Metabolic profiling of peri-implant crevicular fluid in peri-implantitis.

OBJECTS: This study aims to explore the etiology of peri-implantitis by comparing the metabolic profiles in peri-implant crevicular fluid (PICF) from patients with healthy implants (PH) and those with peri-implantitis (PI). MATERIALS AND METHODS: Fifty-six patients were enrolled in this cross-sectional study. PICF samples were collected and analyzed using both non-targeted and targeted metabolomics approaches. The relationship between metabolites and clinical indices including probing depth (PD), bleeding on probing (BOP), and marginal bone loss (MBL) was examined. Additionally, submucosal microbiota was collected and analyzed using 16S rRNA gene sequencing to elucidate the association between the metabolites and microbial communities. RESULTS: Significant differences in metabolic profiles were observed between the PH and PI groups, with 179 distinct metabolites identified. In the PI group, specific amino acids and fatty acids were significantly elevated compared to the PH group. Organic acids including succinic acid, fructose-6-phosphate, and glucose-6-phosphate were markedly higher in the PI group, showing positive correlations with mean PD, BOP, and MBL. Metabolites that increased in the PI group positively correlated with the presence of Porphyromonas and Treponema and negatively with Streptococcus and Haemophilus. CONCLUSIONS: This study establishes a clear association between metabolic compositions and peri-implant condition, highlighting enhanced metabolite activity in peri-implantitis. These findings open avenues for further research into metabolic mechanisms of peri-implantitis and their potential therapeutic implications.

Evaluation of the effect of adjunctive diode laser application on peri-implant crevicular fluid biomarker levels: a randomized controlled trial.

OBJECTIVES: To assess both the clinical and immunological effectiveness of diode laser therapy when used as an adjunct to non-surgical mechanical therapy in managing peri-implantitis. MATERIALS AND METHODS: A cohort of 27 participants, comprising 21 females and 6 males, agreed to take part in this investigation. 37 dental implants with peri-implantitis diagnosis were randomly allocated to either the laser group (n = 19) or the control group (n = 18). Evaluation of peri-implant clinical parameters and collection peri-implant crevicular fluid (PICF) samples occurred at baseline, as well as at 3 and 6-month follow-up intervals. The level of various biomarkers (TWEAK, IL-1ß, sclerostin, IL-17, RANKL, OPG and IL-10) within the PICF were quantified using enzyme-linked immunosorbent assay. RESULTS: Significant time-dependent decreases in clinical and biochemical parameters were detected in both groups compared to the baseline. There were marked differences between the groups in terms of periodontal parameters, except probing depth, and IL-1ß, IL-17, sclerostin levels in PICF at 3rd month follow-up. However, no statistically significant difference was detected at 6th month. CONCLUSIONS: Diode laser seems to be a reliable tool as an adjunct for supporting the nonsurgical mechanical treatment during the early stages of peri-implantitis. Furthermore, the findings suggest that IL-17, sclerostin and IL-1ß may serve as promising biomarkers for assessing efficacy of peri-implantitis treatment. CLINICAL RELEVANCE: Based on these outcomes, clinicians may consider the application of adjunctive use of diode laser to non-surgical peri-implantitis treatment to achieve better clinical and immunological improvements than nonsurgical peri-implantitis therapy alone in just early healing period. However, it should be noted that there was no difference between the two methods in the long term.

Biomarkers from Peri-Implant Crevicular Fluid (PICF) as Predictors of Peri-Implant Bone Loss: A Systematic Review.

The aim of the present systematic review is to summarize current knowledge regarding the analysis of biomarkers extracted from peri-implant crevicular fluid (PICF) as predictors of peri-implant bone loss (BL). An electronic search was conducted on three databases, PubMed/MEDLINE, Cochrane Library, and Google Scholar, to find clinical trials published until 1 December 2022 suitable to answer the following focused question: in patients with dental implants, are biomarkers harvested from PICF predictive of peri-implant BL? The initial search yielded a total of 158 entries. After a full-text review and application of the eligibility criteria, the final selection consisted of nine articles. The risk of bias in included studies was assessed using the Joanna Briggs Institute Critical Appraisal tools (JBI). According to the present systematic review, some inflammatory biomarkers harvested from PICF (collagenase-2, collagenase-3, ALP, EA, gelatinase b, NTx, procalcitonin, IL-1ß, and several miRNAs) seem to be correlated with peri-implant BL and may assist in the early diagnosis of pathological BL, that characterizes peri-implantitis. MiRNA expression demonstrated a predictive potential of peri-implant BL that could be useful for host-targeted preventive and therapeutic purposes. PICF sampling may represent a promising, noninvasive, and repeatable form of liquid biopsy in implant dentistry.

