Scientific Work

Professor Bollen published 70 international scientific articles and 25 national scientific articles. He also published several book or chapters in scientific books.

International Publications

  • 2025

Aghasan E, Hakobyan Ti, Bollen C, Hakobyan G. Immediate full-arch implants and immediate functional loading in periodontally compromised patients. Implants 2025; accepted.

Bollen C, Tipton P, Kocharyan M, Hakobyan G. L’impatto della parodontite sulla salute sistemica e sugli impianti. Implants 2025; 1: 14-19. [Italian]

Margaryan V, Aghasyan E, Yessayan L, Khachatryan H, Bollen C, Hakobyan G. Adjunctive therapea – a promising method in the treatment of periodontal disease. Clin Oral Investig 2025; 29: 78-. doi: 10.1007/s00784-025-06163-1. PMID: 39849187.

Ghambaryan N, Bollen C, Harutyunyan H, Habobyan G. Effect of crown-implant (C/I) ratio of short implants on peri-implant stress: a finte element analysis. Int J Med Sc & Dent Health 2025; 11: 38-47.

Bollen C, Tipton P, Hakobyan G. Impact of periodontitis on systemic health and on implants – Part 2. Implants 2025; 1: 1-4.

  • 2024

Bollen C, Tipton P, Hakobyan G. Impact of periodontitis on systemic health and on implants – Part 2. Ceramic Implants 2024; 3: 20-22.

Aghasyan E, Yessayan L, Ramanarayana B, Bollen C, Khachatryan H, Hakobyan G. Current concepts of non-surgical periodontal therapy in chronic periodontitis. J Dental Oral Health 2024; 5: 1-10.

Bollen C, Tipton P, Kocharyan M, Hakobyan G. Impact of periodontitis on systemic health and on implants. Ceramic Implants 2024; 2: 20-23.

Bollen C, Tipton P, Kocharyan M, Hakobyan G. Impact of periodontitis on systemic health and on implants. Implants 2024; 4: 18-21.

Hakobyan T, Grigoryan A, Bollen C, Hakobyan G. Immediate implant placement & immediate loading with fully digital fabricated screw-retained implant prosthesis. A controlled case series. Bulletin of Stomatology and Maxillo-Facial Surgery 2024;20(2):117-125. doi:10.58240/1829006X-2024.2-117

Bollen C, Jörgens M, Hakobayan G. 1-Piece versus 2-piece ceramic dental implants. British Dental Journal 2024; 236: 383-387.

  • 2023

Bollen C, Jörgens M. Clinical and scientifical differences between 1-piece and 2-piece ceramic dental implants. EDI Journal 2023; 3: 50-54.

Bollen C, Jörgens M. 1-Piece and 2-piece ceramic dental implants. Ceramic Implants 2023: 3: 24-29.

Bollen CML, Hakobyan G. S3 Guidelines on ceramic dental implants and titanium hypersensitivity: statements and recommendations for the worldwide implant dentistry community. Bulletin of Stomatology and Maxillo-Facial Surgery 2023; 19: 75-83. DOI: 10.58240/1829006X-2023.19.71-75.

Bollen CML, Diederich H, Al-Masri M. Cone bean computed tomography in implant dentistry – An update. Journal of Dental Reports 2023; 4: 1-7.

  • 2022

Hakobyan G, Seyranyan A, Yessayan L, Davit M, Bollen C. Surgical regenerative treatment in combination with magnetic laser supportive therapy of peri-implantitis. Bulletin of Stomatology and Maxillo-Facial Surgery 2022; 18: 84-93.

Boogaard M, Bollen C. Immediate implant placement. Implant Dentistry 2022; Oct: 69-76.

Dudeck DU, Bollen CML. Update Oberflächenanalysen: steril verpackte Implantate unter der Lupe. Zahnmedizin up2date. 2022; 16: 1-14. [German]

Bollen C, Tipton P. Shortening implant times by influencing the healing response: the positive effects of platelet-rich fibrin on osseointegration. Clinical Dentistry. 2022; september: 61-64.

Bollen C, Tipton P. Single tooth replacement by ceramic dental implants: a case series. Ceramic Implants 2022: 1; 18-22.

