Peri-implant Mucosa Research Articles

Novel method to obtain human non-separated histological samples for the assessment of peri-implant soft tissue response: A feasibility study.

To introduce a standardized and less invasive clinical model that provides histological information on the abutment-mucosa interface in humans. New experimental healing abutments were left in an open healing position on bone-level implants in the interforaminal region of the mandibles in six edentulous patients. The one-piece abutments were hollow cylinder-shaped with two lateral openings that allow for ingrowth of the peri-implant mucosa into the central abutment cavity. After three months of healing, abutments and ingrown mucosa were sampled and processed for histological analysis in a non-separated resin-embedding technique. To test the validity of the new model, the ingrown tissue was compared to the peri-implant mucosa around the same samples. None of the experimental abutments exhibited signs of failure, and all samples showed mucosal ingrowth to the inner-abutment cavity. Comparison of ingrown tissue and peri-implant mucosa revealed no significant differences regarding the traits: tissue morphology, quality of collagen fibers, and adherence to the abutment. Ingrown mucosa exhibited a tendency for higher leukocyte infiltration. The presented model is a promising approach to reduce invasiveness during the sampling process for human non-separated abutment biopsies.

An In-Vitro Analysis of Peri-Implant Mucosal Seal Following Photofunctionalization of Zirconia Abutment Materials

The presence of epithelial and connective tissue attachment at the peri-implant–soft tissue region has been demonstrated to provide a biological barrier of the alveolar bone from the oral environment. This barrier can be improved via surface modification of implant abutment materials. The effect of photofunctionalization on creating a bioactive surface for the enhancement of the epithelial and connective tissue attachment of zirconia implant abutment’s peri-implant mucosal interface using organotypic model has not been investigated. Therefore, this study aimed to evaluate the soft tissue seal around peri-implant mucosa and to understand the effect of photofunctionalization on the abutment materials. Three types of abutment materials were used in this study; yttria-stabilized zirconia (YSZ), alumina-toughened zirconia, and grade 2 commercially pure titanium (CPTi) which were divided into nontreated (N-Tx) and photofunctionalized group (UV-Tx). The three-dimensional peri-implant mucosal model was constructed using primary human gingival keratinocytes and fibroblasts co-cultured on the acellular dermal membrane. The biological seal was determined through the concentration of tritiated water permeating the material–soft tissue interface. The biological seal formed by the soft tissue in the N-Tx group was significantly reduced compared to the UV-treated group (p < 0.001), with YSZ exhibiting the lowest permeability among all materials. Photofunctionalization of implant abutment materials improved the biological seal of the surrounding soft tissue peri-implant interface.

Effectiveness of the Use of Simultaneous Connective Tissue Grafts and Immediate Post-Extraction Implant Placement: A Literature Review

In recent decades, pink aesthetics represents a relevant factor when evaluating long-term results in implant rehabilitation, mainly in the anterior sector. Immediate implant placement after dental extraction is an alternative for the rehabilitation of edentulous patients, and despite its high success rate, the presence of associated peri-implant tissue recessions has been evidenced within its main complications, and the use of connective tissue grafts are a tool that could preserve the stability of the peri-implant mucosa. The objective of this literature review is to assess the use of simultaneous connective tissue grafts with implant placement immediately after extraction as an alternative to improve peri-implant stability. Good results have been evidenced by applying this technique measured in the pink aesthetic score in scientific studies, benefiting those cases with a fine gingival phenotype. Likewise, fewer recessions of the peri-implant mucosa have been observed, which causes fewer associated complications and constitutes an alternative to achieve long-term stability, improvement of peri-implant tissues and better clinical results. However, it is important to take into account that the gingival phenotype is not the only element to consider in post-extraction implants, since the thickness and integrity of the vestibular cortex, the jumping distance, as well as the design of the implant and the three-dimensional positioning must be evaluated.

