The International Journal of Prosthodontics, Pre-Print
DOI: 10.11607/ijp.8719, PubMed ID (PMID): 38408133February 26, 2024,Pages 1-20, Language: EnglishLorenz, Jonas / Blume, Maximilian / Schwarz, Frank / Weigl, Paul / Ghanaati, Shahram / Sader, Rober A.Purpose: Several procedures are performed to achieve optimal esthetic results in single-tooth
implants. However, there is discordance regarding the potential benefit and risks of immediate
implant loading/provisionalization. The aim of this prospective case series is to investigate
the effect of immediate provisionalization of single-tooth implants at healed sites for periimplant
soft-tissue conditions, focusing on papilla formation around single implants.
Materials and Methods: Twelve patients received a total of 12 implants in the incisor, canine
or premolar region of the upper and lower jaw at healed sites with immediate chair-side
provisionalization. Four months later, the temporary crown was replaced by the permanent
crown. After 40±13.1 months, clinical follow-up was conducted, assessing Probing pocket
depth (PPD); Bleeding on Probing(BoP); Mucosal recession (MR) and Width of Keratinized
Mucosa (KM). Papilla index (PI) was determined immediately after implant placement
(baseline), before removing the temporary crown (t1), 4 weeks after insertion of the definitive
crown (t2) and at the final follow-up examination (t3) to evaluate papilla formation and its
change over time. Results: None of the implants were lost. The mean PPD was 2.5±0.39 mm,
BoP of 25% and 3.5 mm of KM were observed at the final follow-up. No implants showed
MR. PI increased in all patients from 1.5±0.45 at baseline to 2.4±0.56 at t1, 2.6±0.47 at t2 and
3.02.6±0 at t3. The increase in PI between t0 and each individual timepoint from t1-t3 showed
statistical significance. Conclusion: The present results indicate the suitability and benefit of
immediate provisionalization to achieve favorable peri-implant soft-tissue conditions and
papilla formation.
Implantologie, 1/2024
Pages 33-48, Language: GermanLorenz, Jonas / Mitschikjan, Aram / Bornmann, Toni / Gerovac, Dragana / Weigl, Paul / Sader, RobertNotwendigkeit von Modifikationen des Behandlungsplans, technische Komplikationen sowie Hart- und WeichgewebeparameterDie Sofortversorgung im zahnlosen Kiefer bietet dank beschleunigter Behandlung und reduzierter Behandlungstermine viele Vorteile im Vergleich zur konventionellen Versorgung. Das Ziel der in diesem Beitrag vorgestellten klinischen Studie war die Untersuchung eines neuartigen Implantatsystems mit progressivem Gewindedesign für die Sofortversorgung des zahnlosen Kiefers auf vier Implantaten. Dabei wurden die Notwendigkeit von Modifikationen des Behandlungsplans, technische Komplikationen im Rahmen der Implantation und Sofortversorgung sowie Hart- und Weichgewebeparameter nach einjähriger Belastung dokumentiert. In die Studie eingeschlossen waren insgesamt zehn Studienteilnehmer, bei denen die Insertion von 40 Implantaten und deren sofortige provisorische Versorgung erfolgten. Während der provisorischen Phase kam es in einem Fall zu einem Verlust der provisorischen Versorgung einschließlich der vier Implantate. Zudem ging ein weiteres Implantat verloren. Die Guided-Surgery-Planungen bedurften keiner Modifikationen. Im Gegensatz dazu waren bei den Implantatinsertionen und den provisorischen Versorgungen Anpassungen erforderlich. Intraoperativ waren in den meisten Fällen kleinere Variationen des Behandlungsplans nötig, bis hin zur freihändigen Insertion von zwei Implantaten. Die klinischen und radiologischen Ergebnisse der Abschlussuntersuchung nach definitiver prothetischer Versorgung und einer mittleren Belastungsdauer von 16 Monaten (10−24 Monate) sprechen für gesunde periimplantäre Verhältnisse und eine hohe Patientenakzeptanz.