Clinical and immunological evaluation of peri-implant tissues around ultra-polished and conventionally-polished zirconia abutments. A 1-year follow-up randomized clinical trial.

PURPOSE: This is a randomized clinical trial to compare the clinical and immunological performance of ultrasmooth versus conventionally-smooth zirconia abutments placed subgingivally after a period of 1 year. MATERIALS AND METHODS: Sixty-two bone level platform-switched implants (NobelParallel CC) were placed epicrestally in the mandibular molar or premolar region in 62 patients. After osseointegration, implants were restored with auto polymerizing acrylic resin crowns and subsequently randomly allocated to two groups according to the type of screw-retained zirconia crown prescribed. The control group received custom zirconia restoration with the subgingival zirconia part conventionally polished, whereas the test group implants were restored with ultra-polished zirconia abutments. Periodontal parameters (PD, PI, and BOP) and marginal bone level changes (MBLC) were recorded for each implant 2 months after insertion (T0), 1 month after final delivery of the crown (T2), and at the 1-year follow-up (T3). Immunological mediators from gingival crevicular fluid (IL-1α, IL-1ra, and TNF-α) were inspected at 1 month after provisional (T1) and accordingly at T2 and T3. Data was analyzed statistically, and significance level was set to α = 0.05. RESULTS: After 1 year, there were no significant changes in PD control-2.18 ± 0.89 mm and test-2.5 ± 0.72 mm (p = 0.073). PD between T2 and T3 dropped significantly in the test group (p = 0.037) and remained stable in the control group. PI was not different in both groups at T0 (p = 0.518) and T2 (p = 0.817). At T3, the test group (0.9 ± 1.01) had a significantly lower PI than the control group (1.55 ± 1.23) (p = 0.035). There was no difference in BOP positive cases between groups after 1 year (control-61.3%, test-51.7%, and p = 0.455). The amount of IL-1ra decreased significantly in the test group (41.75 ± 57.58) (p = 0.001) but not in the control group (59.59 ± 70.43) (p = 0.177). MBLC for the control and test groups after 1 year were 0.68 ± 0.7 and 0.94 ± 0.65 mm (p = 0.061). CONCLUSIONS: PD dynamics, PI, BOP, and IL-1ra revealed better outcomes around ultra-polished zirconia abutments than around conventionally polished zirconia abutments.

Clinical and biochemical evaluation of oral irrigation in patients with peri-implant mucositis: a randomized clinical trial.

OBJECTIVE: This randomized clinical trial aimed to compare the efficacy of an oral irrigator and an interdental brush in patients with peri-implant mucositis clinically and biochemically at different time points (at baseline and at the 2nd, 4th, and 12th weeks). MATERIALS AND METHODS: Forty-five patients with at least one implant with peri-implant mucositis were included in the present study (n = 45). The patients were divided into three groups: oral irrigator + toothbrush (OI group, n = 15), interdental brush + toothbrush (IB group, n = 15), and toothbrush only (control) (C group, n = 15). The modified plaque index (mPlI), modified sulcus bleeding index (mSBI), probing pocket depth (PPD), probing attachment level (PAL), and bleeding on probing (BOP) were recorded at baseline and at the 2nd, 4th, and 12th weeks. The levels of interleukin 1 beta (IL-1ß), transforming growth factor-beta (TGF-ß), tissue-type plasminogen activator (t-PA), and plasminogen activator inhibitor-1 (PAI-1) were also determined in the peri-implant crevicular fluid samples biochemically. RESULTS: The mSBI and t-PA at the 2nd week (p = 0.003; p = 0.003); the mPlI, mSBI, BOP, t-PA, and PAI-1 at the 4th week (p < 0.05; p < 0.001; p < 0.001; p = 0.015; p = 0.011); and the mPlI, mSBI, IL-1ß, t-PA, and PAI-1 at the 12th week (p < 0.05; p < 0.001; p = 0.013; p < 0.001; p = 0.002) were significantly lower in the OI group compared with those in the C group. Meanwhile, PAI-1 at the 2nd week, mSBI at the 4th week, and t-PA at the 12th week were significantly lower in the OI group compared with those in the IB group (p < 0.001; p = 0.011; p = 0.003). At the 2nd, 4th, and 12th weeks, all other parameters were not statistically different in the three groups. CONCLUSION: The clinical indexes (such as mSBI and BOP) that play an important role in the diagnosis of peri-implant mucositis showed the lowest means (although limited) in the OI group at all evaluation time points. Moreover, when the clinical and biochemistry results were interpreted altogether, it became apparent that the OI group exhibited similar or more effective results than the IB group in resolving peri-implant mucositis. In light of the foregoing, this study concluded that the use of an oral irrigator can be as effective as an interdental brush in interdental cleaning. CLINICAL RELEVANCE: In this study, it is suggested that the regular use of an oral irrigator along with a toothbrush could be an appropriate alternative to other oral hygiene products such as dental floss and interdental brush for the management of peri-implant mucositis by preventing the accumulation of dental plaque (NCT03844035).

