Influence of the Periodontal Status on the Initial-Biofilm Formation on Titanium Surfaces

Comparison of Microbiota in Zirconia and Titanium Implants: A Qualitative Systematic Review

BACKGROUND

In this systematic review, we examine the variations in microbiota on zirconia versus titanium implants, providing insights into their impact on dental health and outcomes. The ongoing discussion regarding whether to use zirconia or titanium for implants underscores the significance of microbiota colonization in determining the longevity and performance of implants.

METHODS

Research questions were formulated following the Participants, Intervention, Comparison, and Outcomes framework, and a PROSPERO protocol was registered. A thorough systematic search was carried out in PubMed, Embase, and Web of Science. Two reviewers independently assessed the reports against the Participants, Intervention, Comparison, and Outcomes criteria, including the inclusion and exclusion criteria. Risk of bias was assessed using the Quality Assessment Tool for In Vitro Studies (QUIN Tool).

RESULTS

Of the 2063 articles identified, 19 articles fulfilled the inclusion criteria and subjected to quality assessment. All of the included studies were in vitro research with low (31.5%) or moderate (36.8%) or high (31.5%) risk of bias and reported data from 2 implant abutments. Zirconia implants displayed a higher occurrence of Gram-negative bacteria, such as Tannerella, Aggregatibacter, and Porphyromonas. In contrast, titanium implants showed a greater prevalence of Gram-positive bacteria, including Streptococcus, Lactobacillus acidophilus, and Staphylococcus species.

CONCLUSION

According to the findings of the current study, both zirconia and titanium implants support the growth of different microorganisms. There were also differences in the quakity and the quantity of microorganisms detected on each material. These differences in microbial profiles indicate that the selection of implant material might impact the microbial ecosystem on the implant surface, potentially affecting clinical outcomes such as infection rates and the longevity of the implant.

Biomedical Applications of Titanium Alloys: A Comprehensive Review

Titanium alloys have emerged as the most successful metallic material to ever be applied in the field of biomedical engineering. This comprehensive review covers the history of titanium in medicine, the properties of titanium and its alloys, the production technologies used to produce biomedical implants, and the most common uses for titanium and its alloys, ranging from orthopedic implants to dental prosthetics and cardiovascular devices. At the core of this success lies the combination of machinability, mechanical strength, biocompatibility, and corrosion resistance. This unique combination of useful traits has positioned titanium alloys as an indispensable material for biomedical engineering applications, enabling safer, more durable, and more efficient treatments for patients affected by various kinds of pathologies. This review takes an in-depth journey into the inherent properties that define titanium alloys and which of them are advantageous for biomedical use. It explores their production techniques and the fabrication methodologies that are utilized to machine them into their final shape. The biomedical applications of titanium alloys are then categorized and described in detail, focusing on which specific advantages titanium alloys are present when compared to other materials. This review not only captures the current state of the art, but also explores the future possibilities and limitations of titanium alloys applied in the biomedical field.

Salivary pellicle modulates biofilm formation on titanium surfaces

OBJECTIVES

The present study aimed to evaluate the potential of the salivary pellicle (SP) formed on titanium (Ti) surfaces to modulate the formation of a biofilm composed of Streptococcus gordonii, Actinomyces naeslundii, Fusobacterium nucleatum, and Porphyromonas gingivalis.

MATERIALS AND METHODS

Ti substrates were incubated for 2 h with a pool of saliva samples obtained from 10 systemically and periodontally healthy subjects. Enamel substrates were included as a biological reference. Scanning electron microscopy (SEM) and Raman spectroscopy analysis were used to analyze the formation of the salivary pellicle. After the SP formation, the surfaces were incubated for 12 h with a mix of Streptococcus gordonii, Actinomyces naeslundii, Fusobacterium nucleatum, and Porphyromonas gingivalis. The number of bacterial cells attached to each surface was determined by the XTT assay while bacterial viability was analyzed by fluorescence microscopy using the LIVE/DEAD® BacLightTM kit.

RESULTS

The SEM and Raman spectroscopy analysis confirmed the presence of a salivary pellicle formed on the tested surfaces. Regarding the biofilm formation, the presence of the SP decreases the number of the bacterial cells detected in the test surfaces, compared with the uncover substrates. Even more, the SP-covered substrates showed similar bacterial counts in both Ti and enamel surfaces, meaning that the physicochemical differences of the substrates were less determinant than the presence of the SP. While on the SP-uncover substrates, differences in the bacterial adhesion patterns were directly related to the physicochemical nature of the substrates.

