Poster 2425, Sprache: Englisch
Objectives: The usage of CAD/CAM-manufactured single implant restorations is a common method in prosthetic dentistry. Several benefits lead to an adhesive connection of individualized ceramic crowns and prefabricated titanium bonding bases. However, the bonding has to resist permanent thermal, chemical and mechanical stress in the oral cavity. The durability of the bonding is a weak point and especially dependent on sufficient surface pretreatment. Cold atmospheric pressure plasma (CAP) is a conventional method for improving surface characteristics in car industry and space engineering. The aim of this study was to evaluate the impact of CAP on shear bond strength in two-piece abutments.
Methods: Two different pretreatment protocols were tested in this study. Ten CAD/CAM-manufactured and sintered crowns of zirconia and ten prefabricated titanium bonding bases were divided into 2 groups (n=5): (A) as specified by the manufacturer (sandblasting (Al2O3, 50μm, 1bar) + adhesive primer (Ceramic Bond, VOCO GmbH, Cuxhaven, Germany)), (B) sandblasting + CAP + adhesive primer. Optimal pretreatment with CAP (piezobrush PZ2, relyon plasma GmbH, Regensburg, Germany) was evaluated in pretrial studies by analyzing water contact angles on polished surfaces after different duration of exposure. The wetting properties suggested a minimal CAP application time of 15 seconds. After pretreating the interfaces, the pieces were glued together under standardized pressure by using Bifix Hybrid-Abutment-Cement by VOCO. The specimens were thermocycled for artificial aging and then shear bond strength (SBS) was measured.
Results: The SBS in two-piece abutments pretreated with CAP was higher than in those without. Mean values differed significantly (Mann-Whitney-Test, p=0.008) from 601.6±86.3N (Group A) to 755.0±37.2N (Group B).
Conclusions: The study showed that additional usage of CAP for surface pretreatment in two-piece abutments leads to a significant increase of shear bond strength by about 25%. Thus, CAP can be recommended as a pretreatment procedure in this special field of indication. Further investigations by using different ceramic materials and luting cements are intended.
Schlagwörter: Two-piece-abutments, shear-bond-strength, pretreatment, cold atmospheric-pressure-plasma, adhesives, zirconia, titanium
Poster 2430, Sprache: Englisch
Background: Asthma is a serious global health problem that has steadily increased in prevalence during the last two decades. It is one of the most common chronic medical conditions affecting children's oral health-related quality of life.
Objective of the study: To assess and compare the dental caries experience and salivary S.mutans level among asthmatic and non-asthmatic children of Davanagere City, India.
Methodology: A cross-sectional comparative study was conducted on 5 to 12-year-old children. Forty asthmatic and 62 healthy children were recruited as study and healthy subjects. Selection criteria: a) children with a diagnosis of asthma as diagnosed by lung function test, who were currently on asthmatic medication b) non-asthmatic status of healthy children was ascertained by asking relevant questions to parents and children which can elicit any symptoms of asthma. Study and healthy subjects were matched for age, gender socioeconomic status, diet, and oral hygiene practices. Dental caries experience for permanent and mixed dentition was assessed by Decayed, Missing, Filled Teeth (DMFT) and decayed, exfoliated, filled (def) index, respectively. Stimulated saliva was collected for S.mutans analysis.
Results: The dental caries experience was found to be high among asthmatic children when compared to healthy children (mean DMFT/def score =3.05 vs 1.92). A high prevalence of dental caries (mean DMFT/def score = 5.27) was seen among asthmatic children who were under beta 2 agonists and had asthma for >4 years. A mean salivary S.mutans colony count (mean colony forming count = 94.1 vs 57.0) was greater among asthmatic children.
Conclusion: The severity of asthma and prolonged duration of asthmatic medication were the contributing factors for dental caries experience among asthmatic children.
Schlagwörter: Dental caries, asthma, beta 2 agonists, S.mutans
Poster 2431, Sprache: Englisch
Oral health is a matter of public health concern, as it affects a large proportion of the population and is linked with overall health status. With the demographic transition, there is a shift in disease profile, unequal distribution of dental professionals, and no existing oral health care system targeting the elders. It possess a challenge for the health authorities to overcome the financial burden for individuals and society. Given the ageing of the population, there is an immediate necessity to develop an oral health care system tailored to provide appropriate care for an ageing population.
The time to plan and act is now
The need of the hour is to develop a potentially effective community-based theoretical model i.e Quality care Age friendly Technologically enabled Interconnected and Competent (QuATIC) – system for elderly, so as to enhance oral health of the elderly and improve their quality of life. In this multilevel model, the upstream level includes policy making, a common risk factor approach, the implementation of geriatric subjects in the dental curriculum, and goal settings for oral health programs. The second level focuses on the methods to tackle social determinants of oral health through life course approach. The third level emphasizes primary care by bringing the competent oral health care system close to the elders. The fourth level pays attention to strengthening community and to provide on-site dental services to reduce transportation barriers. The last level concentrates on individual factors which can influence the utilization of dental services by the elderly. The factors in all these levels should be evidence-based, focusing on effective, efficient, equitable, and holistic care.