Is It Safe to Reuse Healing Abutments? An Experimental Study on IL-1ß and TNF-α Cytokine Levels in Peri-Implant Crevicular Fluid.

PURPOSE: To compare pro-inflammatory cytokine levels in the peri-implant crevicular fluid (PICF) in unused and reused healing abutments. MATERIALS AND METHODS: This study was a controlled randomized, double-blind clinical trial. Seventy-two patients who met the inclusion criteria were divided into two groups. After one-stage implant placement, in group A, an unused healing abutment, and in group B, a reused healing abutment, was connected to the implant fixture. After 2 months, clinical measurements for keratinized gingiva (KG), plaque index (PI), and bleeding index (BI) (Ainamo and Bay) were taken, and PICF sampling was performed to evaluate pro-inflammatory IL-1ß and TNF-α cytokine levels using the ELISA test. Comparison of clinical measurements and cytokine levels between the two study groups was made using the Mann-Whitney test. RESULT: Clinical measurements and sampling were performed on 60 patients (nA = 27, nB = 33). There was no significant difference between the two groups in clinical measurements (BI (p = 0.96) and PI (p = 0.06)) or TNF-α (p = 0.63), and IL-1ß (p = 0.26) cytokine levels. CONCLUSION: Reused healing abutments that are cleaned and sterilized properly do not appear to induce further peri-implant pro-inflammatory response; therefore, they can be utilized temporarily until implant abutment insertion.

Clinical, Radiographic, and Inflammatory Peri-Implant Parameters around Narrow Diameter Implant Crowns among Prediabetic and Non-Diabetic Subjects.

Background and Objectives: To compare the clinical, radiographic, and inflammatory peri-implant parameters around narrow diameter implants (NDI) supported single and splinted crowns in non-diabetics and prediabetes. Materials and Methods: The clinical and radiographic parameters and the levels of IL-6 and TNF-α in the peri-implant crevicular fluid (PICF) of narrow diameter single (NDISCs) and splinted (NDISPs) crown implants were assessed both in non-diabetics and participants with prediabetes. The glycemic state of the patient was assessed using glycated hemoglobin (HbA1c) levels. The peri-implant soft tissue indices (Plaque index (PI), bleeding on probing (BoP), probing depth (PD)) and marginal bone loss were recorded and compared between the groups. Success of the prosthesis was assessed by the frequency of technical complications and patient satisfaction. Inter-group comparison was performed using ANOVA (one-way analysis of variance) while the normal distribution of dependent variables was calculated using Shapiro-Wilk. A p-value of less than 0.05 was considered to be statistically significant. Results: Sixty participants (30 non-diabetics and 30 with prediabetes) with a total of 178 (118 NDISCs and 60 NDISPs) platform-switched NDIs were a part of the study. Of the 118 NDISCs, 56 were placed in the non-diabetic individuals and 62 were placed in the prediabetes group whereas 30 NDISPs each were placed in both the study groups. The clinical parameters of PI, BoP and PD in the single crown and splinted crown groups showed comparable results. However, a statistically significant difference (p-value of less than 0.05) in PI, BoP and PD and in the values of IL-6 and TNF-α was found when a comparison was made between the non-diabetes and prediabetes group. A total of 91% of the patients were satisfied with the esthetics of the implants while 79% of the patients showed satisfaction with function. Conclusions: All the clinical and radiographic parameters were statistically similar in both single and splinted types of narrow diameter implants. However, the bone loss, probing depth, plaque index, and levels of inflammatory markers were statistically higher in prediabetes as compared to non-diabetes implying that a slight hyperglycemic state impacts peri-implant health.

