Assessment of soft and hard tissue changes following micro crestal flap-Alveolar ridge preservation and augmentation at molar extraction sites in patients with stage III/IV periodontitis: A randomized controlled trial.

AIM: This study aimed to assess hard and soft tissue contour changes following micro crestal flap-alveolar ridge preservation (MCF-ARP) and natural healing (NH) in periodontally compromised molar extraction sites and to analyse the feasibility and need for bone augmentation during implant therapy. MATERIALS AND METHODS: Fifty-six patients with 70 sites were randomized into two groups at the site level (35 sites from 31 patients in the test group and 35 sites from 29 patients in the control group). Among whom, four patients contributed one tooth to the control group and one tooth to the test group. Hard tissue indicators were measured using cone beam computed tomography performed before tooth extraction and 6 months after surgery. Soft tissue contour changes were assessed using intraoral scanning performed before and immediately after surgery and also 2 weeks and 1, 3 and 6 months after surgery. RESULTS: Six months after surgery, the MCF-ARP group showed less resorption in buccal bone height (p = .032) and greater augmentation in central bone height (p = .001) and ridge width (p = .009). The mean, vertical and horizontal collapse of buccal soft tissue contour in the MCF-ARP group were 0.95 mm (p = .010), 0.61 mm (p = .019) and 0.56 mm (p = .013) less than that in the NH group, respectively. There were significantly (p = .007) fewer sites in the MCF-ARP group than in the NH group (0% vs. 26.7%) for staged bone augmentation and more sites that could be treated with simple implant procedure in the MCF-ARP group than in the NH group (71.9% vs. 56.6%). CONCLUSIONS: Compared with NH, MCF-ARP reduced bone resorption in periodontally compromised molar extraction sites and maintained the buccal soft tissue contour. MCF-ARP reduces the need for complex bone augmentation procedures in implant therapy. TRIAL REGISTRATION: Chinese Clinical Trial Register (ChiCTR) ChiCTR2200056335. Registered on 4 February 2022, Version 1.0.

Single-cell RNA sequencing reveals different chondrocyte states in femoral cartilage between osteoarthritis and healthy individuals.

Background: Cartilage injury is the main pathological manifestation of osteoarthritis (OA). Healthy chondrocyte is a prerequisite for cartilage regeneration and repair. Differences between healthy and OA chondrocyte types and the role these types play in cartilage regeneration and OA progression are unclear. Method: This study conducted single-cell RNA sequencing (scRNA-seq) on the cartilage from normal distal femur of the knee (NC group) and OA femur (OA group) cartilage, the chondrocyte atlas was constructed, and the differences of cell subtypes between the two groups were compared. Pseudo-time and RNA velocity analysis were both performed to verify the possible differentiation sequence of cell subtypes. GO and KEGG pathway enrichment analysis were used to explore the potential functional characteristics of each cell subtype, and to predict the functional changes during cell differentiation. Differences in transcriptional regulation in subtypes were explored by single-cell regulatory network inference and clustering (SCENIC). The distribution of each cell subtype in cartilage tissue was identified by immunohistochemical staining (IHC). Result: A total of 75,104 cells were included, they were divided into 19 clusters and annotated as 11 chondrocyte subtypes, including two new chondrocyte subtypes: METRNL+ and PRG4+ subtype. METRNL+ is in an early stage during chondrocyte differentiation, and RegC-B is in an intermediate state before chondrocyte dedifferentiation. With cell differentiation, cell subtypes shift from genetic expression to extracellular matrix adhesion and collagen remodeling, and signal pathways shift from HIF-1 to Hippo. The 11 subtypes were finally classified as intrinsic chondrocytes, effector chondrocytes, abnormally differentiated chondrocytes and dedifferentiated chondrocytes. IHC was used to verify the presence and distribution of each chondrocyte subtype. Conclusion: This study screened two new chondrocyte subtypes, and a novel classification of each subtype was proposed. METRNL+ subtype is in an early stage during chondrocyte differentiation, and its transcriptomic characteristics and specific pathways provide a foundation for cartilage regeneration. EC-B, PRG4+ RegC-B, and FC are typical subtypes in the OA group, and the HippO-Taz pathway enriched by these cell subtypes may play a role in cartilage repair and OA progression. RegC-B is in the intermediate state before chondrocyte dedifferentiation, and its transcriptomic characteristics may provide a theoretical basis for intervening chondrocyte dedifferentiation.