All the levels should be interconnected to each other so as to create a sustainable oral health care system. Such combined forces can move a mountain, thereby enhancing the quality of life of elders.
Schlagwörter: Oral care utilization, elderly, geriatric dentistry, dental policy, India
Poster 2437, Sprache: Englisch, Deutsch
Fallbericht: Ein 26-jähriger Patient mit unauffälliger Anamnese stellte sich im Universitätsklinikum Münster mit anhaltenden Beschwerden nach einer alio loco Abszessinzision in Regio 47 vor. Im Orthopantomogramm zeigte sich eine scharf begrenzte, gleichmäßige Radioluzenz in Regio 46-48, die den Verdacht auf eine Zyste aufkommen ließ. Es wurde eine Zystektomie und die chirurgische Entfernung von Zahn 48 durchgeführt. Der pathohistologische Befund ergab das Vorliegen einer odontogenen Keratozyste. Nach 10 Monaten trat ein Lokalrezidiv auf, das durch eine erneute Zystektomie behandelt wurde. Nach 4 Monaten trat erneut eine Fistel auf und die CT-Aufnahme zeigte eine erneute Osteolyse im rechten Unterkiefer. Es folgte eine Teilresektion des Unterkiefers mit Rekonstruktion durch Beckenkamm. Nach 9 Monaten wurde das Metall entfernt und nach weiteren 11 Monaten ohne Rezidiv wurden 2 Implantate eingesetzt. 3 Monate später wurden 2 Kronen eingesetzt.
Diskussion: Nach der aktuellen WHO-Klassifikation von Kopf- und Halstumoren gehört die odontogene Keratozyste zur Gruppe der entwicklungsbedingten odontogenen Zysten. Sie ist die dritthäufigste Kieferzyste und tritt vor allem im Bereich der unteren Weisheitszähne auf. Die Altersverteilung zeigt einen Häufigkeitsgipfel im Alter zwischen 20 und 30 Jahren. Männer sind häufiger betroffen. Die Symptome treten oft erst in Folge einer Sekundärinfektion auf. Die Behandlung der Wahl ist die Zystektomie. Hier liegt die Rezidivrate bei 25 %. Bei einer chirurgischen Resektion beträgt sie weniger als 2 %. Es ist unklar, ob und wann eine implantologische Behandlung nach einer Zystenbehandlung durchgeführt werden kann. Eine funktionelle Rehabilitation ist jedoch ohne Implantate nicht möglich. Die Verwendung von autologem Knochen bleibt der Goldstandard. Sicher ist, dass die Integration des Knochentransplantats abgewartet werden muss. Eine regelmäßige radiologische und klinische Nachkontrolle ist obligat.
Schlussfolgerung: In diesem Fall war es durch die Beckenkammaugmentation und die anschließende Implantatinsertion möglich, zwei festsitzende implantatgetragene Kronen einzusetzen. Aufgrund des Rezidivrisikos sind eine sorgfältige Patientenaufklärung und eine regelmäßige Nachsorge erforderlich. Ein universelles Therapiekonzept kann bei odontogenen Keratozysten nicht propagiert werden.
Schlagwörter: Keratozyste, Implantat, Beckenkammaugmentation
Poster 2439, Sprache: Englisch
Background: In response to the global COVID-19 pandemic, governmental measures have been undertaken. The impact of the crisis on the healthcare of patients with cancer is largely unexplored. This multicenter cohort study aimed to investigate a potential screening delay and its consequences in patients with oral cancer (OC) during the pandemic.
Material and Methods: Data of patients who were first diagnosed with OC during different periods were collected, especially in terms of OC incidence, tumor stage/entity, and time to intervention. The lockdown (LD) (13 March–16 June 2020) and post-lockdown (PLD) (17 June–1 November 2020) periods and the corresponding equivalents in 2018/19 were differentiated and compared.
Results: There was no obvious trend towards a higher incidence of OC or higher tumor stages, whereas a trend towards a shorter time to intervention during the LD2020 could be observed. Subgroup analyses revealed an increased incidence in OC within the PLD2020 in Mainz, which might be explained by the partial closure of dental practices in this federal state during LD.
Conclusions: While there was no overall higher incidence of OC, we found closure of practices during LD possibly delay cancer diagnosis. Therefore, measures must be taken to identify patients at risk and to ensure basic healthcare, especially in the context of dental screening measures.
