Fluorinated hydroxyapatite conditions a favorable osteo-immune microenvironment via triggering metabolic shift from glycolysis to oxidative phosphorylation.

BACKGROUND: Biological-derived hydroxyapatite is widely used as a bone substitute for addressing bone defects, but its limited osteoconductive properties necessitate further improvement. The osteo-immunomodulatory properties hold crucial promise in maintaining bone homeostasis, and precise modulation of macrophage polarization is essential in this process. Metabolism serves as a guiding force for immunity, and fluoride modification represents a promising strategy for modulating the osteoimmunological environment by regulating immunometabolism. In this context, we synthesized fluorinated porcine hydroxyapatite (FPHA), and has demonstrated its enhanced biological properties and osteogenic capacity. However, it remains unknown whether and how FPHA affects the immune microenvironment of the bone defects. METHODS: FPHA was synthesized and its composition and structural properties were confirmed. Macrophages were cultured with FPHA extract to investigate the effects of FPHA on their polarization and the related osteo-immune microenvironment. Furthermore, total RNA of these macrophages was extracted, and RNA-seq analysis was performed to explore the underlying mechanisms associated with the observed changes in macrophages. The metabolic states were evaluated with a Seahorse analyzer. Additionally, immunohistochemical staining was performed to evaluate the macrophages response after implantation of the novel bone substitutes in critical size calvarial defects in SD rats. RESULTS: The incorporation of fluoride ions in FPHA was validated. FPHA promoted macrophage proliferation and enhanced the expression of M2 markers while suppressing the expression of M1 markers. Additionally, FPHA inhibited the expression of inflammatory factors and upregulated the expression of osteogenic factors, thereby enhancing the osteogenic differentiation capacity of the rBMSCs. RNA-seq analysis suggested that the polarization-regulating function of FPHA may be related to changes in cellular metabolism. Further experiments confirmed that FPHA enhanced mitochondrial function and promoted the metabolic shift of macrophages from glycolysis to oxidative phosphorylation. Moreover, in vivo experiments validated the above results in the calvarial defect model in SD rats. CONCLUSION: In summary, our study reveals that FPHA induces a metabolic shift in macrophages from glycolysis to oxidative phosphorylation. This shift leads to an increased tendency toward M2 polarization in macrophages, consequently creating a favorable osteo-immune microenvironment. These findings provide valuable insights into the impact of incorporating an appropriate concentration of fluoride on immunometabolism and macrophage mitochondrial function, which have important implications for the development of fluoride-modified immunometabolism-based bone regenerative biomaterials and the clinical application of FPHA or other fluoride-containing materials.

The influence of guide stabilizers and their application sequences on trueness and precision of surgical guides in free end situations: An in vitro analysis.

OBJECTIVES: To evaluate the impact of guide stabilizers and their application sequences on implant placement accuracy of guided implant surgery in multiple teeth loss at free end. MATERIALS AND METHODS: In this study, 96 implants were placed in the regions of #34, #36, and #37 of 32 identical mandibular models. The influence of using guide stabilizers or not (group A and group B) and various guide stabilizers application sequences (group B: #34 → #36 → #37; group C: #36 → #34 → #37; group D: #37 → #34 → #36) on implant placement trueness and precision was investigated. Data were analyzed using T-tests and one-way ANOVA. RESULTS: Group B showed significant benefits in enhancing implant placement precision. Compared to group A, it resulted in reducing 3D-deviation at crest and 2D deviation in vestibular-oral direction at both crest and apex. Furthermore, group D demonstrated greater improvement in global implant placement precision by reducing 2D deviation in mesial-distal direction at both crest and apex. Among the three different stabilizer application sequences, group D exhibited the highest level of implant placement precision. CONCLUSIONS: In cases of missing teeth at distal free end, the use of guide stabilizers and their application sequences does not have a significant impact on implant placement trueness. However, they do improve implant placement precision compared to methods that do not utilize guide stabilizers. Specifically, applying a guide stabilizer first at the furthest implant site to change teeth loss classification from free end to edentulous space with posterior support is the most reliable sequence.

Surgical performance of dental students using computer-assisted dynamic navigation and freehand approaches.

