Development and applications of peri-implantitis mouse models.

OBJECTIVE: Peri-implantitis is one of the most common complications of implants. However, its pathogenesis has not been clarified. In recent years, mouse models are gradually being used in the study of peri-implantitis. This review aims to summarize the methods used to induce peri-implantitis in mice and their current applications. METHOD: Articles of peri-implantitis mouse models were collected. We analyzed the various methods of inducing peri-implantitis and their application in different areas. RESULTS: Most researchers have induced peri-implantitis by silk ligatures. Some others have induced peri-implantitis by Pg gavage and LPS injection. Current applications of peri-implantitis mouse models are in the following areas: investigation of pathogenesis and exploration of new interventions, comparison of peri-implantitis with periodontitis, the interaction between systemic diseases and peri-implantitis, etc. CONCLUSION: Silk ligature for 2-4 weeks, Pg gavage for 6 weeks, and LPS injection for 6 weeks all successfully induced peri-implantitis in mice. Mice have the advantages of mature gene editing technology, low cost, and short time to induce peri-implantitis. It has applications in the study of pathogenesis, non-surgical treatments, and interactions with other diseases. However, compared with large animals, mice also have a number of disadvantages that limit their application.

Clinical and radiographic outcomes of lateral sinus floor elevation with simultaneous hydrophilic implants placement: A retrospective study of 2-5 years.

AIMS: To investigate the clinical and radiographic outcomes of a chemically modified sandblasted large-grit acid-etched implant (hydrophilic) in lateral sinus floor elevation (LSFE), compared with a conventional one (hydrophobic). MATERIALS AND METHODS: A retrospective study design was adopted. Patients who received LSFE with simultaneous implant placement were recruited. According to different types of implant surfaces, patients were divided into two groups (the hydrophilic group and the hydrophobic group). Implant survival rate (SR), endo-sinus bone stability on the radiographs, mean probing depths, percentage of bleeding on probing, marginal bone loss, and patient satisfaction were evaluated. RESULTS: A total of 106 patients with 180 implants (hydrophilic:101, hydrophobic:79) in 119 maxillary sinuses were included. The follow-up period ranged from 2 to 5 years. Three hydrophobic implants and one hydrophilic implant in four different patients failed. The SR of the hydrophilic group was higher than that of the hydrophobic group but without a significant difference (p > .05). The change and change rate of endo-sinus bone height (ΔESBH and RΔESBH) and bone volume (ΔESBV and RΔESBV) in the hydrophilic group were less than those in the hydrophobic group, with a significant difference at 6 months after implantation. No other significant difference was found between the two groups. CONCLUSION: Within the limitations of this study, both hydrophilic and hydrophobic implants were suitable for LSFE with predictable clinical outcomes. Meanwhile, hydrophilic implants could contribute to the grafted endo-sinus bone stability during healing time.

Titanium particles in peri-implantitis: distribution, pathogenesis and prospects.

Peri-implantitis is one of the most important biological complications in the field of oral implantology. Identifying the causative factors of peri-implant inflammation and osteolysis is crucial for the disease's prevention and treatment. The underlying risk factors and detailed pathogenesis of peri-implantitis remain to be elucidated. Titanium-based implants as the most widely used implant inevitably release titanium particles into the surrounding tissue. Notably, the concentration of titanium particles increases significantly at peri-implantitis sites, suggesting titanium particles as a potential risk factor for the condition. Previous studies have indicated that titanium particles can induce peripheral osteolysis and foster the development of aseptic osteoarthritis in orthopedic joint replacement. However, it remains unconfirmed whether this phenomenon also triggers inflammation and bone resorption in peri-implant tissues. This review summarizes the distribution of titanium particles around the implant, the potential roles in peri-implantitis and the prevalent prevention strategies, which expects to provide new directions for the study of the pathogenesis and treatment of peri-implantitis.

Influence of Dentist-Related Risk Factors on Implant Survival Provided by Dentists Without Structured Training: Results of a Retrospective Cross-Sectional Study.

