The Impact of Implant-Abutment Connection on Clinical Outcomes and Microbial Colonization: A Narrative Review

Microbiological and functional traits of peri-implant mucositis and correlation with disease severity

Osseointegrated dental implants replace missing teeth and create an artificial surface for biofilms of complex microbial communities to grow. These biofilms on implants and dental surfaces can trigger infection and inflammation in the surrounding tissue. This study investigated the microbial characteristics of peri-implant mucositis (PM) and explored the correlation between microbial ecological imbalance, community function, and disease severity by comparing the submucosal microflora from PM with those of healthy inter-subject implants and intra-subject gingivitis (G) within a group of 32 individuals. We analyzed submucosal plaques from PM, healthy implant (HI), and G sites using metagenome shotgun sequencing. The bacterial diversity of HIs was higher than that of PM, according to the Simpson index. Beta diversity revealed differences in taxonomic and functional compositions across the groups. Linear discriminant analysis of the effect size identified 15 genera and 37 species as biomarkers that distinguished PM from HIs. Pathways involving cell motility and protein processing in the endoplasmic reticulum were upregulated in PM, while pathways related to the metabolism of cofactors and vitamins were downregulated. Microbial dysbiosis correlated positively with the severity of clinical inflammation measured by the sulcus bleeding index (SBI) in PM. Prevotella and protein processing in the endoplasmic reticulum also correlated positively with the SBI. Our study revealed PM's microbiological and functional traits and suggested the importance of certain functions in disease severity.IMPORTANCEPeri-implant mucositis is an early stage in the progression of peri-implantitis. The high prevalence of it has been a threat to the widespread use of implant prosthodontics. The link between the submucosal microbiome and peri-implant mucositis was demonstrated previously. Nevertheless, the taxonomic and functional composition of the peri-implant mucositis microbiome remains controversial. In this study, we comprehensively characterize the microbial signature of peri-implant mucositis and for the first time, we investigate the correlations between microbial dysbiosis, functional potential, and disease severity. With the help of metagenomic sequencing, we find the positive correlations between microbial dysbiosis, genus Prevotella, pathway of protein processing in the endoplasmic reticulum, and more severe mucosal bleeding in the peri-implant mucositis. Our studies offer insight into the pathogenesis of peri-implant mucositis by providing information on the relationships between community function and disease severity.

Comparative in vitro evaluation of microgap in titanium stock versus cobalt-chrome custom abutments on a conical connection implant: Effect of crown cementation and ceramic veneering

OBJECTIVE

To compare the implant-abutment connection microgap between computer-aided design and computer-aided manufacturing (CAD/CAM) milled or laser-sintered cobalt-chrome custom abutments with or without ceramic veneering and titanium stock abutments with or without crown cementation.

MATERIAL AND METHODS

Six groups of six abutments each were prepared: (1) CAD/CAM cobalt-chrome custom abutments: milled, milled with ceramic veneering, laser-sintered, and laser-sintered with ceramic veneering (four groups: MIL, MIL-C, SIN, and SIN-C, respectively) and (2) titanium stock abutments with or without zirconia crown cementation (two groups: STK and STK-Z, respectively). Abutments were screwed to the implants by applying 30 Ncm torque. All 36 samples were sectioned along their long axes. The implant-abutment connection microgap was measured using scanning electron microscopy on the right and left sides of the connection at the upper, middle, and lower levels. Data were analyzed using the Kruskal-Wallis test (p < .05).

RESULTS

Mean values (μm) of the microgap were 0.54 ± 0.44 (STK), 0.55 ± 0.48 (STK-Z), 1.53 ± 1.30 (MIL), 2.30 ± 2.2 (MIL-C), 1.53 ± 1.37 (SIN), and 1.87 ± 1.8 (SIN-C). Although significant differences were observed between the STK and STK-Z groups and the other groups (p < .05), none were observed between the milled and laser-sintered groups before or after ceramic veneering. The largest microgap was observed at the upper level in all groups.

CONCLUSIONS

Titanium stock abutments provided a closer fit than cobalt-chrome custom abutments. Neither crown cementation nor ceramic veneering resulted in significant changes in the implant-abutment connection microgap.

Ultrastructural and immunohistochemical evaluation of hyperplastic soft tissues surrounding dental implants in fibular jaws

In reconstructive surgery, complications post-fibula free flap (FFF) reconstruction, notably peri-implant hyperplasia, are significant yet understudied. This study analyzed peri-implant hyperplastic tissue surrounding FFF, alongside peri-implantitis and foreign body granulation (FBG) tissues from patients treated at the Department of Oral and Maxillofacial Surgery, Seoul National University Dental Hospital. Using light microscopy, pseudoepitheliomatous hyperplasia, anucleate and pyknotic prickle cells, and excessive collagen deposition were observed in FFF hyperplastic tissue. Ultrastructural analyses revealed abnormal structures, including hemidesmosome dilation, bacterial invasion, and endoplasmic reticulum (ER) swelling. In immunohistochemical analysis, unfolded protein-response markers ATF6, PERK, XBP1, inflammatory marker NFκB, necroptosis marker MLKL, apoptosis marker GADD153, autophagy marker LC3, epithelial-mesenchymal transition, and angiogenesis markers were expressed variably in hyperplastic tissue surrounding FFF implants, peri-implantitis, and FBG tissues. NFκB expression was higher in peri-implantitis and FBG tissues compared to hyperplastic tissue surrounding FFF implants. PERK expression exceeded XBP1 significantly in FFF hyperplastic tissue, while expression levels of PERK, XBP1, and ATF6 were not significantly different in peri-implantitis and FBG tissues. These findings provide valuable insights into the interconnected roles of ER stress, necroptosis, apoptosis, and angiogenesis in the pathogenesis of oral pathologies, offering a foundation for innovative strategies in dental implant rehabilitation management and prevention.

Limosilactobacillus reuteri as an Adjuvant in the Treatment of Peri-implant Mucositis in Total Rehabilitation: An Exploratory Study

OBJECTIVES

 Mechanical debridement is the traditional method for the treatment of peri-implant mucositis (P-im) and its success depends on the patient's correct oral hygiene. It is believed that probiotics may help by their ability to modulate the oral biofilm, resulting in anti-inflammatory and antibacterial plaque action. The aim of this study was to evaluate the adjuvant effect of the probiotic Limosilactobacillus reuteri (LR) in the mechanical treatment of P-im.

