Efficacy of customized crown-level position jig in measuring peri-implant crestal bone level on periapical radiographs: An in vitro study.

Background/purpose: Accuracy of using implant length on periapical radiographs as calibration reference for measurements has not been verified. This study aimed to verify the measurements of peri-implant crestal bone level (piCBL) on periapical radiographs taken by the paralleling technique and using the implant length for calibration; and to propose a customized crownlevel position (CLP) jig to improve the measurement accuracy of piCBL. Materials and methods: A typodont installed an implant and a screw-retained crown at maxillary central incisor was used. To simulate piCBL, a metal post was placed near the implant at the same height of implant platform. The CLP jig was designed and 3-dimensionally printed out to allow implant projected orthogonally on periapical film. Thirty periapical radiographs were taken using paralleling technique with and without the jig by three examiners. The implant axis and implant length on radiographs were acquired by image segmentation. The discrepancy of piCBL determination (ΔD) from these measurements were compared and further analyzed when using the implant length for calibration. Results: The piCBL measurement errors were smaller when the jig was used for all examiners (P < 0.001). The inter-rater differences were insignificant. After calibration, ΔD with and without jig were 0.09 (0.07-0.11) and 0.43 (0.38-0.49) mm, respectively. Conclusion: Conventional long-cone paralleling technique using true implant length for calibration demonstrated imprecise piCBL measurement on periapical radiographs. Transferring the implant axis to the CLP jig allowed orthogonal projection of radiography which provided reliable measurements of piCBL with an accuracy of less than 0.1 mm.

Systemic antibiotics adjuvants to scaling and root planing in type 2 diabetic and periodontitis individuals: Systematic review with network meta-analysis.

Targeting inflammatory pathways is considered a common strategy to control type 2 diabetes (T2D) and periodontitis. This overview was to validate systemic antibiotics as an adjuvant to scaling and root planing (SRP) for the treatments of periodontal patients with T2D. Literature searches were conducted using Web of Science, PubMed, Cochrane, and EMBASE. Randomized trials comparing SRP and systemic antibiotics on glycated hemoglobin (HbA1c) and probing pocket depth (PPD) in adults with T2D and periodontitis were analyzed using network meta-analysis and meta-regression. At 3-month postintervention, meta-analyses of 16 studies revealed that SRP and SRP plus systemic antibiotics (SRPa) had similar significant effects in reducing HbA1c levels of - 0.72% and - 0.96% respectively. While SRP and SRPa also, respectively, reduced PPD of - 0.67 and - 0.89 mm, SRPa showed a better reduction than SRP. At 6-month postintervention, meta-analyses of 7 trials revealed that only SRP was effective in reducing HbA1c levels (-0.29%) but not SRPa. Although both SRP and SRPa still significantly reduced PPD by - 0.56 and - 0.81 mm, respectively, there was no difference between them. The current overview suggested that routine SRP alone is highly recommended for patients with T2D and periodontitis, since systemic antibiotics as an adjuvant provide a rather short-term effect.

Long-term evaluation of peri-implant keratinized mucosa stability after free epithelialized graft and keratinized mucosa shifting procedures: A retrospective study up to 13 years.

OBJECTIVES: This study aimed to assess the risk of less than 2 mm keratinized mucosa (KM) width occurrence after free epithelialized graft (FEG) and keratinized mucosa shifting (KMS) procedures using survival analysis. In addition, KM dimensional changes were evaluated. MATERIALS AND METHODS: This study included 76 implants in 36 patients with insufficient KM (<2 mm). The implants underwent either FEG or KMS procedures. The mid-buccal KM width was measured from surgery to the end of a one 13-year follow-up period. RESULTS: Mean follow-up durations were 9.2 ± 3.9 years for FEG and 6.3 ± 4.2 years for KMS. Two implants in FEG and nine implants in KMS exhibited a KM width of less than 2 mm during follow-up. The hazard ratios for KMS compared to FEG were 6.48 (crude) and 6.54 (adjusted), both statistically significant (p < .05). The incidence rate of KMS (4.06%) was higher than that of FEG (0.63%), with an average incidence time of 3.38 years for KMS and 8.82 years for FEG post-surgery. FEG showed a significant shrinkage within 6 months (33% ± 22%), whereas KMS demonstrated a gradual decrease over 13 years (34% ± 25%). FEG exhibited significantly greater width change than KMS during a 5-year follow-up (p < .05). CONCLUSIONS: FEG and KMS enhanced PIKM but exhibited different long-term reduction patterns. FEG demonstrated rapid shrinkage, while KMS displayed gradual and continuous reduction. Moreover, KMS presented a higher risk and incidence of KM width less than 2 mm compared to FEG.

