Disinfection and Biocompatibility of Titanium Surfaces Treated with Glycine Powder Airflow and Triple Antibiotic Mixture: An In Vitro Study

Implant survival rate and marginal bone loss of 174 implants with different variables associated over a minimum observational period of 20 years: A retrospective study

PURPOSE

To investigate the long-term implant survival rate and marginal bone loss (MBL) of implants with different variables associated over an observational period of at least 20 years.

MATERIALS AND METHODS

Patients with at least one implant placed prior to 2001 were recalled and visited. Data on implant macro-design, prosthetic aspects, site distribution, and patient-related factors were collected. MBL was evaluated on intraoral X-rays and peri-implant soft tissue parameters were recorded. The patients were asked to fill out a questionnaire to evaluate their satisfaction with the treatment received. Descriptive statistics indicators were estimated. Analysis of variance and analysis of covariance models were used to investigate any differences in the MBL and peri-implant probing depth (PPD) among the variables. A chi-square analysis was performed to investigate any association between different types of prosthetic implant-supported rehabilitations and survival/success outcomes.

RESULTS

Forty-one (41) patients and 174 implants were included with a mean observational period of 23.3 ± 2.8 years. The implant survival and success rates were 96.5% and 83.3% respectively, while 3.5% of early failures were detected. The lowest success rates were observed for implants supporting fixed full-arch rehabilitations (71.05%) and overdenture rehabilitations (86.11%). A mean MBL of 1.81 ± 0.71 mm and a mean PPD of 3.38 ± 1.62 mm were recorded. The interaction between the collected data with MBL and PPD did not reveal any statistically significant differences between the variables (p > 0.05). A statistically significant difference was recorded when analyzing the association between the different types of prosthetic implant-supported rehabilitations and success rates (p = 0.014), with fixed and removable full-arch rehabilitations presenting with lower success rates. Answers to the questionnaire showed a generally high level of satisfaction.

CONCLUSIONS

Within the limits of this retrospective study and based on the results, an implant survival rate higher than 96% was observed after a mean observational period of 23.3 ± 2.8 years. Both the implant survival rate and MBL seemed stable after a mean observational period of 23.3 ± 2.8 years. Implants supporting fixed and removable full-arch rehabilitations seemed to present lower success rates over time. Implant rehabilitation seemed to provide patients with optimal long-term outcomes in terms of functional and psychological aspects.

Impact of Glycine Powder Air-Abrasive Debridement on Peri-Implant Mucositis: A Randomized Control Trial of Clinical, Microbial, and Immunological Changes

AIM

Peri-implant mucositis, a dysbiosis-driven inflammatory disease, is a precursor to peri-implantitis, underscoring the need for early disease management. Therefore, we investigated the efficacy of glycine powder in resolving clinical inflammation and restoring host-microbial homeostasis.

METHODS

Thirty subjects were randomized to receive either glycine powder air-abrasive debridement or ultrasonic instrumentation. Clinical parameters (probe depth [PD], modified Sulcular Bleeding Index [mSBI], modified Plaque Index [mPlI]), biofilm and peri-implant crevicular fluid were collected at baseline and at 1-day, 1-, 3-, 6-weeks and 3- and 6-months post-therapy. Microbial recolonization was examined using 16S rDNA sequencing and immune response was semi-quantified using a bead-based 17-plex microarray.

RESULTS

At 6-months, both groups demonstrated non-significant reductions in mSBI when compared to baseline (p > 0.05, Wald test, mixed model for repeated measures). However, mSBI and PD decreased in the test group from week-1 to 3-months, while control group decreased at 1- and 3-weeks only. mSBI was lower in the test group when compared to controls from Week-1 to 3-months, while PD differed between groups at 6 weeks and 3-months. Glycine group demonstrated significant microbial shifts after 24-h, increases in species richness and health-compatible species, and loss of pathobionts (p < 0.001, Dunn test). Pro-inflammatory cytokines decreased from 1- to 6-weeks or 3-months (p < 0.05, Wald test). Comparable results were obtained in the ultrasonic group at 3-weeks and sustained over 6-weeks post-therapy.