CONCLUSIONS

The salivary pellicle was the main modulator in the development of the biofilm consisting of representative oral bacteria on the Ti substrates.

CLINICAL RELEVANCE

The results of this study provide valuable information on the modulatory effect of the salivary pellicle on biofilm formation; such information allows us to understand better the events involved in the formation of oral biofilms on Ti dental implants.

Oral prosthetic microbiology: aspects related to the oral microbiome, surface properties, and strategies for controlling biofilms

The oral cavity is an environment that allows for the development of complex ecosystems; the placement of prosthetic devices as a consequence of partial or total tooth loss may alter the diversity of microbial communities. Biofilms on the surface of materials used in dental prostheses can promote important changes in the mechanic and aesthetic properties of the material itself and may cause local and systemic diseases for the prosthetic wearer. This review presents the main features of the oral microbiome associated with complete or partial dentures and dental implants. The main diseases associated with microbial colonization of prosthetic surfaces, factors that may affect biofilm formation on prosthetic materials, as well as novel alternative therapies aiming to reduce biofilm formation and/or to eradicate biofilms formed on these materials are also explored.

Biofilm as a risk factor in implant treatment

This article summarizes the microbiological findings at dental implants, drawing distinctions between the peri-implant microbiome and the periodontal microbiome, and summarizes what is known regarding biofilm as a risk factor for specific stages of implant treatment. Targeted microbial analysis is reviewed as well as the latest results from open-ended sequencing of the peri-implant flora. At this time there remains a lack of consensus for a specific microbial profile that is associated with peri-implantitis, suggesting that there may be other factors which influence the microbiome such as titanium surface dissolution. Therapeutic interventions to address the biofilm are presented at the preoperative, perioperative, and postoperative stages. Evidence supports that perioperative chlorhexidine reduces biofilm-related implant complications and failure. Regular maintenance for dental implants is also shown to reduce peri-implant mucositis and implant failure. Maintenance procedures should aim to disrupt the biofilm without damaging the titanium dioxide surface layer in an effort to prevent further oxidation. Evidence supports the use of glycine powder air polishing as a valuable adjunct to conventional therapies for use at implant maintenance visits. For the treatment of peri-implantitis, nonsurgical therapy has not been shown to be effective, and while surgical intervention is not always predictable, it has been shown to be superior to nonsurgical treatment for decontamination of the implant surface that is not covered by bone.

Sex-specific differences in the salivary microbiome of caries-active children

Background and Objectives: Dental caries is a chronic disease affecting young children and has multi-factorial risk factors. The purpose of this work was to identify sex-specific differences in the salivary microbiota within caries-active children. Design: Saliva specimens were collected from 85 children (boys: 41; girls: 44) between the ages of 2-12 years. Salivary microbial DNA was subjected to PCR amplification using V3-V4 16S rDNA-specific primers and next-generation sequencing. Results: Significant sex differences in salivary microbiota were found between caries-active boys versus caries-active girls. Neisseria flavescens, Rothia aeria, and Haemophilus pittmaniae were found at significantly higher levels in caries-active boys. In contrast, Lactococcus lactis, Selenomonas species HOT 126, Actinobaculum species HOT 183, Veillonella parvula, and Alloprevotella species HOT 473 were found at significantly higher levels in caries-active girls. Conclusion: We have found the acid-generating, cariogenic Lactococcus lactis to be much more abundant in caries-active girls than caries-active boys, indicating that this microorganism may play a more significant role in shaping the cariogenic microbiome in girls. In addition, in caries-active girls, Alloprevotella species HOT 473 was the only species that exhibited both significant sex differences (4.4-fold difference; p=0.0003) as well as high abundance in numbers (1.85% of the total microbial population).

Development and viability of biofilms grown on experimental abutments mimicking dental implants: An in vivo model

BACKGROUND

To determine whether an experimental abutment mimicking the macro- and microstructure of a dental implant is a suitable method for recovering biofilm, and to describe the features of biofilms formed around such abutments on healthy implants.

MATERIAL AND METHODS

Experimental abutments were used in 15 patients without peri-implant diseases. After 14 days' absence of dental hygiene in this area, the abutments were retrieved and analyzed through confocal laser scanning microscopy and scanning electron microscopy. The biofilm formation on the surface of the first 5 abutments was determined by a fluorescence-staining method using SYTO9 nucleic acid stain. In order to study the biofilm's coverage and vitality, 10 additional abutments were assessed using live & dead bacterial viability. Descriptive and bivariate analyses of the data were performed.