INTRODUCTION: Nowadays, the training of implant placement has shifted from once entirely instructor-student teaching to the increasing use of computer-assisted simulation. Based on computerized virtual planning, dynamic navigation has been used for implant placement with higher accuracy than the traditional freehand protocol. However, whether dynamic navigation benefits to the training of dental students in implant placement remains controversial. This study aimed to compare the surgical performance of dental students in implant placement using computer-assisted dynamic navigation and freehand approaches. MATERIALS AND METHODS: A total of 20 dental students (6 males, 14 females, age: 25.6 ± 0.5 years) were enrolled in this study. With the traditional freehand approach (training 1) as the control protocol, computer-assisted dynamic navigation (training 2) was used in the training of dental students in implant placement. For each training, both the operating time (OT) of students and placement accuracy represented by the linear (at the implant platform, Dpl, and apex, Dap) and angular (Dan) deviations between the virtually planned and placed implants were recorded. Statistical comparisons were made between the two training protocols as well as male and female surgeons. RESULTS: OT2 was around twice of OT1 (p < .0001), whereas Dan1 was almost three times of Dan2 (p < .0001). Dap1 and Dpl1 were significantly higher than Dap2 (p = .014) and Dpl2 (p = .033) respectively. Besides, male students showed statistically higher Dpl1 (p = .033) and Dan1 (p = .002) than females. No significant difference was found between male and female students in OT1, OT2, Dpl2, Dap1, Dap2 and Dan2. CONCLUSIONS: Within the limitations of this study, the use of computer-assisted dynamic navigation in the preclinical training could improve the surgical performance of the dental students in implant placement. The combination of dynamic navigation with the traditional preclinical surgical training may benefit to dental students and could be applied in dental education.

A Layered Aluminophosphate [C17H21N2]3[Al3(PO4)4]·5H2O with Fluorescent Property Derived from Carbazolyl-Modified Template.

Designing and innovating organic structure-directing agents is the key to synthesizing novel molecular sieve structures. Herein, we design a novel carbazolyl-modified template and further synthesize a two-dimensional layered aluminophosphate with [C17H21N2]3[Al3(PO4)4]·5H2O (denoted as ZHKU-2). ZHKU-2 is composed of AA-stacked [Al3P4O16]3- layers constructed from alternating AlO4 and PO3(=O) tetrahedrons to form a 4.6.8 network featured by capped six-ring secondary building units. Carbazolyl-templated ZHKU-2 exhibits strong purple fluorescence with a high quantum yield of 25.98%. This work expands aluminophosphate materials of the [Al3P4O16]3- family and provides a view for synthesizing new molecular sieves by exploring the organic luminescence structure-directing agents.

Transcriptome analysis of human peri-implant soft tissue and periodontal gingiva: a paired design study.

OBJECTIVES: Limited information is available about the biological characterization of peri-implant soft tissue at the transcriptional level. The aim of this study was to investigate the effect of dental implant on the soft tissue in vivo by using paired samples and compare the differences between peri-implant soft tissue and periodontal gingiva at the transcriptional level. METHODS: Paired peri-implant soft tissue and periodontal gingiva tissue from 6 patients were obtained, and the pooled RNAs were analyzed by deep sequencing. Venn diagram was used to further screen out differentially expressed genes in every pair of samples. Annotation and enrichment analysis was performed. Further verification was done by quantitative real-time PCR. RESULTS: Totally 3549 differentially expressed genes (DEGs) were found between peri-implant and periodontal groups. The Venn diagram further identified 185 DEGs in every pair of samples, of which the enrichment analysis identified significant enrichment for cellular component was associated with external side of plasma membrane, for molecular function was protein binding, for biological process was immune system process, and for KEGG pathway was cytokine-cytokine receptor interaction. Among the DEGs, CST1, SPP1, AQP9, and SFRP2 were verified to be upregulated in peri-implant soft tissue. CONCLUSIONS: Peri-implant soft tissue showed altered expressions of several genes related to the cell-ECM interaction compared to periodontal gingiva. CLINICAL RELEVANCE: Compared to periodontal gingiva, altered cell-ECM interactions in peri-implant may contribute to the susceptibility of peri-implant diseases. At the transcriptional level, periodontal gingiva is generally considered the appropriate control for peri-implantitis, except regarding the cell-ECM interactions.

Optimizing the biodegradability and osteogenesis of biogenic collagen membrane via fluoride-modified polymer-induced liquid precursor process.