CONCLUSIONS

Glycine therapy leads to early and sustained change in host-microbial interactions when compared to ultrasonics, however, the changes wrought by both therapies were sustained for a maximum of 3 months.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT05810558.

Biomaterials science and surface engineering strategies for dental peri-implantitis management

Peri-implantitis is a bacterial infection that causes soft tissue inflammatory lesions and alveolar bone resorption, ultimately resulting in implant failure. Dental implants for clinical use barely have antibacterial properties, and bacterial colonization and biofilm formation on the dental implants are major causes of peri-implantitis. Treatment strategies such as mechanical debridement and antibiotic therapy have been used to remove dental plaque. However, it is particularly important to prevent the occurrence of peri-implantitis rather than treatment. Therefore, the current research spot has focused on improving the antibacterial properties of dental implants, such as the construction of specific micro-nano surface texture, the introduction of diverse functional coatings, or the application of materials with intrinsic antibacterial properties. The aforementioned antibacterial surfaces can be incorporated with bioactive molecules, metallic nanoparticles, or other functional components to further enhance the osteogenic properties and accelerate the healing process. In this review, we summarize the recent developments in biomaterial science and the modification strategies applied to dental implants to inhibit biofilm formation and facilitate bone-implant integration. Furthermore, we summarized the obstacles existing in the process of laboratory research to reach the clinic products, and propose corresponding directions for future developments and research perspectives, so that to provide insights into the rational design and construction of dental implants with the aim to balance antibacterial efficacy, biological safety, and osteogenic property.

Efficacy of a Solution Containing 33% Trichloroacetic Acid and Hydrogen Peroxide in Decontaminating Machined vs. Sand-Blasted Acid-Etched Titanium Surfaces

This in vitro study assessed the efficacy of a solution containing 33% trichloroacetic acid (CCl3COOH; TCA) and hydrogen peroxide (H2O2) in decontaminating machined (MAC) and sand-blasted acid-etched (SBAE) titanium surfaces. A total of 80 titanium disks were prepared (40 MAC and 40 SBAE). Streptococcus sanguinis and Enterococcus faecalis strains were incubated on 36 samples, while the remaining 44 were kept as controls. Roughness analysis and scanning electron microscopy were used to evaluate the surface features before and after TCAH2O2 treatment. The viability of human adipose-derived mesenchymal stem cells (ASCs) after TCAH2O2 decontamination was assessed with a chemiluminescent assay along with cell morphology through fluorescent staining. TCAH2O2 preserved the surface topography of MAC and SBAE specimens. It also effectively eradicated bacteria on both types of specimens without altering the surface roughness (p > 0.05). Also, no significant differences in protein adsorption between the pristine and TCAH2O2-treated surfaces were found (p = 0.71 and p = 0.94). While ASC proliferation remained unchanged on MAC surfaces, a decrease was observed on the decontaminated SBAE specimens at 24 and 48 h (p < 0.05), with no difference at 72 h (p > 0.05). Cell morphology showed no significant changes after 72 h on both surface types even after decontamination. This study suggests TCAH2O2 as a promising decontamination agent for titanium surfaces, with potential implications for peri-implant health and treatment outcomes.

Effects of abutment materials on peri-implant soft tissue health and stability: A network meta-analysis

PURPOSE

This systematic review aimed to evaluate the effect of the abutment material on peri-implant soft tissue health and stability.

STUDY SELECTION

An electronic and hand search was conducted until February 2022. Only prospective randomized trials (RCTs) and controlled clinical trials (CCTs) comparing titanium abutments with abutments made of different materials, with a follow-up of at least 6 months, were selected by two independent reviewers. Data on marginal bone loss (MBL) and peri-implant tissue indexes, i.e., plaque index (PI), bleeding on probing (BOP), probing depth (PD), and recession (REC), were collected. The risk of bias for RCTs and non-RCTs was evaluated according to the tool reported in the Cochrane Handbook for Systematic Reviews of Interventions and the ROBINS-I tool, respectively. Both pairwise and network meta-analyses (NMA) were performed.

