Poster 2481, Language: English, German
Case report: The presented case report shows a 58-year-old patient who was pre-treated alio loco with tumour radical surgery and subsequent radiotherapy for squamous cell carcinoma of the anterior mandible. The vestibule was restored by means of a split skin graft from the thigh, and then an implant-supported prosthetic restoration was attached. After 6 weeks, fixed gingiva had developed and a prosthesis bed was formed. A definitive bar-supported prosthesis was then created. The prosthetic also resulted in an improvement in the mouth opening and soft tissue profile.
Discussion: Studies show that implant-supported mandibular prostheses are a reliable and effective method of reconstructing the edentulous mandible, with high patient satisfaction and significantly improved masticatory function.
Due to advanced mandibular atrophy and the preceding tumour radical surgery, there is an encroachment of the mentalis muscle and the tissue attachments at the alveolar ridge as well as a reduction in the size and shape of the mandible, especially in the vestibular depth. Vestibuloplasty is therefore indicated for long-term stable retention with implants.
It is generally recommended to perform vestibuloplasty 2 months prior to placement of endosseous implants. Alternatively, vestibuloplasty can be performed at the time of implant placement. The use of palatal grafts often results in postoperative pain and the graft size is limited. Split skin grafts are recommended especially when a large graft is required. Immobilisation and adhesion of the split skin graft are critical factors along with adequate vascularisation of the recipient area. In addition, micro-movements during chewing cause local inflammation. Saliva collects under the graft and can separate it from the graft bed. Complications at the donor site are rare. The grafted skin is firm, immobile, stable and can withstand the functional stresses of the prosthesis.
A contraindication exists in patients who require an alveoplasty in addition to the split skin graft. Since the split skin graft is placed supraperiosteally, it precludes simultaneous alveoplasty.
Summary: Without an adequate vestibule, prosthetic rehabilitation in the severely atrophied jaw is almost impossible. To enable a long-term stable implant restoration, a sufficient soft tissue bed with a stable peri-implant tissue and a good hygiene ability must be created. The gold standard for vestibuloplasty is the oral mucosa graft. However, this is only available in limited quantities, so that the split skin graft can be used to cover extensive soft tissue deficits as a result of tumour therapy.
Keywords: Split skin graft, vestibuloplasty, soft tissue replacement
Poster 2486, Language: English, Spanish
Objectives: The aim of the study was to analyse whether the deprogramming of awake bruxism (AB) with new technologies (Biofeedback-Electromyography and E-health or M-health) might have an effect on sleep bruxism (SB).
Materials and Methods: Systematic review of the literature on the topic of bruxism, new technologies, biofeedback, and electromyogram (BF-EMG), with interventions on AB and its effect on SB with the following search terms: (((“BRUXISM”) OR ("SLEEP BRUXISM") OR ("AWAKE BRUXISM")) AND (((“EHEALTH”) OR ("MHEALTH") OR ("SMARTPHONE") OR ("ECOLOGICAL MOMENTARY ASSESSMENT") OR (“DESENCOSTE OS SEUS DENTES”) OR (“BRUXAPP”) OR ("BIOFEEDBACK") OR ("ELECTROMYOGRAPHY"))) An exhaustive search of randomized controlled trials (RCTs) in the bibliographic databases PubMed, EBSCO, Scopus, Web of Science, Ovid, and Google Scholar was performed from September 2020 to April 2022. ). The population of this SR were randomized clinical trials (RCTs) that respected the research question, with adults with AB and/or SB subjected to tests for EMG, biofeedback or use of mobile applications for smartphones (apps). The exclusion criteria were animal studies bruxism studies in children and adolescents, and bruxism treatment techniques that included botulinum toxin, relaxation orthosis (without biofeedback) medications such as treatment, laser, music, physiotherapy, muscle stretching, music, cognitive therapy, and other therapies that do not respect the initial question of this review.