A Novel Multiepitope Fusion Antigen as a Vaccine Candidate for the Prevention of Enterotoxigenic E. coli-Induced Calf Diarrhea.

Calf diarrhea caused by enterotoxigenic E. coli (ETEC) poses an enormous economic challenge in the cattle industry. Fimbriae and enterotoxin are crucial virulence factors and vaccine targets of ETEC. Since these proteins have complicated components with large molecular masses, the development of vaccines by directly expressing these potential targets is cumbersome Therefore, this study aimed to develop a multiepitope fusion antigen designated as MEFA by integrating major epitopes of FanC and Fim41a subunits and a toxoid epitope of STa into the F17G framework. The 3D modeling predicted that the MEFA protein displayed the epitopes from these four antigens on its surface, demonstrating the desired structural characteristics. Then, the MEFA protein was subsequently expressed and purified for mouse immunization. Following that, our homemade ELISA showed that the mouse antiserum had a consistent increase in polyclonal antibody levels with the highest titer of 1:217 to MEFA. Furthermore, the western blot assay demonstrated that this anti-MEFA serum could react with all four antigens. Further, this antiserum exhibited inhibition on ETEC adhesion to HCT-8 cells with inhibitory rates of 92.8%, 84.3%, and 87.9% against F17+, F5+, and F41+ ETEC strains, respectively. Additionally, the stimulatory effect of STa toxin on HCT-8 cells was decreased by approximately 75.3% by anti-MEFA serum. This study demonstrates that the MEFA protein would be an antigen candidate for novel subunit vaccines for preventing ETEC-induced diarrhea in cattle.

Causal relationship between feelings and cognitive decline: An univariable and multivariable Mendelian randomization study.

BACKGROUND: While the impact of depression on cognition is well-documented, the relationship between feelings and cognition has received limited attention. AIM: To explore the potential association between feelings and cognition with a two-sample Mendelian randomization (MR) analysis. METHODS: Our analysis utilized genome-wide association data on various feelings (fed-up feelings, n = 453071; worrier/anxious feelings, n = 450765; guilty feelings, n = 450704; nervous feelings, n = 450700; sensitivity/hurt feelings, n = 449419; miserableness, n = 454982; loneliness/isolation, n = 455364; happiness, n = 152348) in the European population and their impact on cognitive functions (intelligence, n = 269867). Conducting a univariable MR (UVMR) analysis to assess the relationship between feelings and cognition. In this analysis, we applied the inverse variance weighting (IVW), weighted median, and MR Egger methods. Additionally, we performed sensitivity analysis (leave-one-out analysis), assessed heterogeneity (using MR-PRESSO and Cochran's Q test), and conducted multiple validity test (employing MR-Egger regression). Subsequently, a multivariable MR (MVMR) analysis was employed to examine the impact of feelings on cognition. IVW served as the primary method in the multivariable analysis, complemented by median-based and MR-Egger methods. RESULTS: In this study, UVMR indicated that sensitivity/hurt feelings may have a negative causal effect on cognition (OR = 0.63, 95%CI: 0.43-0.92, P = 0.017). After adjustment of other feelings using MVMR, a direct adverse causal effect on cognition was observed (ORMVMR = 0.39, 95%CI: 0.17-0.90, PMVMR = 0.027). While a potential increased risk of cognitive decline was observed for fed-up feelings in the UVMR analysis (ORUVMR = 0.64, 95%CI: 0.42-0.97, PUVMR = 0.037), this effect disappeared after adjusting for other feelings (ORMVMR = 1.42, 95%CI: 0.43-4.74, PMVMR = 0.569). These findings were generally consistent across MV-IVW, median-based, and MR-Egger analyses. MR-Egger regression revealed pleiotropy in the impact of worrier/anxious feelings on cognition, presenting a challenge in identifying the effect. Notably, this study did not demonstrate any significant impact of guilty feelings, nervous feelings, miserableness, or loneliness/isolation on cognition. Due to a limited number of instrumental variables for happiness, this study was unable to analyze the relationship between happiness and cognition. CONCLUSION: This MR study finds that sensitivity/hurt feelings are associated with cognitive decline, while the link between worrier/anxious feelings and cognition remains inconclusive. Insufficient evidence supports direct associations between happiness, guilty feelings, nervous feelings, miserableness, loneliness/isolation, and cognition.