Keywords: Sofortversorgung, zahnloser Kiefer, Guided Surgery, Implantaterfolg
International Journal of Oral Implantology, 4/2022
PubMed ID (PMID): 36377624Pages 327-338, Language: EnglishLorenz, Jonas / Parvini, Puria / Obreja, Karina / Trimpou, Georgia / Linder, Susy / Hölscher, Werner / Dard, Michel / Schwarz, Frank / Sader, RobertPurpose: To assess the clinical performance of a two-piece zirconia implant system (PURE Ceramic Implants, Straumann, Basel, Switzerland) in the maxilla after a follow-up period of more than 1 year.
Materials and methods: A total of 19 patients in three centres received 24 single-tooth implants in the maxilla. The implants were restored after a mean healing period of 7.1 ± 0.4 months (range 7 to 9 months). Implant survival, implant success, Plaque Index, probing pocket depth, bleeding on probing, mucosal recession/creeping attachment, width of keratinised mucosa, papilla index and pink aesthetic score were evaluated after prosthetic loading (T0), after 6 months (T1) and at the final follow-up (T2, mean 15.0 ± 2.1 months, range 12 to 19 months).
Results: All implants survived and were suitable for retaining prostheses. Low values were recorded for Plaque Index (0.38 ± 0.68) and probing pocket depth (2.49 ± 0.49 mm). Bleeding on probing increased significantly from T0 (21.7%) to T1 (50.0%) (P = 0.0342) and then remained stable (50.0% at T2). No recession was detected around any of the implants. A statistically significant increase in attachment level was observed from T0 to T2 (0.79 ± 0.88 mm; P = 0.0196). A papilla index of 2.27 ± 0.81 and pink aesthetic score of 11.67 ± 1.60 at T2 indicated a completely satisfying aesthetic result.
Conclusion: Within the limitations of the present study, the two-piece zirconia implant system investigated achieved fully satisfying functional and aesthetic results.
Keywords: ceramic implant, maxilla, multicentre study, two-piece ceramic implant, zirconia implant
Conflict-of-interest statement: Drs Linder and Dard are employees of Straumann Group (Basel, Switzerland). The other authors report no conflicts of interest relating to this study.
Implantologie, 4/2021
Pages 371-385, Language: GermanLorenz, Jonas / Schröder, Rita / Al-Maawi, Sarah / Tanneberger, Anna / Sader, Robert / Ghanaati, ShahramErgebnisse einer prospektiven randomisierten Studie mit zweijährigem Nachbeobachtungszeitraum Die „Alveolar Ridge Preservation“ (ARP) ist ein Verfahren, um die Resorptionsvorgänge und den damit einhergehenden Volumenverlust des Alveolarknochens nach Zahnextraktion zu minimieren. Ziel der durchgeführten Studie war es, den Einfluss des Augmentationsmaterials bei ARP auf den Implantaterfolg zu untersuchen. In der vorliegenden prospektiven randomisierten Studie erhielten 8 Patienten (3 Frauen, 5 Männer, 39–74 Jahre [Durschnitt: 57 Jahre]) eine ARP mit den Knochenersatzmaterialien Symbios Biphasic BGM (Fa. Algoss Biotechnologies, Wien, Österreich) und Frios Algipore (Fa. Dentsply Sirona, Bensheim, Deutschland) nach Extraktion von 25 Zähnen. Nach einer Belastung von 27 ± 7,55 Monaten wurden das Überleben der Implantate, die Notwendigkeit einer Augmentation, die Sondierungstiefen (ST), die Blutung auf Sondieren (BoP), das Vorhandensein einer Rezession (REZ), die Breite keratinisierter Mukosa (KM), die Ausprägung der Papille („Papilla fill Index“, PI) und das periimplantäre Knochenniveau untersucht. Alle 25 Implantate waren prothetisch nutzbar und es war keine Augmentation erforderlich. Die klinische Untersuchung ergab eine ST von 2,55 ± 0,53 mm (2–4 mm), BoP an 6 Implantaten (24 %), 10 Implantate (40 %) mit einer REZ (1–2 mm), 2,08 ± 0.81 mm (1–3 mm) KM und einen PI von 2,11 ± 0,92 (1–3). Der Unterschied von ST, BoP, REZ, KM und PI zeigte keine statistische Signifikanz. Im Mittel zeigte sich ein Knochenverlust von 0,5 mm mit einem Maximalwert von 2,2 mm. Die erhobenen Parameter und deren statistische Auswertung zeigen keine signifikanten Unterschiede zwischen den Implantaten der beiden Gruppen. Beide Knochenersatzmaterialien scheinen in der Lage, bei ARP ein suffizientes Lager für eine stabile Implantatversorgung zu schaffen.