Técnica vista em enxerto de tecido conjuntivo em área estética peri-implantar – relato de caso

Obtaining a satisfactory soft tissue architecture is a requirement of fundamental importance in rehabilitation with dental implants, especially in aesthetic areas. The objective of this paper is to report a clinical case, in which a connective tissue graft was used by the VISTA technique (Vestibular Incision Subperiosteal Tunnel Access) to gain thickness of the peri-implant mucosa in the premaxillary region. Conclusion: the technique proved to be satisfactory and predictable of success, and could be an excellent alternative for procedures to increase the thickness of the peri-implant mucosa.

Current concepts of surgical methods to increase mucosal thickness during dental implantation ‎

The importance of soft tissues for the maintenance of peri-implant tissue health is one of the most discussed topics in dental implantology. Numerous studies confirm that the presence of soft tissues affects the aesthetic result and the long-term survival of dental implants. It was suggested that surgical procedures aimed to increase peri-implant mucosa improve outcomes of implant treatment. This literature review aims to make an overview of methods of soft tissue management around dental implan

COMPARISON OF THE CONDITION OF THE PERI-IMPLANT ORAL MUCOUS ACCORDING TO THE RESULTS OF DIGITAL MICROSCOPY

The object of the study there is a level of hyperemia of the mucous membrane around the installed intraosseous dental implants with different coating material according to the results of histogram analysis of digital microscopy. The problem to be solved – evaluation of the degree of hyperemia of the periimplant mucosa around intraosseous dental implants coated with rutile, in comparison with titanium implants of VT-6 alloy after prosthetics. Main scientific results: Analysis of digital images using histogram evaluation of the red component of the spectrum showed that 1 month after prosthetics in group 1, which included 20 patients who had intraosseous implants made of titanium alloy TiV6Al (VT-6), the above indicator increased to 191 (St.Err. 4.45). The difference was 4 conventional units. Similarly, in group 2 (16 people) who had intraosseous zirconium implants, there was an increase in the quantitative rate after prosthetics by 9 conventional units, and its value was 194 conventional units (St.Err. 3.64). Since increasing numerical values ​​and shifting the digital histogram to the right is an objective criterion for reducing the intensity of redness, it can be concluded that there is a reduction of mucosal irritation after orthopedic treatment with a predominance of this process in the group of patients who received intraosseous dental implants coated with rutile. The area of practical use of research results: Since the authors first studied the reaction of the peri-implant mucosa in contact with various implant materials at the stages of orthopedic treatment, this is the basis for the introduction into general medical practice of intraosseous dental implants made in Ukraine using rutile application technology. The area of application of an innovative technological product - it is a dental implant practice. The obtained results will allow to use more widely Ukrainian implants of non-demountable construction with a high level of surface preparation, for the purpose of further orthopedic treatment with the use of non-removable metal-ceramic dentures.

Evaluation of the distribution of dendritic cells in healthy peri-implant mucosa in comparison to that of healthy gingiva: an original research

Background: Biofilm formation on the implant surface mainly results in peri-implant diseases which are characterized by the inflammatory destruction of the implant supporting tissues. The host response to infection differs between peri-implantitis and periodontitis, but the mechanisms underlying these differences are not clear till date. In the present study, the distribution of dendritic cell sub populations in healthy peri-implant mucosa (HPIM) was compared with healthy mucosa (HM).Methods: A total of 15 nonsmoker subjects were selected for the study. First sample of healthy mucosa was obtained prior to the implant placement (group I) and second sample of peri-implant mucosa was obtained at the time of placement of gingival former (group II). Immunochemistry was used to quantify dendritic cells in the samples. Statistical analysis used Wilcoxon matched paired test was used to compare the distribution of cells in epithelium and lamina propria.Results: Mean number of factors XIIIa DC in epithelium and lamina propria in group I were 30.37±5.42 and 86.93±13.99 and group II were 50.47±7.27 and 124.33±10.27 respectively. Statistically significant difference in the number of cells in epithelium and lamina propria of group I and group II were noted (p=0.001).Conclusions: In the lamina propria of HPIM, a higher number of factors XIIIa+ DC were observed compared to HM.

Peri-implant mucosal response to implant-supported overdentures: A systematic review and meta-analysis.