Evaluation of students' self-assessment performance in preclinical endodontic training by means of rubrics and a 3D printed model.

BACKGROUND/PURPOSE: Effective evaluation of students' self-assessment ability is crucial. This study was to develop a standardized 3D printed teaching model accompanied by structured scoring rubrics for preclinical endodontic training, to appraise students' self-assessment ability, and to evaluate their perceptions of the training system. METHODS: The 3D printing model was designed to house a standardized central incisor. Forty-four undergraduate dental students were enrolled and their endodontic performance was self-assessed and also rated by a teaching assistant and a tutor using 3 structured rubrics including access cavity, mechanical preparation, and obturation assessments. In total, 21 rubric evaluation items of preclinical tasks were assessed, and the assessment results from the student, teaching assistant, and tutor were compared. Furthermore, questionnaires were used to evaluate students' experiences with the new system. RESULTS: The tutor, teaching assistant, and students all had similar scorings and high intraclass correlation coefficients (ICC) for mechanical preparation and obturation rubrics, while the students had underestimated scores on the access cavity rubric with a rather low ICC of 0.387, which also lead to the underestimated overall scoring (P < 0.05). Among the 21 evaluation criteria, 9 items were rated statistically different (P < 0.05), which denoted the major deficiencies of students' self-assessments. More than 80% of students rated satisfied for most of the questions regarding the new training system, except the tactile sensation, hardness, and radiopacity. CONCLUSION: The proposed standardized 3D printed model and structured scoring rubrics is feasible for preclinical endodontic training, and standardized evaluation of students' self-assessment ability.

Risk assessment of interproximal contact loss between implant-supported fixed prostheses and adjacent teeth: A retrospective radiographic study.

STATEMENT OF PROBLEM: Studies of interproximal contact loss (ICL) associated with implant-supported fixed prostheses (ISFPs) have typically used dental floss or metal strips to determine ICL and have shown a high prevalence of 34% to 66%, which does not match the authors' experience. Moreover, the implant prosthetic factors contributing to ICL have seldom been reported. PURPOSE: The purpose of this clinical study was to examine follow-up radiographs of ISFPs to determine the prevalence of open contacts between the ISFP and adjacent teeth and to assess the risk factors associated with ICL at patient, implant prosthesis, and adjacent tooth levels. MATERIAL AND METHODS: Patients treated with ISFPs at a single clinical center were included. Digital radiographs obtained at the time of ISFP delivery and subsequent follow-up were assessed, and a total of 180 ISFPs with 296 interproximal contacts in 147 patients were screened for analyses. The prevalence and risk factors of ICL at the levels of patient (age, sex, diabetes, smoking, and bruxism), implant prosthesis (follow-up period, arch location, splinting, ceramic or metal materials, screw or cement-retained, and abutment-fixture connection), and adjacent tooth (mesial or distal side, contact with unrestored tooth, composite resin restoration, or fixed prosthesis, vitality, bone height, and contralateral spacing) were analyzed with logistic regressions and generalized estimating equation (GEE) analyses (α=.05). RESULTS: The onset of ICL was from 6 to 96 months after ISFP delivery. The prevalence of ICL at the patient level was 15.0%, at the implant prosthesis level 13.3%, and at the adjacent tooth levels 8.8%. Twenty-six of the participants had 2 or more ISFPs. The multivariable GEE analysis reported that sex at patient level; longer follow-up period and implant prostheses with external hexagonal and internal octagonal connections at implant prosthesis level; and contralateral spacing, contact with composite resin filling and mesial side of ISFP at adjacent tooth level were significant risk factors of ICL, where contralateral spacing had the highest adjusted odds ratio of 20.88 (P=.002). CONCLUSIONS: Most of the ICL were found at the mesial side of ISFPs, and the odds of ICL was significant in participants with longer follow-up periods. Internal hexagonal connections reported relatively lower risk than others. Factors relevant to the anterior component of occlusal force, such as male sex, contralateral spacing at adjacent tooth, and proximal contact of ISFP with resin filling, seem to be high risk factors for ICL.