MATERIALS AND METHODS

 This exploratory study included 29 subjects with implant-supported total rehabilitation and P-im, divided into test (TG) and control (CG) groups, equally subjected to professional mechanical debridement, with the administration of a daily GUM PerioBalance lozenge for 30 days added to the TG. The modified Plaque Index (mPlI) modified Sulcus Bleeding Index (mBI) and pocket depth (PD) were evaluated before the intervention (baseline) and 6 and 10 weeks later.

STATISTICAL ANALYSIS

 Parametric and nonparametric tests with 5% significance level were used in the statistical analysis, using IBM SPSS Statistics 27.0 software.

RESULTS

 Both treatments resulted in reduced mPlI, mBI, and PD at 6 weeks; while from 6 to 10 weeks there was an increase in mPlI and mBI and maintenance of PD. Compared with baseline, differences were close to statistical significance in the reduction in PD at 10 weeks in the CG (p = 0.018), after Bonferroni correction, and statistically significant in the mPlI at 6 weeks in the CG (p = 0.004) and in the TG (p = 0.002) as well as at 10 weeks in the TG (p = 0.016). Comparing the groups in the postintervention assessments, no statistically significant differences were found.

CONCLUSION

 LR adjuvant mechanical treatment of P-im does not show a clear benefit compared with mechanical treatment alone, with both interventions achieving similar clinical results. Further prospective and long-term studies are needed.

Misfit simulation on implant-supported prostheses with different combinations of engaging and nonengaging titanium bases: Part 3: A radiographic evaluation

STATEMENT OF PROBLEM

The fit of implant-supported prostheses plays an important role in their mechanical and biological stability. Clinically, the prosthetic fit is typically assessed radiographically, but this method relies on the operator's subjective evaluation. Whether available digital tools could optimize the evaluation of the prosthetic fit is uncertain.

PURPOSE

The purpose of this in vitro study was to evaluate the influence of an image processing program on the radiographic detection of discrepancies in the active and passive fit of implant-supported prostheses. Two-implant-supported screw-retained prostheses were analyzed by simulating the vertical and horizontal misfits of 3 different implant abutment configurations.

MATERIAL AND METHODS

Seven casts were fabricated using 2 internal-connection titanium implants: 1 control; 3 with vertical (V) misfit of 50 µm, 100 µm, 150 µm; and 3 with horizontal (H) misfit of 35 µm, 70 µm, 100 µm. Thirty bar-shaped zirconia frameworks were fabricated and divided into 3 groups (n=10) according to their attachment to 2 engaging (E-E), 2 nonengaging (NE-NE), and engaging and nonengaging (E-NE) titanium bases. Digital parallel periapical radiographs were made of each specimen in the passive and active fit situation on each cast (1-screw test), except for the E-E specimens, which were only seated on the control, H35, and H70 casts because the fit on the remaining casts was poor. The mean gray value (MGV) was measured at the chosen regions of interest on the second implant (side B) using the ImageJ software program. Differences in the MGV measurements between the passive and active conditions were tested using a t test (α=.05) and compared the different misfit levels using analysis of variance (1-way ANOVA), followed by the Tukey HSD test (α=.05).

RESULTS

The highest values for the differences between passive and active fit were found for the V150 and H100 misfit simulations (P<.05). Statistical differences between the MGVs were found with some exceptions: the smallest simulated misfits (H35 and V50) revealed statistically significant MGV differences from the highest simulated misfits (V150, H100) and from the H70 in the groups where an engaging component was present (P>.05). In the horizontal misfit group of NE-NE abutment configuration, H70 revealed no significant difference from the control group cast (P>.05).

CONCLUSIONS

Measuring MGV differences between passive and active fit could be a promising alternative for detecting 70- to 150-µm gaps in the implant-abutment connection that result from the misfit. However, the procedure was not adequate for detecting <50 µm gaps, cannot be uniformly applied to all types of implant-abutment connections, and requires 2 exposures to X-radiation.

Effect of chemical and electrochemical decontamination protocols on single and multiple-used healing abutments: A comparative analysis of contact surface area, micro-gap, micro-leakage, and surface topography

INTRODUCTION

Although the combined use of chemical and electrochemical decontamination protocols can completely remove contaminants from the surfaces of one-time used healing abutments (HAs), their effectiveness in multiple-used HAs remains unknown. We aimed to investigate the effect of reused HAs frequency on the implant-HA contact surface area, micro-gap, microleakage, and surface topography following chemical and combined chemical and electrochemical decontamination protocols.

METHODS

Ninety bone level titanium implants were assembled with 90 bone level HAs, in which 80 contaminated HA samples were collected from human participants. The retrieved HAs were randomly divided into two groups according to the cleaning protocol: ultrasonication with 5.25% NaOCl solution for 15 min and steam autoclaving (group I); ultrasonication with 5.25% NaOCl solution for 15 min, followed by electrochemical cleaning and steam autoclaving (group II). The control group (group III) comprised 10 new unused HAs. The cleaning protocol was applied after each insertion as follows: (a) single-use and cleaning, (b) double-use and double cleaning cycles, (c) triple-use and triple cleaning cycles, and (d) more than triple-use and more than triple cleaning cycles. The contact surface area and micro-gap were assessed with micro-computed tomography scanning technique, microleakage test using 2% methylene blue staining, surface morphology with scanning electron microscopy, and surface elemental composition with energy-dispersive X-ray spectroscopy analysis.

RESULTS

Group Id exhibited the smallest contact surface area. The values of the micro-gap volumes and microleakage were significantly different (p < 0.001) in the descending order of Id > Ic > Ib > IId > Ia, IIa, and III. Morphological evaluation of Groups IIa, IIb, and IIc revealed that residual biological debris was optimally removed without altering their surface properties.

CONCLUSIONS

Chemical and electrochemical decontamination protocols are more effective than NaOCl cleaning methods, particularly for multiple consecutive uses with better decontamination levels, which decreases micro-gap volume and microleakage without surface alterations. Although the use of combined decontamination protocols for the contact surface area at the implant-HA interface showed comparable results with the control, change in the contact surface area was observed following the NaOCl cleaning methods. Therefore, titanium HA reuse can be considered in multiple times, if they are cleaned and sterilized using combined chemical and electrochemical decontamination protocols.

Influence of the Use of Transepithelial Abutments vs. Titanium Base Abutments on Microgap Formation at the Dental Implant-Abutment Interface: An In Vitro Study

This in vitro study aimed to assess the presence of microgaps at the implant-abutment interface in monolithic zirconia partial implant-supported fixed prostheses on transepithelial abutments versus Ti-base abutments.