Biogenic collagen membranes (BCM) have been widely used in guided bone regeneration (GBR) owing to their biodegradability during tissue integration. However, their relatively high degradation rate and lack of pro-osteogenic properties limit their clinical outcomes. It is of great importance to endow BCM with tailored degradation as well as pro-osteogenic properties. In this study, a fluoride-modified polymer-induced liquid precursor (PILP) based biomineralization strategy was used to convert the collagen membrane from an organic phase to an apatite-based inorganic phase, thus achieving enhanced anti-degradation performance as well as osteogenesis. As a result, three phases of collagen membranes were prepared. The original BCM in the organic phase induced the mildest inflammatory response and was mostly degraded after 4 weeks. The organic-inorganic mixture phase of the collagen membrane evoked a prominent inflammatory response owing to the fluoride-containing amorphous calcium phosphate (F-ACP) nanoparticles, resulting in active angiogenesis and fibrous encapsulation, whereas the inorganic phase induced a mild inflammatory response and degraded the least owing to the transition of F-ACP particles into calcium phosphate with high crystallinity. Effective control of ACP is key to building novel apatite-based barrier membranes. The current results may pave the way for the development of advanced apatite-based membranes with enhanced barrier performances.

2-DG Regulates Immune Imbalance on the Titanium Surface after Debridement.

Peri-implantitis requires clinical treatments comprised of mechanical and chemical debridement to remove bacterial biofilms. Bone regeneration on the titanium surface after debridement has been a topical issue of peri-implantitis treatments. Increasing evidence has revealed that the immune microenvironment plays a key role in regulating the bone regeneration process. However, it remains unclear what kind of immune microenvironment the titanium surface induces after debridement. In the study, model titanium surface after debridement was prepared via biofilm induction and mechanical and chemical debridement in vitro. Then, the macrophages and naïve CD4+ T lymphocytes were cultured on the titanium surface after debridement for immune microenvironment evaluation, with the original titanium surface as the control. Next, to regulate the immune microenvironment, 2-DG, a glycolysis inhibitor, was further incorporated to regulate macrophages and CD4+ T lymphocytes at the same time. Surface characterization results showed that the bacterial biofilms were completely removed, while the micro-morphology of titanium surface altered after debridement, and the element composition did not change. Compared with the original titanium disc, titanium surface after debridement can lead to the inflammatory differentiation of macrophages and CD4+ T lymphocytes. The percentage of M1 and Th17 inflammatory cells and the expression of their inflammatory factor genes are upregulated. However, 0.3 mmol of 2-DG can significantly reduce the inflammatory differentiation of both macrophages and CD4+ T lymphocytes and inhibit their expression of inflammatory genes. In conclusion, although bacterial biofilms were removed from titanium surface after debridement, the surface topography changes could still induce immune imbalance and form an inflammatory immune microenvironment. However, this inflammatory immune microenvironment can be effectively reversed by 2-DG in vitro, thus creating an immune microenvironment conducive to osteogenesis, which might provide a new perspective for future therapy of peri-implantitis.

Prediction of primary stability via the force feedback of an autonomous dental implant robot.

STATEMENT OF PROBLEM: While the high osteotomy and implant placement accuracy via robotic implant surgery has been verified, whether the force feedback in the osteotomy process can be used to determine appropriate primary implant stability remains unknown. PURPOSE: The purpose of this in vitro study was to explore the relationship between the force feedback and the primary stability of implants placed by using an autonomous dental implant robot. MATERIAL AND METHODS: Five groups (n=7) of wooden and polyurethane foam blocks were used to execute an implant surgery by using an autonomous implant robot. Tapered bone-level titanium dental implant replicas were placed in the blocks. The Young modulus, the maximal vertical and lateral drilling resistances, the position accuracy, and the insertion torque of implants were recorded. Simple linear regression, principal component analysis, and multiple linear regression were used. The osteotomy strategy for the implant site was adjusted according to the maximal vertical resistance of the pilot drill to achieve appropriate insertion torque. The correlation, Gompertz growth curve fitting of the insertion torque, and Young modulus were determined. The effect of the drilling resistances on the insertion torque was analyzed using 2-way ANOVA, simple linear regression, and the principal component analysis. RESULTS: The vertical resistance of the Ø2.2-mm pilot drill, the Ø3.5-mm twist drill, and the Ø4.1-mm profile drill had a strong simple linear correlation with the insertion torque of the implants, and the lateral resistance had a moderate linear correlation with the insertion torque. The contributions of these 6 variables to the implant torque, among which the vertical resistance of the twist drill and the pilot drill ranked first and second, were comparable. Adjustments to the strategy of site preparation according to the vertical resistance of the pilot drill achieved appropriate insertion torque (P<.001). CONCLUSIONS: The force feedback of the autonomous dental implant robot was significantly correlated with the insertion torque of implants, which may fit an interpretable mathematical model, allowing dental implants to be placed with predictable primary stability.

