Journal of Periodontal and Implant Science最新文献

Purpose: The nasopalatine canal (NPC) is one of the most significant anatomical markers in the anterior maxillary region. Its location is quite important, especially for implant placement. Therefore, the purpose of this study was to use cone-beam computed tomography (CBCT) to evaluate the morphology, size, and anatomic variations of the NPC.

Methods: A total of 150 individual CBCT images were assessed in various sections to evaluate the dimensions, morphology, and extent of the NPC. Reformatted sagittal images were chosen to classify the shape and course of the canal. The Student's t-test, the χ² test, and Pearson correlation coefficients were used.

Results: The NPC was longer in males than in females, and the mediolateral diameter of the canal was greater in older adults. In sagittal sections, the canal predominantly exhibits a cylindrical shape, while a spindle shape is the least common. In coronal sections, a single shape is most frequently observed, with a Y-shape being the least common. Regarding the orientation of the canal, slanted canals are more prevalent, whereas vertically curved canals are rare. Typically, 2 canal openings are observed, with 4 openings being the least common.

Conclusion: The current study highlights the challenges associated with identifying the anatomical appearance and variations of the NPC. Consequently, possessing a thorough understanding of this anatomy is essential before undertaking any surgical procedures, such as implant placement. This knowledge helps prevent complications such as nerve injury-related loss of sensation, bleeding due to blood vessel injury, and the development of a nasopalatine duct cyst following trauma to the canal during surgery.

Purpose: This research aimed to investigate potential factors associated with the risk of perforation of the labial bone plate, nasal floor, or maxillary sinus floor during immediate implant placement (IIP) in the maxillary premolar area, utilizing a cone-beam computed tomography (CBCT) virtual study.

Methods: CBCT exams from 179 eligible participants, encompassing 716 teeth, were included. Implants were virtually positioned in 2 orientations: along the long axis of the tooth (the prosthetically-driven position) and in an optimal position relative to adjacent anatomical structures (the bone-driven position). Binary logistic regression analysis was employed to assess potential associations between perforation or invasion and various covariates, including sex, age, tooth region, the distance from the tooth apex to the nasal floor or maxillary sinus floor, the angle between the prosthetically- and bone-driven positions (implant-line A angle [ILAA]), and the labial concavity angle (LCA).

Results: The mean ILAA was 18.3°±8.0°, and the angle was significantly larger for the second premolar compared to the first premolar. The mean minimum implant length was 13.0±2.1 mm, with a bone anchorage of 4 mm. The incidence of perforation was 84.1% for the prosthetically-driven position and 40.5% for the bone-driven position. Factors associated with a higher risk of cortical bone wall perforation or invasion of the 2-mm safety margin from surrounding anatomical structures (in the bone-driven position) included female sex, older age, shorter distance from the tooth apex to the nasal cavity/maxillary sinus, and smaller LCA.

Conclusions: A high prevalence of cortical bone wall perforation or invasion of the 2-mm safety margin is anticipated when performing IIP in the maxillary premolar region.

Purpose: This study investigated the effect of implant vertical positioning within alveolar ridge preservation (ARP) sites on implant stability quotient (ISQ) values, which were measured 10 weeks post-implantation.

Methods: Patients who underwent ARP using collagenized deproteinized bovine bone mineral, followed by implant placement in the posterior area, were divided into 2 groups: the within-ARP group and the beyond-ARP group. In the within-ARP group, osteotomy and implant placement occurred within the ARP boundary. In contrast, in the beyond-ARP group, these procedures were performed beyond the ARP boundary, incorporating 3 mm of pristine bone at the implant's apex. Bone quality was assessed by tactile sense, and both insertion torque during implant surgery and ISQ values at 10 weeks post-implant surgery were measured. Multiple linear regression analysis and Pearson correlation analysis were used to explore the relationship between insertion torque and ISQ values.

Results: In total, 30 ARP sites in 28 patients were analyzed. There was no significant difference in bone quality, as determined by tactile sense, between the within-ARP and beyond-ARP groups. At the time of implant placement, the beyond-ARP group exhibited a higher insertion torque (33.33±13.39 Ncm) compared to the within-ARP group (17.08±11.17 Ncm). However, the ISQ values were similar between the 2 groups 10 weeks after implant placement. A positive correlation between insertion torque and ISQ values was confirmed at 10 weeks post-implant.

Conclusions: The engagement of pristine bone may facilitate high insertion torque during the placement of implants in ARP sites. Nevertheless, by 10 weeks post-implantation, the ISQ values were found to be comparable, irrespective of the implant's position.

