The problems caused by proximal contact loss (PCL) of dental implants have been a mainstream research topic in recent years, and scholars are unanimously committed to analyzing their causes and related factors, aiming to identify solutions to the problems related to PCL. The effects of the anterior component of force (ACF), the lifelong remolding of the adult craniofacial jaw and alveolar socket, and the osseointegration characteristics of dental implants are the main causes of PCL. On the one hand, the closing movement of the mandible causes the ACF of the tooth to move through the posterior molar cusp. Moreover, drifting between the upper and lower posterior teeth and mandibular anterior teeth can cause the anterior teeth of the upper and lower jaws to be displaced labially. On the other hand, reconstruction of the jaw, alveolar socket and tooth root, the forward horizontal force of the masticatory muscles, the dynamic component of the jaw and the forward force generated by the oblique plane of the tooth cusp can cause the natural tooth to experience near-middle drift. Additionally, natural teeth can shift horizontally and vertically and rotate to accommodate remodeling of the stomatognathic system and maintain oral function. Nevertheless, the lack of a natural periodontal membrane during implant osseointegration, the lack of a physiological basis for near-medium drift, the small average degree of vertical motion and the integrated silence of dental implants without the overall drift characteristics of natural teeth increases the probability of PCL. The high incidence of PCL is clearly associated with the duration of prosthesis delivery and the mesial position; but it is also affected by the magnitude of the bite force, occlusion, the adjacent teeth, restoration design, implant location, jaw, and patient age and sex. PCL has shown a significant correlation with food impaction, but not a one-to-one correspondence, and did not meet the necessary and sufficient conditions. PCL is also associated with peri-implant lesions as well as dental caries. PCL prevention included informed consent, regular examinations, selection of retention options, point of contact enhancement, occlusal splints, and the application of multipurpose digital crowns. Management of the PCL includes adjacent contact point additions, orthodontic traction, and occlusal adjustment. Existing methods can solve the problem of food impaction in the short term with comprehensive intervention to seek stable, long-term effects. Symmetric and balanced considerations will expand the treatment of issues caused by PCL.
Objective To investigate the physicochemical and biological properties of a new calcium sulfate-based root canal sealer for deciduous teeth containing calcium sulfate hemihydrate, barium sulfate, chlorhexidine acetate, and polyethylene glycol 400 (PEG 400). Methods This study was reviewed and approved by the Ethics Committee. The calcium sulfate hemihydrate and barium sulfate powders with different mass percentages were mixed with liquid PEG 400 at a powder-to-liquid ratio of 3∶1, and chlorhexidine acetate was added to a concentration of 0.2 mg/mL according to the volume of PEG 400. The above materials were mechanically ground at 250 r/min for 24 h to obtain a calcium sulfate-based root canal sealer for deciduous teeth. The sealer was classified into different groups according to mass percentages of components. The mass percentages of components were optimized by performing time, fluidity, and radiopacity experiments, and then the pH, mass loss in vitro, and microscopic morphology of the optimal sealer were evaluated. The antimicrobial properties of the sealer were evaluated by a bacterial-material cocultivation method. The cytocompatibility of the sealer was evaluated by a CCK-8 assay and cytomorphological staining, and its biocompatibility was evaluated by a subcutaneous tissue embedding assay. Results After optimization, mass percentage of calcium sulfate hemihydrate was 80 wt%, and the mass percentage of barium sulfate was 20 wt%. The flowability and radiopacity of the sealer were in accordance with international standards. The pH stabilized between 6-7. On the 7th and 14th days, the pH in the water group was significantly greater than that in the PBS group (P<0.001), although the pH in both groups gradually increased (P>0.05). In vitro degradation experiments, the mass loss of the sealer was approximately 15.17% during the preimmersion period, and rate of mass loss decreased after 3 weeks, reaching only approximately 8.33%. X-ray diffraction (XRD) and scanning electron microscopy (SEM) revealed that the main component of the sealer after hydration was calcium sulfate dehydrate. In bacterial growth assays and cytological tests, the sealer showed significant inhibition of the growth of E. faecalis (P<0.001). After 1 and 4 days of culture, the cell viability in the 1∶10 and 1∶20 sealer extract dilution group was lower than that in the control group (P<0.05). On the 7th day, the 1∶20 sealer extract dilution had no significant effect on cell proliferation (P>0.05). Both the sealer group and the control group (Vitapex and zinc oxide eugenol) caused mild inflammatory reactions in tissue sections. Conclusion In this study, a new type of root canal sealer for deciduous teeth was designed based on calcium sulfate, which has good physicochemical properties and strong antibacterial properties and meets biocompatibility requirements. This study provides an idea for the development of a new type of root canal sealer for deciduous teeth.