Manuskripteingang: 17.06.2021, Annahme: 26.07.2021
Keywords: „Socket Preservation“, Alveolenerhalt, Knochenersatzmaterial, Implantaterfolg, randomisierte kontrollierte Studie
The International Journal of Oral & Maxillofacial Implants, 3/2018
DOI: 10.11607/jomi.6026, PubMed ID (PMID): 29543928Pages 636-644, Language: EnglishLorenz, Jonas / Barbeck, Mike / Kirkpatrick, Charles James / Sader, Robert / Lerner, Henriette / Ghanaati, ShahramPurpose: In this prospective study, the regenerative potential and pathways of a new injectable bone substitute (IBS) material composed of beta-tricalcium phosphate (β-TCP) and hyaluronan were investigated for its application in alveolar bone regeneration within extraction sockets.
Materials and Methods: The bone substitute material was implanted in 44 extraction sockets after removal of teeth not worth preserving in the maxillary and mandibular arches of 21 patients. Four months after augmentation, bone biopsy samples were harvested simultaneously with implant placement for histologic and histomorphometric analysis of tissue reaction and determination of tissue formation (newly formed bone, connective tissue, and remaining IBS) within the augmentation bed. Furthermore, the inserted bone-level implants (C-Tech Esthetic Line) were followed up clinically and radiologically for at least 1 year after prosthetic loading to determine the potential impact of tissue reaction to the IBS on implant stability and performance.
Results: The histologic and histomorphometric analyses revealed a gentle tissue reaction with mainly mononuclear and only few multinucleated giant cells within the implantation bed. Histomorphometric analysis revealed mainly newly formed bone tissue (44.92% ± 5.16%) and connective tissue (52.49% ± 6.43%). Only a few remnants of the IBS (2.59% ± 2.05%) could be found. The IBS, with its easy application and fluidity, seemed to be suitable for three-dimensional stable defects such as the intact extraction socket.
Conclusion: The IBS contributed to an osteoconductive tissue reaction while undergoing a time-controlled degradation. Clinical and radiological follow-up investigation of the implants inserted in the regenerated area revealed that the IBS contributed to a long-term stable implantation bed for dental implants. The appearance of the IBS can be described as a bulk that is formed within the augmentation bed and that promotes new bone formation through an osteoconductive procedure.
Keywords: β-TCP, C-Tech Implants, injectable bone substitute material, socket preservation, tissue engineering
International Poster Journal of Dentistry and Oral Medicine, 5/2016
SupplementPoster 1027, Language: EnglishHoefer, Sebastian Herbert / Lorenz, Jonas / Teiler, Anna / Ghanaati, Shahram / Sader, RobertBackground:
Ewing sarcomas are among the most frequent malignant bone tumors among children and young adults. Extraskeletal Ewing sarcomas are a rarity, even more so within the Head&Neck-Region.. Worldwide there are only a handful of cases published.
Methods:
A 20 years old male patient was presented to our clinic by a colleague in private practice. He had removed a pea-sized pediculated tumor from the anterior base of the mouth which he considered to be a granuloma. The histopathological analysis unveiled a Ewing sarcoma which was validated by two further reference labs.
We proceded to perform an exended excision around the basis of the former tumor pedicule. Within the specimen no remains of the sarcoma could be found. The consecutive radiological diagnostics - MRI & 18F FDG-PET/CT - did not reveal any remaining tumor as well as no suspicious structures for metastasic disease. The interdisciplinary tumor conference agreed upon an adjuvant radio-chemotherapy. This recommendation, however, was rejected by the patient. For this reason consecutive clinical and radiological (MRI and PET/CT) follow-ups were arranged with the patient on a short-time interval basis. For 60 months the patient has been involved in follow-up surveillance. Up tll now there has been no sign of relapse or metastasis.