Explore the Usefulness of Concurrent Chemotherapy in Stage II Nasopharyngeal Carcinoma: A Retrospective Study.

Objective: This study aims to compare the treatment outcomes of concurrent chemoradiotherapy (CCRT) versus radiotherapy (RT) alone in stage II nasopharyngeal carcinoma (NPC) patients. Methods: We retrospectively collected 601 stage II NPC patients treated in two hospitals between June 2003 to June 2016. All patients were divided into the CCRT group (n = 255) and the RT group (n = 346). Overall survival (OS), locoregional failure-free survival (LRFFS), progression-free survival (PFS), and distant metastasis-free survival (DMFS) were assessed using the Kaplan-Meier method. The log-rank test was used to compare the differences between the groups. The Cox-regression hazards model was performed to determine potential prognostic factors. Results: The median follow-up was 99 months. No significant difference was found in locoregional recurrence, distant metastasis, disease progression, and death between the two groups (all p > 0.05). In univariate analysis, the 5-years OS, PFS, LRFFS, and DMFS had no significant differences between the CCRT and RT groups (all p > 0.05). Two-dimensional radiotherapy (2DRT) sub-analysis showed that CCRT remarkably increased DMFS, PFS, and OS rates (all p < 0.05) but not LRFFS (p = 0.258) compared with RT alone. While intensity-modulated radiotherapy (IMRT) sub-analysis showed that the prognosis of the two groups had no significant differences (all p > 0.05). In multivariate analyses, age was significantly and inversely related to OS, PFS, LRFFS, and DMFS. IMRT was an independent favorable factor for improving LRFFS, PFS, and OS. Concurrent chemotherapy was an independent protective factor for DMFS. Conclusion: In the context of 2DRT, it is definite that concurrent chemotherapy provides survival benefits for patients with stage II NPC. While in the IMRT era, the impact of chemotherapy on survival in patients with stage II NPC is weakened. Prospective randomized controlled studies are required to confirm these results.

Periodontal conditions in patients with Sjögren's syndrome: A meta-analysis.

Sjögren's syndrome (SS) is a chronic autoimmune rheumatic disease characterized by a progressive lymphocytic infiltration of salivary glands, resulting in xerostomia and other oral diseases. The pathogenesis and mechanisms of SS on periodontal tissues are not well understood. Furthermore, results of two systemic reviews and meta-analyses in which compared periodontal parameters of patients with SS to healthy subjects were different. To determine whether periodontal conditions in SS were different from healthy controls, we re-examined the issue with a random-effect model, avoiding recruiting active controls and inadequate data conversion. Outcome measures included probing pocket depth (PPD), clinical attachment loss (CAL), plaque index (PI), and gingival index (GI). Recruited individuals comprised 198 patients with SS and 180 subjects for healthy controls. Quantitative analysis revealed higher PI (WMD = 0.76, 95% CI: 0.30, 1.23) and GI (WMD of total = 0.50, 95% CI: 0.01, 0.98) in SS patients who were not categorized into primary or secondary types of SS. PPD and CAL in SS patients was comparable with control subjects. However, heterogeneity was observed among included studies. Thus, results from this and previous analyses should be interpretated carefully, and a well-designed observational study regarding this issue should be conducted.

Recommendations for treating stage I-III periodontitis in the Taiwanese population: A consensus report from the Taiwan Academy of Periodontology.