To systematically review and evaluate the effects of different types of attachments, implant numbers and loading protocols on the peri-implant mucosa of implant-supported overdentures (ISODs). The impact of peri-implant tissue health on the ISOD treatment outcome is unclear, and current evidence is inadequate on this aspect. A systematic literature search for randomised controlled trials or prospective studies was conducted in indexed databases from 1995 to April 2020. The focused question was as follows: How does the peri-implant mucosa respond to implant-supported or implant-tissue-supported complete overdentures based on different types of attachments, implant numbers, and loading protocols, in terms of clinical outcomes achieved [plaque index (PI), gingival index (GI), probing pocket depth (PD) and bleeding index (BI)]? A random- or fixed-effects model was applied to measure the significance of standardised mean differences (SMD) of PD between the groups. Seventeen studies met the eligibility criteria. The SMD for PD between splinted/bar and unsplinted/stud attachments was 0.10mm (95% CI: -0.27 to 0.47; P=.60) and between 2- and 4-implant groups was 0.15mm (95% CI: -0.16 to 0.45; P=.34), which were not statistically significant. Significant difference (P=.003) was observed between immediate/early loading and delayed loading (SMD=0.46mm [95% CI: 0.16 to 0.75]). Probing depth for the immediate loaded implants was significantly higher than for the delayed loading group. No attachment type, implant number or loading protocol seemed to have a clear advantage over the other, in terms of other peri-implant mucosal outcome measures.

Long-Term Efficacy of Variable-Thread Tapered Implants-A Retrospective, Clinical and Radiological Evaluation.

Background and Objective: There is multifaceted evidence that variable-thread tapered implants (VTTIs) offer high primary stability but few regarding the long-term success. This retrospective clinical and radiological cohort study assessed the long-term outcome of VTTIs. Material and Methods: All patients treated in an OMFS practice with NobelActive Internal® VTTI between October 2007 and September 2011 were invited for clinical examination. The outcome variables were (i) survival rate, (ii) implant success according to the “Health Scale for Dental Implants” and (iii) prevalence of peri-implantitis. Furthermore, the effect of local and systemic risk factors was investigated. Results: In 81 subjects (46 females and 35 males, mean age 65.6 years) 270 implants (157 VTTIs and 113 others as a control group) were analyzed. In 7 out of 81 patients (8.6%), 8 out of 157 VTTIs (5.1%) and 5 out of 113 other implants (4.4%) were lost. Peri-implantitis, defined as (i) presence of bleeding on gentle probing (0.25 N) or exudation and (ii) radiographic bone loss exceeding 0.5 mm since implant insertion to last follow-up, was the most common reason for implant loss (11 out of 13, 84.6%). Sixty-six out of 87 VTTIs (75.9%) were successful. Seventeen out of 42 patients (40.5%) developed peri-implantitis on 29 out of 79 VTTI sites (36.7%). Plaque and missing keratinized peri-implant mucosa were identified as potential risk factors for the development of peri-implantitis. Conclusion: Variable-thread tapered implants showed good long-term results, even in low bone quality. Peri-implantitis was the most common reason for implant failure and may be connected to certain risk factors.