Conclusion:
For the treatment of Ewing sarcomas within children and young adults an established S1-Guideline (AWMF) exists that aim primarily at the treatment of skeletal manifestations. For the treatment of Ewing sarcomas of soft tissue, especially within the Head&Neck-region, the guideline presents us with a challenge regarding borders of resection. Despite being a very rare disease specific therapy guidelines should be available also fort he Head&Neck-region.
Keywords: Extra-skeletal ewing sarcoma, intra oral sarcoma, sarcoma treatment
The International Journal of Oral & Maxillofacial Implants, 4/2016
DOI: 10.11607/jomi.4511, PubMed ID (PMID): 27447153Pages 855-864, Language: EnglishHolländer, Jens / Lorenz, Jonas / Stübinger, Stefan / Hölscher, Werner / Heidemann, Detlef / Ghanaati, Shahram / Sader, RobertPurpose: In recent years, dental implants made from zirconia have been further developed and are considered a reliable treatment method for replacing missing teeth. The aim of this study was to analyze dental implants made from zirconia regarding their clinical performance compared with natural teeth (control).
Materials and Methods: One hundred six zirconia implants in 38 adults were analyzed in a clinical study after 1 year of loading. The plaque index (PI), bleeding on probing (BOP), probing pocket depth (PPD), probing attachment level (PAL), and creeping or recession (CR/REC) of the gingiva were detected and compared with natural control teeth (CT). Furthermore, the papilla index (PAP), Periotest values (PTV), microbial colonization of the implant/dental sulcus fluid, and patient satisfaction were assessed.
Results: The survival rate was 100%. No statistical significance was observed between implants and teeth regarding BOP, PPD, and PAL. A statistical significance was detected regarding PI and CR/REC with significantly less plaque accumulation and recession in the study group. Mean PAP was 1.76 ± 0.55, whereas the mean PTV was -1.31 ± 2.24 (range from -5 to +6). A non-statistically significant higher colonization of periodontitis/peri-implantitis bacteria was observed in the implant group. The questionnaire showed that the majority of the patients were satisfied with the overall treatment.
Conclusion: One-piece zirconia dental implants exhibited similar clinical results (BOP, PPD, and PAL) compared with natural teeth in regard to adhesion of plaque (PI) and creeping attachment (CR/REC); zirconia implants performed even better. The favorable results for PA and CR/REC reflect the comparable low affinity of zirconia for plaque adhesion. Patient satisfaction indicated a high level of acceptance for zirconia implants. However, a long-term follow-up is needed to support these findings.
Keywords: clinical study, microbial contamination, patient satisfaction, zirconia, zirconia dental implants
International Poster Journal of Dentistry and Oral Medicine, 5/2015
SupplementPoster 888, Language: German, EnglishGhanaati, Shahram / Lorenz, Jonas Michael / Teiler, Anna / Sader, Robert / Landes, ConstantinBackground: Rheumatoid Arthritis (RA) is the most common inflammatory disease of the joints, affecting various joints. It is observed predominantly in women in the age of 35 and 45 years. Therapy consists of various medications, ranging from anti-inflammatory drugs to immunsuppressant agents and surgical therapy.
Materials and Methods: The presented poster reports the case of a 66 year old female patient with RA and permanent immunosuppressive therapy by Retuximab and Denosumab. Due to increased craniomandibular dysorders the patient has been treated with a condylar prosthesis of the right temporomandibular joint and dental implants in the upper molar region.
Results: The reported patient presented with longlasting suffering from head- and neck- pain of unclear origin. After clinical and radiological examination a severe craniomanibular dysfunction with arthritis of the temporomandibular joint as a consequence of RA could be diagnosed. In 2008 arthroscopy, followed by arthroplasty with an interponate of the fascia of the musculus temporalis was performed. Due to recurring pain and mouth opening restriction removal of the condyle and implantation of a condyle prothesis was performed in 2014. Simultaneously insertion of dental implants placed in the upper molar region (regio 24 and 26) was performed by internal sinus floor elevation.