PURPOSE: To evaluate the cumulative survival rate (CSR) of implants placed by Chinese dentists who lacked structured training and to identify the dentist-related risk factors associated with implant failure. MATERIALS AND METHODS: Data from 2,036 patients who underwent implant-supported restoration at a university-affiliated stomatology hospital were collected. CSR was regarded as the dependent variable. Patient-related characteristics (age, sex, insertion site, and surgical complexity) and dentist-related factors (experience, number of implant brands used, education level, sex, and specialty) were collected as independent variables. The chi-square test was used to identify dentist-related factors for implant failure after addressing patient-related potential confounders using propensity score matching (PSM). Dentist- and patient-related risk factors were further analyzed using multivariable logistic regression within the subgroups. RESULTS: The CSRs were 98.48% for patients (with single or multiple implants) and 98.86% for implants after 48 to 60 months of observation. Dentists with < 5 years of experience and specialists in implant dentistry were significantly associated with implant failure after addressing potential patient-related confounders. Within the group of dentists with < 5 years of experience, complicated cases were the major risk factor. For the group of specialists in implant dentistry, < 5 years of experience and male patient were the major risk factors. CONCLUSION: New dentists (< 5 years of experience) and specialists in implant dentistry are considered to be dentist-related risk factors for implant failure. This confirms that a learning curve exists for new specialists to reach the level of proficiency and expertise. Int J Oral Maxillofac Implants 2023;38:553-561. doi: 10.11607/jomi.9969.

Immediate loaded fixed complete dentures supported by implants in patients with a history of periodontitis: A retrospective cohort study of 2 to 7 years.

STATEMENT OF PROBLEM: The outcome of implant-supported fixed complete dentures in edentulous patients with a history of periodontitis is unclear. PURPOSE: The purpose of this retrospective clinical study was to assess the clinical outcomes of immediate loaded fixed complete dentures in individuals with a history of periodontitis and to analyze risk factors related to implant failure. MATERIAL AND METHODS: A total of 642 implants (146 prostheses) in 119 patients were included. The follow-up period ranged from 2 to 7 years. Implant survival rates, marginal bone loss, mechanical complications, biologic complications, and patient satisfaction were evaluated. The Pearson chi-square test, independent samples t test, and multivariate generalized estimating equation were performed for statistical analysis (α=.05). RESULTS: Eleven implants in 9 patients failed, leading to overall survival rates of 98.3% at the implant level and 92.4% at the patient level. The mean ±standard deviation marginal bone loss was 0.62 ±0.86 mm, and marginal bone loss did not differ significantly between axial and tilted implants (P>.05). Mechanical complications were detected in 55 (37.7%) definitive prostheses; biologic complications were detected in 318 (49.5%) implants. Smokers had a significantly lower survival rate than nonsmokers (odds ratio: 6.880, P=.013). Bruxers had a significantly higher incidence of mechanical complications than nonbruxers (P<.001). CONCLUSIONS: The immediate loaded fixed complete denture supported by implants is a suitable treatment option for edentulous patients with a history of periodontitis, with high survival implant rates. Smoking is a risk factor for implant failure. Bruxism may increase the incidence of mechanical complications with implant-supported fixed complete dentures, and the overall biologic complication incidence is comparatively high.

Radiographic bone volume alteration after jaw cyst enucleation with or without simultaneous bone grafts: A prospective randomized study.

OBJECTIVE: This study was aimed to evaluate bone healing after jaw cyst enucleation with or without bone substitutes by cone beam computed tomography, and to analyze potential influence factors for bone formation as well. MATERIALS AND METHODS: Sixty seven jaw cyst patients were randomly assigned to two groups. Thirty three patients in control group accepted cystectomy without any filling material. The rest 34 bone cavities which filled with xenograft (DBBM, Bio-Oss®) and covered by absorbable membrane (Bio-Gide®) were included in the guided bone regeneration (GBR) group. All patients were examined with cone bean computerized tomography before operation, 3 and 6 months after surgery. Linear regression analysis was applied to evaluate the influence factors of bone healing. RESULTS: There was no significant difference in bone formation rate at 3 months after enucleation, with shrinkage rate (SR) of cystic lesion in control group and GBR group of 26.43 ± 14.98% and 20.78 ± 10.80%, respectively (p > 0.05). Larger shrinkage area in GBR group was detected on postoperative radiographs after 6 months with SR of 60.11 ± 19.23%, when compared to those in patients without filling (6 months SR: 48.63 ± 19.39%, p = 0.018, <0.05). Linear regression analysis showed that cyst size was negatively correlated with bone formation. CONCLUSION: GBR with bovine xenograft and absorbable membrane showed considerable bone regeneration property in the healing of jaw cystic defects after enucleation of radicular cysts. Cyst size showed a suppressive influence on bone formation.