Results: We could only include 2 RCTs with BF-EMG intervention in AB and its effect on SB. RCTs show that there are studies of BF-EMG acting on AB and that BF-EMG may have an effect on SB. (1,2)
Although mobile apps for smartphones can be useful to determine the prevalence and deprogramming of AB, there are no RCTs with mobile apps to be able to confirm that AB deprogramming might be useful in the management of SB. (3,4)
Conclusions: According to the results of the systematic review, it seems possible to partially deprogram SB with BF-EM deprogramming of AB, but the scarcity of RCTs does not allow an unequivocally confirmation of this assumption.
Keywords: Bruxism, sleep bruxism, awake bruxism, E-health, M-health, smartphone, momentary ecological assessment, bruxapp, biofeedback, electromyography
Poster AwardPoster 2487, Language: English
Background: Immediate dental implant placement has been a subject of great interest over the last decade. Here, information regarding the anatomy and bone thickness of the jaw prior to dental implant placement is crucial to increase the surgery’s success and the patient’s safety. The clinical premises for this approach have been controversially discussed. One of those heavily discussed premises is a buccal bone thickness of at least 1 mm thickness. This meta‐analysis aims to systematically review buccal bone thickness (BBT) in healthy patients. Thus, the feasibility of immediate dental implant placement in daily practice can be assessed.
Methods: A search in the electronic databases was performed to identify articles reporting on BBT that was measured by computed tomography in adults.
Results: We were able to find 45 studies, including 4324 patients with 25,452 analysed teeth. The analysis showed a BBT at the alveolar crest of 0.76 ± 0.49 mm in the maxillary frontal and of 1.42 ± 0.74 mm in the maxillary posterior region. In the mandible, the average measured values were similar to those in the maxilla (front: 0.95 ± 0.58 mm; posterior: 1.20 ± 0.96 mm). In the maxillary frontal region 74.4% and in the mandibular frontal region 61.2% of the crestal buccal bones showed widths <1 mm.
Conclusions: In more than 60% of the cases, the BBT at the alveolar crest is <1 mm in maxillary and mandibular frontal regions. This anatomic data supports careful pre‐surgical assessment, planning of a buccal graft, and critical selection of indication for immediate implant placement, especially in the maxillary and mandibular frontal and premolar region.
Keywords: dental implant, tomography, dental implant loading, immediate, alveolar bone, buccal bone thickness
Poster AwardPoster 2489, Language: English
Background: This cross-sectional study aims to compare a new and non-invasive approach using hyperspectral imaging (HSI) with the conventional modified Allen’s test (MAT) for the assessment of collateral perfusion prior to radial forearm free flap harvest in healthy adults.
HSI of the right hand of 114 patients was recorded. Here, three recordings were carried out: (I) basic status (perfusion), (II) after occlusion of ulnar and radial artery (occlusion), and (III) after releasing the ulnar artery (reperfusion). At all recordings, tissue oxygenation/superficial perfusion (StO2 (0–100%); 0–1 mm depth), tissue haemoglobin index (THI (0–100)) and near infrared perfusion index/deep perfusion (NIR (0–100); 0–4 mm depth) were assessed. A modified Allen’s test (control) was conducted and compared with the HSI-results.
Results: Statistically significant differences between perfusion (I) and artery occlusion (II) and between artery occlusion (II) and reperfusion (III) could be observed within the population with a non-pathological MAT (each <0.001). Significant correlations were observed for the difference between perfusion and reperfusion in THI and the height of the MAT (p < 0.05). Within the population with a MAT >8 s, an impairment in reperfusion was shown (each p < 0.05) and the difference between perfusion and reperfusion exhibited a strong correlation to the height of the MAT (each p < 0.01).
Conclusions: The results indicate a reliable differentiation between perfusion and occlusion by HSI. Therefore, HSI could be a useful tool for verification of the correct performance of the MAT as well as to confirm the final diagnosis, as it provides an objective, reproducible method whose results strongly correlate with those obtained by MAT. What is more, it can be easily applied by non-medical personnel.