Standardizing norms for 1286 colored pictures in Cantonese.

This study established psycholinguistic norms in Cantonese for a set of 1286 colored pictures sourced from several picture databases, including 750 colored line drawings from MultiPic (Duñabeitia et al., 2018) and 536 photographs selected for McRae et al. (2005) concepts. The pictures underwent rigorous normalization processes. We provided picture characteristics including name and concept agreement, familiarity, visual complexity, and frequency of modal responses. Through correlational analyses, we observed strong interrelationships among these variables. We also compared the current Cantonese norming to other languages and demonstrated similarity and variations among different languages. Additionally, we embraced the multilingual diversity within the current sample, and found that higher Cantonese proficiency but lower non-native language proficiency were associated with better spoken picture naming. Last but not least, we validated the predictive power of normed variables calculated from typed responses to spoken picture naming, and the consistency between typed and spoken responses. The present norming provides a timely and valuable alternative for researchers in the field of psycholinguistics, especially those studying Cantonese production and lexical retrieval. All raw data, analysis scripts, and final norming results are available online as psycholinguistic norms for Cantonese in the following link at the Open Science Framework: https://osf.io/dz9j6/?view_only=a452d8a56c92430b9dedf21ac26b1bc1 .

Ridge preservation in periodontally compromised molar sockets with and without primary wound closure: A comparative controlled clinical trial.

OBJECTIVE: This study aimed to compare hard- and soft-tissue changes after ridge preservation in periodontally compromised molar sockets with and without primary wound closure. MATERIALS AND METHODS: Forty molars with severe periodontitis requiring extraction were included and allocated to two treatment modalities. After tooth extraction, the sockets were filled with deproteinized bovine bone mineral and covered with a bioabsorbable porcine collagen membrane. Primary wound closure was achieved in the control group, whereas the test group underwent minimally invasive open healing. The dimensions of the bone and soft tissue were recorded at baseline and 6 months. RESULTS: Over 6 months, the control and test groups had similar mean ridge heights at the center of sockets of 8.59 ± 2.47 mm and 8.47 ± 2.51 mm, respectively. The total volume of the control group increased from 1070.17 to 1713.52 mm3 for a mean gain of 643.35 mm3 , whereas that of the test group increased from 992.51 to 1514.05 mm3 for a mean gain of 521.54 mm3 . Compared with the test group, the control group showed a statistically significant decrease in keratinized tissue width of 1.08 ± 1.63 mm. CONCLUSIONS: Bone dimensional changes following ridge preservation with and without primary wound closure were comparable. ARP without primary wound closure preserves more keratinized tissue than that with (Chinese Clinical Trial Registry: ChiCTR-ONN-16009433).

Mechanistic insights into the effects of diuron exposure on Alexandrium pacificum.

