华西口腔医学杂志最新文献

Objectives: This study aims to explore the clinical and pathological characteristics of congenital granular cell tumors and provide some references for clinical diagnosis, differential diagnosis, and treatment.

Methods: Nine ca-ses of congenital granular cell tumors who visited the Children's Hospital of Zhejiang University School of Medicine from February 2008 to March 2022 were retrospectively analyzed. Herein, its clinical characteristics, pathological characteristics, treatment, and prognosis were summarized and analyzed.

Results: We found that nine patients were all female, aged 1‑38 days when they saw the doctor. Three of them were attached in maxillary and the other six were attached in mandible. Meanwhile, six tumors were found during the mother's pregnancy at 28-39 weeks and three tumors were found at the baby's birth. One case was excised surgically under local anesthesia, and the other cases were excised surgically under general anesthesia. After 1 month to 12 years of follow-up, patients have no recurrence, however, two cases emerged new teeth from the tumor resection site. Histopathology of all excised lesions was congenital granular cell lesion.

Conclusions: Congenital granular cell tumor is a benign tumor and the prognosis is good. Therefore, surgical resection of the tumor can be done without extensive resection, and it generally does not relapse. Thus, ultrasonography during pregnancy is an important method for the early detection of congenital granular cell epulis.

Objectives: The expression of osteoprotegerin (OPG) and receptor activator of nuclear factor-κB ligand (RANKL) in human periodontal ligament cells (HPDLCs) was investigated by cell culture under continuous static pressure.

Methods: HPDLCs were primarily cultured by tissue explant method and divided into three groups: group A (13-18 years old), group B (19-29 years old), and group C (30-44 years old). CCK-8 was used to detect the proliferation of HPDLCs. The senescence of HPDLCs was detected by senescence-associated β-galactosidase staining. Cells in the three groups were respectively given 0, 1.5, 3, 6, 12, 24, 48, and 72 h of continuous static pressure in vitro. The expression of OPG and RANKL in the supernatant was detected by enzyme-linked immunosorbent assay.

Results: After continuous static pressure in vitro for stimulation, the expression of OPG and RANKL changed. The expression of OPG increased with time and age (P<0.01). The expression of RANKL increased with time and decreased with age (P<0.01). The ratio of OPG/RANKL initially decreased, increased with time, and then continued to rise with age (P<0.01).

Conclusions: Aging could increase the expression of OPG and the ratio of OPG/RANKL and decrease the expression of RANKL in HPDLCs under continuous static pressure in vitro.

Objectives: To evaluate the effectiveness of an acellular dermal matrix or a connective tissue autograft in the treatment of multiple adjacent gingival recessions through Meta-analysis.

Methods: Randomized controlled trials were screened in four electronic databases in English according to the inclusion and exclusion criteria until April 20, 2022. The main outcome indicators were keratinized gingival tissue width, recession depth, probing depth, clinical attachment level, complete root coverage, and root coverage esthetic score.

Results: Seven randomized controlled trials were included. After 12 months, the connective tissue graft in the control group could increase the keratinized gingival tissue width [mean difference (MD)=-0.28 (-0.47, -0.08), P=0.006], reduce the gingival recession depth [MD=0.23 (0.12, 0.35), P<0.000 1], and improve the complete root coverage [risk ratio=0.80, 95% confidence interval (0.69, 0.93), P=0.003] compared with the acellular dermal matrix in the experimental group. No significant difference was found in probing depth, clinical attachment level, and root coverage esthetic score between groups.

Conclusions: Connective tissue grafts have advantages in increasing the keratinized gingival tissue width, reducing the gingival recession depth, and improving the complete root coverage in surgeries for treating multiple adjacent gingival recessions. Acellular dermal matrices also have some clinical value in terms of operation simplicity and similar effectiveness.

Objectives: The purpose of the study was to evaluate the effect of hydroxyapatite (HA)-based desensiti-zing agents and determine their influence on the bonding performance of mild universal adhesives.

Methods: Mid-coronal dentin samples were sectioned from human third molars and prepared for a dentin-sensitive model. According to desensitizing applications, they were randomly divided into four groups for the following treatments: no desensitizing treatment (control), Biorepair toothpaste (HA-based desensitizing toothpaste) treatment, Dontodent toothpaste (HA-based desensitizing toothpaste) treatment, and HA paste treatment. Dentin tubular occlusion and occluded area ratios were evaluated by scanning electron microscopy (SEM). Furthermore, All-Bond Universal, Single Bond Universal, and Clearfil Universal Bond were applied to the desensitized dentin in self-etch mode. The wettability and surface free energy (SFE) of desensitized dentin were evaluated by contact angle measurements. Bonded specimens were sectioned into beams and tested for micro-tensile bond strength to analyze the effect of desensitizing treatment on the bond strength to dentin of universal adhesives.

