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Dental implants are crucial in contemporary oral rehabilitation, necessitating optimal integration with the surrounding soft tissues for durable success. The attachment between the implant surface and peri-implant mucosa should establish a secure seal to prevent bacterial infiltration and subsequent tissue inflammation. This concise review examines the histological and biological perspectives of peri-implant soft tissue reactions to zirconium and titanium abutments, shedding light on their respective advantages and limitations. While titanium has been the gold standard, zirconia has gained attention due to its biocompatibility and aesthetic appeal. Histological studies show comparable soft tissue attachment and inflammatory responses between the two materials. Further research is needed to explore surface treatments and optimize outcomes in dental implant rehabilitation.

This review article investigates the properties and applications of polyetheretherketone (PEEK) in the field of dental implantology. PEEK has emerged as a significant material of interest due to its mechanical strength, biocompatibility, and radiolucency. The article provides a detailed examination of PEEK’s biocompatibility and the various reinforcements that enhance its performance, including PEEK/HA, PEEK/β-TCP–TiO2, and CFR-PEEK. Focusing on dental applications, we discuss PEEK’s use in implant abutments, fixed dental prostheses, implants, and its commercial forms available for dental use. Further, the mechanical behavior of PEEK and its composites is analyzed, including its elastic behavior under various stress conditions and wear resistance. Moreover, the article conducts an integrative systematic review on the stress distribution in dental implants or abutments made from reinforced PEEK composites, assessed through finite element analysis. The aim of this review is to provide insights into the current state of research, the benefits, challenges, and future prospects of PEEK in implantology, and the biomechanical evaluation methods that underpin the development of this promising material.

Estimating average vertical pillar stresses is a critical step in designing room-and-pillar mines. Several analytical methods can be used to estimate the vertical stresses acting on the pillars. However, the present analytical methods fail to adequately account for the influence of abutments on the distribution of vertical stresses, especially when applied to narrow panel widths and pillar layouts comprising evenly spaced barriers. In this study, a multi-layer perceptron neural network (MLPNN) was applied to predict the vertical loads of regular pillars more accurately. Hundreds of room-and-pillar mine layouts were modeled using a displacement discontinuity method (DDM), and a database of 2355 sampled pillar cases was compiled. The MLPNN was trained based on this database, and its prediction capabilities were further validated using simulations by a finite difference code (i.e., FLAC3D). The model predictions and the FLAC3D simulations reasonably agreed with a regression coefficient of 0.99. The model was also adapted for mine cases with evenly spaced barrier pillars, and its application to a real case study mine has shown to provide accurate pillar stress estimations; hence, this model is suitable for practical use at mines. Even though the MLPNN model cannot be applied universally to all mine situations, it seems as a significant improvement over existing analytical techniques in terms of accounting for the influence of abutments on pillar stresses.

Integral abutment bridges (IABs) are robust structures that avoid the use of bearings and expansion joints and are relatively maintenance-free compared to conventional bridges. The seismic design code of IABs is not fully developed, and the complex soil-abutment interaction is not well understood. Therefore, research was carried out at the Schofield centre, the University of Cambridge, to understand the backfill-abutment interaction under earthquake loading, aimed at developing design guidelines for the industry. Understanding the mechanics by which the foundation soil stiffness and strength govern the abutment deformation and, thus, the earth pressures generated behind the abutment is essential. Two centrifuge tests have been conducted simulating an abutment with the conventional abutment-deck connection (or semi-integral abutment bridge), where moment restraint is released. In this paper, the dynamic response of the abutment founded on dry and liquefiable sandy soil is compared. Different deformation modes have been observed depending on the relative abutmentsoil stiffness. The abutment experienced minimal base displacement in dry sands. Conversely, the abutment witnessed cyclic rotational ratcheting about the deck level in liquefiable soil. The dry soil test helped identify the zones where soil stiffness and strength loss can be critical. In the case of the saturated test, the water table level was up to one-third of the abutment height, fully saturating the foundation soil while the backfill height was dry. The comparative results highlight the vulnerability of semi-integral abutment walls to liquefaction-induced failure, as witnessed in the 2011 Christchurch earthquakes.