Diuron (N-(3,4-dichlorophenyl)-N,N­dimethylurea, DCMU), a ureic herbicide, is extensively used in agriculture to boost crop productivity; however, its extensive application culminates in notable environmental pollution, especially in aquatic habitats. Therefore, the present study investigated the effect of diuron on the dinoflagellate Alexandrium pacificum, which is known to induce harmful algal blooms (HAB), and its potential to biodegrade DCMU. Following a four-day DCMU exposure, our results revealed that A. pacificum proficiently assimilated DCMU at concentrations of 0.05 mg/L and 0.1 mg/L in seawater, attaining a complete reduction (100 % efficiency) after 96 h for both concentrations. Moreover, evaluations of paralytic shellfish toxins content indicated that cells subjected to higher DCMU concentrations (0.1 mg/L) exhibited reductions of 73.4 %, 86.7 %, and 75 % in GTX1, GTX4, and NEO, respectively. Exposure to DCMU led to a notable decrease in A. pacificum's photosynthetic efficacy, accompanied by increased levels of reactive oxygen species (ROS) and suppressed cell growth, with a growth inhibition rate of 41.1 % at 72 h. Proteomic investigations pinpointed the diminished expression levels of specific proteins like SxtV and SxtW, linked to paralytic shellfish toxins (PSTs) synthesis, as well as key proteins associated with Photosystem II, namely PsbA, PsbD, PsbO, and PsbU. Conversely, proteins central to the cysteine biosynthesis pathways exhibited enhanced expression. In summary, our results preliminarily resolved the molecular mechanisms underlying the response of A. pacificum to DCMU and revealed that DCMU affected the synthesis of PSTs. Meanwhile, our data suggested that A. pacificum has great potential in scavenging DCMU.

NLRP3 Inflammasome: An Emerging Therapeutic Target for Alzheimer's Disease.

Alzheimer's disease (AD) is currently the most prevalent neurological disease, and no effective and practical treatments and therapies exist. The nucleotide-binding oligomerization domain-, leucine-rich repeat-, and pyrin domain- containing receptor 3 (NLRP3) inflammasome is vital in the human innate immune response. However, when the NLRP3 inflammasome is overactivated by persistent stimulation, several immune-related diseases, including AD, atherosclerosis, and obesity, result. This review will focus on the composition and activation mechanism of the NLRP3 inflammasome, the relevant mechanisms of involvement in the inflammatory response to AD, and AD treatment targeting NLRP3 inflammasome. This review aims to reveal the pathophysiological mechanism of AD from a new perspective and provide the possibility of more effective and novel strategies for preventing and treating AD.

Multilingual Language Diversity Protects Native Language Production under Different Control Demands.

The use of multiple languages has been found to influence individuals' cognitive abilities. Although some studies have also investigated the effect of multilingualism on non-native language proficiency, fewer studies have focused on how multilingual experience affects native language production. This study investigated the effect of multilingualism on native language production, specifically examining control demands through a semantic Go/No-Go picture naming task. The multilingual experience was quantified using language entropy, which measures the uncertainty and diversity of language use. Control demands were achieved by manipulating the proportion of Go (i.e., naming) trials in different conditions. Results showed that as control demands increased, multilingual individuals exhibited poorer behavioral performance and greater brain activation throughout the brain. Moreover, more diverse language use was associated with higher accuracy in naming and more interconnected brain networks with greater involvement of domain-general neural resources and less domain-specific neural resources. Notably, the varied and balanced use of multiple languages enabled multilingual individuals to respond more efficiently to increased task demands during native language production.

Resting State Network Segregation Modulates Age-Related Differences in Language Production.

Older adults typically exhibit decline in language production. However, how the brain supports or fails to support these processes is unclear. Moreover, there are competing hypotheses about the nature of age-related neural changes and whether age-related increases in neural activity reflect compensation or a decline in neural efficiency. In the current study, we investigated the neural bases of language production focusing on resting state functional connectivity. We hypothesized that language production performance, functional connectivity, and their relationship would differ as a function of age. Consistent with prior work, older age was associated with worse language production performance. Functional connectivity analyses showed that network segregation within the left hemisphere language network was maintained across adulthood. However, increased age was associated with lower whole brain network segregation. Moreover, network segregation was related to language production ability. In both network analyses, there were significant interactions with age-higher network segregation was associated with better language production abilities for younger and middle-aged adults, but not for older adults. Interestingly, there was a stronger relationship between language production and the whole brain network segregation than between production and the language network. These results highlight the utility of network segregation measures as an index of brain function, with higher network segregation associated with better language production ability. Moreover, these results are consistent with stability in the left hemisphere language network across adulthood and suggest that dedifferentiation among brain networks, outside of the language network, is a hallmark of aging and may contribute to age-related language production difficulties.

