Lea Aylin Schmitz

Dr. Lea Aylin Schmitz


Research Focus & Metrics

Academic Career Length

1Year (2026-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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27 February 2026 in Preprints.org
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KPKamelia Parkhoo
Kamelia Parkhoo
LSLea Aylin Schmitz
Lea Aylin Schmitz
LFLuisa Fröb
Luisa Fröb
NGNicole Grüßner
Nicole Grüßner
Georgios RomanosGeorgios Romanos
Georgios Romanos
SGSusanne Gerhardt-Szep
Susanne Gerhardt-Szep
Six dentin adhesives were tested in vitro regarding their cytotoxicity on human fibroblasts. Hybrid Bond, One-up Bond F Plus, AdheSE, Clearfil SE Bond, Optibond Solo Plus and Syntac were tested by using a cell culture model. The several components of dentin adhesives like primer and bonding were analyzed as single and additive applied components as specified by the manufacturer for the application in-vivo. 75 petri dishes were produced per group and all petri dishes (480 ones) were evaluated triangulated. This unique assessment is following our first investigation and the observation period is extended from 24 hours to 48 hours. AdheSE, Clearfil SE Bond, One-up Bond F Plus and Optibond Solo Plus showed statistically significant less amounts of viable cells compared to the cell control. All dentin adhesives except Clearfil SE Bond showed a statistically significant difference regarding the reactivity index in the application comparison. In conclusion, the test materials showed a moderate grade of cytotoxicity with no statistically significant difference regarding the cytotoxicity between the tested self-etch and etch-and-rinse dentin adhesives. However, the results show differences between sequentially and single applied adhesive parts.

28 February 2026 in Preprints.org
Verified
Preprint
Open access
PDF file
LSLea Aylin Schmitz
Lea Aylin Schmitz
KPKamelia Parkhoo
Kamelia Parkhoo
SHStefan Heitkamp
Stefan Heitkamp
Georgios RomanosGeorgios Romanos
Georgios Romanos
EHEva Hermann
Eva Hermann
SGSusanne Gerhardt-Szep
Susanne Gerhardt-Szep
The aim of this study was to investigate the adhesion of primary colonizers of the oral biofilm on five adhesive restorative materials. For each material (Admira Fusion, Clearfil AP-X, Durafill VS, Filtek Supreme XTE, Venus Diamond) sixteen test specimens were prepared according to a standardized protocol. For pellicle formation, the specimens were incubated for two hours at 37 °C with sterile-filtered inactivated human saliva. The bacteria (S. oralis, S. gordonii, S. sanguinis, S. mitis, A. spp.) were cultivated and suspended. A bacteria mix was prepared from the suspensions. The specimens with pellicles were wetted with the bacterial mix and incubated at 37 °C for 8 hours. The total genomic DNA of the adhered bacteria was isolated and subsequently quantified using SYBR Green qPCR. For S. gordonii, S. oralis and A. spp., no significant differences in the amount of adhered bacterial DNA were found between the different materials. DNA concentration of S. mitis was significantly higher on Filtek Supreme XTE compared to the other materials. Significantly higher DNA concentrations of S.sanguinis could also be detected on Filtek Supreme XTE compared to Clearfil AP-AX and Durafill VS.

23 June 2026 in Dentistry Journal
Verified
Journal Article
Open access
PDF file
LSLea Aylin Schmitz
Lea Aylin Schmitz
KPKamelia Parkhoo
Kamelia Parkhoo
SHStefan Heitkamp
Stefan Heitkamp
Georgios RomanosGeorgios Romanos
Georgios Romanos
EHEva Hermann
Eva Hermann
SGSusanne Gerhardt-Szep
Susanne Gerhardt-Szep
Background/Objectives: The aim of this study was to investigate primary colonizers adhering to the oral biofilm on five adhesive restorative materials. Methods: For each material (Admira Fusion, Clearfil AP-X, Durafill VS, Filtek Supreme XTE, and Venus Diamond), sixteen test specimens were prepared according to a standardized protocol. For pellicle formation, the specimens were incubated for two hours at 37 °C with sterile-filtered inactivated human saliva. The bacteria (Streptococcus oralis (S. oralis), Streptococcus gordonii (S. gordonii), Streptococcus sanguinis (S. sanguinis), Streptococcus mitis (S. mitis), and Actinomyces naeslundii (A. naeslundii)) were cultivated and suspended. A bacteria mix was prepared from the suspensions. The specimens with pellicles were wetted with the bacterial mix and incubated at 37 °C for 8 h. The total genomic DNA of the adhered bacteria was isolated and subsequently quantified using SYBR Green qPCR. Results: For S. gordonii, S. oralis, and A. spp., no significant differences in the amount of adhered bacterial DNA were found between the different materials. S. mitis DNA concentration was significantly higher on Filtek Supreme XTE compared to the other materials. Significantly higher DNA concentrations of S. sanguinis could also be detected on Filtek Supreme XTE compared to Clearfil AP-AX and Durafill VS. Conclusions: The investigated restorative materials showed species-specific differences in bacterial adhesion, with Filtek Supreme XTE exhibiting higher adhesion of S. mitis and S. sanguinis, whereas no differences were observed for the other tested species.

19 May 2026 in Dentistry Journal
Verified
Journal Article
Open access
PDF file
KPKamelia Parkhoo
Kamelia Parkhoo
LSLea Aylin Schmitz
Lea Aylin Schmitz
LFLuisa Fröb
Luisa Fröb
NGNicole Grüßner
Nicole Grüßner
Georgios RomanosGeorgios Romanos
Georgios Romanos
SGSusanne Gerhardt-Szep
Susanne Gerhardt-Szep
Objectives: Six dentin adhesives were tested in vitro regarding their cytotoxicity toward human fibroblasts. AdheSE, Clearfil SE Bond, Hybrid Bond, One-up Bond F Plus, Optibond Solo Plus, and Syntac were tested using a cell culture model. The several components of dentin adhesives, like the primer and bonding, were analyzed as single and additive applied components as specified by the manufacturer for application in vivo. Methods: Seventy-five Petri dishes were produced per adhesive and control group, and all 525 Petri dishes were evaluated using multiparametric strategies, i.e., using multiple methods to strengthen the reliability of the results. The multiparametric strategies consisted of automated cell counting for viability, microscopic morphological assessment and lastly of reactivity grading according to ISO 10993-5. These assessments were performed after our initial investigation, and the observation period was extended from 24 h to 48 h. Results: AdheSE, Clearfil SE Bond, One-up Bond F Plus, and Optibond Solo Plus showed statistically significant reductions in viable cells relative to the cell control. All dentin adhesives except Clearfil SE Bond showed a statistically significant difference regarding the reactivity index in the application comparison. Conclusions: The test materials showed a moderate degree of cytotoxicity, with no statistically significant difference between the tested self-etch and etch-and-rinse dentin adhesives. However, the results show statistically significant differences between the adhesives when applied sequentially and once. Further research addressing mechanisms of cytotoxicity is needed for advancement in this field.