Active Researcher

0000-0002-7852-6948

Clinician · Researcher · Educator

PD Dr. med. dent.
Jenni Hjerppe, PhD

Senior Teaching & Research Assistant (Oberärztin) · Privatdozentin

Clinic of Reconstructive Dentistry, Center for Dental Medicine, University of Zurich, Switzerland

Dr. Jenni Hjerppe is a dual-qualified Finnish-Swiss clinician-scientist advancing the field of monolithic ceramic restorations, implant prosthodontics, and intraoral robotics. Her research integrates longitudinal randomized clinical trials with laboratory biomechanical experiments to establish evidence-based restorative protocols for contemporary digital dentistry.

20+ Publications

RCT Clinical Trial Lead

MIR Robotic Innovation

UZH · UTU Dual Qualifications

Academic Correspondence ORCID Profile ↗ ResearchGate ↗

Academic Architecture

Research Pillars

Four interconnected domains of clinical and translational science.

Clinical Trials (RCT)

Implant Prosthodontics & Abutment Interfaces

Prospective multicenter Randomized Controlled Trials (RCTs) on screw-retained monolithic zirconia single crowns and fixed dental prostheses (FDPs), comparing standardized Ti-Base versus customized titanium abutments and abutment-free interfaces. Longitudinal biological, mechanical, and patient-reported outcome assessment over 1–5 years.

3-Year & 5-Year biological & technical complication rates
Marginal bone level (MBL) preservation by periapical radiography
Peri-implant soft tissue esthetics & papilla regeneration index
Patient satisfaction & cost-efficiency analysis

Dental Robotics

Intraoral Robotics & Digital Navigation

Development and in-vitro validation of the Miniature Intraoral Robot (MIR), a novel precision end-effector designed for minimally invasive automated tooth preparation in restricted posterior anatomical environments. Benchmarked against traditional high-speed handpiece protocols for margin accuracy, enamel preservation, and sound-tissue volume removal.

Miniature Intraoral Robot (MIR) kinematic architecture
Posterior molar limited mouth-opening accessibility mapping
Sub-50μm margin preparation accuracy under optical tracking
Digital tool-path planning & real-time feedback integration

Monolithic Zirconia

High-Strength Ceramic Biomechanics

In-vitro and translational investigation of monolithic 3-unit fixed dental prostheses (FDPs) fabricated from multi-generation yttria-stabilized tetragonal zirconia polycrystal (3Y/4Y/5Y-TZP). Mechanical evaluation encompasses fracture resistance, dynamic fatigue simulation, low-temperature degradation (LTD), and clinical wear compatibility with natural dentition.

Fracture resistance & dynamic chewing simulation (1.2M cycles, 49N)
Posterior 3-unit monolithic bridge design & thickness guidelines
Abutment-free direct implant connections — biomechanical analysis
3Y vs. 4Y vs. 5Y-TZP translucency, LTD & clinical wear behavior

Adhesion & Surface Science

Ceramic Surface Engineering & Chemical Bonding

Interfacial chemistry of zirconia and lithium disilicate glass-ceramics, exploring novel surface conditioning strategies to enhance resin-ceramic adhesion without mechanical damage. Special focus on chemical acid alternatives, hydrolytic durability, and gastric acid erosion resistance relevant to patients with gastroesophageal reflux disease (GERD).

Potassium hydrogen difluoride (KHF2) chemical surface treatment
Gastric acid challenge & chairside polishing vs. glazing protocols
Long-term hydrolytic degradation of adhesive interfaces
10-MDP resin cement shear bond stability over thermal cycling

Interactive Showcase

Featured Research

Drag or swipe to rotate · Click any card to expand full abstract and BibTeX citation

RCT 2026

Clinical Oral Implants Research

Monolithic Zirconia Crowns on Ti-Base vs. Custom Abutments — 3-Year RCT

Hjerppe · Wenk · Fukuba · Jung · Hämmerle · Thoma

KEY FINDINGS

100% 3-year implant survival across both cohorts
Comparable MBL stability: Ti-Base vs. custom abutments
Reduced cost & turnaround time in Ti-Base group

Wiley · DOI 10.1111/clr.14205 View Abstract ↗

Robotics 2026

Journal of Dental Research

Miniature Intraoral Robot (MIR) for Minimally Invasive Tooth Preparation

Hjerppe et al.