Boogaard M, Bollen C. Sofortimplantate in Extraktionsalveolen mit synthetischem Kitt- Transplantat. Implantologie. 2022; online published (https://www.zwp- online.info/fachgebiete/implantologie/ sofortimplantation/sofortimplantate-in-extraktionsalveolen-mit- synthetischem-kitt-transplantat).

Boogaard M, Bollen C. The use of a synthetic putty graft in extraction sockets combined with immediate implant installation – 3 cases. J Dent Rep. 2022; 3; 1-9.

  • 2021

Veljanovski D, Atanasovska-Stojanovska A, Pivkova-Veljanovska A, Mijiritsky E, Bollen C. The vertical soft tissue thickness and subcrestal implant placement as factors for peri-implant crestal bone. Open Access Maced J Med Sci. 2021; 9: 257-263.

Bollen C, Tipton P. Working with zirconia implants requires a different approach. J Dent Rep. 2021; 2: 1-9.

Bollen C, Tipton T. Single tooth replacement by ceramic dental implants. Clinical Dentistry 2021; February: 1-6.

Bollen C. The impact of COVID-19 on implant dentistry. J Dent Rep. 2021; 2(1): 1-4.

Bollen C, Dargel I. Replacement of 2 incisors by zirconia implants. Ceramic Implants 2021: 1; 36-39.

Bollen C, Najimi Y & Almasri M. Covid-19 and dental implants: impact and perspectives. Implant Dentistry Today 2021: 01; 7-11.

  • 2020

Bollen C, Dargel I, Almasri M. Replacement of 2 incisors by zirconia implants. An extended case report. Journal Dent Rep. 2020; 1: 1-8.

Bollen C, Almasri M. Zirconium-dioxide as preferred material for dental implants. A narrative review. Part II. Ceramic Implants 2020; 5: 1-5.

Bollen C, Dargel I. Einzelzahnversorgung mit Keramikimplantat nach Trauma. Implantologie Journal. 2020: 7-8; 26-30. [German]

Bollen C, Almasri M. Zirconium-dioxide as preferred material for dental implants. A narrative review. Part I. Ceramic Implants 2020; 4: 20-22.

Bollen C, Almasri M. Zirconia: the material of choice in implant dentistry? Implant Dentistry Today 2020; 3: 8-14.

  • 2018

Bollen CML, Winkel OHC: Implantate und halitosis: gibt es einen Zusammenhang? ZMK 2018; 34: 762- 770. [German]

  • 2017

Bollen CML. Zirconia: the material of choice in implant dentistry? An update. J Dent Health Oral Disord Ther 2017; DOI: 10.15406/jdhodt.2017.06.00219

  • 2016

Bollen C. Myths about Halitosis. J Dent Health Oral Disord Ther 2016; 5: 00143

Bollen CML. “White or Grey? Ceramic or Metal?”. EC Dental Science 2016: 28-29.

Bollen CML. White is the new grey! Oral Health and Dentistry 2016;1: 1-3.

Aydin M, Bollen CML, Özen ME. A halitosis vizsgálati módszereinek diagnosztikai értékelése. Magyar Fogorvos 2016; 4: 184-191. [Hungarian]

Aydin M, Bollen CM, Özen ME. Diagnostic Value of Halitosis Examination Methods. Compend Contin Educ Dent 2016; 37: 174-178.

Bollen C. Save lives: do an HPV-detection test! J Dent Health Oral Disord Ther 2016, 4(1): 00097.

  • 2015

Bollen CML. How to handle halitosis examinations? EC Dental Science 2015; 2.2: 254- 259.

  • 2014

Bollen CML. Peri-Implantitis: A New Disease! J Dent Health Oral Disord Ther 2014; 1(3): 00018.

  • 2012

Bollen CML, Beikler T. Halitosis: the multi-disciplinary approach. Int J Oral Sci. 2012; 4: 55- 63.

  • 2009

Bollen CML, Jepsen S. Halitosis: ein multi-disziplinäres Problem. Prophylaxe Dialog. 2009: 18-21. [German]

Bollen CML, Jepsen S. Halitosis a multi-disciplinary problem. Phrophylaxis Dialogue. 2009: 18-21.