METHODS

Sixty conical connection dental implants were divided into two groups (n = 30). The control group consisted of three-unit bridge monolithic zirconia connected to two implants by a transepithelial abutment. The test group consisted of monolithic zirconia three-unit restoration connected to two implants directly by a titanium base (Ti-base) abutment. The sample was subjected to thermocycling (10,000 cycles at 5 °C to 55 °C, dwelling time 50 s) and chewing simulation (300,000 cycles, under 200 N at frequencies of 2 Hz, at a 30° angle). The microgap was evaluated at six points (mesiobuccal, buccal, distobuccal, mesiolingual, lingual, and distolingual) of each implant-abutment interface by using a scanning electron microscope (SEM). The data were analyzed using the Mann-Whitney U tests (p > 0.05).

RESULTS

The SEM analysis showed a smaller microgap at the implant-abutment interface in the control group (0.270 μm) than in the test group (3.902 μm). Statistically significant differences were observed between both groups (p < 0.05).

CONCLUSIONS

The use or not of transepithelial abutments affects the microgap size. The transepithelial abutments group presented lower microgap values at the interface with the implant than the Ti-base group in monolithic zirconia partial implant-supported fixed prostheses. However, both groups had microgap values within the clinically acceptable range.

Molecular modeling study of micro and nanocurcumin with in vitro and in vivo antibacterial validation

Repurposing natural compounds as inhibitory targets to combat bacterial virulence is an important potential strategy to overcome resistance to traditional antibiotics, in the present study, the antibacterial activity of micro-curcumin and nano-sized curcumin was investigated against four predominant bacterial pathogens, namely, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Bacillus subtilis. Curcumin bactericidal susceptibility could be summarized as the order, P. aeruginosa > B. subtilis > S. aureus > E. coli. Molecular docking analysis was conducted to confirm the impact of curcumin on the most vital and positively identified quorum-sensing pathway signaling proteins SecA-SecY, LsrR, PqsR (MvfR), AgrA which act as key players in the bacterial communication systems. The in silico physicochemical properties revealed that curcumin as a nutraceutical can be classified as a drug-like compound. An in vivo infected wound model was employed in four groups of albino rats. Topical application of nano-curcumin lotion showed a marked reduction in wound area (98.8%) as well as nearly 100% reduction in total bacterial viable count compared to the control group, on the fifteenth day post-treatment post-injury. The obtained data suggested that curcumin nanoparticles exhibited superior antibacterial activity and may possess clinical utility as a novel topical antimicrobial and wound healing agent.

Micro-CT Evaluation of Microgaps at Implant-Abutment Connection

The assessment of microgaps at the implant-abutment interface is an important factor that may influence clinical success. Thus, the aim of this study was to evaluate the size of microgaps between prefabricated and customised abutments (Astra Tech, Dentsply, York, PA, USA; Apollo Implants Components, Pabianice, Poland) mounted on a standard implant. The measurement of the microgap was performed using micro-computed tomography (MCT). Due to 15-degree rotation of samples, 24 microsections were obtained. Scans were performed at four levels established at the interface between the abutment and the implant neck. Moreover, the volume of the microgap was evaluated. The size of the microgap at all measured levels varied from 0.1 to 3.7 µm for Astra and from 0.1 to 4.9 µm for Apollo (p > 0.05). Moreover, 90% of the Astra specimens and 70% of the Apollo specimens did not exhibit any microgaps. The highest mean values of microgap size for both groups were detected at the lowest portion of the abutment (p > 0.05). Additionally, the average microgap volume was greater for Apollo than for Astra (p > 0.05). It can be concluded that most samples did not exhibit any microgaps. Furthermore, the linear and volumetric dimensions of microgaps observed at the interface between Apollo or Astra abutments and Astra implants were comparable. Additionally, all tested components presented microgaps (if any) that were clinically acceptable. However, the microgap size of the Apollo abutment was higher and more variable than that of the Astra one.

Marginal Bone Level and Biomechanical Behavior of Titanium-Indexed Abutment Base of Conical Connection Used for Single Ceramic Crowns on Morse-Taper Implant: A Clinical Retrospective Study

The goal of this retrospective clinical study was to evaluate the behavior of Morse-taper indexed abutments by analyzing the marginal bone level (MBL) after at least 12 months of function. Patients rehabilitated with single ceramic crowns between May 2015 and December 2020 received single Morse-taper connection implants (DuoCone implant) with two-piece straight abutment baseT used for at least 12 months, presenting periapical radiograph immediately after crown installation were enrolled. The position of the rehabilitated tooth and arch (maxilla or mandible), crown installation period, implant dimensions, abutment transmucosal height, installation site (immediate implant placement or healed area), associated with bone regeneration, immediate provisionalization, and complications after installation of the final crown were analyzed. The initial and final MBL was evaluated by comparing the initial and final X-rays. The level of significance was α = 0.05. Seventy-five patients (49 women and 26 men) enrolled had a mean period of evaluation of 22.7 ± 6.2 months. Thirty-one implant-abutment (IA) sets had between 12–18 months, 34 between 19–24 months, and 44 between 25–33 months. Only one patient failed due to an abutment fracture after 25 months of function. Fifty-eight implants were placed in the maxilla (53.2%) and 51 in the mandible (46.8%). Seventy-four implants were installed in healed sites (67.9%), and 35 were in fresh socket sites (32.1%). Thirty-two out of these 35 implants placed in fresh sockets had the gap filled with bone graft particles. Twenty-six implants received immediate provisionalization. The average MBL was −0.67 ± 0.65 mm in mesial and −0.70 ± 0.63 mm in distal (p = 0.5072). The most important finding was the statistically significant difference comparing the values obtained for MBL between the abutments with different transmucosal height portions, which were better for abutments with heights greater than 2.5 mm. Regarding the abutments’ diameter, 58 had 3.5 mm (53.2%) and 51 had 4.5 mm (46.8%). There was no statistical difference between them, with the following means and standard deviation, respectively, −0.57 ± 0.53 mm (mesial) and −0.66 ± 0.50 mm (distal), and −0.78 ± 0.75 mm (mesial) and −0.746 ± 0.76 mm (distal). Regarding the implant dimensions, 24 implants were 3.5 mm (22%), and 85 implants (78%) had 4.0 mm. In length, 51 implants had 9 mm (46.8%), 25 had 11 mm (22.9%), and 33 implants were 13 mm (30.3%). There was no statistical difference between the abutment diameters (p > 0.05). Within the limitations of this study, it was possible to conclude that better behavior and lesser marginal bone loss were observed when using abutment heights greater than 2.5 mm of transmucosal portion and when placed implants with 13 mm length. Furthermore, this type of abutment showed a little incidence of failures within the period analyzed in our study.