RESULTS

We included 18 relevant studies from 1,437 identified studies. Overall, 612 patients were treated, and 848 abutments were inserted. Five studies presented a low risk of bias. Pairwise meta-analysis showed that, as compared to titanium, zirconia abutments presented a significantly reduced MBL (0.20 mm, 95% Confidence Interval CI [0.14-0.26], P < 0.00001). No significant differences were found for the other outcomes. In the NMA, zirconia abutments demonstrated an 83.3% probability of achieving the highest rank in PI, an 87.0% in BOP, and a 65.0% in PD outcome, suggesting that zirconia abutments generally performed better than titanium and alumina abutments.

CONCLUSIONS

Within the limits of the present study, zirconia abutments seem a viable alternative to titanium ones.

Immediate loading full-arch rehabilitation using transmucosal tissue-level implants with different variables associated: a one-year observational study

BACKGROUND

The aim of the present observational study was to investigate the application of transmucosal tissue-level implants in immediate loading full-arch rehabilitation with different variables associated.

METHODS

Patients needing a full-arch implant rehabilitation were recruited and rehabilitated with four transmucosal tissue level implants. Data related to implants' diameters and lengths, jaw distributions, and presence of angulated abutments were collected. The following outcomes were evaluated: survival rate, marginal bone loss (MBL), Plaque Index (PI), bleeding on probing (BoP), probing depth (PD). Descriptive statistical analysis was reported and univariate linear regression models were built to assess a significant correlation between MBL and the different implant related factors.

RESULTS

Twenty patients were rehabilitated for a total implant number of 80; 11 rehabilitations were performed on the maxilla, while 9 were performed on the mandible; 48 implants presented a 3.8 mm diameter and 32 implants presented a 4.25 mm diameter. Implants length varied between 10 to 15 mm; 40 tilted implants were connected to angulated abutment, while 40 straight implants were connected directly to the prostheses (no abutments). At the one year follow-up visit no implants failed resulting in an implant survival rate of 100%. The overall MBL was 1.19±0.30 mm. No statistically significant difference (P>0.05) was highlighted among any of the subgroups analyzed.

CONCLUSIONS

Despite different variables associated, tissue level implants seem to represent a valid option when applied in immediate loading full-arch rehabilitation. Further research and longer observational periods are encouraged to confirm the result.

Bacterial Adhesion of TESPSA and Citric Acid on Different Titanium Surfaces Substrate Roughness: An In Vitro Study with a Multispecies Oral Biofilm Model

This in vitro study analyzed the influence of substrate roughness on biofilm adhesion and cellular viability over triethoxysilylpropyl succinic anhydride silane (TESPSA)- and citric acid (CA)-coated surfaces at 12 and 24 h, respectively. A multispecies biofilm composed of S. oralis, A. naslundii, V. parvula, F. nucleatum, P. intermedia, P. gingivalis, P. endodontalis and F. alocis was developed over titanium discs grouped depending on their roughness (low, medium, high) and antibacterial coating (low-TESPSA, medium-TESPSA, high-TESPSA, and CA). The biofilm was quantified by means of quantitative polymerase chain reaction (PCR) and viability PCR and assessed through confocal laser scanning microscope (CLSM). Quantitative PCR revealed no significant differences in bacterial adhesion and biofilm mortality. CA was the surface with the lowest bacterial counts and highest mortality at 12 and 24 h, respectively, while high harbored the highest amount of biofilm at 24 h. By CLSM, CA presented significant amounts of dead cells compared to medium-TESPSA and high-TESPSA. A significantly greater volume of dead cells was found at 12 h in low-TESPSA compared to medium-TESPSA, while CA also presented significant amounts of dead cells compared to medium-TESPSA and high-TESPSA. With regard to the live/dead ratio, low-TESPSA presented a significantly higher ratio at 12 h compared to medium-TESPSA and high-TESPSA. Similarly, CA exhibited a significantly higher live/dead ratio compared to medium-TESPSA and high-TESPSA at 12 h. This multispecies in vitro biofilm did not evidence clear antiadhesive and bactericidal differences between surfaces, although a tendency to reduce adhesion and increase antibacterial effect was observed in the low-TESPSA and CA.