Results: SEM revealed that the dentin tubule was occluded by HA-based desensitizing agents, and the area ratios for the occluded dentin tubules were in the following order: HA group>Biorepair group>Dontodent group (P<0.05). Contact angle analysis demonstrated that HA-based desensitizing agents had no statistically significant influence on the wettability of the universal adhesives (P>0.05). The SFE of dentin significantly increased after treatment by HA-based desensitizing agents (P<0.05). The micro-tensile bond strength test showed that HA-based desensitizing toothpastes always decreased the μTBS values (P<0.05), whereas the HA paste group presented similar bond strength to the control group (P>0.05), irrespective of universal adhesive types.

Conclusions: HA-based desensitizing agents can occlude the exposed dentinal tubules on sensitive dentin. When mild and ultra-mild universal adhesives were used for subsequent resin restoration, the bond strength was reduced by HA-based desensitizing toothpastes, whereas the pure HA paste had no adverse effect on bond strength.

This article reports a case of using immediate implant placement and immediate restoration combined with measurable implant surgical guides to restore compromised maxillary incisors caused by dental trauma. Target restoration was designed in the exoCAD software preoperatively, intraoral measurements were obtained in three directions, and the correct position of virtual implants was determined in BlueSky Plan 4. Afterward, measurable implant guides were designed and fabricated by 3D printing. Under the guidance of the measurable implant surgical guides and intraoperative measurement, the entry point was determined, the axial direction was verified when drilling to half the depth, and the 3D position was verified when drilling to total depth. Implants were inserted followed by verification once again. The temporary restoration, which was designed based on the target restoration and emergence profile of the original teeth and milled preoperatively, was connected to the implant immediately after surgery. Postoperative accuracy analysis showed that the mean linear deviations between the actual implant position and the pre-planned position were (0.57±0.17) mm at the entry point and (0.82±0.27) mm at the apex, and the mean angular deviation was (1.86±0.89) °, demonstrating that precise implant placement and immediate restoration were implemented.

Objectives: This study aimed to evaluate the efficacy of three methods in root canal retreatment to remove the filling material in the root canals.

Methods: Ninety tooth roots filled by gutta percha or plasticized material (n=45, each) were randomly divided into three groups (n=15). WaveOne (WaveOne group), 1^#P drill+WaveOne (1^#P+WaveOne group), and ultrasound P5 working end ET25+ProTaper Universal (P5+ProTaper Universal group) were used to remove the root canal filling material and prepare for root canal. The operating time of each canal was recorded and the percentage of residual filling material area was measured on the root canal wall of the mesial and distal dissected root section. The degree of deviation of the root canal after operation was measured for the root samples filled by gutta percha.

Results: The type of root filling material and the method of root canal retreatment had no significant effect on the percentage of residual area of the filling material (P>0.05). However, the remaining filling material area of apical 1/3 of the root canal was significantly higher than that of cervical 1/3 of the root canal (P<0.05). The average operating times for removing gutta-percha or plasticized material in the W and 1^#P+WaveOne groups were significantly less than that in the P5+ProTaper Universal group (P=0.000). The root canal retreatment methods had no significant effect on the curvature of the root canal (P=0.650).

Conclusions: WaveOne single file's cleaning ability and center positioning ability were similar to those of ProTaper Universal. Moreover, WaveOne can be independently used for most root canals without a pathway when removing the root canal fillings, thereby simplifying the process of root canal retreatment.

Objectives: To investigate the clinical effect of Er:YAG laser combined with ethylenediamine tetra acetic acid (EDTA) on three-walled periodontal intrabony defects adjacent to implant sites.

Methods: A total of 30 patients with three-walled periodontal intrabony defects adjacent to implant sites were treated with the combination therapy. Patients with three-walled intrabony defects were divided into two groups according to the depth of the intrabony pocket between the implant and natural teeth. Evaluation of wound healing was performed 10 days after the operation, and bone augmentation was evaluated 6 months after the operation.