Electrochemical, Biological, and Technological Properties of Anodized Titanium for Color Coded Implants

Anodization coloring of titanium tools or implants is one of the common methods for the differentiation of each application by its size or type. Commercial purity titanium grade 4 plates (50 × 20 × 0.1 mm) were tested to obtain their electrochemical and other technological properties. The coloring process was done using the potential of 15, 30, 45, 60, and 75 Volts for 5 s in 1 wt. % citric acid in demineralized water solution. Organic acids solutions generally produce better surface quality compared to inorganic acids. The contact angle of colored surfaces was measured by the sessile drop method. Electrochemical impedance spectroscopy and potentiodynamic polarization were used for the determination of selected electrochemical and corrosion parameters of the tested surfaces. It was found that the anodization process decreases corrosion potential significantly. It was also confirmed that a higher potential used for anodization results in higher polarization resistance but also a decrease in corrosion potential. The anodization process at 75 V produces surfaces with the lowest corrosion rate under 1 nm/year and the noblest corrosion potential. It was confirmed that the anodization process in citric acid does not affect titanium cytotoxicity.

Preventing Peri-implantitis: The Quest for a Next Generation of Titanium Dental Implants

Titanium and its alloys are frequently the biomaterial of choice for dental implant applications. Although titanium dental implants have been utilized for decades, there are yet unresolved issues pertaining to implant failure. Dental implant failure can arise either through wear and fatigue of the implant itself or peri-implant disease and subsequent host inflammation. In the present report, we provide a comprehensive review of titanium and its alloys in the context of dental implant material, and how surface properties influence the rate of bacterial colonization and peri-implant disease. Details are provided on the various periodontal pathogens implicated in peri-implantitis, their adhesive behavior, and how this relationship is governed by the implant surface properties. Issues of osteointegration and immunomodulation are also discussed in relation to titanium dental implants. Some impediments in the commercial translation for a novel titanium-based dental implant from "bench to bedside" are discussed. Numerous in vitro studies on novel materials, processing techniques, and methodologies performed on dental implants have been highlighted. The present report review that comprehensively compares the in vitro, in vivo, and clinical studies of titanium and its alloys for dental implants.

Misfit of Implant-Supported Zirconia (Y-TZP) CAD-CAM Framework Compared to Non-Zirconia Frameworks: A Systematic Review

Objective: The aim of the study was to systematically review the overall outcomes of studies comparing the misfit of yttria-stabilized zirconia (Y-TZP) CAD-CAM implant-supported frameworks with frameworks fabricated with other materials and techniques. Methods: An electronic literature search of English literature was performed using Google Scholar, Scopus, Web of Science, MEDLINE (OVID), EMBASE, and PubMed, using predetermined inclusion criteria. Specific terms were utilized in conducting a search from the inception of the respective database up to May 2022. After the search strategy was applied, the data were extracted and the results were analyzed. The focused question was: Is the misfit of the implant-supported zirconia CAD-CAM framework lower than that of non-Y-TZP implant-supported fixed restorations? Results: Eleven articles were included for qualitative assessment and critical appraisal in this review. In the included studies, Y-TZP CAD-CAM implant-supported frameworks were compared to Titanium (Ti), Ni-Cr, Co-Cr, PEEK and high-density polymer, and cast and CAD-CAM frameworks. The studies used scanning electron microscopy, one-screw tests, digital or optical microscopy, 3D virtual assessment, and replica techniques for analyzing the misfit of frameworks. Six studies showed comparable misfits among the Y-TZP CAD-CAM frameworks and the controls. Three studies showed higher misfits for the Y-TZP CAD-CAM frameworks, whereas two studies reported lower misfits for Y-TZP CAD-CAM implant frameworks compared to controls. Conclusion: Y-TZP CAD-CAM implant-supported frameworks have comparable misfits to other implant-supported frameworks. However, due to heterogeneity in the methodologies of the included studies, the overall numerical misfit of the frameworks assessed in the reviewed studies is debatable.

Mechanical, Chemical, and Biological Properties of 3D-Printed Abutments: A Systematic Review

Aim:

A systematic review of the methods of 3D printing and the materials used so far for the manufacture of abutments was performed to evaluate whether their clinical use is indicated through the mechanical, chemical, and biological analyses carried out.

Materials and Methods:

An electronic search conducted by three independent reviewers was carried out in the PubMed, Web of Science, Cochrane Library, Science Direct, and Lilac databases. The inclusion criterion was researching articles in English that contained as subject the manufacturing of abutments through 3D printing/additive manufacturing. Any meta-analyses, reviews, book chapters, abstracts, letters, conferences papers, and studies without abutments printed were excluded.

Results:

We found 780 references, which after applying the exclusion criteria resulted in the final inclusion of seven articles for review. The studies had a high heterogeneity, showing different materials and methodologies to manufacture abutments, which makes a comparison between them difficult, and for this reason it was not possible to carry out a meta-analysis with the data found.

Conclusions:

Even with the limitations found in the present research, it is possible to conclude that printed abutments have adequate mechanical, chemical, and biological properties that can indicate their clinical use. 3D printing presents high accuracy and speed and can produce customized abutments according to each case.

Antimicrobial Efficacy and Permeability of Various Sealing Materials in Two Different Types of Implant–Abutment Connections

The presence of a microgap along an implant–abutment connection (IAC) is considered the main disadvantage of two-piece implant systems. Its existence may lead to mechanical and biological complications. Different IAC designs have been developed to minimise microleakage through the microgap and to increase the stability of prosthodontic abutments. Furthermore, different sealing materials have appeared on the market to seal the gap at the IAC. The purpose of this study was to evaluate the antimicrobial efficacy and permeability of different materials designed to seal the microgap, and their behaviour in conical and straight types of internal IACs. One hundred dental implants with original prosthodontic abutments were divided into two groups of fifty implants according to the type of IAC. Three different sealing materials (GapSeal, Flow.sil, and Oxysafe gel) were applied in the test subgroups. The contamination of implant–abutment assemblies was performed by a joint suspension containing Candida albicans and Staphylococcus aureus. It was concluded that the IAC type had no significant influence on microleakage regarding microbial infection. No significant difference was found between the various sealing agents. Only one sealing agent (GapSeal) was found to significantly prevent microleakage. A complete hermetic seal was not achieved with any of the sealing agents tested in this study.