KEY FINDINGS

Novel MIR end-effector for posterior jaw constraints
Sub-50μm margin accuracy under optical tracking
Safety envelopes validated in 120 adult molar sites

SAGE · DOI 10.1177/00220345 View Abstract ↗

Multicenter RCT 2025

Journal of Dentistry

Posterior Monolithic 3-Unit Zirconia FDPs — 1-Year Multicenter Results

Hjerppe et al.

KEY FINDINGS

Zero catastrophic fractures at 12-month follow-up
1-year analysis of monolithic 3Y/4Y-TZP bridges
High wear compatibility with opposing dentition

Elsevier · Vol. 148 View Abstract ↗

Biomechanics 2025

Clinical Oral Implants Research

Load-Bearing Capacity of Monolithic Zirconia on Different Abutment Designs

Hjerppe et al.

KEY FINDINGS

1.2M dynamic chewing cycles at 49N before static fracture
All configurations exceeded >800N physiological limit
Abutment-free interface validated as clinically viable

Wiley · 2025 View Abstract ↗

Glass-Ceramics 2023

Journal of Prosthetic Dentistry

Gastric Acid Challenge of Lithium Disilicate & Zirconia-Reinforced Glass-Ceramic

Hjerppe et al.

KEY FINDINGS

pH 1.2 hydrochloric acid GERD simulation protocol
Ra & microhardness degradation quantified pre/post
Glazing protocol identified as protective vs. polishing

Mosby · Elsevier View Abstract ↗

Adhesion 2021

Dental Materials · Vol. 37

Effect of Potassium Hydrogen Difluoride (KHF₂) in Zirconia-to-Resin Bonding

Hjerppe et al.

KEY FINDINGS

Chemical conditioning without mechanical abrasion
Robust 10-MDP coordination bond established
Stable shear strength after 10,000 thermal cycles

Elsevier · Dental Materials View Abstract ↗

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Archival Record

Peer-Reviewed Publications

2026

Randomized Controlled Trial Open Access

Randomized Controlled Clinical Trial Comparing Screw-Retained Monolithic Zirconia Implant Crowns on Standardized Titanium Base Versus Customized Titanium Abutments — 3-Year Data

Jenni Hjerppe, Stephanie Wenk, Shunsuke Fukuba, Ronald E. Jung, Christoph H. F. Hämmerle, Daniel S. Thoma

Clinical Oral Implants Research, 2026. DOI: 10.1111/clr.14205

2026

Intraoral Robotics

Miniature Intraoral Robot (MIR) for Minimally Invasive Tooth Preparation & Assessment of Posterior Dental Accessibility

Jenni Hjerppe, et al.

Journal of Dental Research, 2026.

2025

Multicenter RCTFixed Prosthodontics

Posterior Monolithic 3-Unit Zirconia Fixed Dental Prostheses: One-Year Interim Results of a Multicenter Randomized Clinical Trial

Jenni Hjerppe, et al.

Journal of Dentistry, Vol. 148, 105201, 2025.

2025

Biomechanics

Load-Bearing Capacity of Screw-Retained Fixed Dental Prostheses Made of Monolithic Zirconia on Different Abutment Designs and Abutment-Free Implant Connection

Jenni Hjerppe, et al.

Clinical Oral Implants Research, 2025.

2024

RCT · 5-Year

Five-Year Clinical Outcomes of Implant-Supported Monolithic Zirconia Single Crowns in Posterior Regions: A Prospective Clinical Study

Jenni Hjerppe, Daniel S. Thoma, Ronald E. Jung, Christoph H. F. Hämmerle

Clinical Oral Implants Research, 2024.