Cleaning effects of decontamination methods on clinically failed TiUnite implants and their impacts on surface roughness and chemistry: An in vitro pilot study.

PURPOSE: To evaluate the in vitro cleaning effects of different decontamination methods and their impacts on surface characteristics using clinically failed TiUnite implants (Nobel Biocare, Kloten, Switzerland). MATERIALS AND METHODS: Thirty clinically failed TiUnite implants were treated using different decontamination methods. Group 1 (control group) received physiological saline irrigation; Group 2 underwent erythritol powder air polishing (AIRFLOW Master Piezon, EMS Dental, Nyon, Switzerland); Group 3 was treated with erythritol powder air polishing with ethylenediaminetetraacetic acid brushing (FileRite PRC, Pulpdent, Watertown, MA, USA); Group 4 received ultrasonic scaling with polyetheretherketone tips (EMS Dental); Group 5 underwent ultrasonic scaling with polyetheretherketone tips with ethylenediaminetetraacetic acid; and Group 6 was treated with a combination of ultrasonic scaling with polyetheretherketone tips, erythritol powder air polishing and ethylenediaminetetraacetic acid. Surface cleaning effects, quantified by relative contaminated area reduction and visual analogue scale score, as well as surface roughness and chemistry, were assessed after decontamination. The cleaning effects of each decontamination method were also compared between TiUnite and SLA (sandblasted, large-grit acid-etched; Straumann, Basel, Switzerland) implants. RESULTS: Group 6 showed the highest relative contaminated area reduction (stereoscopic microscopy 83.92%, scanning electron microscopy 96.40%), visual analogue scale score (2.83) and reduction in surface roughness (thread bottom -0.78 µm, tip -1.35 µm), as well as an almost maximal decrease in the proportion of carbon (thread bottom -12.33%, tip -8.77%) and increase in that of titanium (thread bottom 13.71%, tip 10.73%). Polyetheretherketone remnants were observed in Groups 4 and 5 but appeared to be reduced in Group 6. When comparing the outcomes with those for SLA implants, no significant differences were found. CONCLUSION: Within the limitations of the present study, the combination of ultrasonic scaling with polyetheretherketone tips, erythritol powder air polishing and ethylenediaminetetraacetic brushing achieved reasonable cleaning effects. The original surface modification did not seem to have any impact on the decontamination results for any of the methods examined.

Effects of Antibiotic Use on Saliva Antibody Content and Oral Microbiota in Sprague Dawley Rats.

Antibiotics are often used to treat systemic diseases not associated with the oral cavity. This application of antibiotics may affect the healthy oral microbiota community, as it destroys the balance between specific bacterial populations throughout the ecosystem and may lead to dysbacteriosis. We hypothesized that the effects on antibiotics on oral microbiota regulation and function would affect antibody content in saliva, depending on the antibiotic type. To address this, a total of 24 Sprague Dawley rats (divided into 4 cages, 6 per pen) were administered amoxicillin (AMX), spiramycin (SP), metronidazole (MTZ), or water (control) daily for 14 days (gavage). After treatment was completed, high-throughput sequencing of 16S rRNA genes was used to determine changes in the composition, metabolic function, and diversity of oral microbiota in the rats. Enzyme-linked immunosorbent assay was used to detect antibodies in saliva, including SIgA, IgG, and IgM. Results showed that AMX, MTZ, and SP significantly affected oral microbiota composition, diversity, and metabolic function in rats. AMX induced substantial changes in the rat salivary antibody concentrations. At the genus level, the relative abundance of Rothia and Haemophilus was higher in the AMX group than in the other groups. In conclusion, antibiotics-induced changes in oral microbiota populations may be associated with changes in salivary antibody concentrations. However, the specific interaction mechanisms remain unknown, and it is still unclear whether significant changes in the oral microbiota cause changes in salivary antibody concentrations or vice versa.

