Oral biofilms attach onto both teeth surfaces and dental material surfaces in oral cavities. In the meantime, oral biofilms are not only the pathogenesis of dental caries and periodontitis, but also secondary caries and peri-implantitis, which would lead to the failure of clinical treatments. The material surfaces exposed to oral conditions can influence pellicle coating, initial bacterial adhesion, and biofilm formation, due to their specific physical and chemical characteristics. To define the effect of physical and chemical characteristics of dental prosthesis and restorative material on oral biofilms, we discuss resin-based composites, glass ionomer cements, amalgams, dental alloys, ceramic, and dental implant material surface properties. In conclusion, each particular chemical composition (organic matrix, inorganic filler, fluoride, and various metallic ions) can enhance or inhibit biofilm formation. Irregular topography and rough surfaces provide favorable interface for bacterial colonization, protecting bacteria against shear forces during their initial reversible binding and biofilm formation. Moreover, the surface free energy, hydrophobicity, and surface-coating techniques, also have a significant influence on oral biofilms. However, controversies still exist in the current research for the different methods and models applied. In addition, more in situ studies are needed to clarify the role and mechanism of each surface parameter on oral biofilm development.

https://www.mdpi.com/1422-0067/19/10/3157/pdf

Influence of Dental Prosthesis and Restorative Materials Interface on Oral Biofilms

Introduction Presence of gap at the implant-abutment interface, leads to microleakage and accumulation of bacteria which can affect the success of dental implants. Aim To evaluate the sealing capability of different implant connections against microleakage. Materials and methods In January 2017 an electronic search of literature was performed, in Medline, EBSCO host and Pubmed data base. The search was focused on ability of different implant connections in preventing microleakage. The related titles and abstracts available in English were screened, and the articles that fulfilled the inclusion criteria were selected for full text reading. Results In this systematic review, literature search initially resulted in 78 articles among which 30 articles only fulfilled the criteria for inclusion and were finally included in the review. Almost all the studies showed that there was some amount of microleakage at abutment implant interface. Microleakage was very less in Morse taper implants in comparison to other implant connections. Majority of studies showed less microleakage in static loading conditions and microleakage increases in dynamic loading conditions. Conclusion In this systematic review maximum studies showed that there was some amount of microleakage at abutment implant interface. External hexagon implants failed completely to prevent microleakage in both static and dynamic loading conditions of implants. Internal hexagon implants mainly internal conical (Morse taper) implants are very promising in case of static loading and also showed less microleakage in dynamic loading conditions. Torque recommended by manufacturer should be followed strictly to get a better seal at abutment implant interface. Zirconia abutments are more to microleakage than Titanium abutments and there use should be discouraged. Zirconia abutments should be only restricted to cases where there was very high demand of aesthetics.

Microleakage at the Different Implant Abutment Interface: A Systematic Review.

Clinical Relevance Clinical procedures should be performed with caution considering that rough surfaces are directly related to higher bacteria adhesion. However, a polishing procedure may lead to a temporary inflammatory tissue reaction.

Monolithic Ceramics: Effect of Finishing Techniques on Surface Properties, Bacterial Adhesion and Cell Viability

Summary


We explore the influence of enamel surface morphology on nanoscale bacterial adhesion forces Three dimensional morphology characteristics of enamel slices, which were treated with phosphoric acid (for 0 s, 5 s, 10 s, 20 s, and 30 s), were acquired Adhesion forces of three initial colonizers (Streptococcus oralis, Streptococcus sanguinis, and Streptococcus mitis) and two cariogenic bacterial strains (Streptococcus mutans and Streptococcus sobrinus) with etched enamel surfaces were determined Comparison of the forces was made by using bacterial probe method under atomic force microscope (AFM) in adhesion buffer



The results showed that enamel morphology was significantly altered by etching treatment The roughness, peak-to-valley height, and valley-to-valley width of the depth profile, surface area, and volume increased linearly with acid exposure time, and reached the maximum at 30s, respectively The adhesion forces of different strains increased accordingly with etching time Adhesion forces of S oralis, S mitis, S mutans, and S sobrinus reached the maximum values of 081 nN, 084 nN, 073 nN, and 064 nN with enamel treated for 20s, respectively, whereas that of S sanguinis at 10s (128nN), and dropped on coarser enamel surfaces