Insights into the phylogeny of the family Deviatidae (Protozoa, Ciliophora, Hypotrichia) based on multi-gene, morphological and ontogenetic information, with the establishment of a new species Deviata multilineae n. sp.

Hitherto, the phylogeny of ciliated protists, an important group of model organisms in many fields, has been mainly based on a single marker gene (SSU rDNA, nuclear small subunit ribosomal RNA gene). However, there is increasing evidence showing this is insufficient to provide robust phylogenies and has resulted in confusing systematics in many ciliates groups. Among these, the phylogenies within family Deviatidae (Spirotrichea, Hypotrichia) are ambiguous due to the dependence on SSU rDNA and undersampling. Here, we provide eight new sequences and conduct phylogenetic analyses based on both multi-gene and single-gene to clarify evolutionary relationships among all deviatids for which gene sequence are available. The results reveal that: (1) the monophyly of Deviatidae is well-supported by both single-gene and concatenated data; (2) the presence of fine cirri and relatively wide spacing of these cirri within all rows are plesiomorphies of Deviatidae; (3) Pseudosincirra longicirrata is closely related to Deviata rositae, which is supported by their shared possession of dorsomarginal kineties; (4) phylogenetic analyses and approximately unbiased test based on multi-gene support a close relationship among taxa lacking dorsomarginal kineties (D. parabacilliformis, D. multilineae nov. spec., D. abbrevescens, D. brasiliensis and Perisincirra paucicirrata); (5) Deviatidae shows a close relationship with Dorsomarginalia and Strongylidium-Hemiamphisiella-Pseudouroleptus assemblage, suggesting the presence/absence of dorsomarginal kineties is phylogenetically informative in this family and presence of them may be a plesiomorphy. Based on the morphological, morphogenetic and phylogenetic data, the evolutionary relationships within Deviatidae are hypothesized, and a new ciliate, Deviata multilineae nov. spec., collected from China, is investigated.

Does the geometry of scan bodies affect the alignment accuracy of computer-aided design in implant digital workflow: An in vitro study?

OBJECTIVES: To compare 2 implant scan bodies with different geometry on the accuracy of the virtual alignment process in the digital workflow. MATERIALS AND METHODS: A master model of the edentulous maxilla with 6 implants and multiunit abutments (MUA) inserted was fabricated. Six dome-shaped and cuboidal scan bodies were mounted on the MUAs, respectively, and consecutively scanned by a laboratory scanner 10 times. The original scans were imported to a dental-specific CAD software and virtually aligned with the default CAD model in the implant library. Thus, 10 aligned models were created. Both the original scans and the aligned models were evaluated by an inspection software for deviation of the scan body surfaces, the centroids of scan body and MUA, the scan body center-axis, and the inter-MUA distances/angles. The two-sample T-test/Mann-Whitney U test were used to analyze the data with the level of significance set at 0.05. RESULTS: The cuboidal group showed significant greater deviations of the model surface (13.9 µm vs. 10.7 µm) and the MUA centroids (31.7 µm vs. 22.8 µm) but smaller deviation of the inter-MUA angle (0.047° vs. 0.070°) than those of the dome-shaped group (p < .05). No significant differences in the deviation of scan body centroids, center-axis, and the inter-MUA distances between the 2 groups were found. CONCLUSIONS: Virtual alignment of implant scan body affected the accuracy of the digital workflow for complete-arch implant-supported prostheses (up to ~30 µm/0.09°). Different geometries of the implant scan body could also influence the transfer accuracy in the CAD process.