  • 1999

Bollen C. The sampling of plaque specimens in oral microbiology. Rev Belge Med Dent. 1999; 54: 190- 194. [French]

Bollen CM, Rompen EH, Demanez J P. Halitosis: a multidisciplinary problem. Rev Med Liege. 1999; 54: 32- 36. [French]

Delanghe G, Bollen C, Desloovere C. Halitosis–foetor ex ore. Laryngorhinootologie. 1999; 78: 521-524. [German]

Delanghe G, Ghyselen J, Bollen C, van Steenberghe D, Vandekerckhove BN, Feenstra L. An inventory of patients’ response to treatment at a multidisciplinary breath odor clinic. Quintessence Int. 1999; 30: 307-310.

Quirynen M, Mongardini C, Pauwels M, Bollen CM, Van Eldere J, van Steenberghe D. One stage full- versus partial-mouth disinfection in the treatment of chronic adult or generalized early-onset periodontitis. II. Long-term impact on microbial load. J Periodontol. 1999; 70: 646- 656.

Quirynen M, Van Eldere J, Pauwels M, Bollen CM, van Steenberghe D. In vitro volatile sulfur compound production of oral bacteria in different culture media. Quintessence Int. 1999; 30: 351-356.

  • 1998

Bollen CM, Mongardini C, Papaioannou W, Van Steenberghe D, Quirynen M. The effect of a one-stage full-mouth disinfection on different intra-oral niches. Clinical and microbiological observations. J Clin Periodontol. 1998; 25: 56-66.

  • 1997

Bollen CM, Lambrechts P, Quirynen M. Comparison of surface roughness of oral hard materials to the threshold surface roughness for bacterial plaque retention: a review of the literature. Dent Mater. 1997; 13: 258-269.

Papaioannou W, Bollen CM, Quirynen M. One-stage full-mouth disinfection to overcome intra-oral transmission of periodontopathogens. Anaerobe. 1997; 3: 163-168.

van Steenberghe D, Yoshida K, Papaioannou W, Bollen CM, Reybrouck G, Quirynen M. Complete nose coverage to prevent airborne contamination via nostrils is unnecessary. Clin Oral Implants Res. 1997; 8: 512- 516.

  • 1996

Bollen CM, Papaioannou W, Van Eldere J, Schepers E, Quirynen M, van Steenberghe D. The influence of abutment surface roughness on plaque accumulation and peri-implant mucositis. Clin Oral Implants Res. 1996; 7: 201-211.

Bollen CM, Quirynen M. Microbiological response to mechanical treatment incombination with adjunctive therapy. A review of the literature. J Periodontol. 1996; 67: 1143-1158.

Bollen CM, Vandekerckhove BN, Papaioannou W, Van Eldere J, Quirynen M. Full- versus partial-mouth disinfection in the treatment of periodontal infections. A pilot study: long-term microbiological observations. J Clin Periodontol. 1996; 23: 960-970.

Papaioannou W, Bollen CM, Van Eldere J, Quirynen M. The adherence of periodonto-pathogens to periodontal probes. A possible factor in intra-oral transmission? J Periodontol. 1996; 67: 1164-1169.

Quirynen M, Bollen CM, Papaioannou W, Van Eldere J, van Steenberghe D. The influence of titanium abutment surface roughness on plaque accumulation and gingivitis: short-term observations. Quintessence Dental Implantology 1996; 3: 681-691. [Japanese]

Quirynen M, Bollen CM, Papaioannou W, Van Eldere J, van Steenberghe D. The influence of titanium abutment surface roughness on plaque accumulation and gingivitis: short-term observations. Int J Oral Maxillofac Implants. 1996; 11: 169-178.

Vandekerckhove BN, Bollen CM, Dekeyser C, Darius P, Quirynen M. Full- versus partial- mouth disinfection in the treatment of periodontal infections. Long-term clinical observations of a pilot study. J Periodontol. 1996; 67: 1251-1259.

  • 1995

Quirynen M, Bollen CM. The influence of surface roughness and surface-free energy on supra- and subgingival plaque formation in man. A review of the literature. J Clin Periodontol. 1995; 22: 1-14.

Quirynen M, Bollen CM, Vandekerckhove BN, Dekeyser C, Papaioannou W, Eyssen H. Full- vs. partial- mouth disinfection in the treatment of periodontal infections: short-term clinical and microbiological observations. J Dent Res. 1995; 74: 1459-1467.