Bacterial Microleakage at the Implant-Abutment Interface: An In Vitro Study

The objective of this study is to evaluate, in vitro, the microleakage of bacteria of 3 different implant connections for a period of 14 days. 60 dental implants (AoN) (n = 20) were distinguished into three groups, accordingly to the type of connection: External Hexagon (EH), Internal Hexagon (IH), and Cone Morse (CM) connection. All implants were inserted and fixed on sterile special vinyl support. Ten fixtures for each group were inoculated in the internal platform with 1.0 μL of Streptococcus oralis (SO) and the other ten with the same amount of Pseudomonas aeruginosa (PA). The penetration of bacterial suspension into the surrounding solution was determined by the observation of the turbidity of the broth. Five implants for each sub-group were randomly observed at SEM, to verify the correct fitting of the abutments. Considering the total of the samples analyzed, CM showed significantly lower bacterial contamination, with respect to IH. In particular, bacterial contamination was found in 45%, 55%, and 20% of EH, IH, and CM, respectively. Analyzing results for the type of inoculated bacteria, P. aeruginosa showed a higher ability to contaminate all the connections, with respect to S. oralis.

Clinical and Radiographic Evaluation of a Novel Triangular Implant Neck Design: A Case Series

The objective of this study was to evaluate the clinical and radiographic behavior of a novel triangular neck implant configuration in partially edentulous patients. Sixteen patients with a mean age of 58.3 years, were rehabilitated with 25 implants inserted in the healed sites of the maxilla and mandible; implant diameter was Ø3.3 and 3.9 mm. Clinical and radiographic measurements were first performed at prosthesis delivery that served as baseline; they were further evaluated after a mean period of 15.6 months. The interproximal peri-implant bone levels were the primary outcome; the mesial and distal data were recorded and a mean value was calculated. Secondary outcomes included peri-implant probing depth (PPD) and bleeding on probing (BoP). The paired t-test was used to compare the radiographic and clinical outcomes between baseline and follow-up. The mean bone levels at the mesial and distal aspects at baseline were 0.45 (0.47) and 0.57 (0.69), respectively; at follow-up they were 0.59 (0.42) and 0.78 (0.59), respectively. The differences were not statistically significant. Similarly, no significant differences were found for the clinical parameters. Within the limitations of the present study, it could be concluded that this new triangular neck bone level implant macro-design was used successfully to treat partially edentulous patients. Larger controlled clinical studies are warranted to confirm the present radiographic and clinical findings.

YoutubeTM Content Analysis as a Means of Information in Oral Medicine: A Systematic Review of the Literature

Background: Oral medicine represents a complex branch of dentistry, involved in diagnosing and managing a wide range of disorders. Youtube^TM offers a huge source of information for users and patients affected by oral diseases. This systematic review aims to evaluate the reliability of Youtube^TM oral medicine-related content as a valid dissemination aid. Methods: The MeSH terms “Youtube^TM” and “oral” have been searched by three search engines (PubMed, ISI Web of Science, and the Cochrane Library), and a systematic review has been performed; the PRISMA checklist has been followed in the search operations. Results: Initial results were 210. Ten studies definitely met our selection criteria. Conclusions: Youtube^TM represents a dynamic device capable of easy and rapid dissemination of medical-scientific content. Nevertheless, the most of information collected in the literature shows a lack of adequate knowledge and the need to utilize a peer-reviewing tool in order to avoid the spreading of misleading and dangerous content.

Sealing Efficacy of the Original and Third-Party Custom-Made Abutments-Microbiological In Vitro Pilot Study

Implant–abutment connection (IAC) is a key factor for the long-term success and stability of implant-supported prosthodontic restoration and its surrounding tissues. Misfit between prosthodontic abutment and implant at the IAC leads to technical and biological complications. Two kinds of prosthodontic abutments are currently available on the market: original and third-party abutments. The aim of this pilot study was to test and compare the internal fit (gap) at the implant–abutment interface depending on the abutment fabrication method based on microbial leakage in static conditions and the need for the use of gap sealing material. Two groups of 40 implants were formed on the basis of the type of abutment. In each of the groups of two implant systems, two subgroups of 10 implants were formed. The tested subgroups consisted of 10 implants with sealing material and a negative control subgroups consisting of 10 implants without any sealing material. The test material, GapSeal (Hager and Werken, Duisburg, Germany) was applied in the test subgroups. The implant–abutment assemblies were contaminated with a solution containing Staphylococcus aureus and Candida albicans for 14 days under aerobic conditions. Results showed that there was no statistically significant difference regarding the microbial leakage between the original and third-party custom-made abutments, regardless of the use of sealing material. It can be concluded that the abutment fabrication method has no significant influence on sealing efficacy regarding the bacterial and fungal leakage in static conditions.

Microgap and bacterial microleakage during the osseointegration period: An in vitro assessment of the cover screw and healing abutment in a platform-switched implant system

STATEMENT OF PROBLEM

Microgap and bacterial microleakage at the implant-prosthetic abutment interface are recognized concerns for implant-supported restorations, leading to inflammation of the peri-implant tissues, with deleterious consequences for crestal bone levels. However, little is known regarding the interface established between the implant and the healing abutment or cover screw placed for the osseointegration phase.

PURPOSE

The purpose of this in vitro study was to characterize the implant-cover screw and implant-healing abutment interfaces of a platform-switched implant system to determine the microgap and bacterial microleakage of the system and evaluate the biological response and functionality of an interface sealing agent.

MATERIAL AND METHODS

The interfacial microgaps of the implant-healing abutment and implant-cover screw interfaces were characterized by scanning electron microscopy (n=10), and bacterial microleakage was evaluated after colonization with Enterococcus faecalis in a 30-day follow-up (n=10). The sealing efficacy and irritation potential of a silicone-based sealer were determined by using the hen's egg test on chorioallantoic membrane assay. The 2-sample t test was performed to compare means between groups, and data presented with the Kaplan-Meier method were compared statistically by using the log-rank test (α=.05).

RESULTS

The interfacial microgap was less than 2.5 μm for both systems. Bacterial microleakage was noted in approximately 50% of the specimens, particularly at early time points, at both the healing abutment and cover screw interfaces. The silicone-based sealer prevented bacterial leakage in the experimental setting.

