The Effects of NF-kB Inhibition with p65-TMD-Linked PTD on Inflammatory Responses at Peri-implantitis Sites

The objective of this study was to find out if suppression of NF-kB complex function by p65-TMD-linked PTD could reduce host inflammation and bone resorption at peri-implantitis sites in rats. Twenty-one male 5-week-old SD rats were divided into three groups: untreated control group (A), silk-induced peri-implantitis group (B), and nt (nucleus transducible)-p65-TMD-treated, silk-induced peri-implantitis group (C). Implant sulcus of a rat in group C were divided into two groups, namely group Cp and Cb. Palatal implant sulcus where nt-p65-TMD solution was applied with an insulin syringe were assigned to group Cp. Buccal implant sulcus without topical nt-p65-TMD application were assigned to group Cb. H&E staining, TRAP staining, and immunohistological staining were done. The crestal bone levels of group A were significantly higher than those of group B at p<0.01. The crestal bone levels of group Cp were significantly higher than those of group Cb at p<0.05. H-E staining showed increased apical migration of junctional epithelium and inflammatory cells in group Cb. TRAP staining revealed more multinucleated osteoclasts in group Cb. As for immunohistological staining, group Cb showed many IL-6-positive cells while group Cp had none. In this study, p65-TMD-linked PTD inhibited NF-kB functions and reduced inflammation and bone resorption at peri-implantitis sites in rats.

Factors influencing the removal torque of palatal implant used for orthodontic anchorage

Background A non-invasive method has recently been introduced to remove osseo-integrated palatal implants by using the implantation ratchet which is designed to screw in or unscrew the implants. Although a proof of concept has been published, the torque involved to successfully explant have not been investigated so far. The aim of this study was to assess the removal torque required to explant osseo-integrated and orthodontically utilized palatal implants, and to identify potentially influencing variables. Materials and method Thirty-one consecutive patients (15 females, 16 males; mean age 24.1 ±7.4 years) with fully osseo-integrated and previously orthodontically loaded palatal implants (Orthosystem®: diameter 4.1mm/length 4.2mm/sandblasted with large grits (SLA) surface) were randomly assigned to either clockwise or counter-clockwise non-invasive explantation. The respective explantation tool with an electric torque control was placed on the abutment connection of the implant and secured by an occlusal screw. The primary outcome studied was maximal removal torque (MRT) needed to detach the implant from its socket which was recorded individually together with other potentially influencing secondary outcomes (gender, age, orthodontic loading time, use of local anaesthetics). Student’s t-test was used to contrast MRT difference for the gender, type of suprastructure, use of local anaesthetics, and rotational direction. Spearman correlations was used to investigate associations between MRT and patient’s age or duration loading time. Results Average MRT (148.6 ± 63.2N/cm) using ratchet as a non-invasive removal method of palatal implant was considered safe. The triangular head fractured of palatal implant at a torque level of 300.1 Ncm. Significantly higher explantation were recorded for male patients compared to female patients (182.0 ± 63.0 Ncm vs 112.8 ± 40.8 Ncm; P=0.001). On the other side, the mean removal torque for palatal removal in clockwise direction was non-significantly different (158.3 ± 58.6 Ncm) compared to counter-clockwise direction (139.4 ± 67.9 Ncm). Neither patient’s age (p=0.324) nor loading time (p=0.214) were significantly correlated with removal torque values. Conclusions Pertinent literature on this subject is practically non-existent, as orthodontics is presumably the only discipline where implant removal represents a treatment success. Mean MRT for successful palatal implant removal was 148.6±63.2Ncm, but a large spectrum was observed (minimum 31.5Ncm, maximum 272.8Ncm). This obvious heterogeneity underlines the importance to investigate possible influencing factors. The safe and simple non-invasive method for palatal implant removal necessitates moderate, but not high torque MRTs, independently of the torque direction. The necessary MRT seems clearly influenced by gender, but less so by patient’s age or loading time.

A simplified method for measurement of palatal bone thickness to select the optimum length of orthodontic mini-implant

Introduction The palatal bone is a suitable site for mini-implant placement due to it being a “rootless area” with dense bone. This application has increased with mini-implant-assisted rapid palatal expansion becoming the preferred method of expansion. It is necessary to measure the vertical bone height with a reasonable accuracy, at the implant insertion site, to utilize the maximum available bone support, and to avoid the risk of perforations. As an accepted method, full-volume cone-beam computed tomography (CBCT) scan is advised for the same. This requires an additional procedure, further, radiation exposure, and cost to the patient. The aim of the study was to establish the utility of lateral cephalogram as a simple and reliable method to measure palatal bone thickness for placement of mini-implants in the 1st premolar and 1st molar region, which are the most common sites of mini-implant placement. Materials and Methods A total of 30 CBCT scans and digital lateral cephalograms of patients were selected and analyzed at the 1st premolar and molar region and were statistically evaluated using Student’s t-test and Wilcoxon rank-sum test. Results The results obtained indicated a highly significant correlation between the measurements obtained on lateral cephalograms at both the 1st premolar and 1st molar areas, P < 0.001. Conclusion The data presented show that lateral cephalometry provides a reliable assessment of the quantity of vertical bone for paramedian insertion of a palatal implant.

Predictive values of resonance frequency analysis as a diagnostic tool in palatal implant loss

ABSTRACTObjectives:To determine the diagnostic value of resonance frequency analysis (RFA) in predicting palatal implant (PI) loss.Materials and Methods:RFA values of 32 patients (study center at Mainz and Dresden) were evaluated in a prospective randomized controlled trial addressing clinical performance of two loading concepts on PI (Orthosystem, Straumann, Basel, Switzerland). Group 1: conventional loading after a 12-week healing period vs group 2: immediate loading within one week after insertion. Stability was assessed by RFA after surgical insertion (T1), one week (T2), and 12 weeks (T3) later.Results:All 32 PI were clinically stable after surgical insertion; 14 PI were loaded conventionally and 18 immediately. One implant in group 1 was lost 6 weeks after insertion. One drop-out was registered in group 2. One false positive and three false negative implant stability quotients (ISQ) were observed. ISQ values of clinically stable PI in group 1 were 67.2 (SD ± 9.5) at T1, 62.3 (SD ± 11.7) at T2, and 68.2 (SD ± 5.5) at T3. Group 2 showed 67.1 (SD ± 11.7) at T1, 65.4 (SD ± 10.4) at T2, and 72.3 (SD ± 5.6) at T3. Differences between groups were not statistically significant for starting time (P = .88) and change from T1 to T2: 0.08 but were significant from T1 to T3: P = .04; (regression analysis).Conclusions:RFA had no sensitivity for prediction of stability. General decrease after primary stability and increase with secondary stability gives support for specificity. Within the limits of the study, only the diagnostic value of RFA identifying stable palatal implants could be confirmed.