  • 1994

Quirynen M, van der Mei HC, Bollen CML, Geertsma-Doornbusch GI, Busscher HJ, van Steenberghe D. Clinical relevance of the influence of surface free energy and roughness on the supragingival and subgingival plaque formation in man, Colloids and Surfaces B: Biointerfaces. 1994; 2: 25-31

Quirynen M, Bollen CM, Eyssen H, van Steenberghe D. Microbial penetration along the implant components of the Brånemark system. An in vitro study. Clin Oral Implants Res. 1994; 5: 239-244.

Bollen CM, Quirynen M. Specimen collection in dental plaque and oral microbiology. Rev Belge Med Dent. 1994; 49: 44-51. [French]

Quirynen M, Bollen CM, Papaioannou W. “Chairside” microbiological tests in periodontics. Rev Belge Med Dent. 1994; 49: 26-43. [French]

Quirynen M, Bollen CM, Willems G, van Steenberghe D. Comparison of surface characteristics of six commercially pure titanium abutments. Int J Oral Maxillofac Implants. 1994; 9: 71-76.

Quirynen M, Van der Mei HC, Bollen CM, Van den Bossche LH, Doornbusch GI, van Steenberghe D, Busscher HJ. The influence of surface-free energy on supra- and subgingival plaque microbiology. An in vivo study on implants. J Periodontol. 1994; 65: 162-167.

  • 1993

Quirynen M, van der Mei HC, Bollen CM, Schotte A, Marechal M, Doornbusch GI, Naert I, Busscher HJ, van Steenberghe D. An in vivo study of the influence of the surface roughness of implants on the microbiology of supra- and subgingival plaque. J Dent Res. 1993; 72: 1304- 1309.

National Publications

  • 2023

Bollen C, Hakobayan G. Eendelige versus tweedelige keramische implantaten. Tandartsprakijk 2023; 6: 10-15.

  • 2021

Bollen C. Positieve effecten van bloedplaatjesrijk fibrine op osseo-integratie. Tandartsenpraktijk 2021: 8:10-14.

Bollen C & Dargel I. Enkeltandsvervanging door een 2-delig zirkonia implantaat na extreme wortelresorptie. Een case-report. Dentista 2021; 1: 46-51.

  • 2020

Bollen C. Het werken met zirconia implantaten vraagt om een andere aanpak! NVOI- Bulletin 2020; 2: 30-35.

  • 2019

Bollen C & Almasri M. Zirkonia: het materiaal bij uitstek voor tandheelkundige implantaten? Tijdschrift voor Bio-Energetische Tandheelkunde 2019; 23: 36-42.

  • 2015

Bollen CML. Mondgeur onderschat? Tijdschrift voor farmacie 2015.

  • 2005

Bollen CML. Lasers in de parodontologie en de implantologie – de Nd: YAG-laser. Dentist News NL 2005; 26: 7-10.

Bollen CML. Les lasers en parodontologie et en implantologie – le laser Nd: YAG. Dentist News F 2005; 26: 7-10.

  • 2003

Bollen C. Halitosespreekuur. Dentist News NL 2003; 24: 5-8.

Bollen C. Consultation sur l’halitose. Dentist News F 2003; 24: 5-8.

  • 2002

Bollen CML. Staalafname van plaques in de orale microbiologie. Best of Dentistry 2002; 11: 9-10.

  • 2001

Bollen CML, van Winkelhoff AJ. Gebruik van doxycycline bij parodontitis. Ned Tandarstenblad 2001; 56: 1131-1133.

  • 1999

Bollen C. Plaque staalname in de orale microbiologie. Belg Tijdschrift Tandheelkunde 1999; 54: 191- 195.

  • 1998

Delanghe G, Bollen C, van Steenberghe D, Feenstra L. Halitosis, foetor ex ore. Ned Tijdschr Tandheelkd. 1998; 105: 314-3177. [Dutch]

  • 1997

Bollen CML, Feenstra L, Ghyselen J, van Steenberghe D. Diagnostic et traitement de l’halitose d’origine buccale en médcine dentaire. Dentiforum 1997; 26: 1-3.

Bollen CML, Feenstra L, Ghyselen J, van Steenberghe D. Diagnose en behandeling van mondgeur in de huistandartspraktijk. Dentiforum NL 1997; 26: 1-3.