BACKGROUND/PURPOSE: Based on the fundamental of the S3-level clinical practice guideline (CPG) for treating stage I-III periodontitis developed by the European Federation of Periodontology (EFP), this consensus report aimed to develop treatment recommendations for treating periodontitis in the Taiwanese population. METHODS: The report was constructed by experts from the Taiwan Academy of Periodontology. The following topics were reviewed: (a) the prevalence of periodontitis in Asia and current status of treatment in Taiwan; (b) specific anatomical considerations for treating periodontitis in Asians; (d) educational and preventive interventions and supragingival plaque control; (d) subgingival instrumentation and adjunctive treatment; (e) surgical periodontal therapy; and (f) maintenance and supportive periodontal care. Recommendations were made according to the evidences from the EFP CPG, the published literature and clinical studies in Asians, and the expert opinions. RESULTS: The treatment recommendations for the Taiwanese population were generally in parallel with the EFP CPG, and extra cautions during treatment and maintenance phases were advised due to the anatomical variations, such as shorter root trunk, higher prevalence of supernumerary distolingual root and lingual bony concavity in mandibular posteriors, and thinner anterior labial plate, of the Asian population. CONCLUSION: The EFP CPG could be adopted for treating periodontitis and maintaining periodontal health of the Taiwanese population, and anatomical variations should be cautious when the treatment is delivered.

Stimulatory effects of Porphyromonas gingivalis GroEL protein on interleukin-6 and interleukin-8 in human osteoblasts.

BACKGROUND/PURPOSE: Porphyromonas gingivalis is an oral pathogen associated with periodontal diseases. P. gingivalis GroEL protein is a stimulator of inflammatory cytokines in macrophages. This study inspected effects of P. gingivalis GroEL protein on production of interleukin (IL)-6 and IL-8 by human osteoblasts. METHODS: Viability of GroEL-treated osteoblasts was analyzed with 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyltetrazolium bromide. Secretion of IL-6 and IL-8 was analyzed using the enzyme-linked immunosorbent assay. Levels of mRNA were analyzed using the reverse transcription and real-time polymerase chain reaction. The antioxidant (curcumin), the p38 mitogen-activated protein kinase (MAPK) inhibitor (SB203580) and the c-Jun N-terminal kinase (JNK) inhibitor (SP600125) were employed to elucidate possible signaling pathways involved. RESULTS: Treatment with GroEL did not affect morphology and viability of osteoblasts. GroEL significantly induced the secretion of IL-6 and IL-8 by osteoblasts in a concentration-dependent pattern. Moreover, the mRNA levels of IL-6 and IL-8 were stimulated by GroEL. The application of SP600125 (10 µM) significantly suppressed the induction of IL-6 and IL-8 by GroEL-treated cells. However, curcumin (20 µM) and SB203580 (20 µM) only down-regulated the stimulatory effects of GroEL on IL-6. CONCLUSION: GroEL protein stimulated the inflammatory reaction of osteoblasts, probably through the activation of p38 MAPK or JNK pathway. The findings suggest that P. gingivalis GroEL may influence the immune functions of osteoblasts and endanger the periodontal health.

Tracking the evolution of the two successful CC59 methicillin-resistant Staphylococcus aureus clones in Taiwan: the divergence time of the two clades is estimated to be the 1980s.

Clonal complex 59 (CC59) is the dominant community-associated methicillin-resistant Staphylococcus aureus (MRSA) strain in Taiwan and includes the Asian-Pacific clone with Panton-Valentine leukocidin (PVL)-negative/staphylococcal cassette chromosome mec (SCCmec) IVg and the Taiwan clone characterised as PVL-positive/SCCmec V (5C2&5). Nevertheless, data on the evolutionary history of the two dominant CC59 MRSA clones in Taiwan are scarce. In this study, a total of 258 CC59 S. aureus strains from Taiwan were classified by multiple-locus variable-number tandem repeat analysis (MLVA), which revealed two major clusters (MT1 and MT2) with distinct mobile genetic elements (MGEs). However, sequencing and PCR mapping of the ß-lactamase-producing plasmid revealed no difference among all CC59 S. aureus strains. Bayesian evolutionary analysis of 18 of the CC59 S. aureus strains based on core genome alignment revealed two clades: (i) Clade A, which shared the samples with MT1, had the features of mainly harbouring gentamicin-resistant MES6272-2 or MES4578, φSA3 translocation in νSaß and SCCmec IVg; and (ii) Clade B, which shared the samples with MT2, had the features of mainly harbouring streptomycin-resistant MESPM1, PVL phage and SCCmec V (5C2&5). Based on the time-calibrated phylogenetic tree, the estimated time of divergence of the two clades was in the 1980s. These results suggest that the CC59 S. aureus progenitor acquired a ß-lactamase-producing plasmid and then developed the varied genetic backgrounds, which were associated with the acquisition and maintenance of distinct MGEs, leading to differences in antimicrobial susceptibility profiles and molecular virulence determinants.