Microbial profiles of peri-implant mucositis and peri-implantitis: Submucosal microbial dysbiosis correlates with disease severity.

OBJECTIVE: To investigate the microbiome characteristics of peri-implant mucositis (PM) and peri-implantitis (PI), and to analyse the correlation between disease severity and submucosal microbial dysbiosis. MATERIALS AND METHODS: A cross-sectional study design was conducted. Submucosal biofilm samples from 27 PM sites and 37 PI sites from 64 patients were collected and analysed using 16S rRNA gene sequencing (Illumina). Differences in microbiological profiles between PM and PI were evaluated using the α-diversity, ß-diversity and linear discriminant analysis effect size (LEfSe) analysis. The relative abundances of the taxa at the phylum and genus levels were compared using the Wilcoxon rank test and logistic regression. The microbial dysbiosis index (MDI) was calculated, and its relationship with clinical measurements (probing depth, bleeding on probing and marginal bone loss, among others) was analysed using Pearson's correlation coefficient. RESULTS: The overall microbiome distribution in the PM and PI sites was similar according to α- and ß-diversity. Twenty-three taxa at the genus level and two taxa at the phylum level showed significant differences in relative abundance between the two clinical classifications. Five taxa at the genus level were screened out for the MDI calculation after logistic regression. No clinical measurements but marginal bone loss showed a significant positive correlation with microbial dysbiosis. CONCLUSION: The microbiome richness, diversity and distribution were similar in PM and PI sites, including both common periodontal bacteria and novel species. In addition, an increase in marginal bone loss was significantly associated with submucosal microbial dysbiosis.

Retrospective Study of Short Versus Standard Posterior Implants and Analysis of Implant Failure Risk Factors.

PURPOSE: To compare the clinical and radiographic outcomes of short implants (≤ 8 mm) vs standard implants (> 8 mm, < 10 mm) and to uncover risk factors influencing implant failure in short implants. MATERIALS AND METHODS: Short and standard implants were compared in the aspect of survival rates, biologic and mechanical complications, and marginal bone loss. To analyze risk factors of implant failure in short implants, several variables were taken into consideration, including sex, age, time interval, arch, implant brand, additional surgery, prosthesis material, restoration, smoking status, and crown-root ratio. RESULTS: Three hundred twenty-one short implants and 136 standard implants were retrospectively followed up from 12 to 104 months with an average of 40 months (3.33 years) in short implants and 34 months (2.83 years) in standard implants. The survival rates of short implants were 95.6% at the implant-based analysis and 94.9% at the patient-based analysis, and rates of 96.3% and 94.0%, respectively, were calculated for standard implants. No statistically significant differences were observed between short and standard implants with respect to survival rate, complications, or marginal bone loss. The failure rates were 4.2% for implants and 5.4% for patients in total implants with an average of 38 months (3.17 years). In analyzing risk factors of short implants for survival rate, single short implants resulted in a higher failure rate compared with splinted short implants, while no significant variable was found in standard implants. CONCLUSION: Short implants tend to be a reliable alternative in atrophic posterior regions. Splinted prostheses were more ideal for short implant restorations.

IL-1 Receptor Antagonist Protects the Osteogenesis Capability of Gingival-Derived Stem/Progenitor Cells under Inflammatory Microenvironment Induced by Porphyromonas gingivalis Lipopolysaccharides.