Early soft tissue response to zirconium oxide and titanium healing abutments in vivo: a study in dogs.

BACKGROUND: This study aimed to investigate the clinical characteristics and early soft tissue response to zirconium oxide (Zr) and titanium (Ti) healing abutments in dogs. METHODS: Eight implants (four at each hemi-mandible) were inserted after bilateral mandibular third and fourth premolars and first molar extraction in dogs. Then, two Zr and two Ti healing abutments were connected to each unilateral mandible eight weeks later. The ligation method was used to create a peri-implant mucositis model and the 24 abutments were divided into four groups: Zr or Ti healing abutments with ligation (ZrL, TiL) or non-ligation (ZrN, TiN). The clinical indices, peri-implant crevicular fluid (PICF), and inflammatory cytokines (TNF-α and IL-1ß) were measured and analyzed on days 0 and 28. The dogs were then sacrificed on day 28, soft tissues around the implants were harvested, and inflammation infiltration was tested by immunohistochemistry. Normal distribution test and two-way analysis of variance was used to analyze the data. RESULTS: The results showed that the clinical indices were similar for Zr and Ti healing abutments. There was significantly more PICF in the ZrL and TiL groups compared to in the ZrN and TiN groups. The TNF-α levels in PICF were significantly different between ZrL and ZrN groups on day 28. And the TNF-α levels in PICF were significantly higher in TiL group on day 28 than that on day 0. However, the number of inflammatory cells was not significantly different between the groups as measured by immunohistochemistry. CONCLUSIONS: These data indicate that soft tissue responses to Zr healing abutments with peri-implant mucositis were comparable to those of Ti healing abutments in vivo, providing a theoretical foundation for the clinical application of Zr abutments.

Impact of implant-abutment connection on osteoimmunological and microbiological parameters in short implants: a randomized controlled clinical trial.

OBJECTIVES: The study aimed to determine the levels of soluble receptor activator of nuclear factor-кB ligand (sRANKL) and osteoprotegerin (OPG) as well as their relative calculated ratio in peri-implant crevicular fluid (PICF) obtained around two different types of implant-abutment connection on short implants following a 12-month monitoring period. Moreover, the levels of a number of oral bacterial species were investigated in the corresponding submucosal biofilm samples. MATERIALS AND METHODS: Thirty short implants were randomly placed in posterior maxillary edentulous sites using a split-mouth design in 15 periodontally healthy subjects. Tapered interference fit (TIF) and taper-integrated screwed-in (TIS) types of implant-abutment connections were selected for investigation. PICF and submucosal biofilm samples were collected 1 month after surgery and repeated 12 months after prosthetic loading. Clinical parameters, including probing depth, dichotomous presence of bleeding on probing, and plaque index, were recorded and digital periapical radiographs were taken at each time point. sRANKL and OPG levels in PICF were analyzed using an enzyme-linked immunosorbent assay. Total bacterial levels, as well as levels of Fusobacterium nucleatum, Porphyromonas gingivalis, Treponema denticola, Tannerella forsythia, Prevotella intermedia, and Streptococcus oralis, were analyzed in the corresponding submucosal biofilm samples using quantitative real-time polymerase chain reaction. RESULTS: The total amount of sRANKL in TIF implants was 2.64-fold lower than that in TIS implants at baseline (P < 0.001), whereas similar levels were found after 12 months (P > 0.05). Accordingly, OPG and RANKL/OPG ratio were similar between the groups at each time point (P > 0.05). Microbiological results were similar in both groups at each time point (P > 0.05). CONCLUSION: The results of this longitudinal study suggested that sRANKL and OPG in PICF, as well as microbiological parameters in submucosal biofilms, were similar between TIF and TIS implants, after a 12-month monitoring period, despite early differences in the former. Therefore, the type of implant-abutment connection does not appear to influence longitudinally the levels of osteoimmunological and microbiological markers in the peri-implant tissues of short implants.