Placement accuracy and primary stability of implants in the esthetic zone using dynamic and static computer-assisted navigation: A retrospective case-control study.

STATEMENT OF PROBLEM: Both the placement accuracy and primary stability of implants are important to implant therapy in the esthetic zone. The effect of dynamic and static computer-assisted navigation on the primary stability of implants in the esthetic zone remains uncertain. PURPOSE: The purpose of this case-control study was to investigate the effect of dynamic and static computer-assisted navigation on the placement accuracy and primary stability of implants in the esthetic zone. MATERIAL AND METHODS: Partially edentulous participants who received at least 1 implant in the anterior maxilla using either fully guided static or dynamic computer-assisted implant surgery (s-CAIS, d-CAIS) from January 2020 to February 2022 were screened. Participant demographic information, timing of implant placement, primary stability represented by the insertion torque value (ITV) in Ncm, and implant survival were collected from the treatment record. Bone quality at the implant sites was determined according to the Lekholm and Zarb classification. The accuracy of implant placement represented by the linear (platform: Dpl, mm; apex: Dap, mm) and angular deviations (axis: Dan, degree) between the planned and placed implants was evaluated based on the preoperative surgical plan and postoperative cone beam computed tomography (CBCT) data. A statistical analysis of the data was completed by using the chi-square, Fisher exact, Student t, and Mann-Whitney U tests (α=.05). RESULTS: A total of 32 study participants (38 implants) were included. The groups of s-CAIS (16 participants, 18 implants) and d-CAIS (16 participants, 20 implants) were statistically comparable in sex (P=.072), age (P=.548), bone quality (P=.671), and timing of implant placement (P=.719). All implants survived during an average follow-up period of 13 months. The d-CAIS group showed close linear deviations (Dpl 1.07 ±0.57 mm, Dap 1.26 ±0.53 mm) but lower angular deviation (Dan 2.14 ±1.20 degrees) and primary stability (ITV 25.25 ±7.52 Ncm) than the s-CAIS group (Dpl 0.92 ±0.46 mm, Dap 1.31 ±0.43 mm, Dan 3.31 ±1.61 degrees, ITV 30.56 ±11.23 Ncm, PDpl=.613, PDap=.743, PDan=.016, PITV=.028). CONCLUSIONS: Comparable linear positioning accuracy and higher angular deviation were found for implants placed in the esthetic zone by using s-CAIS than when using d-CAIS. Higher primary stability of implants may be achieved by using s-CAIS, as s-CAIS seemed to have higher osteotomy accuracy than d-CAIS.

A Mononuclear Iron(II) Spin-Crossover Molecule Decorated by Photochromic Azobenzene Group.

Aiming at constructing photoresponsive spin crossover (SCO) behavior, herein we designed a new ligand Abtz (Abtz = (E)-N-(4-((E)-phenyldiazenyl)phenyl)-1-(thiazol-4-yl)methanimine) which was decorated by a photochromic azobenzene group. Based on this photochromic ligand, a mononuclear Fe(II) SCO molecule [Fe(Abtz)3](BF4)2·(EAC)2 (1, EAC = ethyl acetate) was successfully synthesized and showed a complete one-step SCO behavior. Under continuous UV light and blue-light exposure, the cis-trans photoisomerization of both ligand Abtz and compound 1 in the liquid phase was confirmed through UV-Vis spectra. Moreover, the 1H-NMR spectra of Abtz reveal a trans-cis conversion ratio of 37%. Although the UV-Vis spectra reveal the photochromic behavior for 1 in the solution phase, the SCO behavior in the liquid state is absent according to the variable-temperature Evans method, suggesting the possible decomposition. Moreover, in the solid state, the cis-trans photoisomerization of both Abtz and 1 was not observed, due to the steric hindrance.

Improved accuracy of digital implant impressions with newly designed scan bodies: an in vivo evaluation in beagle dogs.