CONCLUSIONS

The implant-healing abutment and implant-cover screw interfaces of the tested system, despite the low microgap, allowed for bacterial microleakage after internal colonization. The use of a nonirritating silicone-based sealing agent effectively sealed the system.

Microgap and microleakage of a hybrid connection platform-switched implant system in the absence or presence of a silicone-based sealing agent

The present study aims to characterize, for the first time, the microgap and bacterial microleakage of a platform-switched implant system with hybrid connection, screwed at distinct torque values (manufacturer recommended torque-25 N cm-and a reduced torque-5 N cm-mimicking the long-term functional use), in the absence or presence of a silicon-based sealing agent. Microgap was determined through scanning electron microscopy and bacterial microleakage was evaluated in vitro, upon Enterococcus faecalis colonization of the system. The sealing efficacy was evaluated in the absence or presence of a commercially available silicon-based sealer. The cytotoxicity of the sealer was further addressed in vitro, with a fibroblastic cell line, in accordance with reference standards. A low microgap of the implant system was verified, regardless of the applied torque load-maximal values ranged around 0.25 and 1.25 µm, for 25 and 5 N cm torques, respectively. No bacterial microleakage was reported at 25 N cm, while at 5 N cm, leakage was verified on 38% of the samples. The application of a silicon-based sealer-with an adequate cytocompatible profile-was effective on preventing the bacterial microleakage on the assayed experimental setting. The assayed platform-switched implant system with hybrid connection presented a low interfacial misfit and an effective sealing capability at manufacturer recommended torque. Despite the increased microleakage at low torque conditions, the application of a cytocompatible silicon-based sealing agent restored the sealing effectiveness of the system. The use of a silicon-based sealing agent can assist on the maintenance of the sealing effectiveness even at low torque conditions.

Bacterial translocation and microgap formation at a novel conical indexed implant abutment system for single crowns

OBJECTIVES

A conometric concept was recently introduced in which conical implant abutments hold the matching crown copings by friction alone, eliminating the need for cement or screws. The aim of this in vitro study was to assess the presence of microgap formation and bacterial leakage at the Acuris conometric restorative interface of three different implant abutment systems.

MATERIAL AND METHODS

A total of 75 Acuris samples of three implant-abutment systems (Ankylos, Astra Tech EV, Xive) were subjected to microbiological (n = 60) and scanning electron microscopic (SEM) investigation (n = 15). Bacterial migration into and out of the conical coupling system were analyzed in an anaerobic workstation for 48, 96, 144, and 192 h. Bacterial DNA quantification using qrt-PCR was performed at each time point. The precision of the conometric coupling and internal fit of cemented CAD/CAM crowns on corresponding Acuris TiN copings were determined by means of SEM.

RESULTS

qrt-PCR results failed to demonstrate microbial leakage from or into the Acuris system. SEM analysis revealed minute punctate microgaps at the apical aspect of the conometric junction (2.04 to 2.64 µm), while mean cement gaps of 12 to 145 µm were observed at the crown-coping interface.

CONCLUSIONS

The prosthetic morse taper connection of all systems examined does not allow bacterial passage. Marginal integrity and internal luting gap between the ceramic crown and the coping remained within the clinically acceptable limits.

CLINICAL RELEVANCE

Conometrically seated single crowns provide sufficient sealing efficiency, relocating potential misfits from the crown-abutment interface to the crown-coping interface.

Bone loss-related factors in tissue and bone level dental implants: a systematic review of clinical trials

Dental implants are popular for dental rehabilitation after tooth loss. The goal of this systematic review was to assess bone changes around bone-level and tissue-level implants and the possible causes. Electronic searches of PubMed, Google Scholar, Scopus, and Web of Science, and a hand search limited to English language clinical trials were performed according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) guidelines up to September 2020. Studies that stated the type of implants used, and that reported bone-level changes after insertion met the inclusion criteria. The risk of bias was also evaluated. A total of 38 studies were included. Eighteen studies only used bone-level implants, 10 utilized tissue-level designs and 10 observed bone-level changes in both types of implants. Based on bias assessments, evaluating the risk of bias was not applicable in most studies. There are vast differences in methodologies, follow-ups, and multifactorial characteristics of bone loss around implants, which makes direct comparison impossible. Therefore, further well-structured studies are needed.

Evaluation of different materials used for sealing of implant abutment access channel and the peri-implant sulcus microbiota: A 6-month, randomized controlled trial

OBJECTIVE

Peri-implantitis has been attributed to a myriad of factors, including microleakage at the abutment-implant interface. Implant abutment access channel sealing materials (IACSM) are readily used in implant dentistry, with little evidence on their effect on microleakage. This study aims to evaluate the effect of IACSM on the microbial composition in the implant access channel and the peri-implant sulcus.

METHODS

A total of n = 8 patients (64 implants) were included in this single-blinded, randomized controlled trial, whereas four different materials (cotton, polytetrafluoroethylene [PTFE], synthetic foam, or polyvinyl siloxane [PVS]) were randomly placed as an IACSM. Following 6 months, microbial analysis was completed on the IACSM and samples from the peri-implant sulci via PCR and high-throughput sequencing. Bacterial samples on the IACSM and in the peri-implant sulci were classified according to Socransky's microbial complexes.

RESULTS

There was a preponderance of early colonizing bacteria within the IACSM, while the peri-implant sulci were dominated by Orange complex bacteria. The proportion of Red and Orange complex members on the IACSM was significantly less than in the peri-implant sulci. The proportion of Green, Yellow, and Blue complex members found on the IACSM was significantly greater than in the peri-implant sulci. Atopobium, a diverse species not included in the microbial complexes, was frequently detected in the peri-implant sulcus samples.

CONCLUSIONS

No detectable effects of IACSM on the microbial community in the peri-implant sulcus or on the IACSM were identified. Variation of bacterial species was most dependent on the individual patient. No significant differences were found in the periodontal parameters between the different treatment groups.

Pull-off resistance of a screwless implant-abutment connection and surface evaluation after cyclic loading

PURPOSE

The aim of this study was to investigate to what extent cyclic load affects the screwless implant-abutment connection for Morse taper dental implants.

MATERIALS AND METHODS

16 implants (SICvantage max) and 16 abutments (Swiss Cross) were used. The screwless implant-abutment connection was subjected to 10,000 cycles of axial loading with a maximum force of 120 N. For the pull-off testing, before and after the same cyclic loading, the required force for disconnecting the remaining 6 implant-abutment connections was measured. The surface of 10 abutments was examined using a scanning electron microscope 120× before and after loading.