Associations of alveolar bone loss and interleukin-1ß levels in one- and two-stage surgical procedures: a randomized prospective trial.

OBJECTIVE: Dental implants have been widely and successfully used in recent years as an alternative treatment for removable and fixed dental prostheses. The aim of this randomized prospective study was to determine the alveolar bone loss rate (ABLR) and IL-1ß levels in one- and two-stage surgical procedures. MATERIALS AND METHODS: This study included 40 patients with a single missing tooth in the posterior mandible; dental implants were inserted using a one-stage surgical procedure (Group I) or a two-stage surgical procedure (Group II). All clinical periodontal parameters were recorded; peri-implant crevicular fluid (PICF) samples were collected before loading (T0) and during the third (T1) and sixth (T2) months after loading. ABLR values were evaluated at T0 and T2 by using dental tomography. PICF was analysed after T2 samples were collected. The study was registered through clinicaltrials.gov; identifier NCT03045458. RESULTS: This study found that, the probing pocket depth was found to be significantly higher in Group I than Group II at both T1 and T2 (p < .05). There was no significant difference in other clinical parameters between the groups (p > .05). There was a significant difference between Group I ABLR values at T0 and T2 (p < .05). The PICF IL-1ß levels were not significantly different between groups (p > .05). CONCLUSIONS: Within the limitations of the short observational period and small sample size of this study, two-stage implant placement shows comparable clinical outcomes to implants placed using a one-stage placement protocol.

Protein biomarkers and microbial profiles in peri-implantitis.

OBJECTIVES: The aim of the present investigation was to determine the profile of peri-implant crevicular fluid (PICF) biomarkers combined with microbial profiles from implants with healthy peri-implant tissues and peri-implantitis to assess real-time disease activity. MATERIAL AND METHODS: Sixty-eight patients were included in this cross-sectional study. They were divided into two groups: 34 patients with at least one healthy implant (control) and 34 with at least one peri-implantitis affected implant (test). Total DNA content and qPCR analysis for periodontal bacteria obtained from subgingival plaque samples (Aggregatibacter actinomycetemcomitans, Prevotella intermedia, Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola) and a PICF analysis for IL-1ß, VEGF, MMP-8, TIMP-2, and OPG were performed. The individual and combined diagnostic ability of each biomarker for peri-implantitis and target bacterial species were analyzed. RESULTS: The mean concentration of IL-1ß (44.6 vs. 135.8 pg/ml; P < 0.001), TIMP-2 (5488.3 vs. 9771.8 pg/ml; P = 0.001), VEGF (59.1 vs. 129.0 pg/ml; P = 0.012), and OPG (66.5 vs. 111.7 pg/ml; P = 0.050) was increased in the peri-implantitis patients. The mean expression of MMP-8 (6029.2 vs. 5943.1 pg/ml; P = 0.454) and did not reveal a meaningful difference among groups. Total bacterial DNA of selected microorganisms was associated with a threefold or greater increase in peri-implantitis although no statistical significant difference. The ability to diagnose diseased sites was enhanced by T. denticola combined with IL-1ß, VEGF, and TIMP-2 PICF levels. CONCLUSION: The present data suggest that the increased levels of the selected PICF-derived biomarkers of periodontal tissue inflammation, matrix degradation/regulation, and alveolar bone turnover/resorption combined with site-specific microbial profiles may be associated with peri-implantitis and could have potential as predictors of peri-implant diseases.

Evaluation of peri-implant crevicular fluid prostaglandin E2 levels in augmented extraction sockets by different biomaterials.

