Allt sedan implantologins intåg har konventionellt framställda, dvs. gjutna underkonstruktioner betraktats som det främsta alternativet vid brokonstruktioner för tandersättningar. Den digitala processteknologins utveckling har introducerat CAD/CAM som ett alternativ med kapacitet att minimera risken för operatörsberoende avvikelser och ge bättre möjlighet till en konstruktion med mer homogen struktur och goda mekaniska egenskaper. CAD/CAM- framställda konstruktioner med flera led, kan dock variera utifrån material, anslutning på distans- eller implantatnivå samt passform mellan konstruktion och distans eller implantat. Emellertid kan de nya materialen som introduceras bidra med andra tekniska och biologiska komplikationer som kan uppstå med tiden.
Övergripande mål med föreliggande avhandlingsarbete var att bidra till förståelse avseende risker för komplikationer med skruvretinerade CAD/CAM-framställda brokonstruktioner.
I Delarbete I (in vitro-studie) utvärderades effekten av bristande passform med skruvretinerad konstruktion på implantatnivå via uppkomst av sprickor i implantat med olika benstöd. I Delarbete II rehabiliterades delvis tandlösa patienter med en skruvretinerad metallkeramisk konstruktion i koboltkrom antingen på distans- eller implantatnivå. I Delarbete III behandlades tandlösa patienter i överkäken med antingen fyra eller sex implantat och skruvretinerad titan-akrylkonstruktion. I Delarbete IV behandlades tandlösa
patienter med avtagbara täckproteser retinerade till implantatstödda titanbarer. I delarbete III och IV utvärderades även oral hälsorelaterad livskvalitet.
Kliniskt var förändringen av den marginala bennivån inte signifikant oavsett anslutningsförfarande (Delarbete II), retention (Delarbete III-IV) och materialval (Delarbete II, III och IV). Inga komplikationer registrerades på underkonstruktionerna ochen hög patienttillfredsställelse uppgavs efter behandling (Delarbete III, IV). Baserat på de studier som ingår i avhandlingen kan följande slutsatser dras: (i) risken för implantatsprickor i skruvretinerad fast protetik på implantatnivå är låg, även vid fall med en sämre passform, (ii) enligt 1-års-uppföljningen i Delarbete II, rekommenderas att skruvretinera på distansnivå för fastsittande implantatprotetik, (iii) det kostnadseffektiva alternativet med fyra implantat för en fastsittande fullbrokonstruktion i överkäken kan betraktas som ett säkert och likvärdigt alternativ till behandling med sex implantat, (iv) implantatstödda fullbrokonstruktioner och implantatretinerade täckproteser är förenade med hög patienttillfredsställelse, relaterat till estetik och tuggfunktion, främst till följd av protesernas goda stabilitet, (v) få tekniska och biologiska komplikationer observerades för implantatprotetik i form av sektionsbroar, fullbroar och täckproteser. Trots allt rapporterades en betydande andel ytfrakturer för fullbroar i överkäken vid 1- och 3-årsuppföljningen. Tandvårdspersonal behöver vara medvetna om att uppföljande besök kan krävas för underhåll av protetiska konstruktioner.
ACKNOWLEDGEMENTS
This doctoral thesis would not have come to be without the contribution of many people during the seven years of study. In particular, I would like to express my deepest gratitude to the following individuals:
Associate Professor Jonas Peter Becktor, my main supervisor. I thank you for the constant support of my work, for the motivation, the knowledge you shared with me and for sustaining me in many aspects. I truly value your constant availability and great generosity. We have been working together throughout all these years and you encouraged me to be professional and do the right thing even when the road got tough. I am looking forward to a continuing collaboration in the future.
Professor Ann Wennerberg, my co-supervisor. Thank you for your invaluable advice, steady guidance and support particularly during challenging moments. You have motivated and encouraged me many times. I consider myself blessed for the chance I have had, to work with you and to learn from your expertise and passion.
Dr. Denis Cecchinato. Thanks for your guidance and for giving me the chance to start this adventure. Thank you for sharing your research, clinical knowledge and expertise with me. I have learnt an immense amount from you. I really admire your energy, endurance and your ability to never give up.
Dr. Ryo Jimbo, my co-supervisor. Thanks for helping me during the initial steps my academic journey. People take different paths and I wish you all the best for your future life.
Professor Tomas Albrektsson. Thanks for your constant availability, invaluable lessons and the valuable advice during the research project. Dr. Anders Halldin. Thanks for your friendship, for sharing your deep knowledge about FEA analysis and for helping me many times. The meetings with you were based on spontaneous scientific debate and I have to express my regret to not having the chance to meet you lately with the same frequency as before.
Professor Jan Lindhe. Thanks for your friendship and precious advice both in the field of science and daily life. From you I have learnt the high value of analysis and synthesis. I look forward to meet you and your dear wife Annalena soon again.
Dr. Michele Stocchero. Thanks for the constant support and your strong encouragement to do my best. You took care of me in many aspects with invaluable assistance. I appreciate your great talent and deepest scientific capability. Our “state of flow” is doing research and we have spent outstanding and unrepeatable moments working together and having fun at the same time. I have learned from you to be patient, calm and wait, wait, wait. I wish we can keep on with this pace in a scientific collaboration and true friendship.
Dr. Silvia Galli. Being a wonderful lady, wife, mother, dentist and, most of all, a superb scientist at the same time is a difficult task. Only geniuses can succeed that. Thanks for your endless support. I wish all the best for you, for your sweet kids Filippo and Federico, and for the amazing Stefano (The “Bura”).
Dr. Yohei Jinno. We spent time together working and having fun. I have learned from you the rigor of methodology and I appreciate your absolute dedication to work. I admire how much energy you have. I wish to have a continue collaboration even if you are in Japan. Good luck my dear friend, you will be Professor for sure. Arigatou
Dr. Bruno Chrcanovic. Thanks for the time you dedicated to me and for your help. You were always ready to reply immediately to any of my requests. I really admire your immense knowledge in the scientific world and I am very honoured to have had the chance to collaborate with you.
Senior Lecture Evaggelia (Lisa) Papia. We have spent time doing research and having fun and I have to express my gratitude for your sincere friendship. You have a superb gift of helping others anytime and I am grateful for your valuable comments and for always giving me the right suggestions.
Special thanks to Dentsply-Sirona who partially supported the 4 studies included in this thesis (IIS-D-2012-031 - IIS D-2012-051 - IIS-D-2013-021 - IIS-D-2014-083).
In particular I have to express my gratitude to Dr. Stig Hansson and Dr. Carin Hostner, who have always replied to my requests, forms, questions and for their contribution in this project.
The Covid-19 pandemic has changed our life and even my dissertation and final preparation has been affected.
I want to express my regret not to be able to organise a party for all the people with whom I have shared these 7 years and who helped me in many ways.
In particular I would like to express my deepest gratitude to