Soluble expression and purification of recombinant bovine ferritin H-chain.

Ferritin is a potential medicine delivery vehicle and vaccine platform, and its efficient expression is a prerequisite for widespread application. This study introduces a soluble expression strategy for recombinant bovine ferritin heavy chain (rFTH) in a prokaryotic system and an improved protein purification method. The amplified rFTH gene was ligated into the prokaryotic expression vector pET30a. The recombinant vectors with the N-terminal His-tag(N-His) or C-terminal His-tag(C-His) were translated and expressed separately. The results showed that the solubility of rFTH with C-His was significantly higher than that with N-His. The expression of rFTH with C-His was attempted at 37 °C and 16 °C, respectively. The results showed that the proportion of soluble protein expressed at 37 °C was more than 90%, higher than that expressed at 16 °C. Then rFTH with C-His was purified successfully using anion exchange chromatography, modified PEG precipitation, and dialysis. The rFTH protein was characterized using SDS-PAGE, Native-PAGE, Western blot, transmission electron microscopy, and dynamic light scattering. The results demonstrated that the purified rFTH protein self-assembled into ferritin nanoparticles with a regular shape and uniform size. This study sheds new light on the soluble expression of ferritin and provides a foundation for the construction of bovine ferritin nanoparticle production platforms.

LncRNA MAGI2-AS3-Encoded Polypeptide Restrains the Proliferation and Migration of Breast Cancer Cells.

Accumulating articles have reported the coding potential of long non-coding RNAs (lncRNAs). However, only a few lncRNAs-encoded peptides have been studied. Breast cancer (BRCA) progression-related gene modules were determined by weighted gene co-expression network analysis (WGCNA). Cell viability, proliferation, and migration capacities were assessed by Cell counting kit-8 (CCK8), 5-ethynyl-2'-deoxyuridine (EdU), and transwell assays. Immunofluorescence (IF) assay was implemented to observe protein expression. Co-immunoprecipitation (Co-IP) and high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) were employed to analyze MAGI2 antisense RNA 3 (MAGI2-AS3)-ORF5-interacted proteins. WGCNA identified that MEpurple and MEblack modules were significantly negatively correlated with T stage in BRCA patients. MAGI2-AS3 was screened as one of the differentially expressed (DE) lncRNAs with translational potential in MEblack and MEpurple modules in BRCA. The data in The Cancer Genome Atlas (TCGA) uncovered that MAGI2-AS3 abundance was significantly decreased in invasive BRCA patients, and it had high diagnostic and prognostic values. MAGI2-AS3-ORF5 notably restrained BRCA cell viability, proliferation, and migration. Mechanically, MAGI2-AS3-ORF5 might affect the progression of BRCA cells by binding to extracellular matrix (ECM)-related proteins. MAGI2-AS3-ORF5 played an anti-tumor role by inhibiting BRCA cell viability, proliferation, and migration. MAGI2-AS3-ORF5 might modulate BRCA cell migration through ECM-associated proteins.

Task difficulty modulates age-related differences in functional connectivity during word production.

Older adults typically report increased difficulty with language production, while its neural bases are less clear. The current study investigated the neural bases of age-related differences in language production at the word level and the modulating effect of task difficulty, focusing on task-based functional connectivity. Using an English phonological Go/No-Go picture naming task, task difficulty was manipulated by varying the proportion of naming trials (Go trials) and inhibition trials (No-Go trials) across runs. Behaviorally, compared to younger adults, older adults performed worse, and showed larger effects of task difficulty. Neurally, older adults had lower within language network connectivity compared to younger adults. Moreover, older adults' language network became less segregated as task difficulty increased. These results are consistent with the Compensation-Related Utilization of Neural Circuits Hypothesis, suggesting that the brain becomes less specified and efficient with increased task difficulty, and that these effects are stronger among older adults (i.e., more dedifferentiated).

A rare gas-containing lumbar synovial cyst treated by percutaneous transforaminal endoscopic cystectomy: A case report and literature review.