Objective To compare the effects of 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP)- and silane-based primers with those of MDP-based primers on zirconia-resin bonding via multiple levels of aging. Methods Zirconia blocks were divided into 4 groups (n = 21) according to the primer used: MDP-based Z-Prime Plus (ZP), silane-based Monobond-S (MS), MDP- and silane-based Clearfil Ceramic Primer (CCP) and no primer (Blank). After pretreatment with or without the primers followed by bonding with cement Duo-Link, each group was subdivided into 3 subgroups (n = 7) according to aging level: 24 hours of water storage at 37 ℃ (24 h), 30 days of water storage at 37 ℃(30 d), and 30 d plus 3 000 thermal cycles (30 d/TC). After aging, shear bond strength (SBS) tests and failure mode analyses were conducted. Results ZP, MS and CCP groups had greater SBSs than did the BLANK group (P<0.01). From 24 h to 30 d, the shear bond strength significantly increased (P<0.05); however, the shear bond strength decreased significantly from 30 d to 30 d/TC (P<0.01) and fell below baseline (30 d/TC vs. 24 h, P<0.01). Within the primer groups, CCP exhibited a higher SBS than ZP and MS at each aging level (P<0.001). The bonding strength of ZP was greater than that of MS at 30 d (P = 0.029) but lower than that of MS at 30 d/TC (P = 0.037). From 30 d to 30 d/TC, the percent decrease in the bonding strength of ZP was significantly greater than that of MS (82.43% vs. 64.90%). Conclusion MDP-based primers function better for zirconia-resin bonding when they contain silane coupling agents.
Objective To summarize the clinicopathological characteristics and prognostic factors of salivary duct carcinoma (SDC) patients. Methods This study was reviewed and approved by the Ethics Committee, and informed consent was obtained from the patients. The clinical data of 30 SDC patients who were admitted to the Fourth Hospital of Hebei Medical University from 2014 to 2022, including case records, pathological diagnoses, immunohistochemical indicators, treatment methods, follow-up data, and other data, were retrospectively analyzed. SPSS 26.0 software was used to process the data and construct relevant curves. The chi-square test was used to analyze the correlation between different immunohistochemical indices and the recurrence and metastasis of SDC, and a single factor was used to analyze clinical prognostic factors. Results Among the 30 SDC patients, the male-to-female ratio was 5∶1, with a median age of 61.5 years. Approximately 60% of cases occurred in the parotid gland, whereas the remainder occurred in the submaxillary gland, sublingual gland, or minor salivary gland. Among them, 19 patients were androgen receptor-positive, 23 patients were human epidermal growth factor receptor-2 positive, and 26 patients were Ki-67 positive. Postoperative follow-up was 18-94 months, with a median follow-up of 37 months. There were 13 cases of recurrence and 14 cases of distant metastasis. The 5-year overall survival rate was only 31.2%. The long-term survival of patients who underwent postoperative radiotherapy and chemoradiotherapy was better than that of patients who underwent surgery alone (P= 0.027). T stage and lymph node invasion were associated with prognosis and survival (P<0.05). There was a correlation between a Ki-67-positive cell count ≥ 40% and postoperative recurrence or metastasis (P = 0.025). Conclusion Radical surgery combined with postoperative radiotherapy and chemoradiotherapy is helpful for improving long-term overall survival, and tumor T stage and lymph node metastasis may be the main factors affecting the prognosis of patients with SDC. Patients with Ki-67-positive cell counts ≥ 40% are prone to postoperative recurrence or metastasis.