Mesenchymal stem cells (MSCs) have been considered to be a future treatment option for periodontitis due to their excellent regenerative capability. However, it is still a challenge to protect MSCs' biological properties from multiple bacterial toxins in local inflammatory environment. The present study is aimed at investigating the treatment effect of interleukin-1 receptor antagonist (IL-1ra) on cell proliferation, migration, and osteogenic differentiation of gingival-derived mesenchymal stem cells (GMSCs) under an inflammatory microenvironment induced by Porphyromonas gingivalis lipopolysaccharides (P. gingivalis-LPS). GMSCs derived from Sprague-Dawley (SD) rats' free gingival tissues were treated with P. gingivalis-LPS (10 µg/mL) to create in vitro inflammatory environment. Different concentrations of IL-1ra (0.01-1 µg/mL) were used to antagonize the negative effect of LPS. Cell behaviors including proliferation, cloning formation unit (CFU), cell migration, osteogenic differentiation, mineral deposition, and cytokine production were assessed to investigate the protection effect of IL-1ra on GMSCs under inflammation. The toll-like receptor 4 (TLR4)/nuclear factor kappa B (NF-κB) pathway activated by LPS was evaluated by real-time quantitative polymerase chain reaction (RT-PCR) and western blot. In response to P. gingivalis-LPS treatment, cell numbers, cloning formation rate, cell migration rate, proinflammatory cytokine production, and osteogenic differentiation-associated protein/mRNA expressions as well as mineralized nodules were suppressed in a time-dependent manner. These negative effects were effectively attenuated by IL-1ra administration in a time- and dose-dependent manner. In addition, mRNA expressions of TLR4 and IkBα decreased dramatically when IL-1ra was added into LPS-induced medium. IL-1ra also reversed the LPS-induced TLR4/NF-κB activation as indicated by western blot. The present study revealed that IL-1ra decreased inflammatory cytokine production in a supernatant, so as to protect GMSCs' osteogenesis capacity and other biological properties under P. gingivalis-LPS-induced inflammatory environment. This might be explained by IL-1ra downregulating TLR4-mediated NF-κB signaling pathway activation.

Antimicrobial photodynamic therapy versus antibiotics as an adjunct in the treatment of periodontitis and peri-implantitis: A systematic review and meta-analysis.

BACKGROUND: Clinical efficacy of antimicrobial photodynamic therapy (aPDT) as compared to antibiotics in periodontitis and peri-implantitis has been tested in several clinical trials. Yet controversial results were reported. The aim of the present study was to answer the question: "Will adjunctive antimicrobial photodynamic therapy be more effective than antibiotics agent in the treatment of periodontitis and peri-implantitis?". METHODS: Publications compared outcomes between aPDT and antibiotics in adult patients with periodontitis or peri-implantitis, containing more than 3-month follow-up duration, were involved in the systematic review and meta-analysis. PubMed, EMBASE and Cochrane Central were searched until December of 2020. Clinical parameters including pocket probing depth (PPD), clinical attachment level (CAL), and bleeding on probing (BOP) were evaluated. The risk of bias was assessed by Cochrane Collaboration Tool. Weighted mean differences (WMD), 95 % confidence interval(CI) and heterogeneity were estimated by Review Manager software. RESULTS: 10 trials in periodontitis and 5 trials in peri-implantitis were included. Meta-analysis outcomes revealed equal clinical evidence for aPDT and antibiotics in periodontitis and peri-implantitis. In addition, aPDT significantly reduced the red complex in both diseases. However, owing to the heterogeneity of protocols in articles and the limited number of studies, the comparative conclusion remained unconfirmed. CONCLUSION: aPDT can be considered as an alternative to antibiotics in the treatment of peri-implantitis and periodontitis. Given that high heterogeneity in outcome was found in this review, future long-term clinical trials with standard aPDT and antibiotic treatment should be tested to arrive at a firm conclusion.

Changes in the surface topography and element proportion of clinically failed SLA implants after in vitro debridement by different methods.