Corrosion Resistance and Titanium Ion Release of Hybrid Dental Implants

One of the strategies for the fight against peri-implantitis is the fabrication of titanium dental implants with the part close to the neck without roughness. It is well known that roughness favors osseointegration but hinders the formation of biofilm. Implants with this type of structure are called hybrid dental implants, which sacrifice better coronal osseointegration for a smooth surface that hinders bacterial colonization. In this contribution, we have studied the corrosion resistance and the release of titanium ions to the medium of smooth (L), hybrid (H), and rough (R) dental implants. All implants were identical in design. Roughness was determined with an optical interferometer and residual stresses were determined for each surface by X-ray diffraction using the Bragg-Bentano technique. Corrosion studies were carried out with a Voltalab PGZ301 potentiostat, using Hank's solution as an electrolyte at a temperature of 37 °C. Open-circuit potentials (Eocp), corrosion potential (Ecorr), and current density (icorr) were determined. Implant surfaces were observed by JEOL 5410 scanning electron microscopy. Finally, for each of the different dental implants, the release of ions into Hank's solution at 37 °C at 1, 7, 14, and 30 days of immersion was determined by ICP-MS. The results, as expected, show a higher roughness of R with respect to L and compressive residual stresses of -201.2 MPa and -20.2 MPa, respectively. These differences in residual stresses create a potential difference in the H implant corresponding to Eocp of -186.4 mV higher than for the L and R of -200.9 and -192.2 mV, respectively. The corrosion potentials and current intensity are also higher for the H implants (-223 mV and 0.069 μA/mm²) with respect to the L (-280 mV and 0.014 μA/mm² and R (-273 mV and 0.019 μA/mm²). Scanning electron microscopy revealed pitting in the interface zone of the H implants and no pitting in the L and R dental implants. The titanium ion release values to the medium are higher in the R implants due to their higher specific surface area compared to the H and L implants. The maximum values obtained are low, not exceeding 6 ppb in 30 days.

Relevant Aspects of Titanium Topography for Osteoblastic Adhesion and Inhibition of Bacterial Colonization

The influence of the surface topography of dental implants has been studied to optimize titanium surfaces in order to improve osseointegration. Different techniques can be used to obtain rough titanium, however, their effect on wettability, surface energy, as well as bacterial and cell adhesion and differentiation has not been studied deeply. Two-hundred disks made of grade 4 titanium were subjected to different treatments: machined titanium (MACH), acid-attacked titanium (AE), titanium sprayed with abrasive alumina particles under pressure (GBLAST), and titanium that has been treated with GBLAST and then subjected to AE (GBLAST + AE). The roughness of the different treatments was determined by confocal microscopy, and the wettability was determined by the sessile drop technique; then, the surface energy of each treatment was calculated. Osteoblast-like cells (SaOs-2) were cultured, and alkaline phosphatase was determined using a colorimetric test. Likewise, bacterial strains S. gordonii, S. oralis, A. viscosus, and E. faecalis were cultured, and proliferation on the different surfaces was determined. It could be observed that the roughness of the GBLAST and GBLAS + AE was higher, at 1.99 and 2.13 μm of Ra, with respect to the AE and MACH samples, which were 0.35 and 0.20 μm, respectively. The abrasive treated surfaces showed lower hydrophilicity but lower surface energy. Significant differences could be seen at 21 days between SaOS-2 osteoblastic cell adhesion for the blasted ones and higher osteocalcin levels. However, no significant differences in terms of bacterial proliferation were observed between the four surfaces studied, demonstrating the insensitivity of bacteria to topography. These results may help in the search for the best topographies for osteoblast behavior and for the inhibition of bacterial colonization.