Abstract Background Repeated removal and replacement of healing abutments result in frequent injuries to the soft tissues. Purpose The purpose of this study was to evaluate the effect of disconnection/reconnection of laser microgrooved vs. machined healing and prosthetic abutments on clinical periodontal parameters, marginal bone levels, and proinflammatory cytokine levels around dental implants. Material and methods Twenty-four patients each received 2 implants with one-stage protocol in a split-mouth design on the same jaw. In each patient, one healing and prosthetic abutments with a laser microgrooved surface (LMS group) and one healing and prosthetic abutments with machined surface (MS group) were used. Four months following implant placement (T0), the healing abutments were disconnnected and reconnected three times to carry out the impression procedures and metal framework try-in. Four weeks later (T1), definitive prosthetic abutments were installated with screw-retained crowns. Modified plaque index (mPI), modified gingival index (mGI) bleeding on probing (BOP), and probing depth (PD) were recorded at T0 and T1. At the same time points, samples for immunological analyses were taken from the sulcus around each implant. Peri-implant crevicular fluid (PICF) samples were analyzed for interleukin-1beta (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor (TNF)-α levels using the ELISA kit. Results At T0 and T1, mPI and mGI showed no statistical difference between the two groups, while higher PD and BoP values were noted for the MS group (P < 0.05). The mean PICF volume and mean concentrations of IL-1β, IL-6, and (TNF)-α in the LMS group were statistically less than those in the MS group (P < 0.05). In addition, comparison of IL-6 and IL-1β mean concentrations at T0 and T1 in the MS group showed a statistically significant increase (p < 0.05) over time, which was not noted for the LMS. Conclusion Disconnection/reconnection of healing and prosthetic abutments with a laser-microgrooved surface resulted in less inflammatory molecular response compared with conventional machined ones. Trial registration ClinicalTrials.gov NCT04415801 , registered 03/06/2020

Aim. To compare the efficiency of removable mini-implant retained dentures using different types of attachment.Materials and methods. The study included 51 edentulous patients. The patients were divided into three groups according to the attachment type and abutment shape: 1) ball-and-socket attachment, ball abutment (n = 26); 2) locator attachment, equator abutment, XiVE LOCATOR system (n = 14); 3) bar attachment (n = 11). Removable dentures were made of ordinary acrylic plastic. The placement of intraosseous dental implants with their sublingual engraftment was performed according to the traditional two-stage delayed-load procedure. The efficiency of implants was evaluated using the method of M.Z. Mirgazizov and the eponymous index. The dynamics of vertical bone resorption around implants was determined using dental panoramic radiography (6 months, 1 and 2 years after the treatment). A periotest was performed 6 months after the end of the orthopaedic treatment.Results. The one-year survival rate of implants reached 96.2% in group 1, amounting to 100% in groups 2 and 3. The two-year survival rate came to 92.3% in group 1, reaching 92.9% and 100% in groups 2 and 3, respectively. Inflammatory phenomena characteristic of peri-implantitis were noted one year after the implant placement in 7.7% (n = 2) of patients in group 1 and in 7.1% of patients in group 2, with no inflammatory phenomena being observed in group 3. Two years after the implant placement, peri-implantitis was observed in 19.2% and 21.4% of patients in groups 1 and 2, respectively, coming to 9.1% in group 3. The periotest revealed that six months after the placement, implant stability was higher in group 3 for both the lower and upper jaw (in comparison with groups 1 and 2), as evidenced by the shift in periotest values towards the negative part of the scale.Conclusion. The study revealed that bar attachment, as well as locator attachment (equator abutments), of removable dentures supported by mini implants is more efficient as compared to the ball-and-socket attachment.

The role of abutments on the seismic vulnerability of bridges has been relatively little studied in geotechnical literature. To cover this gap, 3D numerical simulations were herein performed, by studying the seismic performance of three single-span bridge configurations. The numerical models used OpenSees to account the effects due to soil structure interaction between the deck and the abutments. In particular, advanced materials were implemented to model the non-linear hysteresis and plasticity that are responsible for soil deformations and, thus, structural damage. A probabilistic-based approach was considered and analytical fragility curves were developed to account modeling uncertainties. The role of bridge deformability was investigated by considering several limit states based on the calculation of the longitudinal displacements of the deck.

Recently, tissue-level implants with a convergent collar have been introduced. While different studies have investigated the outcomes of this implant design in the rehabilitation of single teeth, its use in full-arch rehabilitation has yet to be investigated. The present case report describes the clinical outcomes of a full-arch immediate loading rehabilitation using tissue-level implants, with and without using implant-abutment units, with 2 years of follow-up. A female patient with mandibular terminal dentition and a high level of bone resorption (distal areas with a few millimeters of residual bone in the vertical dimension and both distal and anterior areas with narrow crestal bone in the horizontal dimension) was seen at the C.I.R Dental School, Turin, Italy. The patient was seeking to be rehabilitated with fixed prosthodontics, and she was found eligible for an immediate loading implant full-arch rehabilitation. Four implants were inserted in the same appointment. The two anterior implants were inserted straight and connected directly to the prosthesis (no abutments); the two distal implants were tilted in order to avoid the alveolar nerve and connected to two 30° angulated abutments. Two years post-implant placement, all of the implants were successfully integrated, resulting in an implant survival rate of 100%. The peri-implant soft tissues were stable at all the implant sites. No differences were highlighted between those implants with and without abutments. Within the limitations of the present clinical report, implant full-arch rehabilitations with tissue-level implants both with and without implant-abutment units showed optimal outcomes after two years of follow-up. Further research is encouraged to confirm whether this implant design may be a valid alternative to traditional implants in this type of rehabilitation, with or without implant-abutment units.