Spinal synovial cysts are rare entities for which standard surgical strategies are inconsistent. Here, we present an uncommon intraspinal gas-containing synovial cyst treated by percutaneous transforaminal endoscopic cystectomy. A 52-year-old man presented with radicular pain and intermittent claudication that had persisted for one month. Computed tomography revealed an intraspinal cystic lesion anteromedial to the left L4-L5 articular joint and the center of the lesion manifested gas contents. A transforaminal endoscopic procedure was performed and confirmed as a safe and minimally invasive technique for gas-containing lumbar synovial cysts. It provides a valuable substitution and supplementation to open surgery.

Induced Pluripotent Stem Cells and Their Applications in Amyotrophic Lateral Sclerosis.

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease that results in the loss of motor function in the central nervous system (CNS) and ultimately death. The mechanisms underlying ALS pathogenesis have not yet been fully elucidated, and ALS cannot be treated effectively. Most studies have applied animal or single-gene intervention cell lines as ALS disease models, but they cannot accurately reflect the pathological characteristics of ALS. Induced pluripotent stem cells (iPSCs) can be reprogrammed from somatic cells, possessing the ability to self-renew and differentiate into a variety of cells. iPSCs can be obtained from ALS patients with different genotypes and phenotypes, and the genetic background of the donor cells remains unchanged during reprogramming. iPSCs can differentiate into neurons and glial cells related to ALS. Therefore, iPSCs provide an excellent method to evaluate the impact of diseases on ALS patients. Moreover, patient-derived iPSCs are obtained from their own somatic cells, avoiding ethical concerns and posing only a low risk of immune rejection. The iPSC technology creates new hope for ALS treatment. Here, we review recent studies on iPSCs and their applications in disease modeling, drug screening and cell therapy in ALS, with a particular focus on the potential for ALS treatment.

Intraoperative dexmedetomidine on postoperative pain in gastrointestinal surgery: an observational study.

BACKGROUND: Dexmedetomidine (DEX) is widely used for adjuvant sedation and analgesia in gastrointestinal surgeries. The authors aimed to reassess the effects of intraoperative DEX on acute pain by comprehensive analysis of the multiple dimensions of pain. MATERIALS AND METHODS: In this multicentre cohort study, patients undergoing gastrointestinal surgeries were prospectively enrolled in the China Acute Postoperative Pain Study. Patients were divided into DEX and non-DEX groups based on whether DEX was used during surgery. Patient satisfaction with pain treatment (rated on a numeric rating score, 0-10) and other pain-related outcomes were evaluated using the International Pain Outcome Questionnaire on the first postoperative day. The effects of intraoperative DEX were analyzed using logistic or linear regression for dichotomous or continuous variables, respectively. Propensity score matching and subgroup analyses were performed to appraise the correlation between intraoperative DEX and postoperative pain outcomes. RESULTS: Of the 1260 patients eligible for analysis, 711 (56.4%) received intraoperative DEX. Propensity score matching resulted in 415 patients in each group. Intraoperative DEX was associated with higher patient satisfaction (ß: 0.556; 95% CI: 0.366-0.745), and a decrease in the percentage of time spent in severe pain (ß: -0.081; 95% CI: -0.104- -0.058), anxiety (odds ratio: 0.394; 95% CI: 0.307-0.506), helplessness (odds ratio: 0.539; 95% CI: 0.411-0.707), and postoperative opioid consumption (ß: -16.342; 95% CI: -27.528- -5.155). CONCLUSIONS: Intraoperative DEX was associated with the prognosis of acute postoperative pain in multiple aspects in patients undergoing major gastrointestinal surgery, including increased patient satisfaction, and a reduction in the duration of severe pain, postoperative anxiety and helplessness, and postoperative opioid consumption. Future studies to determine the dose and timing of DEX administration on pain-related outcomes are warranted.

Multivariate decoding methods reveal how speaking two dialects affects executive functions.