BACKGROUND: The accuracy of digital impressions for fully edentulous cases is currently insufficient for routinely clinical application. To overcome the challenge, a modified scan body was introduced, which demonstrated satisfactory accuracy in vitro. The aim of this study was to evaluate the accuracy of digital impressions using the modified scan bodies with extensional structure versus scan bodies without extensional structure in mandible with two implants in beagle dogs. METHODS: The unilateral mandibular second premolar to second molar were extracted in four beagle dogs. Twelve weeks later, two implants were placed. Five repeated digital impressions were performed with an intraoral scanner on each dog using each of the two different scan bodies: Group I-scan body without extensional structure (SB); Group II-scan body with extensional structure (SBE). The scans were exported to Standard Tessellation Language (STL) files to serve as test data. The dogs were sacrificed and the dissected mandibles were digitalized with a lab scanner to provide reference data. Linear and angular deviations were calculated in an inspection software for accuracy assessment. Statistical analysis was performed with two-way ANOVA. The level of significance was set at α = 0.05. RESULTS: For trueness assessment, the mean of absolute linear/angular deviations were 119.53 µm/0.75 degrees in Group I and 68.89 µm/0.36 degrees in Group II. SBE was more accurate than SB regarding both linear (p = 0.008) and angular (p = 0.049) deviations. For precision assessment, the mean of absolute linear/angular deviations were 63.01 µm/0.47 degrees in Group I and 38.38 µm/0.24 degrees in Group II. No significant difference was found. CONCLUSIONS: The application of SBE significantly improved the trueness of digital impressions in mandible with two implants compared to SB. No significant difference was found in terms of precision.

Analysis of the sagittal root angle and its correlation with hard and soft tissue indices in anterior teeth for immediate implant evaluation: a retrospective study.

BACKGROUND: To assess the root angle characteristics of maxillary incisors, and to analyze the relationship between the root angle and other implant-related anatomical indices to use the sagittal root angle as an index for immediate implant evaluation and design. METHODS: A random sample consisting of 400 cone-beam computed tomography (CBCT) images and 65 maxillary plaster models were selected for the present study. CBCT and stereolithography (STL) scan images were imported as DICOM files into coDiagnostiX software for matching the hard and soft tissue. The angle between the long axis of the anterior tooth and the corresponding alveolar bone and implant-related hard and soft tissue indices were measured in the sagittal section. Descriptive statistics, frequency analysis, multi-level comparisons, and correlation analyses were performed. RESULTS: The average sagittal root angles were 15° at the central incisor and 19° at the lateral incisor. The root angle in males was significantly larger than that in females, and increased with age. The largest angle, 22.35°, was found in the lateral incisors of the oldest (> 50 years old) male group. The root angle was found to correlate with coronal buccal bone thickness, coronal palatal bone thickness, apical buccal bone thickness, palatal bone thickness, and the below apex bone thickness. CONCLUSIONS: The sagittal root angle could reflect the distribution of other implant-related anatomical indices, which may provide additional reference for the evaluation of immediate implant placement.

Immediate Implant Placement with Buccal Bone Augmentation in the Anterior Maxilla with Thin Buccal Plate: A One-Year Follow-Up Case Series.

PURPOSE: To evaluate the buccal bone thickness of immediate implant placement with buccal bone augmentation in patients with a thin buccal plate in the esthetic zone. MATERIALS AND METHODS: Eighteen consecutive patients requiring a single tooth replacement in the anterior maxillary zone with a thin plate (<1 mm) were included and received immediate implant placement with narrow-diameter implants. Patients received buccal bone augmentation (both internal and external socket bone grafting) with deproteinized bovine bone mineral (DBBM) and an absorbable membrane. The final restoration was delivered after 8 months. Cone-beam CT scans were performed before surgery (CBCT0), immediately after surgery (CBCT1), at final restoration delivery (CBCT2), and at 1-year follow-up after the final restoration (CBCT3) to evaluate the buccal bone thickness and ridge width. A repeated measures ANOVA and Bonferroni correction for multiple comparisons were applied for statistical analysis of changes within different time points (α = 0.05). RESULTS: Fifteen of the 18 enrolled patients were available for analysis at the 1-year follow-up after final restoration. The mean buccal bone thickness at 2 mm apical to the implant-abutment junction (IAJ-2) were 3.59 mm (range: 3.04-4.58 mm), 2.79 mm (range: 2.25-3.78 mm), and 2.52 mm (range: 1.72-3.36 mm), respectively, at CBCT1, CBCT2, and CBCT3. A statistical significance was observed for buccal bone thickness change between CBCT1 and CBCT2 at IAJ-2 (F = 17.948, p = 0.001). The net gains of the ridge width from CBCT0 to CBCT1, CBCT1 to CBCT2, and CBCT2 to CBCT3 were 1.08 mm, -0.94 mm and -0.04 mm at 4 mm apical to the cementum-enamel junction, respectively. No statistical significance was observed for the change in ridge width from CBCT0 to CBCT3 (F = 10.518, p = 1.000). CONCLUSIONS: Simultaneous buccal bone augmentation may maintain a predictable buccal bone thickness for immediate implant placement in the maxillary anterior sites with a thin buccal plate (<1 mm) at 1-year follow-up after final restoration.