Purpose: The purpose of this study was to compare the bone healing potential of 1-, 2-, and 3-wall defects following alveolar ridge preservation (ARP) treatment, as well as to evaluate the efficacy of ARP as a treatment option for destructive sites.

Methods: Three groups, characterized by 1-, 2-, and 3-wall defects, were randomly assigned to the maxillary second, third, and fourth premolars in each of 8 beagle dogs. Each defect was created at either the mesial or distal root site of the tooth, which was hemi-sectioned and extracted. The contralateral root was preserved to superimpose with the experimental site for histomorphometric analysis. For each site, either spontaneous healing (SH; control) or ARP (test intervention) was randomly applied. Each group was divided in half and underwent a healing period of either 4 or 12 weeks. The Mann-Whitney U test and Kruskal-Wallis test were used for histomorphometric analyses. Statistical significance was set at P<0.05.

Results: Qualitative analysis revealed a higher percentage of new bone in the apical area compared to the coronal area, regardless of defect type and healing period. In quantitative analysis, the 3-wall defect exhibited a significantly higher percentage of mineralization in the ARP group after 12 weeks of healing (ARP: 61.73%±7.52%; SH: 48.84%±3.06%; P=0.029). An increased percentage of mineralization was observed with a greater number of remaining bony walls, although this finding did not reach statistical significance.

Conclusions: Within the limitations of this study, ARP treatment for compromised sockets appears to yield a higher percentage of mineralization compared to SH. Although the effectiveness of the remaining bony walls was limited, their presence appeared to improve the percentage of mineralization in ARP treatment.

The oral cavity provides an ideal environment for microorganisms, including bacteria, viruses, and fungi, to flourish. Increasing attention has been focused on the connection between the oral microbiome and both oral and systemic diseases, spurring active research into the collection and analysis of specimens for healthcare purposes. Among the various methods for analyzing the oral microbiome, saliva analysis is especially prominent. Saliva samples, which can be collected non-invasively, provide information on the systemic health and oral microbiome composition of an individual. This review was performed to evaluate the current state of the relevant research through an examination of the literature and to suggest an appropriate assay method for investigating the oral microbiome. We analyzed articles published in English in SCI(E) journals after January 1, 2000, ultimately selecting 53 articles for review. Articles were identified through keyword searches in the PubMed, Embase, Cochrane, Web of Science, and CINAHL databases. Three experienced researchers conducted full-text assessments following title and abstract screening to select appropriate papers. Subsequently, they organized and analyzed the desired data. Our review revealed that most studies utilized unstimulated saliva samples for oral microbiome analysis. Of the 53 studies examined, 29 identified relationships between the oral microbiome and various diseases, such as oral disease, Behçet disease, cancer, and oral lichen planus. However, the studies employed diverse methods of collection and analysis, which compromised the reliability and accuracy of the findings. To address the limitations caused by methodological inconsistencies, a standardized saliva assay should be established.

Purpose: Quantitative polymerase chain reaction (qPCR) has recently been employed to measure the number of bacterial cells by quantifying their DNA fragments. However, this method can yield inaccurate bacterial cell counts because the number of DNA fragments varies among different bacterial species. To resolve this issue, we developed a novel optimized qPCR method to quantify bacterial colony-forming units (CFUs), thereby ensuring a highly accurate count of bacterial cells.

Methods: To establish a new qPCR method for quantifying 6 oral bacteria namely, Porphyromonas gingivalis, Treponema denticola, Tannerella forsythia, Prevotella intermedia, Fusobacterium nucleatum, and Streptococcus mutans, the most appropriate primer-probe sets were selected based on sensitivity and specificity. To optimize the qPCR for predicting bacterial CFUs, standard curves were produced by plotting bacterial CFU against Ct values. To validate the accuracy of the predicted CFU values, a spiking study was conducted to calculate the recovery rates of the predicted CFUs to the true CFUs. To evaluate the reliability of the predicted CFU values, the consistency between the optimized qPCR method and shotgun metagenome sequencing (SMS) was assessed by comparing the relative abundance of the bacterial composition.

Results: For each bacterium, the selected primer-probe set amplified serial-diluted standard templates indicative of bacterial CFUs. The resultant Ct values and the corresponding bacterial CFU values were used to construct a standard curve, the linearity of which was determined by a coefficient of determination (r²) >0.99. The accuracy of the predicted CFU values was validated by recovery rates ranging from 95.1% to 106.8%. The reliability of the predicted CFUs was reflected by the consistency between the optimized qPCR and SMS, as demonstrated by a Spearman rank correlation coefficient (ρ) value of 1 for all 6 bacteria.

Conclusions: The CFU-based qPCR quantification method provides highly accurate and reliable quantitation of oral pathogenic bacteria.