RESULTS

The pull-off test showed a significant decrease in the vertical force required to pull the abutment from the implant with mean 229.39 N ± 18.23 before loading, and 204.30 N ± 13.51 after loading (P<.01). Apart from the appearance of polished surface areas and slight signs of wear, no visible damages were found on the abutments.

CONCLUSION

The deformation on the polished abutment surface might represent the result of micro movements within the implant-abutment connection during loading. Although there was a decrease of the pull-off force values after cyclic loading, this might not have a notable effect on the clinical performance.

Evaluation of biofilm colonization on multi-part dental implants in a rat model

BACKGROUND

Peri-implant mucositis and peri-implantitis are highly prevalent biofilm-associated diseases affecting the tissues surrounding dental implants. As antibiotic treatment is ineffective to fully cure biofilm mediated infections, antimicrobial modifications of implants to reduce or prevent bacterial colonization are called for. Preclinical in vivo evaluation of the functionality of new or modified implant materials concerning bacterial colonization and peri-implant health is needed to allow progress in this research field. For this purpose reliable animal models are needed.

METHODS

Custom made endosseous dental implants were installed in female Sprague Dawley rats following a newly established three-step implantation procedure. After healing of the bone and soft tissue, the animals were assigned to two groups. Group A received a continuous antibiotic treatment for 7 weeks, while group B was repeatedly orally inoculated with human-derived strains of Streptococcus oralis, Fusobacterium nucleatum and Porphyromonas gingivalis for six weeks, followed by 1 week without inoculation. At the end of the experiment, implantation sites were clinically assessed and biofilm colonization was quantified via confocal laser scanning microscopy. Biofilm samples were tested for presence of the administered bacteria via PCR analysis.

RESULTS

The inner part of the custom made implant screw could be identified as a site of reliable biofilm formation in vivo. S. oralis and F. nucleatum were detectable only in the biofilm samples from group B animals. P. gingivalis was not detectable in samples from either group. Quantification of the biofilm volume on the implant material revealed no statistically significant differences between the treatment groups. Clinical inspection of implants in group B animals showed signs of mild to moderate peri-implant mucositis (4 out of 6) whereas the mucosa of group A animals appeared healthy (8/8). The difference in the mucosa health status between the treatment groups was statistically significant (p = 0.015).

CONCLUSIONS

We developed a new rodent model for the preclinical evaluation of dental implant materials with a special focus on the early biofilm colonization including human-derived oral bacteria. Reliable biofilm quantification on the implant surface and the symptoms of peri-implant mucositis of the bacterially inoculated animals will serve as a readout for experimental evaluation of biofilm-reducing modifications of implant materials.

One-Piece Titanium Implants: Retrospective Case Series

Purpose

One-piece titanium implants are not routinely used for reconstruction after tooth loss. Several limitations seemed to be apparent although the concept provides a straightforward approach for different clinical situations. A clinical documentation of five prosthetic restorations with one-piece titanium implants serving as a relevant treatment option in dental surgery is pursued. We demonstrate the feasibility and benefits of one-piece titanium implants for fixed dental prosthesis. Detailed descriptions of the technical features and the surgical approach by means of clinical cases are given. The prosthetic workflow when working with one-piece titanium implants is depicted in detail as well as examples for implant-supported tooth replacement in the posterior region and the esthetic zone. Conditions of applications regarding different timing of implant placement using the system and its limitations are discussed.

Results

Clinical cases with a follow-up period of up to 10 years are presented to prove the long-term success of one-piece titanium implants in terms of bone and soft-tissue stability respecting the biological criteria for periodontal health.

Conclusions

One-piece titanium implants represent a reliable treatment method for single-tooth replacements. Clinical success with long-time bone stability around the implantation site can be achieved. Taken into account the requirements for periodontal tissue stability, uneventful healing without extensive tissue loss is demonstrated by means of clinical cases presenting patients with periodontitis.

Mechanical Pull-Out Test of a New Hybrid Fixture-Abutment Connection: An In Vitro Study

Implant abutment connection was described among the main causes of peri-implant bone resorption. The aim of this in vitro study was to test the coupling capacity, the surface modification of a new hybrid connection and the influence of repeated connection activations caused during the main clinical and laboratory phases. A total of 40 implant-abutment screw retained systems with 10°-conical and internal hexagon connection were tested. The connection was screwed, fixed to the universal test machine, removed the screw and a pull-out test was performed. Test was repeated five times in succession. Also Scanning Electron Microscopy (SEM) was used to detect microscopically surface modification. Analysis of variance and Tukey tests were used for the statistical analysis. Pull-out test reveals a mean value of 131.35 ± 16.52 Newton Centimeter (N·cm). For each single activation, results from first to fifth were: 113.9 ± 13.02, 126.1 ± 12.81, 138.11 ± 15.15, 138.8 ± 11.90 and 140 ± 12.99 N·cm. A statistically significant difference between the measurements and an increase in the removal force was shown. The collected data supports the use of this new type of connection, resulting in a very strong interface between implant and abutment. Also, repeated activation of connection can promote a better coupling of the implant-abutment interface.

Marginal Adaptation and Microbial Leakage at Conometric Prosthetic Connections for Implant-Supported Single Crowns: An In Vitro Investigation

Encouraging clinical results were reported on a novel cone-in-cone coupling for the fixation of dental implant-supported crowns (Acuris, Dentsply Sirona Implants, Mölndal, Sweden). However, the presence or absence of a microgap and a potential bacterial leakage at the conometric joint has not yet been investigated. A misfit and a resulting gap between the conometric components could potentially serve as a bacterial reservoir that promotes plaque formation, which in turn may lead to inflammation of the peri-implant tissues. Thus, a two-fold study set-up was designed in order to evaluate the bidirectional translocation of bacteria along conometrically seated single crowns. On conometric abutments filled with a culture suspension of anaerobic bacteria, the corresponding titanium nitride-coated (TiN) caps were fixed by friction. Each system was sterilized and immersed in culture medium to provide an optimal environment for microbial growth. Positive and negative controls were prepared. Specimens were stored in an anaerobic workstation, and total and viable bacterial counts were determined. Every 48 h, samples were taken from the reaction tubes to inoculate blood agar plates and to isolate bacterial DNA for quantification using qrt-PCR. In addition, one Acuris test system was subjected to scanning electron microscopy (SEM) to evaluate the precision of fit of the conometric coupling and marginal crown opening. Throughout the observational period of one week, blood agar plates of the specimens showed no viable bacterial growth. qrt-PCR, likewise, yielded a result approaching zero with an amount of about 0.53 × 10⁻⁴ µg/mL DNA. While the luting gap/marginal opening between the TiN-cap and the ceramic crown was within the clinically acceptable range, the SEM analysis failed to identify a measurable microgap at the cone-in-cone junction. Within the limits of the in-vitro study it can be concluded that the Acuris conometric interface does not allow for bacterial translocation under non-dynamic loading conditions.