Objective To evaluate the applicability of a modified U-shaped forearm flap for the repair of small- and medium-sized defects in the oral and maxillary areas to provide a reference for clinicians. Methods This study was reviewed and approved by the Ethics Committee, and informed consent was obtained from the patients. Ten patients with small- and medium-sized defects in the oral and maxillary areas underwent surgical repair using modified U-shaped forearm flaps. There were 8 males and 2 females aged 43-72 years. The donor site was apposed primarily after harvesting the modified U-shaped forearm skin flap. The flaps ranged from 6 cm × 4 cm to 8 cm × 5 cm in size. Six months after the operation, hand movements (finger extension, fist clenching, wrist rotation upward and wrist rotation downward), the forearm donor site, hand sensations and the satisfaction score for the postoperative quality of the scar at the donor site were evaluated (0 to 10; 0: very unattractive, 10: very satisfactory). Results A total of 10 patients with modified U-shaped forearm flaps survived. One patient developed venous crisis 24 hours after surgery and survived after surgical exploration. Delayed healing occurred at the donor site of the forearm in 1 patient, and the wounds at the donor site of the forearm in the other patients all healed in the first stage. One patient presented with dysesthesia in the hand 2 weeks after surgery and recovered within 3 months. Six months after surgery, all patients had no limited hand movement and no paresthesia at the forearm donor site or hand. The patients were basically satisfied with the appearance of the donor site,and the average satisfaction score of the subjective questionnaire was 8.4 points. Conclusion Modified U-shaped forearm flaps can directly close forearm donor site wounds, which avoids surgical trauma to the secondary donor site and significantly reduces related complications. Modified U-shaped forearm flaps provide an alternative to conventional forearm flaps for the repair of small- and medium-sized defects in the oral and maxillary areas.
Objective To investigate the clinical efficacy of disc repositioning surgery combined with orthodontic treatment in patients with temporomandibular disorder and facial asymmetry. Methods One patient who underwent disc repositioning surgery combined with orthodontic treatment for temporomandibular joint disorder and facial asymmetry was reported. Preoperatively, the patient had a skewed shape of the opening, mild pressure pain in the right preauricular region with left mandibular deviation, and a mismatch between the width of the upper and lower dental arches. In the arthrosurgery department, bilateral temporomandibular disc replacement and anchorage were performed through a transauricular incision, and an auxiliary splint was worn to stabilize the jaw position for 6 months. In the orthopedic department, maxillary skeletal expansion was used in combination with the multiloop edgewise archwire technique to reconstruct the occlusion after 16 months of orthodontic treatment. Results The deviation was corrected by wearing an occlusal splint for six months after joint repositioning and anchoring; moreover, the pain symptoms disappeared, and the cone beam CT examination showed that the bilateral temporomandibular joint space was uniformly enlarged, the lower alveolar ridge midline deviated to the right, the posterior regions of the teeth were bilaterally inverted, and the anterior region and the posterior region of the left side were open. The orthodontic treatment matched the width of the upper and lower dental arches and established the cuspal molar neutrality relationship and the normal overjet coverage of the anterior teeth; additionally, the mandibular position was not obviously skewed. A review of the results of the related literature shows that abnormal occlusal relationships, such as mismatched arch width and skewed occlusal plane, can cause adaptive mandibular deviation, which can lead to the occurrence of TMD. Temporomandibular joint disc anchorage with splint treatment can effectively improve maxillofacial deformity in young TMD patients. After the establishment of a stable, physiologically functional disc-condylar relationship, orthodontic treatment is required to remove the interfering factors to rebuild the occlusion, and long-term postoperative review and follow-up are needed. Conclusion In patients with TMD and mandibular accommodative deviation due to occlusal anomalies, establishing a normal disc-condylar relationship and eliminating occlusal interference through disc repositioning surgery combined with orthodontic treatment can effectively improve facial shape and establish a stable jaw position.