Tilted implants applied to immediate load on edentulous jaw: 6 years follow‐up

Background: Tilted implants favor the rehabilitation of implant-supported prostheses in patients with atrophic jaws. This technique has positive aspects for both the professional and the patient as it simplifies treatment, minimizes the surgical procedure, allows the placement of more implants, improves bone anchorage, reduces treatment time, and reduces costs. Aim/Hypothesis: The aim of this study was to evaluate, clinically and radiographically, inclined implants used in the rehabilitation of fully edentulous jaws submitted to immediate loading with a six-year time interval. Materials and Methods: This prospective study included 5 patients who underwent implant placement and rehabilitation with a protocol-type prosthesis. In the immediate preoperative period (T0), 6 months postoperative (T6) and 72 months postoperative (T72), the stability of the inclined distal and anterior axial implants were assessed using Smat Peg, bone loss around the implant with digital radiographs in the software Sidexis XG version 2.5 and clinical evaluation of the peri-implant mucosa through probes with periodontal probe, on the mesial, distal, vestibular and palatal surfaces of the implants and data were submitted to statistical evaluation (P < 0.05). Results: There was no significant difference for stability between times T0, T6 and T72. The radiographic analysis showed that the marginal bone loss on the mesial face was lower in the inclined implants (T72 = 0.51), when compared to the axial T72 = 0.57), and the reverse occurred for the distal face where the bone loss was higher for inclined implants (0.75) when compared to axial implants (0.38). The surveys showed peri-implant health for both inclined and axial implants. Conclusions and Clinical Implications: We conclude that the implants inclined under immediate load showed good stability and preservation of peri-implant tissues in the studied period, suggesting that this type of treatment is a good alternative for rehabilitation of the jaws with large bone resorption. Keywords: Dental Implants, Edentulous jaw, Marginal Bone Loss, Tilted Implants

Effect of connective tissue grafting on buccal bone changes based on cone beam computed tomography scans in the esthetic zone of single immediate implants: A 1-year randomized controlled trial.

BackgroundConnective tissue grafting has a beneficial effect on the peri‐implant mucosa, but the effect of grafting the buccal mucosa on buccal bone thickness (BBT) has not been investigated, although BBT is proposed to be a key factor for the soft‐tissue contour. The aim of this trial was to assess the outcome of a connective tissue graft (CTG) in the esthetic zone of single immediate implants on the change of BBT according to cone beam computed tomography (CBCT) scan analysis.MethodsIn a 1‐year randomized controlled trial, 60 patients received an immediately placed implant and provisionalization, either combined with CTG (test group) or without CTG (control group). CBCTs were taken preoperatively (Tpre) and 1 year after definitive restoration (T2). Any change in BBT was assessed at different implant levels. Additionally, the change in mid‐buccal mucosal level (MBML) and approximal marginal bone level were assessed.ResultsFifty‐five patients were available for statistical analysis (test group, n = 28; control group, n = 27). At T2, the average change in BBT was significantly larger in the test group (−0.84 ± 0.61 mm) than in the control group (−0.46 ± 0.54 mm, P = 0.02). A MBML gain of 0.07 ± 0.85 mm in the test and a MBML loss −0.52 ± 1.16 mm in the control group was observed at T2. Average loss of marginal bone was 0.05 ± 0.33 mm and 0.01 ± 0.38 mm, respectively.ConclusionsThe application of CTG in the esthetic zone of immediately placed and provisionalized implants is accompanied with more loss of BBT, but at the same time better maintains the mid‐buccal mucosal level.

The biological width around implant.

The concept of biological width has been proposed and widely used in oral implantation. This review aimed to summarize the biological width around implant in detail. An electronic search of the literature prior to March 2019 was performed to identify all articles related to biological width in periimplant soft tissue. The search was conducted in the MEDLINE (National Library of Medicine) database accessed through PubMed with no date restriction. The following main keywords were used: "implant", "biological width", "soft tissue", "junctional epithelium", "peri-implant epithelium", "connective tissue", "gingiva", "mucosa" (connecting multiple keywords with AND, OR). The identified researches focused on several aspects related to biological width in oral implantation, namely the concept, formation, remodeling, dimension, structure and function. Based on of the reviewed literature, the concept, formation, remodeling, structure, dimension, and functional significances of periimplant biological width are explored in this narrative review. The formation of biological width around implant is a complex process after several weeks of healing. The biological width around implant is a 3-4mm distance from the top of the peri-implant mucosa to the first bone-to-implant contact or the stabilized top of the adjacent bone, consisting of sulcular epithelium, junctional epithelium and fibrous connective tissue between the epithelium and the first bone-to-implant contact or the stabilized top of the adjacent bone. The biological width forms a biological barrier against the bacteria, influences the remodeling of soft and hard tissue around implant and has implications for clinical aspects of dental implantation.

Validity of fractal analysis of implants in individuals with healthy and diseased peri-implant mucosa.