In conclusion, enamel micro-scale morphology may significantly alter the direct adhesion forces of bacteria And there may be a threshold roughness for bacterial adhesion on enamel surface SCANNING 9999:1–9, 2015 © 2015 Wiley Periodicals, Inc

https://onlinelibrary.wiley.com/doi/pdf/10.1002/sca.21218

Effect of enamel morphology on nanoscale adhesion forces of streptococcal bacteria : An AFM study

Statement of problem During the insertion appointment, the practitioner is often faced with the need to adjust ceramic surfaces to fit a restoration to the adjacent or opposing dentition and soft tissues. Purpose The purpose of this study was to assess the ceramic surface smoothness achieved with various commercially available ceramic polishing kits on different commonly used ceramic systems. The reliability of the cost of a polishing kit as an indicator of improved surface smoothness was assessed. Material and methods A total of 350 ceramic surfaces representing 5 commonly available ceramic systems (IPS Empress Esthetic, IPS e.max Press, Cergo Kiss, Vita PM 9, Imagine PressX) were treated with 5 types of ceramic polishing systems (Cerapreshine, 94006C, Ceramiste, Optrafine, Zenostar) by following the manufacturers' guidelines. The surface roughness was measured with a profilometer (Taylor Hobson; Precision Taylor Hobson Ltd). The effects of ceramic systems and polishing kits of interest on surface roughness were analyzed by 2-way ANOVA, paired t test, and Bonferroni corrected significance level. Results The ceramic systems and polishing kits statistically affected surface roughness ( P P Conclusions The inclusion of a diamond polishing paste step is recommended to improve surface smoothness ( P P >.30).

Adjusting dental ceramics: An in vitro evaluation of the ability of various ceramic polishing kits to mimic glazed dental ceramic surface.

Morphology and bacterial colonisation of tooth/ceramic restoration interface after different cement excess removal techniques

This study evaluated the in vitro bacterial microleakage at the implant-abutment interface of three prosthetic connections: external (EH) and internal hexagon (IH) and taper connection (TC: solid [ST], taper with internal hexagon [IT], and short taper [OT]). Escherichia coli (E coli) and Streptococcus sanguinis (S sanguinus) were inoculated in the apical portion of the abutment screw, which was immersed in sterile brain-heart infusion broth for 14 days. There were no differences between the percentages of bacterial infiltration for IH (9.09%), ST (21.74%), IT (22.73%), and OT (11.11%). EH did not present viable bacteria. There were no significant differences in the counts of connections inoculated and not infiltrated by E coli or S sanguinis nor in those infiltrated by both bacteria (one-way analysis of variance, P < .05). Except for EH, all implant designs and abutments showed bacteria that were capable of surviving and causing infiltration.

The Impact of Conical and Nonconical Abutments on Bacterial Infiltration at the Implant-Abutment Interface.

Objective: The aim of this study was to evaluate the internal and marginal adaptation of inlays fabricated from different types of impressions (conventional and digital) and different ceramics (feldspathic and lithium disilicate). Material and Methods: Forty premolars were prepared for all-ceramic inlay restoration and assigned to 4 groups (n=10), according to the impression method (conventional with addition silicone and digital impressions) and ceramic type (lithium disilicate and feldspathic ceramic blocks). For each type of impression, 10 inlays were fabricated from lithium disilicate blocks and the other 10 from feldspathic ceramic blocks, by means of the CAD-CAM system. The internal adaptation was analyzed by replica. The marginal fit was analyzed under a stereomicroscope by directly measuring the gap formed between the inlay and the tooth in the proximal and occlusal regions. Results: The marginal or internal adaptations were not affected by type of impression (conventional = digital impression), irrespective of the ceramic type. Only the internal adaptation was affected by material, i.e., feldspathic ceramic had lower values than disilicate ceramic, when considering the digital impression. Conclusion: The conventional and digital impressions promote similar marginal and internal adaptation of tested feldspathic and disilicate ceramic inlays. For digital impression the feldspathic ceramic showed better internal adaptation than lithium disilicate.  Keywords Ceramics; Dental internal adaptation; Dental marginal adaptation; Dental impression technique.

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Elen Guerra

Papers

Morphology and bacterial colonisation of tooth/ceramic restoration interface after different cement excess removal techniques

The Impact of Conical and Nonconical Abutments on Bacterial Infiltration at the Implant-Abutment Interface.

Effect of different impression methods and ceramic materials on adaptation of inlays