Results: Primary healing in group 1 was 92.31%, primary healing in group 2 was 82.35%. No significant difference was observed between the two groups (P>0.05). Bone augmentation in group 1 and group 2 were (2.85±1.81), (4.92±2.22) mm. There was significant difference between the two groups (P<0.05). New bone growth occurred more slowly in group 1 (0.70 mm±0.32 mm) than in group 2 (1.25 mm±0.47 mm) (P>0.05). Probe depths (PD), clinical attachment levels (CAL), and sulcus bleeding indices (SBI) showed no statistically significant difference between the two groups (P>0.05). The one-year survival rate of natural tooth in group 1 and group 2 were 100%, 94.2%, and the one-year survival rate of implants in both groups was 100%.

Conclusions: The effect of bone augmentation with combination therapy was more ideal in group 2 than in group 1. Implant placement with combination therapy may be a viable technique to reconstruct three-walled intrabony defects due to the space maintenance provided by implants and bone grafts and the good root surface biocompatibility provided by the Er:YAG laser and EDTA.

Objectives: To investigate the role and molecular mechanism of necrostatin-1 (Nec-1), a specific programmed cell necrosis inhibitor, in promoting the oxidative stress response of macrophages under high glucose (HG) environment.

Methods: Macrophages were cultured in control (5.5 mmol·L^-1 glucose) or HG (25 mmol·L^-1 glucose) medium for 72 h. The HG+Nec-1 group was given HG and 5 μmol·L^-1 Nec-1. Reactive oxygen species (ROS) level, malondialdehyde (MDA) activity, and superoxide dismutase (SOD) activity were measured by 2'-7'dichlorofluorescin diacetate, MDA, and SOD enzyme linked immunosorbent assay kits, respectively. Moreover, receptor interacting protein 1 (RIP1) expression was assessed through real-time quantitative polymerase chain reaction (qRT-PCR) and Western blot (WB). Finally, after the expression of RIP1 in macrophages was silenced, the effect of HG environment on oxidative stress response was evaluated in the gene-deficient cells.

Results: The HG group had increased ROS level and MDA activity (P<0.000 1) and decreased SOD activity (P<0.000 1) compared with the control group. The HG+Nec-1 group had higher ROS level and MDA activity (P<0.000 1) and lower SOD activity (P<0.01) than the HG group. The qRT-PCR and WB results showed that RIP1 mRNA level (P<0.001) and protein expression level (P<0.000 1) in the HG group were significantly higher than those in the control group, and RIP1 mRNA and protein expression levels in the HG+Nec-1 group were significantly lower than those in the HG group (P<0.000 1). After RIP1 was silenced effectively (P<0.001) with si-RNA, the ROS level and MDA activity of the HG+si-RIP1 group decreased compared with those of the HG+si-negative control (si-NC) group (P<0.001), and SOD activity in the HG+si-RIP1 group increased than that in the HG+si-NC group (P<0.000 1).

Conclusions: HG promotes oxidative stress on macrophages by upregulating RIP1 expression.

Objectives: To observe the effect of type 2 diabetes mellitus (T2DM) on mandibular bone regeneration and the expression of factors related to T helper cell 17 (Th17 cell) and regulatory T cell (Treg cell) in mice.

Methods: Thirty-six 6-week-old C57BL/6J male mice were randomly divided into normal control (NC) and T2DM groups. Fasting blood glucose levels were detected 0 d, 7 d, 14 d, and 28 d after surgery for mandibular defects. Hematoxylin-eosin (HE) staining was used in observing the bone after 7 d, 14 d, and 28 d of the healing process. Immunohistochemical staining was used in observing the expression of alkaline phosphatase (ALP), Runt-related transcription factor 2 (RUNX2), forkhead box protein P3 (Foxp3), retinoic acid related orphan receptor gamma T (RORγt), and protein tyrosine phosphatase non-receptor type 2 (PTPN2) after 7 d, 14 d, and 28 d of healing.

Results: HE staining showed that the area with new bones in the T2DM group was significantly smaller than that in the NC group. Immunohistochemical staining showed that the expression of osteogenesis related proteins ALP and RUNX2 were significantly reduced in the T2DM group. In addition, the number of RORγt positive cells increased, whereas the number of Foxp3 positive cells and the expression PTPN2 decreased significantly in the mandibular bone defect in mice with T2DM.

Conclusions: T2DM significantly inhibit mandibular bone regeneration in mice. Decline in PTPN2 expression and the transition of Treg and Th17 may be the underlying molecular mechanisms.