OBJECTIVES: This study compares peri-implant crevicular fluid (PICF) prostaglandin E2 (PGE2) levels, clinical parameters and implant stability quotient (ISQ) values around implants placed in augmented extraction sockets. MATERIALS AND METHODS: The sockets (24 in total) were randomly augmented using either EMD or Bio-Oss Collagen. Implant placements were performed after three months of healing. ISQ readings were evaluated at three points: at the time of surgery, at the first month and at the third month. PICF was collected for PGE2 evaluation after the first and the third months of implant surgery. RESULTS: After the first month, a higher level of PICF PGE2 was observed in the EMD group than in the Bio-Oss Collagen group, and this increase was of statistical significance; however, at the third month there was no statistically significant difference in PICF PGE2 levels between the two groups. For implants placed in EMD sites, ISQ values were statistically higher at the third month than at the first month, while no significant differences in ISQ value were detected between the first and third months in Bio-Oss Collagen sites. CONCLUSIONS: The results of this research suggest that both EMD and Bio-Oss Collagen are effective treatment modalities for stimulating the formation of new bone at extraction sites prior to implant surgery.

Quantification and Influence of IL-1ß on Pain and Inflammatory Response after Placement of a Cement-Screw-Retained Restoration.

Background: The objective of this study was to evaluate the pain and inflammatory response in soft tissues using healing and prosthetic abutments of different diameters and lengths. Methods: The study population was rehabilitated with Astra Tech EV single implants (Dentsply Sirona, Atlantis, Dentsply Sirona S.A., Barcelona, Spain) of 4.2 and 4.8 millimetres in diameter in the upper and lower maxilla and loaded with custom abutments digitally designed using Dentsply Sirona's Virtual Atlantis Design software (Atlantis WebOrder, Dentsply Sirona S.A., Barcelona, Spain), version 4.6.5. The custom abutments had a larger diameter than the healing abutments to evaluate for biomarkers through ELISA. Results: Rehabilitations in the mandible and with healing abutments with diameters less than 4.29 mm and rehabilitators with diameters less than 2.18 mm elicited a higher pain and inflammatory response and, in turn, higher interleukin-1ß values. Conclusions: Greater inflammation was evident in cases in which healing abutments with reduced diameter were used compared to the same subsequent rehabilitation with prosthetic abutments with larger diameters.

Expression of IL-1ß, IL-6, TNF-α, and a-MMP-8 in sites with healthy conditions and with periodontal and peri-implant diseases: A case-control study.

Background: This study evaluated the gingival crevicular fluid (GCF) and Peri- implant crevicular fluid (PICF) concentrations of interleukin-1 beta (IL-1ß), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α) and active metalloproteinase-8 (a-MMP-8) in sites with healthy conditions vs. sites affected by periodontitis (PER) and peri-implantitis (PIM). Methods: Periodontally healthy (PH) sites with PER, sites with peri-implant health (PIH), and sites with PIM were investigated intra-individually, according to the inclusion criteria of each group. Probing pocket depth (PPD), plaque index, gingival index, and the presence or absence of bleeding on probing (BoP) were evaluated. In GCF and PICF samples, IL-1ß, IL-6, and TNF-α were quantified by ELISA Duoset® kit in combination with Ultramark® micro-ELISA digital reader; a-MMP8 concentration was analyzed by a chairside test (Perio/ImplantSafe®) in combination with a digital reader (ORALyzer®). Results: The concentrations of IL-6 and IL-1ß, TNF-α, and a-MMP-8 were significantly higher in the PIM and PER sites compared to healthy sites (P<0.05). Significantly higher concentrations of IL-1ß and a-MMP-8 were found in PIM vs. PER sites (P<0.05), while the concentrations of IL-6 and TNF-α did not differ between the PIM and PER groups (P>0.05). Conclusion: aMMP-8, IL-6, IL-1ß, and TNF-α presented higher GCF/PICF concentrations in diseased periodontal and peri-implant sites. However, only the concentrations of IL-1ß and a-MMP-8 were significantly higher in PIM than in PER sites.

Mass spectrometry-based proteomic applications in dental implants research.

Dental implants have been established as successful treatment options for missing teeth with steadily increasing demands. Today, the primary areas of research in dental implantology revolve around osseointegration, soft and hard tissue grafting as well as peri-implantitis diagnostics, prevention, and treatment. This review provides a comprehensive overview of the current literature on the application of MS-based proteomics in dental implant research, highlights how explorative proteomics provided insights into the biology of peri-implant soft and hard tissues and how proteomics facilitated the stratification between healthy and diseased implants, enabling the identification of potential new diagnostic markers. Additionally, this review illuminates technical aspects, and provides recommendations for future study designs based on the current evidence.

Significance of keratinized mucosa around dental implants: a prospective comparative study.

