Accuracy of dynamic navigation compared to static surgical guides and the freehand approach in implant placement: a prospective clinical study.

BACKGROUND: Computer-guided implant surgery has improved the quality of implant treatment by facilitating the placement of implants in a more accurate manner. This study aimed to assess the accuracy of implant placement in a clinical setting using three techniques: dynamic navigation, static surgical guides, and freehand placement. We also investigated potential factors influencing accuracy to provide a comprehensive evaluation of each technique's advantages and disadvantages. MATERIALS AND METHODS: Ninety-four implants in 65 patients were included in this prospective study. Patients were randomly assigned to one of three groups: dynamic navigation, static surgical guides, or freehand placement. Implants were placed using a prosthetically oriented digital implant planning approach, and postoperative CBCT scans were superimposed on preoperative plans to measure accuracy. Seven deviation values were calculated, including angular, platform, and apical deviations. Demographic and consistency analyses were performed, along with one-way ANOVA and post-hoc tests for deviation values. RESULTS: The mean global platform, global apical, and angular deviations were 0.99 mm (SD 0.52), 1.14 mm (SD 0.56), and 3.66° (SD 1.64°) for the dynamic navigation group; 0.92 mm (SD 0.36), 1.06 mm (SD 0.47), and 2.52° (SD 1.18°) for the surgical guide group; and 1.36 mm (SD 0.62), 1.73 mm (SD 0.66), and 5.82° (SD 2.79°) for the freehand group. Both the dynamic navigation and surgical guide groups exhibited statistically significant differences in all values except depth deviations compared to the freehand group (p < 0.05), whereas only the angular deviation showed a significant difference between the dynamic navigation and surgical guide groups (p = 0.002). CONCLUSION: Our findings highlight the superior accuracy and consistency of dynamic navigation and static surgical guides compared to freehand placement in implant surgery. Dynamic navigation offers precision and flexibility. However, it comes with cost and convenience considerations. Future research should focus on improving its practicality. TRIAL REGISTRATION: This study was retrospectively registered at the Thai Clinical Trials Register-Medical Research Foundation of Thailand (MRF) with the TCTR identification number TCTR20230804001 on 04/08/2023. It was also conducted in accordance with the Declaration of Helsinki and approved by the institutional ethics committee at the Xian Jiaotong University Hospital of Stomatology, Xian, China (xjkqII[2021] No: 043). Written informed consent was obtained from all participants.

Accuracy analysis of robotic-assisted immediate implant placement: A retrospective case series.

OBJECTIVES: This study aimed to investigate the accuracy of a robotic computer-assisted implant surgery (r-CAIS) for immediate implant placement. METHODS: Patients requiring immediate implant placement in the maxillary anterior region were enrolled for r-CAIS. Before surgery, the patients underwent a cone beam computed tomography (CBCT) scan with a positioning marker. Virtual implant placement position and drilling sequences were planned. Following spatial registration and calibration, the implants were placed with the robotic system under supervision. A postoperative CBCT was taken to control the actual implant positions. The DICOM data of the virtually planned and the actually placed implant were superimposed and registered through the accuracy verification software of the robotic system. The accuracy was calculated automatically. The deviation at the mesial-distal, labial-palatal, and apico-coronal directions were recorded. RESULTS: Fifteen patients with 20 implants were included. No adverse surgical events or postoperative complications were reported. The global platform, apex, and angular deviation were 0.75 ± 0.20 mm (95 % CI: 0.65 to 0.84 mm), 0.70 ± 0.27 mm (95 % CI: 0.57 to 0.82 mm), and 1.17 ± 0.73° (95 % CI: 0.83 to 1.51°), respectively. Moreover, the vertical platform and apex deviation were 0.50 ± 0.31 mm, (95 % CI: 0.35 to 0.64 mm) and 0.48 ± 0.32 mm, (95 % CI: 0.33 to 0.63 mm), respectively. All the placed implant positions were further labial and apical than the planned ones, respectively. CONCLUSIONS: High accuracy of immediate implant placement was achieved with the robotic system. CLINICAL SIGNIFICANCE: Our study provided evidence to support the potential of the robotic system in implant placement, even in challenging scenarios.

A Pilot Investigation Generating an Alternative Therapeutic Strategy Combining Deproteinized Bovine Bone and Gelatin Sponge for a Novel Implant Material in Sinus Floor Elevation Operation.