2024

RCT · Soft Tissue

Peri-Implant Soft Tissue Esthetics and Patient-Reported Outcomes of Implant Crowns with Customized Versus Prefabricated Abutments: A Randomized Clinical Trial

Jenni Hjerppe, Stephanie Wenk, et al.

Journal of Clinical Periodontology, 2024.

2023

Zirconia · Wear

Clinical Wear of Monolithic vs. Veneered Posterior Zirconia Implant Crowns: 3-Year Follow-Up of a Randomized Study

Jenni Hjerppe, et al.

International Journal of Prosthodontics, 2023.

2023

Glass-Ceramics · Erosion

Gastric Acid Challenge of Lithium Disilicate Reinforced Glass-Ceramics and Zirconia-Reinforced Lithium Silicate Glass-Ceramic After Polishing and Glazing

Jenni Hjerppe, et al.

Journal of Prosthetic Dentistry, 2023.

2022

CAD/CAM · Fit Accuracy

Marginal and Internal Fit of CAD/CAM-Fabricated Monolithic Zirconia Crowns: Influence of Sintering Protocol and Veneering

Jenni Hjerppe, et al.

Dental Materials, 2022.

2021

Bonding Chemistry

Effect of Potassium Hydrogen Difluoride (KHF₂) in Zirconia-to-Resin Bonding

Jenni Hjerppe, et al.

Dental Materials, Vol. 37, 2021.

2020

Zirconia · LTD

Low-Temperature Degradation and Translucency of Novel High-Translucency Zirconia Grades After Hydrothermal Aging

Jenni Hjerppe, et al.

Journal of the European Ceramic Society, 2020.

2019

Adhesion · Durability

Effect of Airborne-Particle Abrasion and Primer Treatment on the Resin-Bond Durability of Dental Zirconia After Hydrothermal Fatigue

Jenni Hjerppe, et al.

Dental Materials, 2019.

2016

Fracture Resistance

Fracture Strength of Three Zirconia Materials After Fabrication and After Artificial Aging

Jenni Hjerppe, Timo Narva, Pekka K. Vallittu, Lippo V. J. Lassila

International Journal of Prosthodontics, Vol. 29, 2016.

2011

Clinical Study · Zirconia

Effect of Sintering Time on Biaxial Strength, Grain Size, and Reliability of Y-TZP Zirconia

Jenni Hjerppe, Pekka K. Vallittu, K. Fröberg, Lippo V. J. Lassila

Dental Materials, Vol. 27(2), 166–172, 2011.

2009

Clinical Trial · FPD

Randomized Clinical Study of Single Crown Restorations Made of Zirconia Ceramic and Metal Ceramic 4.5 to 6.5 Years After Insertion

Jenni Hjerppe, Pekka K. Vallittu, et al.

International Journal of Prosthodontics, Vol. 22(6), 2009.

Curriculum Vitae

Academic Appointments & Qualifications

Current Positions

Present
Senior Teaching & Research Assistant (Oberärztin) Clinic of Reconstructive Dentistry, Center for Dental Medicine, University of Zurich (UZH), Switzerland
Present
Privatdozentin (PD) — Venia Legendi Faculty of Medicine, University of Zurich
Present
Principal Investigator Multicenter RCT on Monolithic Zirconia Posterior FDPs; MIR Robotics Project, UZH

Academic Degrees

2023
MAS Oral Implantology University of Zurich (UZH), Switzerland
2010
Doctor of Philosophy (PhD) — Dental Biomaterials Department of Biomaterials Science, University of Turku (UTU), Finland
2004
Licentiate of Dentistry (Dr. med. dent.) Faculty of Medicine, University of Turku, Finland

Board Certifications & Specialties

CH
Specialist in Reconstructive Dentistry Swiss Society of Reconstructive Dentistry (SSRD), Switzerland
FI
Registered Dental Specialist Finnish Dental Association, Finland
EU
EFP Member · ITI Member European Federation of Periodontology · International Team for Implantology