OBJECTIVE: To evaluate the surface topography and element proportion changes in clinically failed implants after different modalities in vitro debridement and to compare the cleaning effect of different method combinations. MATERIAL AND METHODS: Thirty clinical failed implants were treated by different debridement methods in vitro as follows: Group 1: physiologic saline irrigation; Group 2: glycine powder air polishing; Group 3: glycine powder air polishing + ethylenediaminetetraacetic acid (EDTA); Group 4: polyetheretherketone (PEEK) tip ultrasonic scaling; and Group 5: PEEK tip ultrasonic scaling + EDTA. The relative contaminated area reduction (RCAR), visual analogue scale (VAS, the higher value means, the better cleaning effect) and surface roughness were assessed using scanning electron microscopy (SEM), stereoscopic microscopy (SM) and white light interferometry (WLI). Surface chemistry was determined by energy dispersive spectroscopy (EDS). RESULTS: Group 4 and Group 5 showed higher RCARs (82.90%, 82.89%), VAS scores (2.61, 2.33) and roughness reductions (-0.85 µm, -1.80 µm). Group 3 attained the highest decrease of C% (carbon, -26.67%), O% (oxygen, -13.71%) and N% (nitrogen, -5.66%), and the highest increase of Ti% (titanium, 49.67%). PEEK remnants were detected on the implant surface of Groups 4 and 5. CONCLUSION: Within the limitation of the present in vitro design, PEEK tip ultrasonic scaling was more effective in eliminating visible contamination, while glycine powder air polishing combined with EDTA treatment was more conducive to expose the original surface element distribution. Both methods have their own advantages in decontamination, but none of them could reconstruct the surface as the pristine implant.

The comparative evaluation of transcrestal and lateral sinus floor elevation in sites with residual bone height ≤6 mm: A two-year prospective randomized study.

OBJECTIVES: To compare clinical and radiographic outcomes between transcrestal sinus floor elevation (TSFE) and lateral sinus floor elevation (LSFE) approaches of simultaneous implant placement in atrophic maxilla. MATERIALS AND METHODS: Patients with a residual bone height (RBH) ≤6 mm were enrolled and randomly assigned to TSFE and LSFE groups. Patients in both groups simultaneously underwent sinus floor elevation with bovine-derived xenograft and implant placement. Clinical and radiographic results were evaluated immediately after surgery and after 6, 12, 18, and 24 months. The endo-sinus bone gain (ESBG), apical implant bone height (ABH), endo-sinus bone-implant contact rate (EBICR), and crestal bone level (CBL) were assessed using panoramic radiographs. RESULTS: Forty-one implants (TSFE: 21, LSFE: 20) were placed in cases with a mean RBH of 3.77 ± 1.16 mm. All implants obtained clinical success and satisfactory ESBG at 24 months. No significant differences were found in ESBG and ABH between two groups immediately after surgery, but LSFE group showed significantly higher values than TSFE group thereafter. Grafts in TSFE group reached stability 6 months earlier than that in LSFE group. In both groups, EBICR was almost 100%, and CBL showed no detectable changes. CONCLUSIONS: LSFE can achieve higher ESBG 2 years after surgery. Otherwise, TSFE could be an alternative to LSFE, when the access for lateral window preparation is limited. Both approaches were highly predictable for RBH ≤6 mm during 24-month observation period for the implants placed simultaneously.

The effects of cigarettes and alcohol on intestinal microbiota in healthy men.

Human intestinal microbiota is affected by the exogenous microenvironment. This study aimed to determine the effects of cigarettes and alcohol on the gut microbiota of healthy men. In total, 116 healthy male subjects were enrolled and divided into four groups: non-smoking and non-drinking (Group A), smoking only (Group B), drinking only (Group C), and smoking and drinking combined (Group D). Fecal samples were collected and sequenced using 16S rRNA to analyze the microbial composition. Short-chain fatty acid (SCFAs) levels in feces were determined by gas chromatography. We found that cigarette and alcohol consumptions can alter overall composition of gut microbiota in healthy men. The relative abundances of phylum Bacteroidetes and Firmicutes and more than 40 genera were changed with cigarette and alcohol consumptions. SCFAs decreased with smoking and alcohol consumption. Multivariate analysis indicated that when compared with group A, group B/C/D had higher Bacteroides, and lower Phascolarctobacterium, Ruminococcaceae_UCG-002, Ruminococcaceae_UCG-003, and Ruminiclostridium_9 regardless of BMI and age. Additionally, the abundance of Bacteroides was positively correlated with the smoking pack-year (r = 0.207, p < 0.05), the abundance of predicted pathway of bacterial toxins (r = 0.3672, p < 0.001) and the level of carcinoembryonic antigen in host (r = 0.318, p < 0.01). Group D shared similar microbial construction with group B, but exerted differences far from group C with lower abundance of Haemophilus. These results demonstrated that cigarette and alcohol consumption separately affected the intestinal microbiota and function in healthy men; furthermore, the co-occurrence of cigarette and alcohol didn't exacerbate the dysbiosis and cigarette played the predominated role on the alteration.