Biological Oriented Immediate Loading: A New Mathematical Implant Vertical Insertion Protocol, Five-Year Follow-Up Study

One of the current major challenges in implant therapy is to minimize marginal bone loss around implants, since it can trigger bacterial colonization of the implant’s neck, leading to its failure. The present study aimed (1) to scientifically validate a new mathematical rule based on soft tissues thickness, for choosing the correct implant position with respect to the bone level, in order to provide a better tissue adaptation to the abutment/implant surface to avoid bacterial invasion, and (2) to apply this mathematical rule to the Biological Oriented Immediate Loading (B.O.I.L.) surgical protocol, avoiding peri-implant bone resorption. N. 127 implants were inserted following B.O.I.L. protocol: implants were placed according to the mathematical rule Y = X − 3, which correlates the position of the implant from the bone crest level (Y) with the thickness of the soft tissues (X). All the implants were inserted in fresh extraction sockets, and immediately loaded with temporary abutments and prostheses. Bone levels were evaluated through radiographic examination just after surgical procedure (T0), and after 10 days (10D), 6 months (6M), 1 year (1Y), and 5 years (5Y). After 5 years, the implant survival rate was 100%, with a medium marginal bone loss around implants of 0.0704 mm (SD = 0.169 mm). One-way ANOVA, followed by Tukey’s multiple comparison test was performed for statistical evaluations (p < 0.05). This protocol provided a safe and successful procedure, with a good soft tissue seal against bacterial challenge. The application of the mathematical rule allows the implant placement in a correct vertical position from the bone crest, avoiding bone resorption and bacterial infiltrations. Moreover, the use of Multi Unit Abutment (MUA) determined a stable biological seal, favouring the implant healing and preserving the adhesion of hemidesmosomes to the titanium of MUA.

Curcumin Nanocrystals: Production, Physicochemical Assessment, and In Vitro Evaluation of the Antimicrobial Effects against Bacterial Loading of the Implant Fixture

Background: This study aimed to prepare and study physicochemical properties as well as the antibacterial action of curcumin nanocrystals inside the implant fixture against Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and Enterococcus faecalis (E. faecalis). Methods: Curcumin nanocrystals were prepared via precipitation combined with the spray drying method. The produced curcumin nanocrystals were characterized by dynamic light scattering (DLS), scanning electron microscopy (SEM), powder X-ray diffraction (PXRD), and Fourier transform infrared spectroscopy (FTIR). Moreover, the in vitro antimicrobial effect of curcumin nanocrystals inside the implant fixture was assessed against E. coli, S. aureus, and E. faecalis. All implant-abutment assemblies were immersed in bacterial suspensions and were incubated at 24, 48, and 72 h. The contents of each implant were cultured to count the colony of bacteria at 37 °C for 24 h. Results: The prepared curcumin nanocrystals with a mean particle size of 95 nm and spherical morphology exhibited a removal rate of 99.99% for all bacteria. In addition, the colony-forming unit (CFU) of bacteria in exposure to nanocrystals significantly was reduced (p < 0.010) by increasing the time. Conclusions: Curcumin nanocrystals can be used inside the implant fixture as an antimicrobial agent in order to more stabilization of the implant.

Antibacterial effect of nanocurcumin inside the implant fixture: An in vitro study

Objectives

Infections after implant placement are the main reasons for the failure of implant treatments. The present study aimed to evaluate the antibacterial effects of nanocurcumin inside the implant fixture against Escherichia coli, Staphylococcus aureus, and Enterococcus faecalis.

Materials and Methods

Twenty seven implants were classified in three groups for testing the antibacterial effect of nanocurcumin, chlorhexidine (as negative control), and distilled water (as negative control). Each group was then divided into three subgroups to study the effect of the applied torque on the antimicrobial effect of nanocurcumin. All implant abutment assemblies were submerged in bacteria suspension and were incubated at 37°C for 24 hours. The contents of each implant were removed to count the colony of bacteria on the surface of plates containing nutrient agar.

Results

Results indicated that the inhibitory rate of bacteria by nanocurcumin was above 99% in all bacteria. Besides, by increasing the amount of applied torque from 10 to 35 N.cm, the CFU of bacteria in exposure to nanocurcumin significantly were decreased (p‐value < 0.01).

Conclusion

The results of this study revealed that nanocurcumin can be used inside the implant fixture in order to use antimicrobial effects and further stabilization and success of the implant.

Microbial Community-Driven Etiopathogenesis of Peri-Implantitis

Osseointegrated dental implants are a revolutionary tool in the armament of reconstructive dentistry, employed to replace missing teeth and restore masticatory, occlusal, and esthetic functions. Like natural teeth, the orally exposed part of dental implants offers a pristine nonshedding surface for salivary pellicle-mediated microbial adhesion and biofilm formation. In early colonization stages, these bacterial communities closely resemble those of healthy periodontal sites, with lower diversity. Because the peri-implant tissues are more susceptible to endogenous oral infections, understanding of the ecological triggers that underpin the microbial pathogenesis of peri-implantitis is central to developing improved prevention, diagnosis, and therapeutic strategies. The advent of next-generation sequencing (NGS) technologies, notably applied to 16S ribosomal RNA gene amplicons, has enabled the comprehensive taxonomic characterization of peri-implant bacterial communities in health and disease, revealing a differentially abundant microbiota between these 2 states, or with periodontitis. With that, the peri-implant niche is highlighted as a distinct ecosystem that shapes its individual resident microbial community. Shifts from health to disease include an increase in diversity and a gradual depletion of commensals, along with an enrichment of classical and emerging periodontal pathogens. Metatranscriptomic profiling revealed similarities in the virulence characteristics of microbial communities from peri-implantitis and periodontitis, nonetheless with some distinctive pathways and interbacterial networks. Deeper functional assessment of the physiology and virulence of the well-characterized microbial communities of the peri-implant niche will elucidate further the etiopathogenic mechanisms and drivers of the disease.