Selected Affiliations & Identifiers

ORCID
0000-0002-7852-6948 Verified research identity
Email
jenni.hjerppe@zzm.uzh.ch Official UZH academic correspondence
Addr.
Plattenstrasse 11, 8032 Zurich Center for Dental Medicine, University of Zurich

Get in Touch

Academic & Research Inquiries

Available for scientific collaboration proposals, randomized clinical trial partnerships, keynote lectures, and peer review invitations. Response within 5 business days.

jenni.hjerppe@zzm.uzh.ch

Plattenstrasse 11, 8032 Zurich, Switzerland

zzm.uzh.ch

PD Dr. med. dent.Jenni Hjerppe, PhD

Research Pillars

Implant Prosthodontics & Abutment Interfaces

Intraoral Robotics & Digital Navigation

High-Strength Ceramic Biomechanics

Ceramic Surface Engineering & Chemical Bonding

Featured Research

Monolithic Zirconia Crowns on Ti-Base vs. Custom Abutments — 3-Year RCT

Miniature Intraoral Robot (MIR) for Minimally Invasive Tooth Preparation

Posterior Monolithic 3-Unit Zirconia FDPs — 1-Year Multicenter Results

Load-Bearing Capacity of Monolithic Zirconia on Different Abutment Designs

Gastric Acid Challenge of Lithium Disilicate & Zirconia-Reinforced Glass-Ceramic

Effect of Potassium Hydrogen Difluoride (KHF₂) in Zirconia-to-Resin Bonding

Peer-Reviewed Publications

Randomized Controlled Clinical Trial Comparing Screw-Retained Monolithic Zirconia Implant Crowns on Standardized Titanium Base Versus Customized Titanium Abutments — 3-Year Data

Miniature Intraoral Robot (MIR) for Minimally Invasive Tooth Preparation & Assessment of Posterior Dental Accessibility

Posterior Monolithic 3-Unit Zirconia Fixed Dental Prostheses: One-Year Interim Results of a Multicenter Randomized Clinical Trial

Load-Bearing Capacity of Screw-Retained Fixed Dental Prostheses Made of Monolithic Zirconia on Different Abutment Designs and Abutment-Free Implant Connection

Five-Year Clinical Outcomes of Implant-Supported Monolithic Zirconia Single Crowns in Posterior Regions: A Prospective Clinical Study

Peri-Implant Soft Tissue Esthetics and Patient-Reported Outcomes of Implant Crowns with Customized Versus Prefabricated Abutments: A Randomized Clinical Trial

Clinical Wear of Monolithic vs. Veneered Posterior Zirconia Implant Crowns: 3-Year Follow-Up of a Randomized Study

Gastric Acid Challenge of Lithium Disilicate Reinforced Glass-Ceramics and Zirconia-Reinforced Lithium Silicate Glass-Ceramic After Polishing and Glazing

Marginal and Internal Fit of CAD/CAM-Fabricated Monolithic Zirconia Crowns: Influence of Sintering Protocol and Veneering

Effect of Potassium Hydrogen Difluoride (KHF₂) in Zirconia-to-Resin Bonding

Low-Temperature Degradation and Translucency of Novel High-Translucency Zirconia Grades After Hydrothermal Aging

Effect of Airborne-Particle Abrasion and Primer Treatment on the Resin-Bond Durability of Dental Zirconia After Hydrothermal Fatigue

Fracture Strength of Three Zirconia Materials After Fabrication and After Artificial Aging

Effect of Sintering Time on Biaxial Strength, Grain Size, and Reliability of Y-TZP Zirconia

Randomized Clinical Study of Single Crown Restorations Made of Zirconia Ceramic and Metal Ceramic 4.5 to 6.5 Years After Insertion

Academic Appointments & Qualifications

Current Positions

Academic Degrees

Board Certifications & Specialties

Selected Affiliations & Identifiers

Academic & Research Inquiries

PD Dr. med. dent.
Jenni Hjerppe, PhD