The purpose of this study was to determine whether fractal analysis could discriminate the peri-implant trabecular bone between individuals with healthy peri-implant mucosa and peri-implant disease using digital periapical radiographs. The electronic health records of patients with a dental implant were reviewed to determine their eligibility. One hundred four patients (aged 27-89years) were included and divided into three groups. Group 1) Individuals with healthy peri-implant mucosa; Group 2) Individuals with peri-implant mucositis; or Group 3) Individuals with peri-implantitis. The following clinical measurements for each dental implant were extracted: probing depth (PD), clinical attachment level (CAL), and the presence or absence of bleeding on probing (BOP). Digital periapical images of the implant were used to calculate the fractal dimension (FD) for each implant at two regions of interest (ROI). Summary statistics were calculated for mean PD, mean CAL, mean percent BOP, and mean FD by group. Differences among groups were tested using one-way analysis of variance (ANOVA). Spearman nonparametric correlations were tabulated for mean PD, mean CAL, mean percent BOP, and mean FD. The only measure that did not demonstrate significant differences among groups was FD (p=.559) with all other measures demonstrating a significant difference (p<.001). Based on this study, FD of the peri-implant bone calculated from a periapical radiograph does not appear to be a valid method to distinguish between healthy and diseased implants, while clinical measures of PD, CAL, and BOP are useful for the diagnosis of peri-implant health, peri-implant mucositis, and peri-implantitis.

PSEUDOCARCINOMATOUS HYPERPLASIA IN A PATIENT WITH PERI-IMPLANT DISEASE: A CASE REPORT

Pseudocarcinomatous hyperplasia (PCH) consists of a non-neoplastic epithelial hyperplasia that can mimic squamous cell carcinoma (SCC) both clinically and histopathologically. Some inciting factors have been associated with PCH, including trauma, infection, chronic inflammation, and neoplasia. A 57-year-old female patient, heavy smoker, was referred with complaint of pain at level of the tooth #16, where there was an implant. Clinical examination revealed discharge of pus and swelling of the peri-implant mucosa. Radiographic examination showed progressive bone loss around the dental implant. Therefore, the implant was removed, and the surrounding soft tissue was sent for histopathologic analysis, which revealed foci of the hyperplastic epithelium in the connective tissue that projected from the surface epithelium, surrounding isolated bone trabeculae, and admixed with chronic inflammation. In this case, a relationship between peri-implantitis and PCH is probable, which should be included within the histopathologic spectrum of this peri-implant disease, to avoid misdiagnosis with SCC.

The lack of keratinized mucosa is associated with poor peri-implant tissue health: a cross-sectional study

ObjectivesThe aim of this cross-sectional study is to determine the association between the absence of keratinized mucosa and peri-implant tissue health.Methods and materialsThis cross-sectional study comprised 412 implants from 200 patients from faculty-based clinics. Demographic, medical, and clinical information were collected. The modified sulcus bleeding index, modified plaque index, mucosal recession, probing depth, bone level, the width of keratinized mucosa, and implant status were evaluated by three calibrated examiners. Each implant was categorized into either of two peri-implant mucosa groups: keratinized mucosa (KM) or non-keratinized mucosa (NKM). The chi-square test was performed to the association between the keratinized mucosa groups and peri-implant clinical parameters and peri-implant status. Multiple logistic regression models were analyzed to test potential associations between peri-implant clinical parameters and the presence or absence of keratinized mucosa.ResultsThirty-two implants (7.8%) were categorized into the NKM group. The prevalence of peri-implantitis was 12.5% and 8.3% at the subject level and implant level, respectively. The NKM group was associated with more plaque accumulation, mucosal recession, interproximal bone level ≥ 3 mm, and peri-implantitis (p < 0.05). After controlling for confounding factors, the NKM group demonstrated higher plaque accumulation, mucosal recession, and interproximal bone level ≥ 3 mm with adjusted odds ratios of 2.98 (1.33–6.66), 3.20 (95% CI, 1.03–9.90), and 4.62 (1.70–12.58), respectively.ConclusionWithin the limitation of this study, the lack of keratinized mucosa around the dental implants was significantly associated with more plaque accumulation, mucosal recession, interproximal bone level ≥ 3 mm, and peri-implantitis.