Post-acute psychological effects of classical serotonergic psychedelics: a systematic review and meta-analysis.

BACKGROUND: Scientific interest in the therapeutic effects of classical psychedelics has increased in the past two decades. The psychological effects of these substances outside the period of acute intoxication have not been fully characterized. This study aimed to: (1) quantify the effects of psilocybin, ayahuasca, and lysergic acid diethylamide (LSD) on psychological outcomes in the post-acute period; (2) test moderators of these effects; and (3) evaluate adverse effects and risk of bias. METHODS: We conducted a systematic review and meta-analysis of experimental studies (single-group pre-post or randomized controlled trials) that involved administration of psilocybin, ayahuasca, or LSD to clinical or non-clinical samples and assessed psychological outcomes ⩾24 h post-administration. Effects were summarized by study design, timepoint, and outcome domain. RESULTS: A total of 34 studies (24 unique samples, n = 549, mean longest follow-up = 55.34 weeks) were included. Classical psychedelics showed significant within-group pre-post and between-group placebo-controlled effects on a range of outcomes including targeted symptoms within psychiatric samples, negative and positive affect-related measures, social outcomes, and existential/spiritual outcomes, with large between-group effect in these domains (Hedges' gs = 0.84 to 1.08). Moderator tests suggest some effects may be larger in clinical samples. Evidence of effects on big five personality traits and mindfulness was weak. There was no evidence of post-acute adverse effects. CONCLUSIONS: High risk of bias in several domains, heterogeneity across studies, and indications of publication bias for some models highlight the need for careful, large-scale, placebo-controlled randomized trials.

Long non-coding RNA and mRNA expression profiles in peri-implantitis vs periodontitis.

BACKGROUND AND OBJECTIVE: Peri-implantitis is a biofilm-mediated infectious disease that results in progressive loss of implant-supporting bone. As compared to its analogue periodontitis, peri-implantitis is generally known to be more aggressive, with comparatively rapid progression and less predictable treatment outcomes, especially when advanced. An understanding of molecular mechanisms underpinning the similarities and differences between peri-implantitis and periodontitis is essential to develop novel management strategies. This study aimed to compare long non-coding RNAs (lncRNAs) and messenger RNA (mRNA) expression profiles between peri-implantitis and periodontitis. METHODS: Inflamed soft tissue from peri-implantitis and periodontitis lesions, and healthy gingival tissue controls were analyzed by microarray. Cluster graphs, gene ontology (GO) analysis, and pathway analysis were performed. Quantitative real-time PCR was employed to verify microarray results. The expression levels of RANKL and OPG in the three tissue types were also evaluated, using qRT-PCR. Coding non-coding (CNC) network analyses were performed. RESULTS: Microarray analyses revealed 1079 lncRNAs and 1003 mRNAs as differentially expressed in peri-implantitis when compared to periodontitis. The cyclooxygenase-2 pathway was the most up-regulated biological process in peri-implantitis as compared to periodontitis, whereas hemidesmosome assembly was the most down-regulated pathway. Osteoclast differentiation was relatively up-regulated, and RANKL/OPG ratio was higher in peri-implantitis than in periodontitis. CONCLUSIONS: The study demonstrated that peri-implantitis and periodontitis exhibit significantly different lncRNA and mRNA expression profiles, suggesting that osteoclast differentiation-related pathways are comparatively more active in peri-implantitis. These data highlight potential molecular targets for periodontitis and peri-implantitis therapy development.

Improved scanning accuracy with newly designed scan bodies: An in vitro study comparing digital versus conventional impression techniques for complete-arch implant rehabilitation.