OBJECTIVE: The aim of this investigation was to evaluate the significance of keratinized mucosa (KM) around dental implants both clinically and biochemically for 12 months. MATERIAL AND METHODS: Fifteen edentulous patients treated with implant-retained overdentures in edentulous mandible (four implants per patient). Based on the presence of keratinized mucosa on the buccal surfaces, implants were divided into two groups: Implants having minimal 2 mm of KM on their buccal surfaces and implants having no KM on their buccal surfaces. Thirty-six implants were included in the evaluations; 19 implants in 15 patients had minimal 2 mm of KM on their buccal surfaces and 17 implants in 15 patients had no KM on their buccal surfaces. Clinical measurements of Plaque Index, Gingival Index, probing depths, and Bleeding on Probing were performed and peri-implant crevicular fluid (PICF) were collected immediately before loading (baseline) and at 6th, 12th months after loading. Interleukin-1 beta (IL-1 ß) and tumor necrosis factor-alpha (TNF-α) have been assessed in the crevicular fluid. Results were analyzed by repeated-measures of variance (ANOVA) and Wilcoxon signed rank tests. RESULTS: After 12 months of evaluation the results of ANOVA showed that implants with KM had lower levels of TNF-α total amounts than implants without KM (P < 0.05). Additionally, TNF-α total amounts were significantly higher at 12(th)  month compared to baseline for implants without KM (P < 0.05). Plaque index and Gingival index values were also found significantly higher for implants without KM (P < 0.05). For IL-1 ß and PICF volume levels the differences between the implant groups were non significant, whereas the differences between the periods were significant. (P < 0.05) Additionally, both of the groups had higher levels of PII and BoP scores when compared to baseline (P < 0.05). CONCLUSIONS: The results of this study showed that an adequate band of keratinized mucosa was related with less plaque accumulation and mucosal inflammation as well as pro-inflammatuar mediators, suggesting that it may be critical especially for plaque control and plaque associated mucosal lesions around dental implants.

Biochemical Evaluation of the Effects of Concentrated Growth Factor Liquid on Osseointegration: A Split-Mouth Design Study.

PURPOSE: To investigate cytokine levels in peri-implant crevicular fluid and thus evaluate the effects of concentrated growth factor (CGF) on osseointegration. MATERIALS AND METHODS: A total of 40 mandibular implants were symmetrically placed in a group of 20 systemically healthy patients enrolled in the study. In each patient, one implant wetted with liquid infiltrated from fibrin matrix was placed in the test side (Group L), and the other implant was placed in the control side without the application of any material (Group C). Peri-implant crevicular fluid was collected at 2, 4, and 12 weeks later. Marginal bone loss was measured with panoramic radiographs taken immediately after implant placement and at 12 weeks. Resonance frequency analysis (RFA) of the implants was performed intraoperatively and at 4 and 12 weeks. RESULTS: Stability values of the implants in the CGF liquid-treated sites were higher than those of the control group at week 12 (P = .005). There was no statistically significant difference between the two groups in terms of marginal bone loss (MBL). Group L showed increased levels of tumor necrosis factor alpha (TNF-α) and receptor activator of nuclear factor kappa-B ligand (RANKL) at 2 and 4 weeks. Also, levels of osteoprotegerin (OPG) were higher in Group L at week 4 compared to Group C (P = .033). CONCLUSIONS: The increased TNF-α, RANKL, and OPG levels in this study demonstrate that CGF liquid can be used to accelerate peri-implant bone remodeling in the early phase of osseointegration.

Osteogenic markers in peri-implant crevicular fluid in immediate and delayed-loaded dental implants: A randomized controlled trial.