Bollen CML. Troisieme congres international sur l’halitose. Dentist News F 1997; 18: 7- 10.

Bollen CML. Derde international congress over halitose. Dentist News F 1997; 18: 7-10.

Quirynen M, Bollen C, van Steenberghe D. De snelheid van plaquegroei is patiënt gebonden. Tandheelkundige Tijdingen 1997; 25: 63-77.

Bollen CML, Papaioannou W, Quirynen M. De rol van intra-orale transmissie van paropathogenen in de plaquevorming. Tandheelkundige Tijdingen 1997; 25: 78-90.

  • 1996

Quirynen M, Vandekerckhove B, Bollen CML. Klinische en microbiologische voordelen van een optimale monddefsinfectie bij patiënten met gevorderde parodontitis. Tandartsenwereld 1996; 77: 5-8.

Quirynen M, Vandekerckhove B, Bollen CML. De volledige monddesinfectie in de behandeling van chronische volwassen parodontitis. Tandheelkundige Tijdingen 1996; 24: 67-71.

Bollen C. Full-mouth disinfection and hard surface smoothening reduce the subgingival microbial load. Tandheelkundige Tijdingen 1996; 227-231.

  • 1995

Bollen CML. Etiologie, microbiële detectie en behandeling van parodontale infecties. Tandartsenkrant 1995; 5: 6-10.

  • 1994

Quirynen M, Bollen CML, Papaioannou W. “Chairside” microbiologische testen in de parodontologie. Belg Tijdschrift Tandheelkunde 1994; 49: 26-43.

Bollen CML, Quirynen M. Plaque staalname in de microbiologie. Belg Tijdschrift Tandheelkunde 1994; 2: 44-51.

Books or Chapters in Books

  • 2021

Bollen C, Dargel I. Einzelzahnversorgung mit Keramikimplantat nach Trauma. In: Isbaner G. Jahrbuch Implantologie ’21. Oemus Media 2021: pp. 102-106. [German].

  • 2009

Vandekerckhove B, Bollen C. Epidemiologie bij de algemene bevolking, bijzondere bevolkingsgroepen en bij een multidisciplinair halitosespreekuur. In: van Steenberghe D (ed): Ademgeur. Prelum uitgevers, Houten 2009; pp. 3-10.

  • 1998

Bollen CML, Papaioannou W, Quirynen M. The contribution of intra-oral translocation of pathogenic organisms in dental plaque formation. In Busscher HJ, Evens LV (eds): Oral biofilms and plaque control. Harwood academic publishers, Amsterdam 1998; pp. 233- 243.

  • 1997

Bollen CML, Papaioannou W, Quirynen M. The influence of the surface roughness of intra-oral hard substrata on the early subgingival colonisation by anaerobic bacteria. Short term microbiological observations. In: Eley AR, Bennett K (eds): Anaerobic pathogens. Sheffield academic press, Sheffield 1997; pp. 309-317.

Quirynen M, Bollen CML, Vandekerckhove BNA, Papaioannou W, Eyssen H. The effect of a fullmouth disinfection on the periodontopathic anaerobic population in the oral cavity. A pilot study. In: Eley AR, Bennett K (eds): Anaerobic pathogens. Sheffield academic press, Sheffield 1997; pp. 281-291.

  • 1996

Vandekerckhove B, Bollen C. Tandpasta ’s en mondspoelmiddelen. Universitaire pers Leuven, Leuven 1996.

Bollen CML. Full-mouth disinfection and hard surface smoothening reduce the subgingival microbial load. Universitaire pers Leuven, Leuven 1996.

  • 1995

Quirynen M, Bollen CML, Eyssen H, van Steenberghe D. Microbiological aspects of the passive fit at the implant/abutment junction. In Naert IE (ed): Passive fit of implant supported superstructures. Fiction or reality? Leuven university press, Leuven 1995; pp. 87- 97.

  • 1994

Quirynen M, Papaioannou W, Bollen CML, van Steenberghe D. Major impact factors on the composition of the microflora around osseointegrated implants. In vivo and in vitro experiments. Proceedings 1st world congress of osseointegration. Venice 29/09/1994 – 02/10/1994; pp. 133-142.