OBJECTIVES: To compare the accuracy of an original and two newly designed CAD/CAM scan bodies used in digital impressions with one another as well as conventional implant impressions. MATERIAL AND METHODS: A reference model containing four implants was fabricated. Digital impressions were taken using an intraoral scanner with different scan bodies: original scan bodies for Group I (DO), CAD/CAM scan bodies without extensional structure for Group II (DC), and CAD/CAM scan bodies with extensional structure for Group III (DCE). For Group IV, conventional splinted open-tray impressions (CI) were taken. The reference model and conventional stone casts were digitalized with a laboratory reference scanner. The Standard Tessellation Language datasets were imported into an inspection software for trueness and precision assessment. Statistical analysis was performed with a Kruskal-Wallis test and Dunn-Bonferroni test. The level of significance was set at α = .05. RESULTS: The median of trueness was 35.85, 38.50, 28.45, and 25.55 µm for Group I, II, III, and IV, respectively. CI was more accurate than DO (p = .015) and DC (p = .002). The median of precision was 48.40, 48.90, 27.30, and 19.00 for Group I, II, III, and IV, respectively. CI was more accurate than DO (p < .001), DC (p < .001), and DCE (p = .007). DCE was more accurate than DC (p < .001) and DO (p < .001). CONCLUSIONS: The design of the extensional structure could significantly improve scanning accuracy. Conventional splinted open-tray impressions were more accurate than digital impressions for full-arch implant rehabilitation.

Correlation of anterior overbite with root position and buccal bone thickness of maxillary anterior teeth: a CBCT study.

PURPOSE: To investigate the correlation of anterior overbite with the sagittal root position (SRP) and buccal bone thickness (BBT) of the maxillary anterior teeth. METHODS: Cone-beam computed tomography (CBCT) data of southern Chinese patients who underwent CBCT examinations between November 2016 and December 2016 were collected. The anterior overbite was the predictor variable while the SRP and the BBT at 4 mm apical to the cementoenamel junction (CEJ-4) and midpoint of the root of the maxillary anterior teeth were set as the primary and secondary outcome variables, respectively. All measurements were done by two calibrated examiners. Correlations between variables were analyzed by the Spearman's correlation coefficient. The significance level was set at P < 0.05. RESULTS: CBCT data of 146 patients (65 men and 81 women) with a mean age of 44.2 ± 13.4 years were analyzed, and of the 876 maxillary anterior teeth evaluated, 9.8% were presented with deep overbites. Most of roots of the anterior teeth (94.9%) were positioned against the buccal cortical plate, of which, in 63.8% of them the apex was not covered by bone along the long axis of the tooth. The mean BBT at CEJ-4 was 0.89 mm at the central incisor, 0.85 mm at the lateral incisor and 0.84 mm at the canine. The overbite was positively correlated with SRP Class I subtypes and the BBT at CEJ-4 (P < 0.05). CONCLUSION: Deep overbite was more frequently accompanied by bone fenestration in the anterior maxillary areas.

Clinical and Radiologic Outcomes of Submerged and Nonsubmerged Bone-Level Implants with Internal Hexagonal Connections in Immediate Implantation: A 5-Year Retrospective Study.

PURPOSE: To evaluate the 5-year clinical and radiologic outcome of immediate implantation using submerged and nonsubmerged techniques with bone-level implants and internal hexagonal connections and the effects of potential influencing factors. MATERIALS AND METHODS: A total of 114 bone-level implants (XiVE S plus) with internal hexagonal connections inserted into 72 patients were included. Patients were followed up for 5 years. A t-test was used to statistically evaluate the marginal bone loss between the submerged and nonsubmerged groups. The cumulative survival rate (CSR) was calculated according to the life table method and illustrated with Kaplan-Meier survival curves. Comparisons of the CSR between healing protocols, guided bone regeneration, implants with different sites, lengths, and diameters were performed using log-rank tests. RESULTS: The 5-year cumulative implant survival rates with submerged and nonsubmerged healing were 94% and 96%, respectively. No statistically significant differences in terms of marginal bone loss, healing protocol, application of guided bone regeneration, implant site, or length were observed. CONCLUSIONS: High CSRs and good marginal bone levels were achieved 5 years after immediate implantation of bone-level implants with internal hexagonal connections using both the submerged and nonsubmerged techniques. Factors such as implant length, site, and application of guided bone regeneration did not have an impact on the long-term success of the implants.