Long-term outcomes of osteotome sinus floor elevation with or without bone grafting: The 10-year results of a randomized controlled trial.

AIMS: To assess the long-term clinical and radiographic results of implants placed using osteotome sinus floor elevation (OSFE) with or without bone grafting. MATERIALS AND METHODS: Forty-five patients were randomly assigned into two groups: Group 1 (OSFE with deproteinized bovine bone mineral) and Group 2 (OSFE without grafting). The patients were recalled at 1, 3, 5 and 10 years after surgery. The implant survival, endo-sinus bone gain (ESBG), marginal bone loss (MBL), peri-implant bone height (PBH, distance from the most coronal level to the most apical level of bone-to-implant contact), prosthesis survival and hardware complications, and peri-implant soft tissue conditions were assessed. RESULTS: Forty patients attended the 10-year examination. Mean residual bone height was 4.58 ± 1.28 mm. The 10-year cumulative survival rate was 90.7% for Group 1 and 95.0% for Group 2. The PBH was 5.89 ± 1.24 mm for Group 1 and 5.74 ± 1.43 mm for Group 2 at 10 years. The ESBG of both groups remained stable after 3 years. Two-thirds of the implants were free of hardware complications. No significant differences in MBL and peri-implant tissue parameters were found. CONCLUSION: OSFE with or without grafting both yielded predictable clinical outcomes with similar PBH (ClinicalTrials.gov. NCT01619956).

Likelihood of needing facial bone augmentation in the anterior maxilla of Chinese Asians: A cone beam computed tomography virtual implant study.

BACKGROUND: The perfect position and axis of an implant is often limited by the morphology of the alveolar ridge, especially in Asians. PURPOSE: The aim of this study was to investigate the frequency at which ideal implant placement position in the anterior maxilla of Chinese Asians would require facial bone augmentation given by an initial facial bone profile. MATERIALS AND METHODS: Implants were virtually placed in 303 sites without tooth loss in the anterior maxilla. The incidence and characters of implant facial plate fenestration were analyzed. If there was no facial fenestration, the thinnest buccal plate (TB) amount adjacent to the implant was measured and recorded. RESULTS: A total of 79 (26.07%) sites showed fenestrations. The mean length, width, and area of exposure in the fenestration sites were 2.94 ± 1.67 mm, 1.52 ± 0.97 mm, and 2.84 ± 3.13 mm2 , respectively. In the nonfenestrated sites, the TB of facial bone around the virtual implants was 1.10 ± 0.78 mm. Among the 224 nonfenestrated sites, 126 sites had a TB of less than 1 mm. CONCLUSIONS: It can be concluded that the initial facial bone profile should be considered when designing restorations and choosing an optimal implant position in the anterior maxilla.

Retrospective study on the clinical outcomes of small-diameter implants supporting fixed prostheses without bone augmentation in the posterior region after 2 to 12 years.

BACKGROUND: Small-diameter implants (SDIs: diameter <3.5 mm) are often chosen as an alternative to bone augmentation in clinical practice, but the scientific evidence regarding SDI application in the posterior area remains deficient. PURPOSE: To evaluate the clinical and radiographic outcomes of SDIs supporting fixed prostheses without bone augmentation in the posterior region, and to analyze the potential influencing factors related to SDI failures. MATERIALS AND METHODS: Clinical and radiographic data of 243 SDIs in 156 patients were retrospectively assembled after 2 to 12 (mean 4.75) years of follow-up. Implant and prosthesis failures, mechanical and biological complications, and radiographic marginal bone loss (MBL) were evaluated. The influence of patient/implant characteristics and prosthetic design on SDI failures was investigated. RESULTS: Five implants in five patients failed, contributing to 10-year cumulative survival rates of 97.9% on an implant-based analysis and 96.8% on a patient-based analysis. Biological complications and mechanical complications were detected in 22 (9.1%) and 31 (12.8%) of implants, respectively. No implant fracture was detected. Peri-implant MBL during 10 years was 0.60 ± 0.90 mm on average. The implant type (bone-level or tissue-level) was the only factor that significantly influenced SDI failures. CONCLUSION: SDIs supporting fixed prostheses in the posterior region achieved predictable long-term clinical outcomes. However, tissue-level titanium SDIs should be avoided where possible.