Schlagwörter: COVID-19, SARS-CoV-2, oral cancer, oral malignant lesions, screening; precursor lesions, lockdown, pandemic, head and neck cancer, HNSCC
Poster 2440, Sprache: Englisch
Questions: Orofacial clefts (CLP) are among the most common congenital malformations of the orofacial system with a prevalence of approximately 1:500 live births, and are often associated with malocclusions and abnormalities in tooth formation, eruption, position and tooth number2. The nature and frequency of malposition are of great interest with regard to orthodontic treatment planning and rehabilitation of these patients. Therefore, the aim of the present study was a retrospective analysis and three-dimensional evaluation of the nature and frequency of occlusal and den-tal malposition and their association with the cleft type.
Methods: A total of n = 58 cleft patients, born in between 1982-2010, which had been treated in the Department of Orthodontics, Medical Faculty Carl Gustav Carus, TU Dresden, were systematically evaluated. Thirty-one of them met the inclu-sion criteria: non-syndromic unilateral (UCLP) or bilateral (BCLP) orofacial cleft, sufficient documentation, mixed or permanent dentition, intact initial plaster cast, which were recorded by means of a 3D-scanner (OrthoxScan, Dentau-rum, Ispringen, Germany) and measured three-dimensionally (CleftDynamic, S.K.M. Informatik GmbH, Schwerin, Germany) to evaluate occlusal and dental malposition. Statistical evaluation was carried out by comparison of mean values using the software SPSS Statistics 27.0 (IBM Deutschland GmbH, Ehningen, Germany) (significance level p = 0.05).
Results: As the most common finding, an aberration of the inclination and angulation as well as a distal position of the upper central incisors (tooth 11 and 21) could be determined, whereat the extent of these anomalies was significantly correlated to the cleft side. Overjet and overbite of these teeth werealso significantly smaller on the cleft side; in addition, in the area of the first permanent molar a cross bite could be found, which was also significantly more frequently located on the cleft compared to the non-cleft side.
Conclusions: Abnormalities of the upper central incisors most frequently occur in cleft patients and are strongly correlated to the cleft side, but a cross bite in the region of the first permanent molar can also be frequently found compared to the non-cleft side. This should be taken into account concerning orthodontic treatment planning in these patients.
Schlagwörter: Cleft lip and palate, oral clefts, tooth malpositions, digital analysis, 3D model
Poster 2453, Sprache: Englisch
The most common form of cystic lesions affecting the maxillofacial region are odontogenic cysts. It is classified into developmental and inflammatory origin, in which the developmental group includes keratocysts and dentigerous cysts and inflammatory group includes radicular cysts. The odontogenic keratocyst was first termed by Philipsen and designated by the World Health Organization as a keratocystic odontogenic tumour, now reclassified from benign odontogenic tumour to odontogenic developmental cyst due to the emergence of marked evidence of morphogenesis and biological behaviour. Its occurrence is anywhere in the jaws, but 70% of cases involve the posterior body of the mandible. It is more prevalent in males, especially in the second and third decade of life. It has characteristic histopathological and clinical features that makes this cyst special in its aggressive behavior and higher recurrence. It can also be classified on the basis of appearance as unilocular or multilocular. Smaller odontogenic keratocysts are unilocular, but larger lesion mostly associated with multilocular appearance. Multilocular odontogenic keratocysts are most commonly accompanied with syndromes, but unilocular are not. In this present case it is unilocular and not associated with syndromes. Radiographically, it appears as well-defined unilocular or multilocular radiolucency with thin radiopaque borders. Conventional radiographic imaging, such as panoramic views and intraoral periapical films, are adequate to estimate the size and determine the location of an KCOT. However, the clinical use for cone-beam computed tomography (CBCT) is increasing and provides more information about the extent and borders of the large lesions. This poster explains an atypical appearance of odontogenic keratocyst with an absence of scalloping border and septa; usually smaller lesion lesions are associated with unilocular appearance, but here is a larger lesion associated with unilocular appearance.
Schlagwörter: Odontogenic keratocyst, keratocystic odontogenic tumour, cone beam computed tomography, aspiration
Poster 2455, Sprache: Englisch
Chelitis granulomatosis is a rare, persistent, painless, idiopathic chronic swelling of the lip. It is a manifestations of orofacial granulomatosis(OFG), which is characterized by non- necrotizing granulomatous inflammation of the oral and maxillofacial region. Clinically, chelitis granulomatosa represents labial enlargement, perioral and mucosal swelling, and oral ulcerations. OFG is an increasingly recognized entity. The exact etiology of not clear, and therefore the precise treatment and long-term prognosis remain uncertain. Chelitis granulomatousa has no predisposition to race, sex, or age, and the incidence is 0.08 % in the general population. Clinician should know about the history, clinical features, etiopathogenesis, and proper investigations to diagnose the disease so as to provide various means of treatment. We present a case report of a 45-year-old male patient with histopathologically confirmed chelitits granulomatosa, which is diagnosed and managed with a nonsurgical treatment approach. The present case highlights the importance of thorough investigations in the diagnosis of this lesion, as the findings mimic many other granulomatous conditions.
Schlagwörter: Chelitis granulomatousa, lip swelling, granulomas, giant cell