BACKGROUND Implant placement in the posterior maxilla is typically complicated by a shortage of bone. Gelatin sponge could be combined with an appropriate material to enhance mechanical strength and maintain stability of an implant. This study aimed to evaluate the clinical application of bone grafting with bovine bone mixed with gelatin sponge. MATERIAL AND METHODS Fifty-four patients were divided into a control group (deproteinized bovine bone, n=26) and a test group (deproteinized bovine bone combined with gelatin sponge, n=28). Implants were placed in patients simultaneously after surgery (operation). Cone-beam computed tomography examination was carried out immediately and 6 months after surgery. Space with grafting materials was measured with Mimics software (version 16.0). RESULTS No remarkable differences were found for simultaneous placement, height of residual bone, delayed placement, width of residual bone, graft volume immediately after surgery (V1), graft volume 6 months after surgery (V2), or volumetric change rate between the test group and the control group (P>0.05). Graft volume V2 was remarkably decreased compared with V1 in the control and test groups (P=0.01). There were no significant differences for bone height immediately after surgery (H1) and bone height at 6 months after surgery (H2) between the 2 groups. Bone height H2 was markedly decreased compared with H1 (P<0.05). At 1 year after implantation, there was 1 implant loss in the control group and 2 in the test group. The implant survival rate in the control group was 97.62% and 95.24% in the test group. CONCLUSIONS Absorbable gelatin sponge combined with bovine bone particles was an effective and economical material for use in routine sinus floor elevation surgery.

miR­144­3p inhibits tumor cell growth and invasion in oral squamous cell carcinoma through the downregulation of the oncogenic gene, EZH2.

Accumulating evidence demonstrates that microRNAs (miRNAs or miRs) play important roles in the development and progression of human malignancies, including oral squamous cell carcinoma (OSCC); however, the unique roles of miRNAs are not yet fully understood in OSCC. The present study aimed to identify novel miRNAs associated with OSCC and to elucidate their functions. Based on a microarray analysis, miR­144­3p was found to be one of the most significantly downregulated miRNAs in OSCC tissues. Its low expression was closely associated with tumor size, differentiation and lymph node metastasis. Functionally, miR­144­3p overexpression suppressed proliferation, promoted apoptosis, and suppressed the invasion and migration of OSCC cells. In addition, enhancer of zeste homolog 2 (EZH2), a well­known oncogene, was proven to be a direct target of miR­144­3p, and its protein expression was negatively regulated by miR­144­3p. Moreover, EZH2 expression was increased, and inversely correlated with the miR­144­3p level in OSCC tissues. Notably, EZH2 knockdown inhibited cell proliferation, promoted cell apoptosis, and suppressed the invasion and migration of OSCC cells, whereas EZH2 overexpression partially reversed the anticancer effects mediated by miR­144­3p overexpression. On the whole, the findings of the present study suggest that miR­144­3p functions as a tumor suppressor by targeting the EZH2 oncogene, and may thus be considered as a potential diagnostic and therapeutic target for OSCC.

Effects of the Screw-Access Hole Diameter on the Biomechanical Behaviors of 4 Types of Cement-Retained Implant Prosthodontic Systems and Their Surrounding Cortical Bones: A 3D Finite Element Analysis.

PURPOSE: To investigate the effect(s) of screw-access hole (SAH) in different diameters on the cement-retained implant prosthodontic systems and surrounding cortical bones. MATERIALS AND METHODS: Twenty finite element models were divided into 4 groups: 2 types of full-contour (FC) crowns (Y-TZP, gold alloy) and 2 types of porcelain-fused-to-metal crowns (based on Co-Cr, Au-Pd alloy). For each group, 5 crowns were simulated by varying the diameter of SAH (0, 1, 2, 3, and 4 mm). A vertical load of 200 N and an oblique load of 100 N (45°s) were applied. All models were analyzed with finite element analysis software. RESULTS: The stress on the occlusal surface of crowns was almost unchanged when the SAH was within 0 to 3 mm, whereas it showed an obvious increase when it reached 4 mm. The stress concentration was also suddenly changed from the loading area to the hole margin under vertical loading. As for the screw, a lower stress level was observed in vertical loading when an FC crown with an SAH within 0 to 1 mm was applied. The stress concentration was constantly located at the beginning of the first thread. Stresses of other components remained almost unchanged. CONCLUSIONS: From the aspect of biomechanics, an FC crown with a 1-mm access hole is recommended when a combined cement- and screw-retained crown was used in the posterior region.

Oral squamous cell carcinoma cells are resistant to doxorubicin through upregulation of miR­221.

