A, control group; B, pulsed CO2 laser irradiation; C, coated with 38%Ag(NH3)2F; and D, laser irradiation plus fluoride. Scanning electron microscope (SEM) analysis was performed. RESULTS: As shown by SEM, group A showed clear dentinal tubuli, group B showed melted surface without dentinal tubule openings, group C showed thicker melted layer without dentinal tubule openings, and group D showed the thickest melted and recrystallized layer on dentine surface. CONCLUSIONS: Both pulsed CO2 laser irradiation and 38%Ag(NH3)2F treatment can seal dentinal tubule. The combination of these two techniques can form a synergistic effect.