Keywords: hyperspectral imaging, Allen’s test, radial forearm free flap, microvascular surgery, microsurgery, reconstructive surgery, perfusion monitoring, flap imaging
Poster AwardPoster 2492, Language: English
Aim: Patient-individual bone plates from titanium alloy (TiAl4V ELI) can be generated by 3D printing. Directly after printing, the samples have a very rough surface requiring further processing. The aim of the present study was to analyse the effect of different grinding and polishing procedures on sample surface and in vitro biocompatibility to make sure that the clinically approved material properties of the titanium alloy were not compromised by these treatments.
Materials and Method: Initial average surface roughness of 3D printed titanium discs (Ti6Al4V ELI) (d=5mm or 10 mm, h=2 mm), produced by selective laser melting (SLM; Ra=22.7 µm), was reduced by sandblasting followed by barrel finishing, electro-polishing, or plasma-polishing and was then evaluated using tactile surface quality measurement (DIN ISO EN 4288). Biocompatibility of the different sample groups (n=6-9 each) was assessed by quantification of metal-ion release, indirect cell viability and cytotoxicity tests as well as direct cell adhesion, analysed by fluorescence and scanning electron microscopy (SEM). Mouse fibroblasts (L929), osteosarcoma cells (Saos-2), human primary gingival fibroblast as well as human gingival epithelial cells were used in this study, respectively. Statistical evaluation was performed with the Kruskal Wallis test, followed by a posthoc Dunn's test to perform multiple comparisons.
Results: All tested treatments were suitable to obtain surface roughness values within the effective roughness spectrum (Ra 0.2 2 µm). Sandblasted, barrel finished, and electro-polished samples showed high cell viability in indirect tests, as well as good cell adhesion and proliferation when seeded directly with cells. In contrast, plasma-polished samples showed significantly reduced cell viability in indirect tests and very low attached cell numbers after direct colonization, probably caused by the high amount of vanadium ions, which could be found in the cell culture medium after metal-ion release from the plasma-polished samples.
Conclusions: Bone plates from titanium alloy generated by 3D printing are suitable for clinical use and are in line with the requirements for medical devices according to ISO 10993-5. However, relating to metal-ion release, post-printing treatment must be taken into consideration, critically.
Keywords: Ti-6Al-4V, laser powder bed fusion, vanadium, in vitro cytotoxicity, post-processing procedures
Poster 2496, Language: English
Introduction: Oral lichen planus is a chronic autoimmune, mucocutaneous disease affecting oral mucosa. Chronic periodontitis is microbe-associated chronic inflammation of the supporting tissues of teeth. There is an increase in systemic pro-inflammatory cytokines specifically TNF-ᵅ in both diseases.
Dental plaque, which is a primary causative factor for periodontitis, may exacerbate the OLP lesions. Also, gingival lesions in oral lichen planus may indirectly increase the risk of plaque-induced periodontitis when symptoms associated with such lesions impede the maintenance of proper oral hygiene and may enhance the risk of periodontal tissue destruction.
Objectives: To compare and evaluate the clinical findings and patient-related factors of various OLP types in patients with and without periodontitis.
Methodology: This study compared 4 groups, i.e: Group 1= Reticular without periodontitis; Group- 2=Reticular with periodontitis; Group-3= Erosive without periodontitis; Group-4=Erosive with periodontitis. Periodontitis criteria was as given by Tonetti et al, and OLP scoring criteria was as given by Escudier et al.
Results: Within the limits of this study, group 2 presented with more number of cases with higher score in terms of burning sensation (p=.036), site, and severity (p=.003) compared to group 1. Group 4 had more cases with a higher score in terms of burning sensation (p=.019), pain (p=.007), site, and severity compared to group 3.
Conclusion: Reticular and erosive OLP exhibit higher severity scores and more symptoms in patients with periodontitis as compared to the ones without periodontitis.