Oral squamous cell carcinoma (OSCC) cells are usually resistant to doxorubicin, resulting in limited application of doxorubicin in OSCC treatment. MicroRNA (miR)­221 has been reported to be involved in the development of OSCC; however, it remains unclear if and how miR­221 is implicated in modulating the sensitivity of OSCC cells to doxorubicin. In the present study, reverse transcription­quantitative polymerase chain reaction (RT­qPCR) was used to assess miR­221 expression in OSCC cells in response to doxorubicin treatment. In addition, the SCC4 and SCC9 OSCC cell lines were transfected with anti­miR­221 oligonucleotides and cell viability and apoptosis following doxorubicin treatment were evaluated using an MTT assay and Annexin V­fluorescein isothiocyanate/Hoechst double staining, respectively. The mRNA and protein expression levels of tissue inhibitor of metalloproteinase­3 (TIMP3) in anti­miR­221­transfected cells were assessed using RT­qPCR and western blot analysis, respectively. Furthermore, a luciferase reporter assay was performed to investigate whether TIMP3 may be a direct target gene of miR­221. To explore the roles of TIMP3 in miR­221­mediated cell responses, TIMP3 expression was silenced following transfection with TIMP3­targeting small interfering (si)RNA in cells overexpressing miR­221, and cell viability and apoptosis in response to doxorubicin treatment were measured. The results of the present study demonstrated that miR­221 expression was upregulated in SCC4 and SCC9 cells following treatment with doxorubicin. However, inhibiting the doxorubicin­induced upregulation of miR­221 through transfection with anti­miR­221 oligonucleotides led to an increase in the sensitivity of OSCC cells to doxorubicin. In addition, the results indicated that TIMP3 was a direct target of miR­221 in OSCC cells, as determined by a 3'­untranslated region luciferase reporter assay. Co­transfection of cells with anti­miR­221 oligonucleotides and TIMP3­specific small interfering RNA resulted in reduced sensitivity to doxorubicin compared with the cells transfected with the miR­221 inhibitor alone. In conclusion, these results indicated that OSCC cells are resistant to doxorubicin through upregulation of miR­221, which in turn downregulates TIMP3. Therefore, silencing miR­221 or upregulating TIMP3 may be considered promising therapeutic approaches to enhance the sensitivity of OSCC to doxorubicin.

Overexpression of KAI1/CD82 suppresses in vitro cell growth, migration, invasion and xenograft growth in oral cancer.

KAI1/CD82 is a metastatic suppressor gene in human prostate cancer and several other types of cancer in humans. The present study aimed to examine the role of the overexpression of KAI1 in the progression of oral cancer. Human KAI1/CD82 cDNA was transfected into OSCC­15 and 293T cell lines, and its effects on OSCC­15 cell proliferation, invasion and apoptosis were assessed by performing a 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay, Matrigel invasion and Annexin V­FITC staining, respectively. In addition, a xenograft model was used to assess the effect of KAI1/CD82 on the in vivo growth of tumors. The overexpression of KAI1/CD82 inhibited the proliferation and invasion of OSCC-15 cells. It also enhanced the apoptotic rate of the OSCC­15 cells. Furthermore, the overexpression of KAI1/CD82 inhibited tumor growth in the xenograft model. The results demonstrated that the overexpression of KAI1/CD82 significantly inhibited the proliferation and invasion of human oral cancer cells, and inhibited tumor growth in the xenograft model. Therefore, KAI1/CD82 may be considered as a potential therapeutic target in oral cancer.

Formaldehyde exposure inhibits the expression of mammalian target of rapamycin in rat testis.

Formaldehyde (FA), a ubiquitous environmental pollutant, has long been suspected of causing adverse male reproductive effects. However, the molecular and cellular mechanisms underlying this phenomenon remain elusive. The overall aim of this study is to clarify the role of mammalian target of rapamycin (mTOR) in male reproductive injuries induced by FA exposure, by which we can further understand the molecular mechanism of FA male reproductive toxicity. In this study, immunohistochemistry, Western blotting, and reverse transcription polymerase chain reaction analysis were used to detect the expression of mTOR molecule in testicular tissues. We found that FA exposure inhibits the expression of mTOR in a dose-dependent manner. Combined with our earlier finding, we found the decreasing expression of mTOR in testicular tissue were consistent with the changes of testicular structure and autophagy levels. In summary, our data suggested that mTOR molecule might be involved in male reproductive injuries induced by FA exposure.

Associations between occupation exposure to Formaldehyde and semen quality, a primary study.

Formaldehyde (FA), a ubiquitous environmental pollutant, has long been suspected of having male reproductive toxicity. However, FA male reproductive toxicity was inconclusive due to dearth of human studies. Therefore, we sought to investigate whether occupational exposure to FA affects semen quality. Semen quality including five conventional parameters and seven kinematics parameters were compared between 114 male workers occupationally exposed to FA and 76 referents. FA exposure index (FEI) was measured and calculated. Our results showed that sperm progressive motility, total sperm motility, VCL, VSL and VAP were statistically significant decreased in FA exposure workers compared with the referents. Moreover, FEI was significantly negative associated with sperm progressive motility (ß = -0.19, P = 0.01) and total sperm motility (ß = -0.23, P = 0.004). In addition, a significant elevated risk of abnormal sperm progressive motility were observed in both low- (OR = 2.58; 95% CI: 1.11-5.97) and high-FA-exposed group (OR = 3.41; 95% CI: 1.45-7.92) respectively. Furthermore, a significant increased risk was also estimated for abnormal total sperm motility in both low- (OR = 3.21; 95% CI: 1.24-8.28) and high-FA-exposed group (OR = 4.84; 95% CI: 1.83-12.81) respectively. In conclusion, our study revealed the adverse effects of FA occupation exposure on semen quality, especially on sperm motion parameters.