Mechanical properties, accuracy, and cytotoxicity of UV-polymerized 3D printing resins composed of Bis-EMA, UDMA, and TEGDMA.

STATEMENT OF PROBLEM: Three-dimensional printing has the potential for clinical applications, and additive manufacturing materials for dental use merit further investigation. PURPOSE: The purpose of this in vitro study was to evaluate the properties of materials formulated with ethoxylated bisphenol A-dimethacrylate (Bis-EMA), urethane dimethacrylate (UDMA), and triethylene glycol dimethacrylate (TEGDMA) as 3D printing resins for ultraviolet digital light processing (UV-DLP) 3D printers and to characterize the mechanical and biological properties and accuracy of the printed objects. MATERIAL AND METHODS: Ten different light-polymerized resins were formulated using Bis-EMA, UDMA, and TEGDMA. Their viscosities were measured, and only 7 resins with viscosities lower than 1500 centipoise (cP) were selected for 3D printing and further material characterization. The light-polymerized resins were printed into representative shapes using a custom-made 3D printer equipped with a 405-nm UV-DLP projector as the light source. The printed specimens were subjected to biologic, mechanical, and accuracy tests, and the data were submitted to 1-way ANOVA and Tukey post hoc comparisons (α=.05). RESULTS: Photopolymerizable resins made of Bis-EMA, UDMA, and TEGDMA were successfully formulated for 3D printing to fabricate objects of various shapes and sizes. TEGDMA served as the diluent to reduce the viscosity and increase the degree of conversion, while UDMA and Bis-EMA provided strength as demonstrated by the mechanical testing. All the printed objects passed cytotoxicity testing. The flexural strengths of the printed specimens ranged between 60 MPa and 90 MPa; flexural modulus ranged between 1.7 GPa and 2.1 GPa; and surface hardness ranged between 14.5 HV and 24.6 HV. These represent similar mechanical properties to those of currently used clinical resin materials. In the accuracy test, the resin mixture composed of 80% Bis-EMA, 10% UDMA, and 10% TEGDMA had the highest accuracy, with a 0.051-mm deviation from the original design. CONCLUSIONS: Bis-EMA, UDMA, and TEGDMA are good candidates for the formulation of 3D printing resins for dental use. The printed objects demonstrated favorable biological and mechanical properties. Further, the accuracy of the printed specimens showed potential for clinical application.

Parathyroid hormone gene-activated matrix with DFDBA/collagen composite matrix enhances bone regeneration in rat calvarial bone defects.

BACKGROUND: Gene-activated matrix (GAM) induces sustained local production of growth factors to promote tissue regeneration. GAM contains a plasmid DNA (pDNA) encoding target proteins that is physically entrapped within a biodegradable matrix carrier. GAM with a pDNA encoding the first 34 amino acids of parathyroid hormone (PTH 1-34) and a collagen matrix enhances bone regeneration in long bone defects. Demineralized freeze-dried bone allograft (DFDBA) is a widely used osteoinductive bone graft. The present study determined the osteogenic effects of PTH-GAM with a collagen or DFDBA/collagen composite (D/C) matrix for treating craniofacial bone defects. METHODS: We constructed a pDNA encoding human PTH 1-34 and performed cyclic AMP ELISA to verify the bioactivity of PTH 1-34. Next, we generated a D/C matrix and PTH-GAMs containing a collagen matrix (PTH-C-GAM) or D/C matrix (PTH-D/C-GAM). Rats with critical-sized calvarial bone defects were divided into four groups, namely, untreated rats (sham group) and rats grafted with D/C matrix, PTH-C-GAM, or PTH-D/C-GAM (D/C, PTH-C-GAM, or PTH-D/C-GAM groups, respectively). PTH expression was determined by performing immunohistochemical staining after 4 and 8 weeks. New bone formation was evaluated by performing radiography, dual-energy X-ray absorptiometry, microcomputed tomography, and histological examination. RESULTS: PTH pDNA-transfected cells secreted bioactive PTH 1-34. Moreover, PTH was expressed at 4 and 8 weeks after the surgery in rats in the PTH-C-GAM group but not in rats in the D/C group. New bone formation in the calvarial bone defects, from more to less, was in the order of PTH-D/C-GAM, PTH-C-GAM, D/C, and sham groups. CONCLUSION: Our results indicate that PTH-GAM with a collagen matrix promotes local PTH production for at least 8 weeks and bone regeneration in craniofacial bone defect. Moreover, our results indicate that replacement of the collagen matrix with the D/C matrix improves the osteogenic effects of PTH-GAM.