Effects of Hypochlorous Acid and Hydrogen Peroxide Treatment on Bacterial Disinfection Treatments in Implantoplasty Procedures

One of the main problems in oral implantology today is peri-implantitis, which affects almost 20% of dental implants placed in patients. One of the most commonly used techniques to eliminate bacterial biofilm is the implantoplasty, that consists of the mechanical modification of the implant surface topography followed by treatments with chemical reagents for decontamination. In this study, the main aim is to evaluate the use of two different chemical treatments based on hypochlorous acid (HClO) and hydrogen peroxide (H₂O₂). For this purpose, 75 titanium grade 3 discs were treated with implantoplasty according to established protocols. Twenty-five discs were used as controls, 25 were treated with concentrated HClO and 25 were treated with concentrated HClO followed by treatment with 6% H₂O₂. The roughness of the discs was determined using the interferometric process. Cytotoxicity with SaOs-2 osteoblastic cells was quantified at 24 and 72 h, whereas bacteria proliferation using S. gordonii and S. oralis bacteria was quantified at 5 s and 1 min of treatment. The results showed an increase in the roughness values, the control discs had an Ra of 0.33 μm and those treated with HClO and H₂O₂ reached 0.68 μm. Cytotoxicity was present at 72 h, together with a significant proliferation of bacteria. These biological and microbiological results can be attributed to the roughness produced by the chemical agents that triggered bacterial adsorption while inhibiting osteoblast adhesion. The results indicate that even if this treatment can decontaminate the titanium surface after implantation, the produced topography will generate an environment that will not favor long-term performance.

Evaluation of the Photoactivation Effect of 3% Hydrogen Peroxide in the Disinfection of Dental Implants: In Vitro Study

Photoactivation of 3% hydrogen peroxide with a 445 nm diode laser represents a relatively new, insufficiently researched antimicrobial method in the treatment of peri-implantitis. The purpose of this work is to evaluate the effect of photoactivation of 3% hydrogen peroxide with a 445 nm diode laser, and to compare the obtained results with 0.2% chlorhexidine treatment and 3% hydrogen peroxide treatment without photoactivation, in vitro, on the surface of dental implants contaminated with S. aureus and C. albicans biofilms. Previously, 80 infected titanium implants with S. aureus and C. albicans cultures were divided into four groups: G1-negative control (no treatment), G2-positive control (0.2% chlorhexidine), G3 (3% hydrogen peroxide), and G4 (photoactivated 3% hydrogen peroxide). The number of viable microbes in each sample was determined by the colony forming unit (CFU) count. The results were statistically processed and analyzed, showing a statistically significant difference across all groups compared to the negative control (G1), and the absence of a statistically significant difference between groups G1-G3. The new antimicrobial treatment, according to the results, could be worthy of further analysis and research.

Dislodgment Resistance, Adhesive Pattern, and Dentinal Tubule Penetration of a Novel Experimental Algin Biopolymer-Incorporated Bioceramic-Based Root Canal Sealer

The currently available bioceramic-based sealers still demonstrate low bond strength with a poor seal in root canal despite desirable biological properties. Hence, the present study aimed to determine the dislodgment resistance, adhesive pattern, and dentinal tubule penetration of a novel experimental algin-incorporated bioactive glass 58S calcium silicate-based (Bio-G) sealer and compared it with commercialised bioceramic-based sealers. A total of 112 lower premolars were instrumented to size 30. Four groups (n = 16) were assigned for the dislodgment resistance test: control, gutta-percha + Bio-G, gutta-percha + BioRoot RCS, and gutta-percha + iRoot SP, with exclusion of the control group in adhesive pattern and dentinal tubule penetration tests. Obturation was done, and teeth were placed in an incubator to allow sealer setting. For the dentinal tubule penetration test, sealers were mixed with 0.1% of rhodamine B dye. Subsequently, teeth were cut into a 1 mm-thick cross section at 5 mm and 10 mm levels from the root apex, respectively. Push-out bond strength, adhesive pattern, and dentinal tubule penetration tests were performed. Bio-G showed the highest mean push-out bond strength (p < 0.05), while iRoot SP showed the greatest sealer penetration (p < 0.05). Bio-G demonstrated more favourable adhesive patterns. No significant association was noted between dislodgment resistance and dentinal tubule penetration (p > 0.05).