Azonnali implantáció és lágyrészformázás saját foggal kombinált ideiglenes PMMA felépítménnyel

Manapság az implantológia fejlődésével lehetővé vált, hogy fogeltávolítást követő azonnali implantátum beültetés eseténmegőrizzük az eredeti lágyrész viszonyokat, ezzel megteremtve egy esztétikus és hosszútávon funkcionáló pótláselkészítésének lehetőségét. Fontos lépés az azonnali implantációt követően a lágyrészek formázásához, megőrzéséhezaz ideiglenes pótlás készítése. Egyszerű és hatékony megoldás lehet gyári PMMA (poli metil-metaklirlát) ideiglenesfelépítményt az eltávolított fog koronai részével kombinálni.Esetbemutatásunkban a balesetben eltört első metszőfoggal jelentkező páciensünknél azonnali implantáció mellettdöntöttünk. A papillák és lágyrészviszonyok megőrzése érdekében azonnali ideiglenes koronát készítettünk egy PMMAideiglenes implantátumfejet és az eltávolított fog koronáját felhasználva. A gyógyulást követően, a végleges pótlás készítésekoregyéni lenyomati fejet használva lemintáztuk a megformázott ínyviszonyokat, majd cirkónium egyéni implantátumfelépítményt és e.max préskerámia koronát készítettünk végleges pótlásként.

Volumetric assessment of tissue changes following combined surgical therapy of peri-implantitis: A pilot study.

To assess volumetric tissue changes at peri-implantitis sites following combined surgical therapy of peri-implantitis over a 6-month follow-up period. Twenty patients (n=28 implants) diagnosed with peri-implantitis underwent access flap surgery, implantoplasty at supracrestally or bucally exposed implant surfaces and augmentation at intra-bony components using a natural bone mineral and application of a native collagen membrane during clinical routine treatments. The peri-implant region of interest (ROI) was intra-orally scanned pre-operatively (S0), and after 1 (S1) and 6 (S2) months following surgical therapy. Digital files were converted to standard tessellation language (STL) format for superimposition and assessment of peri-implant volumetric variations between time points. The change in thickness was assessed at a standardized ROI, subdivided into three equidistant sections (i.e. marginal, medial and apical). Peri-implant soft tissue contour area (STCA) (mm2 ) and its corresponding contraction rates (%) were also assessed. Peri-implant tissues revealed a mean thickness change (loss) of -0.11 and -0.28mm at 1 and 6months. S0 to S1 volumetric variations pointed to a thickness change of -0.46, 0.08 and 0.4mm at marginal, medial and apical regions, respectively. S0 to S2 analysis exhibited corresponding thickness changes of -0.61, -0.25 and -0.09mm, respectively. The thickness differences between the areas were statistically significant at both time periods. The mean peri-implant STCA totalled to 189.2, 175 and 158.9mm2 at S0, S1 and S2, showing a significant STCA contraction rate of 7.9% from S0 to S1 and of 18.5% from S0 to S2. Linear regression analysis revealed a significant association between the pre-operative width of keratinized mucosa (KM) and STCA contraction rate. The peri-implant mucosa undergoes considerable volumetric changes after combined surgical therapy. However, tissue contraction appears to be influenced by the width of KM.

Rehabilitation of one-piece screw-retained implant crowns placed at second-stage surgery-a retrospective patient series.