The effect of partially exposed connective tissue graft on root-coverage outcomes: a systematic review and meta-analysis.

The aim of this systematic review was to compare the root-coverage outcomes of using a partially exposed connective tissue graft (CTG) technique with a fully covered CTG technique for root coverage. An electronic search up to February 28th , 2017, was performed to identify human clinical studies with data comparing outcomes of root coverage using CTG, with and without a partially exposed graft. Five clinical studies were selected for inclusion in this review. For each study, the gain of keratinized gingiva, reduction of recession depth, number of surgical sites achieving complete root coverage, percentage of root coverage, gain of tissue thickness, and changes of probing depth and clinical attachment level were recorded. Meta-analysis for the comparison of complete root coverage between the two techniques presented no statistically significant differences. A statistically significant gain of keratinized tissue in favor of the sites with an exposed CTG and a tendency of greater reduction in recession depth were seen at the sites with a fully covered CTG. Based on the results, the use of a partially exposed CTG in root-coverage procedures could achieve greater gain in keratinized gingiva, while a fully covered CTG might be indicated for procedures aiming to reduce recession depth.

Human Beta-Defensin-2 and -3 Mitigate the Negative Effects of Bacterial Contamination on Bone Healing in Rat Calvarial Defect.

Bacterial contamination during the healing of bone defects frequently compromises the effects of bone regenerative therapy. Human beta-defensin-2 (hBD2) and -3 (hBD3) are antimicrobial peptides of human innate immune system with a broad antibacterial spectrum and rare bacterial resistance. The purpose of this study was to determine the effect of hBD2 and hBD3 on the healing of bacteria-contaminated bone defects. Rat bone marrow stromal cells (BMSCs) were infected with adenovirus to overexpress hBD2 or hBD3. Treatment with the conditioned medium derived from the BMSCs overexpressing defensins could concentration dependently reduce the viable Staphylococcus aureus numbers in the colony formation assay. In addition, the antimicrobial effect of BMSCs overexpressing defensins was verified with a diffusion chamber model in rats. Furthermore, we established a S. aureus-contaminated rat calvarial defect model and demonstrated that S. aureus contamination significantly compromised the bone regenerative effect after treatment with wild-type BMSCs. When defensin-overexpressing BMSCs were implanted into the S. aureus-contaminated defect, the viable S. aureus numbers were dramatically reduced and the negative effects of S. aureus contamination on bone healing were significantly mitigated. In conclusion, application of hBD2 or hBD3 promotes the healing of S. aureus-contaminated bone defects.

Association between monocyte chemoattractant protein-1 -2518 A/G gene polymorphism and the outcome of the nonsurgical periodontal treatment.