INTRODUCTION: The study evaluates the levels of matrix metalloprotease-8 (MMP-8), and Cathepsin-K (CatK) in peri-implant crevicular fluid (PICF) among patients with immediate loaded (IL) and delayed-loaded (DL) implants at different time points to know the inflammation and osteogenic status. METHODS: The study population consisted of two groups (n = 25, each group) with a mean age of 28.7 ± 3.5 years, and PICF was collected. MMP-8 and CatK levels were quantified through ELISA. RESULTS: We observed the concentrations of inflammatory markers (MMP-8 and CatK) at three time points in the IL and DL groups. The mean concentration of MMP-8 in the IL group was 9468 ± 1230 pg/mL, 5547 ± 1088 pg/mL, and 7248 ± 1396 pg/mL at 2 weeks, 3 months, and 12 months, respectively; while in the DL group was 10 816 ± 779.7 pg/mL, 9531 ± 1245 pg/mL, and 9132 ± 1265 pg/mL at 2 weeks, 3 and 12 months, respectively. The mean concentration of Cat-K in the IL group was observed at 422.1 ± 36.46 pg/mL, 242.9 ± 25.87 pg/mL, and 469 ± 75.38 pg/mL at 2 weeks, 3, and 12 months, whereas in the DL group was 654.6 ± 152.9 pg/mL, 314.7 ± 28.29 pg/mL, and 539.8 ± 115.1 pg/mL at 2 weeks, 3 months and 12 months, respectively. CONCLUSION: In this study, the levels of CatK and MMP-8 levels decline at 12 months in both groups, and the IL group shows lower values compared to the DL group; however, no significant changes were observed after analyses were adjusted for multiple comparisons (p > 0.025). Therefore, there is not much difference observed in the inflammation process between immediate and delayed loading. (Clinical trial identifier: CTRI/2017/09/009668).

Evaluation of the correlation between interleukin 1ß levels in peri-implant crevicular fluid as an adjunctive diagnostic marker with clinical and radiographic parameters for assessing the peri-implant health status.

Background: Interleukin-1ß (IL-1ß) is one of the most important cytokines that seems to have an important role in the inflammatory process in gingival and peri-implant tissues. As peri-implant crevicular fluid (PICF) provides with a more swift and objective measure of the disease activity, the present study was conducted to evaluate IL-1ß level in PICF as a biochemical marker and to investigate its correlation with clinical parameters and radiological parameters. Materials and Methods: After evaluating all the patients following inclusion and exclusion criteria, 60 patients were selected for the study. After 3-4 months of implants placement, the implants were exposed following standard surgical procedure. PICF sample from implant site was taken 3 days after suture removal with gingival former still in place followed by measurement of clinical and radiological parameters. Results: There was significant increase in IL-1ß levels in both the follow-ups from baseline with variable and minimal change in the clinical parameters and radiological parameters as well, which shows that IL-1ß levels change significantly even when there is a minimal gingival inflammation. Conclusion: Therefore, IL-1ß level in PICF can be used as an adjunctive diagnostic marker to clinical and radiographic parameters for assessing the peri-implant health status.

Expression of circulating cell-free nucleic acids around miniscrew implant during orthodontic tooth movement-a prospective study.

OBJECTIVES: Literature shows that the expression of various biomarkers in peri-miniscrew crevicular fluid (PMICF) is related to the stability of miniscrew implants (MSIs). The present study investigated the role and alterations in levels of circulating cell-free nucleic acids (cfNAs) in PMICF before and after orthodontic loading. MATERIAL AND METHODS: This prospective study consisted of forty-six MSIs placed between the second premolar and first molar in the maxillary and mandibular arches. Direct loading was done after 3 weeks of MSI insertion with nickel-titanium closed coil spring exerting a force of 200 g. The PMICF sample was collected at various time intervals, and the level of cfNA was determined. Clinical parameters, including implant mobility and gingival health, were also assessed. Pre-loading and post-loading parameters were assessed using Wilcoxon's rank-sum test. RESULTS: Among 46 MSIs, 36 were stable during the study and 10 MSIs showed peri-implant inflammation and increased mobility. There was a significant rise in the cfNA concentration 24 h after implant insertion (0.4 ± 0.86 ng/µl). The level of cfNAs significantly decreased over 3 weeks and reached the baseline level (0.2 ± 0.31 ng/µl). There was also a significant rise in the levels of cfNA (0.8 ± 0.70 ng/µl) at 24 h after loading MSIs, which gradually decreased to 0.2 ± 0.24 ng/µl after 63 days. The expression of cfNAs was on the average 0.32 units more in the cases with failed implants (P = 0.05). CONCLUSIONS: cfNA levels in PMICF showed an upward trend 24 h after MSI insertion and 24 h after orthodontic loading. The expression of cfNA was more in cases with failed MSIs. Hence, the cfNAs can be considered as a prognostic biomarker of MSI stability.