Objective To explore the diagnosis and treatment of fourth branchial cleft deformity. Methods The clinical data of a patient with bilateral fourth branchial cleft deformity in the neck were summarized, and the literature was reviewed. Results The patient was a 17-year-old male who had a painless lump in his neck for 10 years. During specialized examination, a lump approximately 4.0 cm × 3.0 cm in size could be palpated subcutaneously on the right side of the neck, with clear boundaries, a regular shape, a soft texture, and a wave-like sensation without obvious tenderness. A fistula with a size of approximately 0.5 cm × 0.5 cm could be observed on the left side of the neck, and yellow clear liquid could be seen flowing out of the fistula. The surrounding skin was locally red and swollen, and the surface temperature of the skin was elevated. Computed tomography examination demonstrated a circular cystic low-density shadow approximately 4.4 cm × 3.4 cm in size in the right supraclavicular and anterior cervical regions. A flocculent isodense image could be observed in the middle; moreover, nodular calcification could be observed at the edge, and the surrounding fat spaces were blurred. The enhanced scan showed mild enhancement of the cyst wall but no obvious enhancement of the contents. On the left side, a circular nodular shadow with a diameter of approximately 1.4 cm could be seen, with enhanced scanning and circular enhancement. The surrounding skin was thickened, and the subcutaneous fat gap was blurred. Multiple small lymph nodes could be observed on both sides of the neck, with the larger nodes having a short diameter of approximately 0.8 cm. The size and morphology of the thyroid gland were not significantly abnormal, and there was no obvious abnormal density shadow inside of the gland. Upon admission, the diagnosis was a fourth gill fissure cyst in the right neck and a fourth gill fissure fistula in the left neck. Under general anesthesia and intravenous anesthesia, right branchial cleft cyst resection and left branchial cleft fistula resection were performed. Postoperative pathological examination demonstrated a left branchial cleft fistula and a right branchial cleft cyst. The wound healed by first intention, and there was no recurrence after 6 months of follow-up. According to the literature, fourth branchial cleft deformity is a congenital developmental abnormality of the branchial apparatus, the incidence of which accounts for only 1% of all branchial cleft deformities; moreover, it often occurs on the left side. The anatomical position is often located in the cervical root and supraclavicular region, thus demonstrating cysts or sinuses adjacent to the thyroid gland. The diagnosis should be confirmed by anatomical location, imaging examination or laryngoscopy combined with postoperative pathological results and should be differentiated from cervical masses such as thyroglossal duct cysts and lymph node metastasis. The main treatment methods include surgical procedures and endoscopic cauterization of the internal fistula. The prognosis is generally good, and there is a risk of recurrence; however, cancer rarely occurs. Conclusion Deformity of the fourth branchial fissure is very rare; thus, it should be identified early to avoid excessive and ineffective surgical drainage, reduce potential complications during resection and completely remove the lesion to prevent recurrence.
Graphene family nanomaterials (GFNs) are highly popular in the field of bone tissue engineering because of their excellent mechanical properties, biocompatibility, and ability to promote the osteogenic differentiation of stem cells. GFNs play a multifaceted role in promoting the bone regeneration microenvironment. First, GFNs activate the adhesion kinase/extracellularly regulated protein kinase (FAK/ERK) signaling pathway through their own micromorphology and promote the expression of osteogenesis-related genes. Second, GFNs adapt to the mechanical strength of bone tissue, which helps to maintain osseointegration; by adjusting the stiffness of the extracellular matrix, they transmit the mechanical signals of the matrix to the intracellular space with the help of focal adhesions (FAs), thus creating a favorable physiochemical microenvironment. Moreover, they regulate the immune microenvironment at the site of bone defects, thus directing the polarization of macrophages to the M2 type and influencing the secretion of relevant cytokines. GFNs also act as slow-release carriers of bioactive molecules with both angiogenic and antibacterial abilities, thus accelerating the repair process of bone defects. Multiple types of GFNs regulate the bone regeneration microenvironment, including scaffold materials, hydrogels, biofilms, and implantable coatings. Although GFNs have attracted much attention in the field of bone tissue engineering, their application in bone tissue regeneration is still in the basic experimental stage. To promote the clinical application of GFNs, there is a need to provide more sufficient evidence of their biocompatibility, elucidate the mechanism by which they induce the osteogenic differentiation of stem cells, and develop more effective form of applications.