Dental Implant Surface Decontamination and Surface Change of an Electrolytic Method versus Mechanical Approaches: A Pilot In Vitro Study

Dental implants are the preferred fixed oral rehabilitation for replacing lost teeth. When peri-implant tissues become inflamed, the removal of plaque accumulating around the implant becomes imperative. Recently, several new strategies have been developed for this purpose, with electrolytic decontamination showing increased potential compared to traditional mechanical strategies. In this in vitro pilot study, we compare the efficacy of an electrolytic decontaminant (Galvosurge^®) with an erythritol jet system (PerioFlow^®) and two titanium brushes (R-Brush™ and i-Brush™) in removing Pseudomonas aeruginosa PAO1 biofilms from implants. Changes in the implant surface after each approach were also evaluated. Twenty titanium SLA implants were inoculated with P. aeruginosa and then randomly assigned to each treatment group. After treatment, decontamination efficacy was assessed by quantifying colony-forming units (log10 CFU/cm²) from each implant surface. Scanning electron microscopy was used to analyse changes in the implant surface. With the exception of R-Brush, all treatment strategies were similarly effective in removing P. aeruginosa from implants. Major surface changes were observed only in implants treated with titanium brushes. In conclusion, this pilot study suggests that electrolytic decontamination, erythritol-chlorhexidine particle jet system and i-Brush™ brushing have similar performance in removing P. aeruginosa biofilm from dental implants. Further studies are needed to evaluate the removal of more complex biofilms. Titanium brushes caused significant changes to the implant surface, the effects of which need to be evaluated.

Can Abutment with Novel Superlattice CrN/NbN Coatings Influence Peri-Implant Tissue Health and Implant Survival Rate Compared to Machined Abutment? 6-Month Results from a Multi-Center Split-Mouth Randomized Control Trial

Background: The aim of the present multi-center split-mouth randomized control trial was to investigate the effect on peri-implant tissue of abutment with chromium nitride/ niobium nitride (CrN/NbN) coatings (superlattice) compared to traditional machined surface. Methods: Two adjacent posterior implants were inserted in 20 patients. A machined abutment was randomly screwed on either the mesial or distal implant, while a superlattice abutment was screwed on the other one. Implant survival rate, peri-implant probing depth (PPD), plaque index (PI), and bleeding index (BI) were collected 6 months after surgery, while marginal bone loss (MBL) was evaluated at T0 and T6.; Results: Implant survival rate was 97.7%. A total MBL of 0.77 ± 0.50 mm was recorded for superlattice abutments, while a mean MBL of 0.79 ± 0.40 mm was recorded for the abutment with machined surface. A mean PPD of 1.3 ± 0.23 mm was recorded for the superlattice Group, and a mean PPD of 1.31 ± 0.3 was recorded for the machined surface Group. PI was of 0.55 ± 0.51 for superlattice Group and 0.57 ± 0.50 for machined Group, while BI was of 0.47 ± 0.49 for superlattice Group and of 0.46 ± 0.40 for the machined one. No statistically significant difference was highlighted between the two Groups (p > 0.05). Conclusions: After a 6-month observational period, no statistically significant differences were highlighted between superlattice abutment and traditional machined abutment. Further in vitro studies as well as clinical research with longer follow-ups are required to better investigate the surface properties of the novel abutments’ superlattice coating and its effect on the oral tissues.

Evaluation of Load Distribution in a Mandibular Model with Four Implants Depending on the Number of Prosthetic Screws Used for OT-Bridge System: A Finite Element Analysis (FEA)

In full-arch implant rehabilitations, when the anterior screw abutment channel compromises the aesthetic of the patient, the OT-Bridge system used with its Seeger rings may provide the necessary retention of the prosthesis. However, no studies have evaluated the forces generated at the Seeger level during loading. This Finite Element Analysis aims to investigate the mechanical behavior of Seeger rings in a mandibular model with four implants and an OT-Bridge system, used without one or two anterior prosthetic screws. A 400 N unilateral load was virtually applied on a 7 mm distal cantilever. Two different variables were considered: the constraint conditions using two or three screws instead of four and the three different framework materials (fiberglass reinforced resin, cobalt-chrome, TiAl6V4). The FEA analysis exhibited tensile and compressive forces on the Seeger closest to the loading point. With the resin framework, a tension force on abutment 3.3 generates a displacement from 5 to 10 times greater than that respectively expressed in metal framework materials. In a full-arch rehabilitation with four implants, the case with three prosthetic screws seems to be a safer and more predictable configuration instead of two. Considering the stress value exhibited and the mechanical properties of the Seeger, the presence of only two prosthetic screws could lead to permanent deformation of the Seeger in the screwless abutment closest to the loading point.