This article focuses on preclinical studies and reviews the available evidence from the literature on dental implant and abutment materials in the last decade. Specifically, different peri-implantitis materials and how surface modifications may affect the peri-implant soft-tissue seal and subsequently delay or hinder peri-implantitis are examined. This review analyzed more than 30 studies that were Randomized Controlled Trials (RCTs), Controlled Clinical Trials (CCTs), or prospective case series (CS) with at least six months of follow-up. Meta-analyses were performed to make a comparison between different implant materials (titanium vs. zirconia), including impact on bone changes, probing depth, plaque levels, and peri-implant mucosal inflammation, as well as how the properties of the implant material and surface modifications would affect the peri-implant soft-tissue seal and peri-implant health conditions. However, there was no clear evidence regarding whether titanium is better than other implant materials. Clinical evidence suggests no difference between different implant materials in peri-implant bone stability. The metal analysis offered a statistically significant advantage of zirconia implants over titanium regarding developing a favorable response to the alveolar bone.

Aim: The purpose of this study was to evaluate the prevalence of causes of fixed dental prosthesis failures in Indian population. Materials and method: A total of 158 patients were selected for the study who reported to the OPD of the Department of prosthodontics, Karnavati School of Dentistry, with complaints related to fixed dental prosthesis (FDP). Site and condition of the prosthesis and its abutments were evaluated and the cause of failure was classified accordingly by John J. Manappallil′s classification. Results: Majority of failures (32.27%) were found to be class III failure followed by class VI failure (24.05 %). 13.29 % failures were Class IV, 12.65 % failures were identified as class II, 12.02 % failures as class V and 5.69 % failures were categorized in class I failure. Conclusion: Though earlier literature reported caries as the most common cause of fixed dental prosthesis failure, however present study reported class III failures, which include unserviceable restorations due to defective margins, technical failures or esthetic considerations as the most common cause. Therefore proper design of prosthesis is of utmost importance and should be kept in mind during fabrication of FDP.

Background/purpose: A bacterial adhesion to implant surfaces is a first stage of peri-implant mucositis and peri-implantitis. The aim of this longitudinal study was to examine the quantitative and qualitative biofilm formation on healing screws and the presence of periodontal pathogens in peri-implant crevicular fluid (PCF). In each of the 30 participants, one healing screw was adapted to every single implant. Materials and methods: Thirty patients, 18 females and 12 males, were selected. Thirty healing abutments were left in situ for 20, 30 and 90 days. At regular times, the presence/absence of bleeding on probing (BOP) was determined. The specific periodontal pathogens were determined in PCF, by polymerase chain reaction (PCR). After 20, 30 and 90 days, the healing screws were removed and analyzed to establish the total bacterial count by a culture method. Results: BOP+ increased significantly after 90 days. Biofilm was detected on all healing abutments and the number of cultivable oral flora showed a significant increase from 20 days to 30 days and to 90 days. At 90 days, the anaerobic counts constituted the bulk of plaque examined and Veillonella spp. were present in higher percentages levels (19.82%) among the Gram-negative bacteria. No significant differences among the experimental groups were detected in the frequencies of detection of each monitored bacteria in PCF. Conclusion: The healing screws left in situ for a period of 90 days caused a peri-implant inflammation and the presence of periodontal pathogenic bacteria in the peri-implant sulcus, due to the plaque accumulation on screw surfaces.

Aim Bacterial adherence to implants is considered to be an important event in the pathogenesis of bacterial infections. In fact, this infection process is a first stage of peri-implant mucositis and peri-implantitis, and a positive correlation has been found between oral hygiene and marginal bone loss around implants in the edentulous mandible. Surface properties of transgingival implant components are important determinants in bacterial adhesion. The purpose of this study was to characterize the biofilm formation, in vivo, on healing screws made of titanium alloy or coated with a combination of anatase and Bactercline® product. Materials and methods Twenty-five patients, between 21- 37 years, in excellent systemic health, participated in this study. In each of the 25 participants, one anatase-Bactercline® coated healing screw (Test) and one titanium alloy (TI6Al4V) healing screw (Control) were adapted to two different implants. Quantitative and qualitative biofilm formation on healing abutments was analyzed by culture method.Results Bacterial adherence to the two different healing screws used in this study were compared. Statistically significant differences were found between the Control and the Test group for both aerobic and anaerobic bacterial counts (p