Successful treatment of endodontic and periapical diseases requires the elimination of bacteria and microbial biofilms from root canals. Currently, the most preferred irrigation method involves the delivery of sodium hypochlorite via the combination of a syringe and ultrasonic activation. Calcium hydroxide is the main choice for intracanal medicament between endodontic appointments and treatment. However, conventional chemical disinfection of root canals is controversial due to drug permeability and drug resistance. New small biomolecule formulations with high penetrability and bioremediatory capacity, including antimicrobial peptides such as M33D and LL-37, antisense RNA ASwalR/ASvicR and nanoparticles such as silver nanoparticles, mesoporous calcium-silicate nanoparticles and chitosan nanoparticles, have effective antibacterial and antibiofilm properties for use in root canal systems and dentinal tubules, thereby promoting the healing of apical lesions. However, the in vivo drug stability, biosafety, and clinical efficacy of small biomolecule formulations need further investigation. Future research will still focus on the improvement and combination of traditional drugs, as new small molecule formulations and ideal disinfectant drugs need to be developed. In the present paper, we reviewed the development of new antibacterial agents and application of small biomolecule formulations for chemical disinfection of infected root canals.
Oral lichenoid drug reactions (OLDRs) are inflammatory reactions of the oral mucosa caused by the use of specific drugs in sensitive individuals and are classified as oral lichenoid lesions (OLLs). Its clinical and pathological manifestations do not have significant specificity compared to other types of OLL. Various types of drugs have been reported to induce OLDR, including antihypertensive drugs, nonsteroidal anti-inflammatory drugs, hypoglycemic drugs, antipsychotics, and immunosuppressants, among other drugs. Apart from local or systemic administrate glucocorticoids, the most effective treatment measure is to stop using suspicious drugs. Most patients can achieve significant relief from mucosal ulcers and erosion, but white lines may still remain. OLDR has been widely reported in the literature. However, due to a lack of systematic understanding, we do not have a recognized standard for the diagnosis and treatment of this disease. There are still doubts about the causal relationship between related drugs and oral lichen-like lesions. In response to the abovementioned problems, we searched the literature on drug-related oral lichen planus and lichen-like lesions at home and abroad over the past 20 years, most of which were case reports and only a few of which were case-control studies. This article describes the current research status of lichenoid lesions from four perspectives: concepts, suspicious drugs, clinical and pathological manifestations, and treatment prognosis. We hope to provide a theoretical reference for the prevention, diagnosis, and clinical treatment of related lichenoid lesions. A literature review demonstrated that there are still many unclear issues related to the etiology, pathogenesis, clinical diagnosis and treatment, treatment prognosis, and other aspects of this disease, and further clinical and basic research is needed for in-depth exploration.
Adjunctive interventions for accelerating orthodontic tooth movement have been a hot topic of interest in orthodontics. Prolonged orthodontic treatment is often associated with multiple potential complications, such as decalcification, caries, root resorption, and gingival inflammation. Therefore, applying adjunctive interventions that accelerate orthodontic tooth movement and reduce the duration of orthodontic treatment can provide patients with numerous benefits that are of profound clinical significance. Currently, adjunctive interventions for accelerating orthodontic tooth movement can be divided into two main categories: surgical and nonsurgical. Surgical interventions, represented by corticotomy and modified corticotomy procedures, are the most common in clinical practice and can minimize the treatment duration, augment alveolar bone, and expand the range of orthodontic tooth movement. However, these procedures are inevitably traumatic and have many risks and limitations that prevent them from being widely used in clinical practice. In recent years, multiple modified corticotomy techniques, such as corticision, piezocision, micro-osteoperforation, and discision, have been proposed; these techniques can reduce soft and hard tissue damage and the incidence of postoperative complications and are relatively easy to perform in the clinic. Corticotomy and other improved surgical techniques can shorten the duration of orthodontic treatment to a certain extent and promote the recovery of periodontal health with no adverse effects on periodontal, dental, or pulp tissues. However, in clinical application, several potential side effects (such as periodontal tissue damage, root resorption, loss of pulp vitality, etc) and shortcomings need further research with long-term follow-up.
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