How speaking two languages affects executive functions has been a long-standing debate and the mechanisms underlying the observed cognitive advantages of bilingualism remain unspecified. Here, using multivariate pattern classification methods, we decoded spatial patterns of neural signals associated with Flanker task performance in mono-dialectal and bi-dialectal speakers of Chinese. While univariate approach to even-related potentials (ERPs) showed no between-group difference, decoding accuracy of ERPs was reduced in bi-dialectal as compared to mono-dialectal speakers in both congruent-neutral and incongruent-neutral classifications. There was no effect of bidialectalism, however, on decoding accuracy of alpha-band oscillations, an electrophysiological index implicated in inhibition. Behavioural data analysed using the Drift Diffusion Model (DDM) showed facilitating effects of bidialectalism on non-decision times but no effect on drift rates. These findings demonstrate that using two dialects on a daily basis enhances general attentional deployment rather than affecting specific component of executive functions such as inhibitory control. Given that the two dialects of Chinese differed almost exclusively in phonology, the bidialectalism effect was most likely motivated by resolving phonological competition at lexical processing level.

Three-dimensional position changes of unopposed molars before implant rehabilitation: a short-term retrospective cohort analysis.

OBJECTIVE: To investigate the spatial changes of unopposed molars within the period between the antagonist extraction and the final implant restoration using data from cone beam computed tomography. METHODS: A total of 59 patients with 68 unopposed molars were included in this study. Three-dimensional models reconstructed from cone beam computed tomography data before and after loss of the antagonist were superimposed to measure the spatial changes. The overeruption and tipping of target teeth were calculated by coordinate values. RESULTS: The result of overeruption over the study period (9.2 ± 4.3 months) was expressed by two values: the mean overeruption of molar cups (0.432 mm) and the maximum overeruption of cusps (0.753 mm), which were statistically significant compared to the baseline level (p < 0.001). The average tipping was 1.717 degrees in the buccal direction. CONCLUSIONS: Unopposed molars displayed overeruption throughout the study period (9.2 ± 4.3 months), which indicates that the clinicians should pay attention to the possibilities of overeruption and make appropriate interventions in their clinical practice. The establishment of three-dimensional measuring methods using cone beam computed tomography data helps analyze spatial changes.

Assessment of soft and hard tissue characteristics of ridge preservation at molar extraction sites with severe periodontitis: a randomized controlled trial.

BACKGROUND: Changes in alveolar bone dimension after tooth extraction may affect placement of the subsequent implant, resulting in ridge deficiency that can adversely impact long-term implant stability or aesthetics. Alveolar ridge preservation (ARP) was effective in reducing the amount of ridge resorption following tooth extraction. There is sparse evidence regarding the benefit of ARP at periodontally compromised molar extraction sockets. This study will be a randomized trial to assess the soft tissue contour, radiographical, and histological changes of ARP at molar extraction sites in order to compare severe periodontitis cases with natural healing results and determine the most beneficial and least traumatic clinical treatment for such patients. METHODS: This research is designed as a two-group parallel randomized controlled trial. The total number of tooth extraction sites will be 70 after calculation with power analysis. Teeth will be randomly assigned to two groups with the test group conducting ridge preservation and the control group healing naturally. Periodontal examination, cone beam-computed tomography (CBCT) data, and stereolithographic (STL) files obtained by intraoral scanning will be collected through the follow-up period, and bone biopsy samples would be obtained during implant surgery. The primary outcomes are the vertical and horizontal change of alveolar ridge measured on CBCT images, soft tissue contour changes evaluated by superimposing the digital impressions, alterations of mucosa thickness (as measured by superimposing the CBCT data and STL files), histological features of implant sites and periodontal parameter changes. The secondary outcomes are patient-reported post-operative reaction and conditions of simultaneous bone graft or sinus lifting procedures during implantation. DISCUSSION: This study will provide information about hard and soft tissue dimension changes and histomorphology evaluation following ARP and natural healing in periodontally compromised molar sites, which may contribute to complement the missing information of ARP at periodontally compromised molar extraction sockets. TRIAL REGISTRATION: Chinese Clinical Trial Register (ChiCTR) ChiCTR2200056335. Registered on February 4, 2022, Version 1.0.