Discussion: In case of a severe RA significant improvement of craniomandibular disorders could be achieved by arthroscopy, arthroplasty and implantation of a condylar prosthesis. Thereby improvement of mouth opening could be achieved. Further, simultaneous insertion of dental implants in the upper molar region was performed to competely restore oral function. The presented implantologic treatment presents under specific, complicating circumstances such as RA and immunosuppressive medication a limiting case of implant rehabilitation.
Keywords: Rheumatoid Arthritis, Condylar Prothesis, Dental Implantat, Craniomandibular Dysfunction
International Poster Journal of Dentistry and Oral Medicine, 3/2015
Poster 907, Language: German, EnglishLorenz, Jonas Michael / Schlee, Markus / Lerner, Henriette / Barbeck, Mike / Sader, Robert / Ghanaati, ShahramIntroduction: The presented poster reports the analysis of a b-TCP-based paste-like bone substitute material for socket preservation and sinus augmentation procedures. Preliminary histological and histomorphometrical results from a multi-centre study are presented.
Materials and Methods: Sockets of teeth not worth preserving were augmented according to a standardised study protocol with a b-TCP-based paste-like bone substitute material (Cerasorb Paste, Curasan, Kleinostheim, Germany) and covered with a xenogenic collagen membrane. Further, in cases of reduced dentition and atrophy of the alveolar crest in the upper molar region, sinus floor augmentation was performed to enlarge the amount of local bone previous to insertion of dental implants. After an integration period of three months, implants were inserted in the augmented region simultaneously with bone biopsy extraction for histological and histomorphometrical analysis. Additionally, the inserted implants were investigated with a focus on implant stability and achieved red-white aesthetics.
Results: The bone substitute material investigated showed favourable handling and easy application in the sockets of extracted teeth and sinus cavities. A complete and marginal filling of both sockets and sinus cavities could be achieved due to the adhesion and "flow-ability" of the material. Histologic and histomorphometrical results from a preclinical in vivo study in rats showed a biphasic arrangement of the bone substitute material with an inner core and an outer ring, which prevents early ingrowth of connective tissue in the implantation bed. Further, outspreading vessels and no signs of a foreign body reaction to the bone substitute material were obvious.
Conclusion: Preliminary clinically results from a multi-centre study investigation of a paste-like b-TCP-based bone substitute material for socket preservation and sinus augmentation showed favourable handling and suitability for augmentation procedures. Further, histological and histomorphometrical in vivo analysis showed good integration of the bone substitute material in the peri-implant tissue, a high rate of vascularisation and no signs of a foreign body reaction.
Keywords: b-TCP, bone substitute material, socket preservation, sinus floor augmentation, foreign body reaction
International Poster Journal of Dentistry and Oral Medicine, 3/2015
Poster 908, Language: German, EnglishLorenz, Jonas Michael / Barbeck, Mike / Schlee, Markus / Lerner, Henriette / Sader, Robert / Ghanaati, Shahramin vivo analysis of tissue reactionIntroduction: The aim of the presented research was to analyse and compare the tissue reaction to different xenogeneic bone substitute materials (Bio-Oss®, BO and BEGO Oss®, BGO) of different processing techniques and material-specific characteristics in vivo.
Materials and Methods: Two bone substitute materials were implanted subcutaneously in CD-1 mice for up to 60 days. Tissue formation, implant bed vascularisation and the formation of multinucleated giant cells were investigated histologically and histomorphometrically.
Results: Both bone substitute materials showed good integration within the peri-implant tissue and no signs of adverse effects. Both groups presented an increasing vascularisation over the whole study period. Within the implantation bed of the bone substitute of low sintering temperature (BO), few multinucleated giant were obvious on the surface of small sized bone substitute granules in the early integration period, while the tissue reaction to the bigger granules at later stages consisted mainly of mononuclear cells. In contrast, the tissue reaction to the bone substitute material of high sintering temperature (BGO) consisted of a biomaterial surface associated multinucleated giant cells.
Discussion: The tissue reactions to the low and high sintering temperature bone substitute materials investigated showed distinct differences, mainly in the formation and migration of multinucleated giant cells. As both biomaterials have the same origin, the observed differences seem to be related to the different processing techniques and the resulting different physico-chemical structures.
Keywords: bone substitute materials, xenogenic, foreign body cell reaction, multinucleated giant cells