Full-mouth implant restoration has become an important method for restoring missing teeth. Over the past few years, there has been a rapid advancement in the field of computer-aided implantology, marked by significant innovations in digital implant planning and guided surgery. These improvements provide a more precise, simple, minimally invasive, and fast approach to the treatment of edentulous jaw, realizing the concept of “starting with the goal in mind, restoration-oriented”. This article aims to summarize the application of implant guides in full-mouth implant surgery and restoration, and to discuss their advantages and disadvantages.

Objective To study the three-dimensional changes of soft and hard tissue in male patients with unilateral non-syndromic cleft lip and palate in the mixed dentition period before and after maxillary protraction. Methods Twenty male patients with unilateral non-syndromic cleft lip and palate in the mixed dentition period treated by maxillary anterior traction in the Department of Orthodontics of Affiliated Stomatological Hospital of Nanjing Medical University were selected (average age (10.6±1.23) years old). Cone beam CT was taken before and after treatment. Dolphin 3D 11.95 software was used for three-dimensional measurement and analysis. SPSS 25.0 software package was used for statistical analysis. The self-controlled paired t test was used to compare the changes in soft and hard tissues of male patients with unilateral cleft lip and palate before and after treatment. The changes in the anterior displacement of the ANS point, the anterior displacement of point A, and the posterior displacement of point B were tested using the one-sample t test. Results The sagittal skeletal changes were significantly increased in ∠SNA (P<0.01), ∠ANB (P<0.01), Y axis (P<0.05), the forward displacement of ANS point(P<0.01)and A point(P<0.01)and the backward displacement of B point (P<0.01), but ∠SNB(P<0.05) was decreased significantly. The vertical skeletal changes showed that ∠MP-FH(P<0.01), ∠MP-SN (P<0.05) and the distance of ANS-Me(P<0.05)were increased significantly, but ∠SN-PP(P<0.01)was decreased significantly. The dental changes including ∠U1-NA(P<0.01), the distance of U1-NA(P<0.01), ∠U1-SN(P<0.01), overjet and the Wits were increased significantly, but ∠ L1-NB(P<0.01), the distance of L1-NB(P<0.01)and ∠L1-MP(P<0.01)were decreased significantly. The changes of soft tissue including ∠S-Ns-Sn(P<0.01), ∠Sn-Ns-Bs(P<0.01), the distance of UL-EP(P<0.01)and LL-UL(P<0.01)were increased significantly. Conclusion After the treatment of maxillary protraction, the forward growth of maxilla will be possibly promoted on patients with cleft lip and palate in the peak of growth timing, as well as the intermaxillary relationship and soft tissue profile, but the side effects should be paid attention to.

Objective To explore the therapeutic effect of injectable plateletrich fibrin(i-PRF) as a scaffold for pulp regeneration surgery in young permanent teeth with pulp necrosis. Methods Sixty young children with permanent tooth pulp necrosis who underwent pulp regeneration surgery in the Department of Stomatology of our hospital from March 2021 to October 2022 were included. The differentiation between the i-PRF group(33 cases)and the blood clot group(27 cases) was based on the different scaffold materials used during the treatment process. Follow up for 1 year, cone beam CT(CBCT) was used to measure the apical foramen diameter, dentin wall thickness, root length, root canal area, and root area of the affected tooth before treatment, at 3, 6, 9 and 12 months of treatment. The increase in root length, increase in dentin wall thickness, decrease in apical foramen diameter, increase in root area, decrease in root canal area, and clinical data between the two groups of patients before and after treatment were compared. The tooth color, pulp vitality, and tooth eruption height of two groups of patients were recorded before and after treatment. Results At 9 and 12 months post surgery follow-up, the root length, dentin wall thickness, and root area of the i-PRF group were higher than those of the blood clot group(P<0.05). According to the results of the last follow-up, it was calculated that the increase in root length, dentin wall thickness, and root area in the i-PRF group were higher than those in the blood clot group, and the differences were statistically significant(P<0.05). There was no statistically significant difference in the changes in tooth color, positive pulp vitality, and eruption height between the two groups of patients(P>0.05). Conclusion The use of blood clots and i-PRF as scaffolds for pulp regeneration in the treatment of young permanent tooth pulp necrosis has been proven to be effective, but the use of i-PRF as a scaffold is more effective in promoting root growth and increasing dentin wall thickness.

Objective To analyze the effect of different lateral occlusion patterns on the stress distribution of All-on-4 implanted fixed dentures. Methods A model of All-on-4 implant fixed denture was established, and lateral balanced occlusion, group functional occlusion, and canine protection occlusion was simulated by changing the loading method. The selected loading force was 200 N vertically and 30 N horizontally. Results The maximum stress values of each part of the simulated balanced occlusion model were the smallest, while the maximum stress values of each part of the canine protection model were the largest. The maximum stress values of each part of the group functional occlusion model were slightly larger than those of the balanced occlusion model, but significantly smaller than those of the canine protection model. Conclusion Group function occlusion could be selected for the lateral occlusion in the final restoration of All-on-4 implant prosthesis.