RESULTS

A global plaque coverage of the abutments was observed in all cases. The submucosal area of the abutment was mostly covered with biofilm (over 21%). Moreover, significant differences between supra- and subgingival locations were detected.

CONCLUSIONS

This in vivo experimental model allows detailed observation of the extensive plaque growth found on exposed experimental abutments mimicking dental implants when hygiene measures are absent. The biofilm coverage is significantly higher in the supragingival zone than in the subgingival portion.

Clinical aspects and polymorphisms in the LTA, TNFA, LTB genes and association with dental implant loss

BACKGROUND

This study shows the relationship between host factors and environmental factors in the influence of susceptibility to loss of dental implants.

PURPOSE

The aim of this study was to investigate the association of clinical aspects and tag SNPs of the genes LTA, TNFA, and LTB with dental implant loss.

MATERIALS AND METHODS

The subjects consisted of 244 patients, divided into two groups: control group (C)-163 individuals who did not lose any implants, being in function for at least 6 months; and study group (S)-81 individuals who had lost at least one implant. DNA was collected from saliva, and the genotypes were determined by real time PCR. Univariate and multivariate analysis were employed p < .05.

RESULTS

After multivariate analysis, dental implant loss remained associated with the presence of teeth (p = .011), a larger amount of placed implants (p = .001), and allelle C of rs2009658 of the LTA gene (p = .006). For the other tag SNPs of these studied genes, there was no association between the groups C and S with dental implants loss.

CONCLUSION

Presence of teeth, number of placed implants and allele C of rs2009658 of LTA gene were associated with implant loss.

Effect of sucrose on biofilm formed in situ on titanium material

BACKGROUND

Because sucrose may change the composition of biofilms formed on dental surfaces, the aim of this study was to evaluate in situ the effect of this dietary sugar on biofilm formation on titanium surface.

METHODS

In this blind, crossover, in situ study, 10 volunteers wore, in 3 phases of 7 days each, a palatal appliance containing titanium specimens. In each phase, the specimens were treated extraorally with 20% sucrose solution at a frequency of 4 or 8 times per day. As control, no treatment was rendered (0×). At the end of each phase, the biofilms were collected for biochemical analysis of biofilm wet weight (biomass), protein concentration, soluble (S-EPS), and insoluble (I-EPS) extracellular polysaccharides and intracellular polysaccharides (IPS), and for microbiologic analysis by checkerboard DNA-DNA hybridization (for levels and proportions of 40 bacterial species). Biochemical data were analyzed by linear regression and microbiological findings by Friedman and Dunn tests (α = .05).

RESULTS

A positive significant linear relationship was found among sucrose exposure (0×, 4×, and 8×) and biomass, S-EPS, I-EPS and IPS (p < 0.05). The biofilms treated with sucrose (4× and/or 8×) presented higher mean total levels of the 40 bacterial species evaluated, higher proportions of red complex species and lower proportions of the host-compatible green complex species, in comparison with the control group (p < 0.05).

CONCLUSION

The findings of the present study suggest that daily sucrose exposure has a harmful effect on the composition of biofilms formed on titanium surfaces.

Anti-Bacteria and Microecosystem-Regulating Effects of Dental Implant Coated with Dimethylaminododecyl Methacrylate

The effects of dimethylaminododecyl methacrylate (DMADDM) modified titanium implants on bacterial activity and microbial ecosystem of saliva-derived biofilm were investigated for the first time. Titanium discs were coated with DMADDM solutions at mass fractions of 0 mg/mL (control), 1, 5 and 10 mg/mL, respectively. Biomass accumulation and metabolic activity of biofilms were tested using crystal violet assay and MTT (3-(4,5-Dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. 16S rRNA gene sequencing was performed to measure the microbial community. Live/dead staining and scanning electron microscopy (SEM) were used to value the structure of biofilm. The results showed that the higher mass fraction of DMADDM the coating solution had, the significantly lower the values of metabolic activity and accumulated biofilms got, as well as fewer live cells and less extracellular matrix. Moreover, 5 mg/mL of DMADDM was the most effective concentration, as well as 10 mg/mL. In microecosystem-regulation, the DMADDM modified titanium implant decreased the relative abundance of Neisseria and Actinomyces and increased the relative abundance of Lactobacillus, a probiotic for peri-implant diseases. In conclusion, via inhibiting growth and regulating microecosystem of biofilm, this novel titanium implant coating with DMADDM was promising in preventing peri-implant disease in an ‘ecological manner’.