Endo-sinus bone formation after transalveolar sinus floor elevation without grafting with simultaneous implant placement: Histological and histomorphometric assessment in a dog model.

AIM: To evaluate endo-sinus new bone formation and implant osseointegration after transalveolar sinus floor elevation (TSFE) and simultaneous implant placement without any grafting materials and to investigate the influence of implant surface modification on bone healing process under this circumstance. MATERIALS AND METHODS: Transalveolar sinus floor elevation and simultaneous implant placement were conducted bilaterally on 12 Labrador dogs. No grafting materials were used during surgery. Implants with two different surfaces (SLA and SLActive) were placed in a split-mouth design. The animals were sacrificed 4, 8 and 24 weeks after surgery for histological and histomorphometric assessments. Bone-to-implant contact (BIC%), alveolar bone height (ABH) and the percentages of mineralized bone (MB%) in the area of interest were analysed. The probing depth (PD) and bleeding on probing (BOP) were also assessed to describe peri-implant health conditions. RESULTS: Sprouts of new bone in direct contact with implant surface were seen in the elevated area at every time point. Newly formed woven bone under sinus membrane was visible. SLActive implants exhibited favourable results compared with SLA implants regarding ABH at 4 weeks and BIC% at 4 and 8 weeks. Sites with BOP positive could be observed in both groups at any time point. No newly formed bone can be found on the implant apex with either SLA or SLActive surfaces at any time point. CONCLUSIONS: Spontaneous new bone formation from the parent bone walls could be observed after TFE without any grafting materials. No clear evidence of bone formation from the Schneiderian membrane could be found. Even though there were trends for quicker bone response of SLActive implants, this study failed to show the absolute advantage of SLActive in achieving endo-sinus bone formation.

IL-1/TNF-α Inflammatory and Anti-Inflammatory Synchronization Affects Gingival Stem/Progenitor Cells' Regenerative Attributes.

Cytokines play major roles in tissue destruction/repair. The present study investigates proliferative and osteogenic differentiation potentials of gingival mesenchymal stem/progenitor cells (G-MSCs), influenced by IL-1/TNF-α inflammatory/anti-inflammatory conditions. Human G-MSCs were isolated, characterized, and cultured in basic medium (control group, M1), in basic medium with IL-1ß, TNF-α, and IFN-γ (inflammatory group, M2) and with IL-1ra/TNF-αi added to M2 (anti-inflammatory group, M3). MTT tests at days 1, 3, and 7 and CFU assay at day 12 were conducted. Osteogenic differentiation was analyzed by bone-specific transcription factors (RUNX2), alkaline phosphatase (ALP), type I collagen (Col-I), osteopontin (OPN), and osteonectin (ON) expression at days 1, 3, 7, and 14 and Alizarin red staining at day 14. At day 3, the control group showed the highest cell numbers. At day 7, cell numbers in inflammatory and anti-inflammatory group outnumbered the control group. At day 12, CFUs decreased in the inflammatory and anti-inflammatory groups, with altered cellular morphology. The anti-inflammatory group demonstrated elevated bone-specific transcription factors at 14 days. After 14 days of osteogenic induction, calcified nodules in the anti-inflammatory group were higher compared to control and inflammatory groups. For regeneration, initial inflammatory stimuli appear essential for G-MSCs' proliferation. With inflammatory persistence, this positive effect perishes and is followed by a short-term stimulatory one on osteogenesis. At this stage, selective anti-inflammatory intervention could boost G-MSCs' differentiation.