Objective To compare the impact of NaClO and EDTA pretreatment on the enamel surfaces pore exposure rate, resin infiltration effectiveness and shear bond strength between the enamel white spot lesions (WSLs) and resin composite. Methods A total of 104 sound premolars were selected for the study. 4 mm×4 mm×2 mm enamel blocks from 64 sound premolars were cut in the center of the buccal surfaces of the teeth. All blocks were randomly divided into five groups: group SE(sound enamels as negative control); group DE(enamel blocks demineralised as positive control); group RI(resin infiltration); group N/RI(5.25% NaClO pretreatment and resin infiltration) and group E/RI(17% EDTA pretreatment and resin infiltration). The pore exposure rate of enamel surfaces and resin penetration depths were observed by scanning electron microscopy(SEM) and confocallaser scanning microscopy(CLSM) in each group. The remaining 40 premolars were cut from the cervical roots and the residual crowns were embedded in self-condensing resin material(buccal surfaces of the enamel exposed only). According to the grouping information, the samples were given the corresponding pretreatments and resin infiltration respectively and were bonded with a cylindrical resin cylinder on the buccal enamel surface for shear bond test. The shear bond strength and fracture modes were recorded and analyzed in each group. Results Compared to group RI, the pore exposure rate of the enamel surface, resin penetration depths, and percentage of resin penetration area in the N/RI and E/RI groups were significantly increased(P<0.05). The shear bond strength of the samples in group SE was the highest, and the lowest in group DE. Compared to group DE, the shear bond strength in groups RI, N/RI, and E/RI was significantly increased(P<0.05). Conclusion Enamel surface pretreatment with 5.25% NaClO or 17% EDTA has been demonstrated to effectively enhance the enamel pore exposure rate, resin penetration depth and the shear bond strength between WSLs and resin composite.

Objective To explore the differences and similarities in the changes of pulp repair response after direct pulp capping with iRoot BP Plus and MTA. Methods A total of 36 male SD rats were randomly divided into 3 groups, namely iRoot BP Plus group, MTA group and blank control group. Dental pulp exposure and direct pulp capping was performed on both sides of maxillary first molars of each rat. Four rats were randomly selected and sacrificed from each group at 7, 14, and 28 days postoperatively, and the specimens were taken for hematoxylin-eosin (HE) staining, and then each index was observed. Results ①From the perspective of dentin tubular formation quality, at 14 d and 28 d, there were statistical differences between iRoot BP Plus group and MTA group(P<0.05), and iRoot BP Plus was significantly better than MTA in terms of quality of restorative dentin formation. ②At 14 days after operation, iRoot BP Plus had a greater area of neodontinin than that in MTA group(P<0.05). Conclusion Both iRoot BP Plus and MTA can promote the formation of restorative dentin bridges after direct pulp capping, and the formation quality is high. The long-term effects need to be further studied.

Objective To compare the effects of different attachments and their placement positions on the correction movements of intrusion, extrusion, rotation, and torque in the right mandibular canine using the three-dimensional finite element method. Methods A female patient treated in the Department of Orthodontics at the Urumqi City Stomatology Hospital in 2022 was chosen as the model subject. A three-dimensional finite element model was constructed to simulate various conditions of the right mandibular canine undergoing intrusion, extrusion, rotation, and torque movements with 21 different types of attachments placed at various positions. A load of 11.821 N was applied at the corresponding positions of the aligner attachments, and simulations were performed in Abaqus 6.14 software to collect stress and displacement distribution maps along with maximum stress and displacement values. Results In the simulation of orthodontic treatment for extrusion, the highest periodontal ligament Von Mises stress(PVMS)values and canine displacement occurred when the attachment was located at the upper region of buccal incisal. For the intrusion group, it was observed that PVMS values and contact stress of the alveolar bone, canine, aligner, and attachment gradually increased as the attachment position moved from the upper region to the lower region. In the torque simulation, the canine PVMS was the highest when the attachment was on the buccalupper region. In the rotation group, canine displacement incrementally increased as the attachment moved from the upper region to the lower region, regardless of whether it was on the lingual or buccal side. Conclusion ①For the extrusion, intrusion, and torque movements of the lower canine, the most suitable attachment positions are on the middle lingual side and middle buccal sideof the canine; for the rotational movement of the lower canine, the attachments should be placed on the middle buccal side, and lower lingual side. ②The lingual position of the tooth attachment greatly influences tooth movement and the distribution of stress.