Clinical Outcomes of Dental Implants with Two Different Internal Connection Configurations—A RCT

Background: The aim of the present study was to highlight clinical and radiographical differences among implants sharing the same macro-geometry but with two different prosthodontic connections. Methods: Patients requiring at least 2 implants in the posterior area of the jaw were randomly divided into two groups (Conical (CS) and Internal Hexagonal (IH) connection). At implant surgery (T0), insertion torque, implant stability quotient (ISQ values recorded by resonance frequency analysis, RFA), and soft tissue thickness (STH) were assessed. A 1-abutment/1-time protocol was applied, and the prosthesis was realized following a fully digital workflow. At the 36-month follow-up periapical x-rays were taken. In order to statistically analyse differences among the two groups and the different variables, paired T-test was used. Linear regression analysis was conducted to analyze how marginal bone loss (MBL) was affected by other independent variables. A neural network created to predict the success (good or not good) of the implant itself was implemented. Results: 30 out of 33 patients (14 males, 16 females, mean age: 68.94 ± 13.01 years) (32 CS and 32 IH) were analyzed. No implants failed. Marginal bone loss at the 3-year time-point was 0.33 ± 0.34 mm and 0.43 ± 0.37 mm respectively for CS and IH with a significant difference between the two groups (p = 0.004). The presence of keratinized gingiva (p = 0.034) significantly influenced MBL. Conclusions: Both the implant connections investigated presented optimal clinical outcomes with minimal marginal bone loss; however, CS implants and implants with the presence of a greater width of keratinized tissue presented significantly lower MBL.

Antibacterial Adhesion Strategy for Dental Titanium Implant Surfaces: From Mechanisms to Application

Dental implants are widely used to restore missing teeth because of their stability and comfort characteristics. Peri-implant infection may lead to implant failure and other profound consequences. It is believed that peri-implantitis is closely related to the formation of biofilms, which are difficult to remove once formed. Therefore, endowing titanium implants with anti-adhesion properties is an effective method to prevent peri-implant infection. Moreover, anti-adhesion strategies for titanium implant surfaces are critical steps for resisting bacterial adherence. This article reviews the process of bacterial adhesion, the material properties that may affect the process, and the anti-adhesion strategies that have been proven effective and promising in practice. This article intends to be a reference for further improvement of the antibacterial adhesion strategy in clinical application and for related research on titanium implant surfaces.

Comparison of the Clinical Outcomes of Titanium and Zirconia Implant Abutments: A Systematic Review of Systematic Reviews

Background: Dental implants are widely used and in order to answer to esthetic demands, zirconia has been introduced as an abutment material as an alternative to titanium. Several studies have been published on this topic, but the results have been often inconsistent. The objective of the present study is to systematically analyze the existing literature comparing clinical outcomes of titanium and zirconia implant abutments. The study was designed as a systematic review of systematic reviews. Methods: This systematic review is in accordance with the Transparent Reporting of Systematic Reviews and Meta-analyses. A MEDLINE/PubMed, Cochrane Database of Systematic Reviews and SCOPUS literature search was performed up to and including June 2021. Data were extracted independently by two reviewers and tAMSTAR2 was used to assess the quality of the systematic reviews. Results: The electronic search identified 1146 papers, and 175 duplicates were removed. After manual screening, 954 studies were excluded and the final analysis was conducted on 11 papers. Both mechanical and esthetic outcomes and biological complications were analyzed. Conclusions: It can be concluded that titanium abutments have a better mechanical resistance than zirconia ones. Plaque accumulation is reported to be slightly higher on titanium but without any significant inflammatory process. The esthetic outcomes seem to be more related to the thickness (>3 mm) of the soft tissues than to the abutment material.