Gingival biotypes are used to describe the morphological characteristics of periodontal tissue. According to thickness, the gingiva can be divided into thin and thick gingival biotypes. The gingival biotype has a wide range of influential factors and can be measured by various methods. In the process of oral treatment, to achieve good therapeutic effects and obtain a clear prognosis, it is particularly important to study the gingival biotype. This article reviews the influential factors and methods for assessing the gingival biotype. The results of literature review show that, factors influencing the gingival biotype include individual factors related to sex, age and ethnicity and oral soft and hard tissue characteristics related to crown shape, tooth position, alveolar bone thickness, keratinized gingival width and gingival papilla height. Gingival hypertrophy mainly occurs in young males and in people with square and round crowns, thicker alveolar bones and wider keratinized gingiva. With the development of methods for measuring the gingival biotype ranging from the traditional direct observation method, direct measurement methods and periodontal exploration methods to cone beam computed tomography and ultrasound have increased the accuracy of these measurements.

Objective This study aims to compare the osteogenic effects of implanting demineralized dentin matrix and acellular dentin matrix in bone defect areas.Methods Demineralized dentin matrix and acellular dentin matrix were prepared.Twenty-four male SPF-grade SD rats were randomly divided into four groups:demineralized group(group A),acelluar group(group B),Bio-Oss bone powder group(group C),and blank control group(group D),with six rats in each group.All rats were subjected to general anesthesia to prepare bilateral femoral bone defects.Rats in groups A,B,and C were implanted with demineralized dentin matrix,acellular dentin matrix,and Bio-Oss bone powder at the bone defect area,respectively,while rats in group D were not implanted with any material.At 4 and 8 weeks after surgery,three rats were randomly executed in each group.The healing of the bone defect area was ana-lyzed through gross observation.The concentrations of osteogenic indicators bone morphogenetic protein-2(BMP-2)and alkaline phosphatase(ALP)were detected by serology.The distribution of high-density gray area(representing bone healing)in the bone defect area was observed by X-ray examination,and the formation of new bone was observed by his-tomorphology.The rate of new bone formation was calculated.Results At 4 and 8 weeks,the bone formation ability of group A was more active than that of the other groups;the concentrations of BMP-2 and ALP in group A were higher than those in the other groups,and the differences were statistically significant(P<0.05).At 8 weeks,the imaging obser-vation showed that the high-density gray area in the bone defect of group A was evenly distributed.The histomorphologi-cal observation showed the regular arrangement of bone matrix in group A.The rate of new bone formation in group A was 28.51%±0.55%at 4 weeks and 32.57%±2.28%at 8 weeks,both of which were significantly higher than those in the other groups(P<0.05).Conclusion Demineralized dentin matrix has better osteogenic potential than acellular dentin matrix.

Chronic periodontitis is a chronic inflammatory disease caused by plaque microorganisms, and removal of plaque and calculus is the gold standard for nonsurgical periodontal treatment. However, complete debridement is difficult, especially in some complex anatomical sites. Excessive scaling may result in the loss of healthy cementum and lead to dental hypersensitivity. Studies have shown that a diode laser can exhibit the best performance in an environment with blood because its wavelengths (630-1 064 nm) are close to the absorption peaks of heme and melanin and they have broad application prospects in the oral field. In nonsurgical periodontal treatment, diode lasers have three treatment modes: soft diode laser, antimicrobial photodynamic therapy and low-level laser therapy, which can be used alone or in combination. Although diode lasers cannot replace mechanical treatment to remove calculus, they can remove infected periodontal pocket epithelium, change the microcirculation to promote wound healing, reduce bleeding and relieve pain through photothermal effects and biological stimulation. The effect of diode laser treatment depends on the treatment dose. It is necessary to precisely control the output intensity and control the irradiation time to avoid thermal damage to the tissue. In the future, extensive research at the molecular level is needed to reveal the tissue response. At the same time, more high-quality, large-sample randomized controlled trials are needed to standardize the use of lasers for different stages and grades of periodontitis.

Objective : To evaluate the clinical effect of endoscopic-assisted subgingival scaling and root planning (SRP) in the treatment of periodontitis. Methods: PubMed, EMBASE, The Cochrane Library, Web of Science, CNKI, WanFang Data, and VIP databases were searched for randomized controlled trials (RCTs) related to endoscopy-assisted SRP. The search time limit was from the establishment of the database to September 15, 2021. The outcome indicators included in the study included the plaque index (PLI), probing depth (PD), attachment loss (AL), and bleeding index (BI). Review Manager 5.4 and Stata 12.0 software were used for the meta-analysis. Results: A total of 111 studies were retrieved, and 5 quantitative studies were included after screening. Meta-analysis showed that for sites with 4 mm ≤ PD < 6 mm, 3 and 6 months after treatment, there was no significant difference in the PD value between the endoscope assisted group and the simple SRP group (P > 0.05); for sites with PD ≥ 6 mm, the PD value of the endoscope assisted group was smaller than that of the simple SRP group 3 and 6 months after treatment. The difference between the two groups was statistically significant (P < 0.05), but there was no significant difference in PLI, Al or BI between the two groups (P > 0.05). Conclusion Compared with simple SRP, the auxiliary use of endoscopy has a better effect on reducing PD in deep periodontal pockets (PD ≥ 6 mm). However, for clinical indicators such as PLI, AL, and BI, there was no difference between the therapeutic effects of the two methods.

Objective : To evaluate the clinical effect of enamel matrix derivative(EMD) assisted with connective tissue graft(CTG) in the treatment of gingival recession. Methods : Search The Cochrane Library, PubMed, EMbase, Web of Science, Wanfang Public Database,VIP database and CNKI to search for randomized controlled trials of EMD in the treatment of gingival recession. The search period is from the establishment of the databases to October 3, 2022. The test group was treated with EMD+CTG, while the control group was treated with CTG alone. Meta-analyses were performed using Review Manager 5.4.1 and Stat12.0. Results: Meta analysis results showed that only 12 months after treatment, there was a statistically significant difference in the PD and CAL outcome indicators between the EMD assisted treatment group and the control group [MDPD=-0.10, 95% CI (-0.19, -0.01), P = 0.03], [MDCAL=-0.38, 95% CI(-0.71, -0.04), P = 0.03]. There was no significant difference between the test group and the control group in other indicators. Conclusion EMD assisted CTG in the treatment of gingival recession may be beneficial to the reduction of PD and CAL.