BACKGROUND/PURPOSE: Elevated monocyte chemoattractant protein-1 (MCP-1) is related to severe periodontal destruction. Furthermore, MCP-1 -2518 A/G gene polymorphism affects MCP-1 after inflammatory stimuli. This study analyzed the association between MCP-1 -2518 gene polymorphism and the outcome of nonsurgical periodontal treatment. METHODS: Forty periodontal patients were recruited and MCP-1 -2518 A/G gene polymorphisms were analyzed using polymerase chain reaction-restriction fragment length polymorphism assay. The clinical periodontal parameters, including probing depth (PD), clinical attachment level (CAL), gingival index (GI), bleeding index (BI) and plaque index (PI), were recorded before and six weeks after nonsurgical periodontal therapy. Patients were divided into chronic periodontitis (CP) or aggressive periodontitis (AP). Multiple linear regression analysis was performed to investigate certain predictors of the therapy outcome. RESULTS: The frequency of MCP-1 -2518 genotype-positive (carrying allele G) was 42.5%. Poor treatment outcome in PD, GI and BI improvement could be predicted with MCP-1 -2518 A/G genotype and aggressive periodontitis status as the predictor variables. In contrast, MCP-1 -2518 A/A genotype and aggressive periodontitis status could predict better treatment response in PD and BI improvement. However, MCP-1 -2518 genotype did not affect the treatment outcome in patients with chronic periodontitis. CONCLUSION: MCP-1 -2518 A/G genotype might be useful in predicting less favorable nonsurgical treatment outcome in patients with aggressive periodontitis. However, MCP-1 -2518 gene polymorphism may not play a role in patients with chronic periodontitis. This study suggests that MCP-1 -2518 genotype may influence the outcome of nonsurgical periodontal treatment in aggressive periodontitis patients.

Levels of high-mobility group box-1 in gingival crevicular fluid in nonsmokers and smokers with chronic periodontitis.

BACKGROUND/PURPOSE: High-mobility group box-1 (HMGB1), a proinflammatory cytokine, plays a role in inflammatory disorders. Smoking is a well-established risk factor for periodontal disease. The aim of this study was to compare the levels of HMGB1 in the gingival crevicular fluid from periodontally healthy nonsmokers, chronic periodontitis nonsmokers, and chronic periodontitis smokers. Furthermore, the relationship between levels of HMGB1 and periodontal parameters was examined. METHODS: Periodontal parameters of 17 nonsmokers with chronic periodontitis, nine smokers with chronic periodontitis, and nine periodontally healthy nonsmokers were examined. Gingival crevicular fluid samples were collected, and the levels of HMGB1 were analyzed using the enzyme-linked immunosorbent assay. RESULTS: The median level of HMGB1 was statistically significantly higher in chronic periodontitis nonsmokers (37.5 ng/mL) than in chronic periodontitis smokers (9.5 ng/mL) and periodontally healthy nonsmokers (3.7 ng/mL). There was no significant difference in the levels of HMGB1 between chronic periodontitis smokers and periodontally healthy nonsmokers. Levels of HMGB1 were positively correlated with plaque index, gingival index, probing depth, and clinical attachment level of nonsmokers. However, no significant correlations were found between levels of HMGB1 and all periodontal parameters examined in chronic periodontitis smokers. CONCLUSION: Chronic periodontitis nonsmokers had elevated levels of HMGB1 in gingival crevicular fluid. Moreover, the levels of HMGB1 were correlated with severity of periodontitis. Chronic periodontitis smokers exhibited lower levels of HMGB1 than chronic periodontitis nonsmokers. Further research is needed for understanding the role of HMGB1 in smoking and pathogenesis of periodontitis.

Influence of Sinus Floor Configuration on Grafted Bone Remodeling After Osteotome Sinus Floor Elevation.

BACKGROUND: This study investigates influence of the sinus floor configuration on dimensional stability of grafted bone height after the osteotome sinus grafting procedure. METHODS: Forty single-tooth dental implants inserted after placement of bioglass and/or allograft into the sinus area using an osteotome technique in 37 patients were evaluated in this retrospective study. Periapical radiographs were taken using the long-cone technique before and after implant placement. Specifically, radiographic measurements of grafted bone height at the mesial and distal side of each implant were taken, and the sinus floor configuration was classified into concave, angle, and flat according to the sinus floor profile at the implant site. Furthermore, the intruding angle, defined as the angle between the implant axis and sinus floor, was measured. RESULTS: All implants were clinically stable during a mean follow-up period of 39.2 months. Mean initial gain of sinus grafted bone height was 7.0 ± 1.9 mm, and later it was reduced to 4.6 ± 1.9 mm at follow-up (P <0.001). A greater reduction in grafted bone height was revealed in the flat sinus group compared with the concave group (P <0.001). Results from the linear regression showed larger intruding angles were statistically significantly associated with a greater reduction in grafted bone height (r2 = 0.55, P <0.001). CONCLUSION: All bioglass and/or allograft placed in the maxillary sinus after the osteotome technique underwent remodeling and shrinkage; however, the outcome of the procedure was more predictable in sinuses with a concave floor and small implant-intruding angles.