Objective To evaluate the effect of sodium hypochlorite and Ultra Clean on root canal cleaning and dentin structure. Methods A total of 129 single canal isolated teeth were collected and root canal was prepared to M # with Waveone Gold nickel titanium file. After preparation, they were divided into 3 groups by random number table according to irrigant:group A sodium hypochlorite + normal saline, group B sodium hypochlorite +EDTA, and group C sodium hypochlorite +Ultra Clean. The dye was stained with 1% methylene blue solution, and the penetration depth and range of the dye solution were observed under a type microscope. The removal of debris and stain layer in the root canal was observed by digital camera and scanning electron microscope. The change of dentin microstructure was analyzed by Fourier infrared spectrometer. Results In the upper middle part of the root canal, the penetration depth and range of group C were greater than those of groups A and B (P<0.05); the percentage of debris in group C was lower than that of groups A and B (P<0.05), and the stain layer score in groups B and C was lower than that of group A (P<0.05). In the lower root canal segment, groups B and C were superior to group A in the evaluation of permeability, debris and stain removal (P<0.05). The demineralization ability and exposure of dentin collagen fiber in group C were higher than those in group A and blank group (P<0.05). Conclusion Sodium hypochlorite combined with Ultra Clean is considered to have good cleaning effect and strong demineralization ability, but it may slightly increase the exposure of organic matter such as collagen fiber.

Xeroderma pigmentosum (XP) is a rare autosomal recessive disorder related to XP gene variation, often causing secondary malignant tumors. This article reports a case of a young child with secondary squamous cell carcinoma of the lower lip caused by xeroderma pigmentosum. Through a review of relevant literature, the clinical characteristics, pathogenesis, clinical pathological manifestations, and prognosis of XP are discussed.

Objective To utilize the dental implant robot in the clinical instruction of oral implantology in order to popularize the technology and serve the medical education. Methods The effectiveness of the robotics teaching approach was assessed through a questionnaire. Results The dental implant robot technology has certain advantages in the clinical teaching of oral implant majors. Conclusion With the increasing popularity of digital implantation, the emerging dental implant robot has a wide range of applications and many advantages. It is very necessary to introduce it into the clinical teaching of oral implant majors.

Pulp regeneration is currently a hot topic in pulp disease research. With the development of regenerative medicine, pulp regeneration is transitioning from basic research to clinical applications, and stable results have been observed in some cases. However, achieving higher success rates and restoring pulp function remains a challenge in the field of pulp disease. Stem cells, growth factors, and scaffold materials are fundamental elements of tissue engineering. In recent years, dental pulp regeneration related scaffolds have received widespread attention, and new progress has been made in natural, human, and artificially synthesized scaffold materials. This article reviews the scaffold materials for pulp regeneration, aiming to provide reference for the selection of scaffold materials for dental pulp regeneration.

With the continuous progress of modern stomatology technology, intentional tooth replantation has become an effective treatment method for pulp and periapical diseases, as well as dental hard tissue diseases. It also provides functional treatment measures for preserving single tooth with severe periodontal destruction, subgingival tooth tissue defects, and jaw-bone cysts. In this paper, we systematically reviewed the extension of clinical application scope of the intention replantation, the different clinical operation (including teeth with only pulpal and periapical disease or teeth with severe periodontal destruction) during tooth replantation to provide reference for clinical application.

Occlusal reconstruction is an important method of restoring a normal occlusal relationship to the natural dentition. The correct choice of lateral occlusion scheme is necessary for physiological occlusal reconstruction. The main lateral occlusion schemes for the occlusal reconstruction of the natural dentition are canine protection and group function. This article reviews the effects of lateral occlusion schemes on the stomatognathic system and factors affecting the choice of lateral occlusion schemes in the occlusal reconstruction of natural dentition. According to the literature review, the lateral occlusion schemes affect the physiological functions of the stomatognathic system. Both lateral occlusion schemes have less impact on the temporomandibular joint. Group function produces greater EMG activity, jaw movement velocity, and jaw lateral freedom than canine protection. The lateral occlusion schemes of the natural dentition should be selected according to the degree of lateral movement, types of static occlusion, and age of patients. For patients with Angle’s Class Ⅲ malocclusion, skeletal Class Ⅱ,Ⅲ malocclusion, and the elderly, group function is recommended, while canine protection is more recommended for young adults. For patients who eventually need to achieve canine protection, it is recommended to design group function in the early stage of lateral movement, and gradually transition to canine protection with the increase of lateral movement. Thus, clinicians need to fully understand the influencing factors of lateral occlusion selection during occlusal reconstruction in natural dentition, providing a basis for the development of personalized diagnostic and treatment plans.

In recent years, natural antimicrobial biomaterials have received widespread attention due to their rich sources, broad antimicrobial spectrum, high antimicrobial activity, good biocompatibility, etc. They play an important role in caries prevention and treatment by inhibiting the formation of biofilm and removing the formed biofilm. In this paper, we summarize the inhibitory effects of different natural antimicrobial biomaterials on Streptococcus mutans, the main caries-causing organism, and its biofilm, with a view to providing theoretical references for caries prevention and treatment.