To evaluate the esthetic and functional rehabilitation of single implants delivering the final crown during second-stage surgery. In 26 single-tooth implants, the impressions were taken immediately after implant placement to fabricate the final crowns. During the second-stage surgery, the screw-retained hybrid crowns were delivered. Six months to 3years after placement of the crown, a modified pink esthetic score (PES) was measured. Additionally, the number of treatment sessions was recorded. The mesial and distal contact points and the static and dynamic occlusion were examined. Patients' satisfaction was measured using a questionnaire. In this retrospective study, 21 posterior and 5 anterior implants were included. The average pink esthetic score was 11.3 out of 14. The most frequent limitations were incomplete papillae and deficits of the alveolar ridge. The average number of appointments was three, consisting of impression taking and surgery consent, implant placement, and crown delivery. Average patients' satisfaction was 46.7 out of 50 and thus, extremely high. The presented approach allows the second-stage surgery and delivery of the final restoration for single-tooth implants in the same session. As the peri-implant mucosa is adapted to the final restoration in the first place, a more natural emergence profile is achieved. However, there is an increasing risk for reduced or missing papillae. Patients' satisfaction is generally very high. A method for direct definitive prosthetic restoration during the exposure of single-tooth implants is examined, advantages and disadvantages will be described, and patient acceptance is validated.

Soft tissue healing around platform-switching and platform-matching single implants: A randomized clinical trial.

Implants with platform-switching (PS) design have been demonstrated to reduce marginal bone loss. However, the influence on peri-implant soft tissue healing is unclear. This study was designed to investigate its effect on peri-implant soft tissue healing after implant uncovery. Non-smokers needing two implants in different quadrants were recruited in this study. For each individual, one PS and one platform-matching (PM) implants were placed using two-stage protocol. Following 2 to 8 months of healing, all implants were uncovered and connected to the corresponding healing abutments. Clinical measurements and peri-implant crevicular fluid (PICF) were taken at 1-, 2-, 4-, and 6-week after 2nd stage surgery. The cytokine concentrations in PICF were analyzed. Peri-implant mucosa (1 × 2 × 2mm) was harvested around the healing abutment for the analysis of gene expression at uncovery and 6-week post-uncovery. Eighteen participants (nine males; 51.7 ± 14.9 years) were recruited. Compared to PM, PS showed significantly lower probing depth (PD) at 1- and 2-week as well as modified sulcus bleeding index (mSBI) at 1-, 4-, and 6-week (P<0.05). Over time, a decrease in osteoprotegerin and interleukin-1β concentrations in PICF along with an increase in receptor activator of unclear factor kappa-B ligand, periostin, and peroxidasin gene expressions in peri-implant mucosa were noted within both groups (P<0.05) without significant intergroup differences. Within the limits, implants with PS design rendered significant benefits over PM design in PD and mSBI reduction during a 6-week healing. However, molecular changes within PICF and peri-implant mucosa as a response to PM and PS appear negligible.

Maxillary implant overdenture retained by four unsplinted attachments and opposed by a natural or fixed dentition: One-year clinical outcomes.

The aim of this prospective study was to evaluate the implant, prosthesis, and patient-reported outcomes of maxillary removable prostheses retained by 4 implant-supported study abutments after a follow-up period of 1year in patients with natural teeth or a fixed rehabilitation in the mandible. A total of 30 patients were included, and all received 4 implants in the upper maxilla. After 12weeks, the prostheses were connected to the implant with unsplinted attachments. The implant and prosthodontics outcomes were assessed over a follow-up period of 1year. Patient-reported outcome measures (PROMs) were evaluated with the Oral Health Impact Profile (OHIP-20) questionnaire and an adaptation of the McGill Denture Satisfaction Instrument using a visual analogue scale (VAS). A single patient dropped out. At the post-operative 12-week follow-up, 79.3% (95% CI: 64.6%-94.1%) of the patients displayed peri-implant mucosa hyperplasia and 69.0% (95% CI: 52.1%-85.8%) showed pain. After 1year, 16 implants failed in 10 patients, leading to an implant survival rate of 86.2% (95% CI: 79.0%-92.5%), and the mean peri-implant bone loss was 1.01±0.77mm (95% CI: 0.85-1.16mm). The prosthesis survival rate was 96.6% (95% CI: 82.2%-99.9%). The OHIP-20 and VAS scores both improved significantly from baseline to 1year (p<.001). The implant survival rate was lower compared to the literature for the upper maxilla. Despite the encountered problems, PROMs showed significant improvement with the implant overdenture retained by 4 unsplinted implants compared to conventional dentures.