Purpose: The aim of this study was to evaluate bone regeneration using whitlockite (WH) nanoparticles, collagenated bovine bone mineral, and an activin A/BMP2 chimera (AB204) on calvarial defects in rats.

Methods: This study was conducted using 8 rats. Five-millimeter circular defects were formed on each side of the calvaria. The defects were randomly assigned to 3 groups (BO group: BioOss collagen, BO/WH group: BO + WH, and BO/WH/AB204 group: BO + WH + AB204). After healing periods of 2 and 4 weeks, histological and histomorphometric analyses were performed after sacrifice.

Results: The BO/WH/AB204 group showed superior bone healing compared to the other 2 groups (BO and BO/WH). In the BO and BO/WH groups, new bone formation was found in the defect margin. However, in the BO/WH/AB204 group, new bone was observed on the upper and lower surfaces of the grafted area. The new bone area of the BO/WH/AB204 group at 4 weeks was significantly higher than that of the same group at 2 weeks. At 4 weeks, the total augmented area and material area in the BO/WH/AB204 group were significantly lower than the corresponding values at 2 weeks.

Conclusions: The BO/WH/AB204 group showed superior results of bone regeneration at 2 and 4 weeks compared to the BO and BO/WH groups. AB204 seems to play an important role in bone regeneration.

Purpose: The aim of this study was to evaluate the effects of Frondoside A (FA) on the osteogenic differentiation of human periodontal ligament (PDL) cells.

Methods: Human PDL cells were cultured in osteogenic medium and treated with FA at concentrations of 0, 0.05, and 0.2 µM for 14 days. The expression levels of genes associated with osteogenic differentiation were assessed using quantitative real-time polymerase chain reaction analysis. Subsequently, RNA sequencing was performed to identify enriched gene sets following FA treatment. Alkaline phosphatase (ALP) activity was measured to confirm the osteogenic potential of FA.

Results: Treatment with 0.2 µM FA significantly increased the expression levels of runt-related transcription factor 2 (RUNX2), ALP, and osteocalcin (OCN) at day 3, while also significantly elevating the expression of dentin sialophosphoprotein (DSPP), RUNX2, ALP, OCN, and osterix (OSX) at day 14 (P<0.017). Hallmark gene sets enriched during FA treatment were associated with the KRAS (normalized enrichment score [NES]=2.02, Q=0.000), interferon alpha (IFN-α) (NES=1.88, Q=0.001), IFN-γ (NES=1.85, Q<0.001), hypoxia (NES=1.79, Q=0.001), and p53 (NES=1.77, Q=0.001) signaling pathways. Additionally, treatment with 0.2 µM FA significantly intensified ALP staining at day 14 (P<0.05).

Conclusions: Within the limitations of this study, FA treatment influenced periodontal regeneration by promoting the osteogenic differentiation of human PDL cells.

Purpose: In this study, we examined the facial, dental, periodontal, and tomographic features associated with excessive gingival display (EGD) when smiling in young adults self-reporting a "gummy smile," categorized by potential etiology.

Methods: The study included 25 healthy adults (18-42 years old; 23 women and 2 men) who self-reported EGD. Participants completed a health questionnaire and underwent a periodontal examination assessing probing depth, clinical attachment level, keratinized gingival width, and gingival thickness (GT). Extraoral and intraoral photographs were taken for smile analysis and to determine facial and dental characteristics. Cone-beam computed tomography (CBCT), performed with a lip retractor in place, was used to measure the distance from the gingival margin (GM) to the cementoenamel junction (CEJ), the distance from the CEJ to the alveolar crest, buccal bone thickness, and GT. The extent of EGD when smiling was quantified as the distance from the GM at the upper central incisor to the upper lip edge when smiling fully. The smile was categorized into 4 types based on gingival exposure characteristics observed during full smile.

Results: Most participants were female (92%), with a mean age of 28.77±6.56 years. The average EGD was 4.2±2.44 mm, extending bilaterally from the anterior to the posterior maxilla. Two primary etiological factors were identified, alone or in combination: vertical maxillary excess (VME), predominantly indicated by an anterior maxillary height greater than 29 mm and a large interlabial gap; and altered passive/active eruption (APE), primarily characterized by square teeth (64%), upper central incisor width-to-height ratio (CIW:CIH) exceeding 87.5%, and GM-CEJ distance on CBCT exceeding 2 mm.

Conclusions: These findings suggest a multifactorial etiology of EGD, primarily associated with VME and APE. Clinical periodontal examination, CBCT conducted with a lip retractor, CIW:CIH, and soft tissue facial cephalometric analysis may aid in identifying the etiological factors of EGD.