Systematic Review and Meta-Analysis on Incidence of Altered Sensation of Mandibular Implant Surgery.

Altered sensation (including paresthesia, dysesthesia and hypoesthesia) after mandibular implant surgery may indicate transient or permanent injury of the inferior alveolar nerve and the mental branch, and considerably lower patients' satisfaction about the therapy. Previous studies have shown a great degree of variability on the incidence of altered sensation. We here reported the incidence of altered sensation after mandibular implant surgery based on a meta-analysis of 26 articles published between 1990.1.1 and 2016.1.1. Study quality and risk of bias was assessed and the studies with a lower score were excluded in the meta-analysis. Data synthesis was performed using the logistic-normal random-effect model. The meta-analyses revealed that the short-term (10 days after implant placement) and long-term (1 year after implant placement) incidence was 13% (95% CI, 6%-25%) and 3% (95% CI, 1%-7%), respectively. (2) For the patients who initially reported altered sensation, 80% (95% CI, 52%-94%) of them would return to normal sensation within 6 months after surgery, and 91% (95% CI, 78%-96%) of them would return to normal sensation one year after surgery. We concluded that dentist-patient communication about the risk of altered sensation is critical to treatment planning, since the short-term incidence of altered sensation is substantial (13%). When a patient reports altered sensation, regular assessment for 6 months would help tracing the changes of symptoms. In terms of long-term follow-up (1 year after surgery), the incidence is much lower (3%) and most patients (91%) would return to normal sensation.

Surgical considerations and management of bilateral labially impacted canines.

Canines are among the most commonly impacted teeth. When a canine is positioned labially, the untoward soft-tissue responses following surgical exposure may cause unfavorable esthetic outcomes. Therefore, decision making as to the choice of a proper surgical technique to uncover labially impacted teeth is critical. This case presentation describes two different surgical approaches for two maxillary impacted canines in a 12-year-old girl. A sequential approach included a first stage of surgical exposure using apically positioned flaps and orthodontic extrusion of both impacted teeth. A successive laterally positioned flap was used for the left maxillary canine to achieve a harmonious soft-tissue contour. In this case, close monitoring and cooperation during the various treatment phases led to proper canine positioning and a successful esthetic result, with good periodontal health and functional occlusion.

Significance of the width of keratinized mucosa on peri-implant health.

In implant therapy, the adequate state of peri-implant tissue health and soft-tissue aesthetics is the essential criterion of restorative success. The need for keratinized mucosa for the maintenance of peri-implant health and soft-tissue integration remains a debated issue. The aim of this paper is to provide a narrative review of the current literature concerning the significance of keratinized mucosa with respect to the clinical parameters of monitoring oral hygiene practice and tissue status. The published studies revealed that there were conflicting results with regard to the influence of keratinized mucosa on plaque score and soft-tissue inflammation. Most studies showed that the amount of soft-tissue recession was significantly increased at implant sites with narrow keratinized mucosa, but the amount of keratinized mucosa had little effect on deepening of peri-implant pockets. The evidence related to the effect of keratinized mucosa on the changes of attachment or bone levels is limited, and conclusions could not be drawn at present. Further, this review found that a band of keratinized mucosa was not absolutely necessary for the maintenance of peri-implant tissue, whereas lack of adequate keratinized mucosa around the implant might impede proper oral hygiene performance and compromise the aesthetic results. In conclusion, because there is a wide variety of clinical features in patients pursuing implant therapy, individual consideration of treatment strategies for the patient with minimal keratinized mucosa is recommended.