Keywords: Oral lichen planus (OLP), cytokines, inflammation, periodontitis
Poster 2497, Language: English
Questions: The bond strength of orthodontic brackets can be influenced by numerous factors, including pre-treatment of the tooth surface, type of the bonding system, mastication forces during treatment, and the type, size, and design of the bracket (1).
The aim of the present study was to compare the shear bond strength (SBS) and the adhesive remnant index (ARI) at the enamel-bonding interface between brackets of different base sizes, including a new very small self-ligating-bracket (MiniQuick), not yet on the market, using two different methods of enamel surface pre-treatment.
Methods: Freshly extracted bovine permanent incisors (n=360) were used in this study, which were embedded in Technovit®4004 (Kulzer GmbH, Hanau, Germany) and divided into six groups (n=60) dependent on enamel surface pre-treatment (Airflow, Rocatec) and bracket type (Sprint II, Micro Sprint, MiniQuick; Forestadent Bernhardt Förster GmbH, Pforzheim Germany). Pre-treatment included Airflow technique (Clinpro™ Prophy Powder, 3M Espe, Neuss, Germany; core size 45μm) and Rocatec technique (Aluminium oxid powder, core size 50μm), respectively, thereafter all teeth were etched with 35% phosphoric acid, followed by water spray and compressed air. Transbond™ XT light cure primer and adhesive (3M™ Unitek, Landsberg am Lech, Germany) and Valo® Cordless curing light (Ultradent Products Inc., South Jordan, UT, USA), 5s each, were used for bonding. Thus, 720 brackets were fixed with two on each tooth surface, respectively. After de-bonding (universal testing machine TIRAtest-2720, Schalkau, Germany; pressure force of 1kN maximum, testing speed of 0.5mm/min according to DIN ISO 11405/2003), SBS and ARI was evaluated in all groups. Statistics were conducted using two-way ANOVA, significance level p≤ 0.05.
Results: All groups showed a high SBS with similarly comparable high mean values. A statistically significant difference could only be detected between Sprint II and MiniQuick brackets and between Airflow and Rocatec pre-treatment. ARI score 2 and 1 revealed a high percentage in all groups.
Conclusions: MiniQuick brackets showed not only similar but also statistically significant higher mean SBS values compared to the other two bracket types, which indicates, that despite their reduced size, they are suitable for clinical use. In this context, pre-treatment with Airflow showed a positive influence on the bonding process.
Acknowledgements: This research was supported by FORESTADENT® Bernhard Förster GmbH, Pforzheim, Germany, who provided the test brackets.
Keywords: Shear bond strength, Adhesive Remnant Index, surface pre-treatment, bracket base
Poster AwardPoster 2498, Language: English
Dental agenesis is the most common developmental aberration in humans, and it is typically linked with a variety of other oral anomalies. Although tooth agenesis is not a serious public health problem, it can cause speech, masticatory, aesthetic, and functional problems. A 6-year-old male patient reported with complaint of non-eruption of teeth and difficulty in mastication. History revealed patient had multiple congenital missing teeth without any significant medical and dental history. After radiographic investigation, a diagnosis of oligodontia was made. After considering the young age and growth of the patient, a conservative approach of rehabilitation of non-syndromic oligodontia patient with maxillary overlay denture and mandibular conventional complete denture was planned and fabrication was carried out. A satisfactory clinical outcome was achieved. The aim and objective of this scientific poster is to report a conservative management in a patient with non-syndromic oligodontia.
Keywords: Anodontia, congenital missing teeth (CMT), hypodontia, non-syndromic oligodontia, overlay denture
Poster AwardPoster 2504, Language: English
Loss of eye can occur due to any congenital defect, developmental agenesis, infection, traumatic exposure or tumour, resulting in significant physical, psychological, and emotional problems. Rehabilitation of such patients is both emotionally and prosthetically a really phenomenal task. The patient reported with the chief complaint of a missing left eye along with missing multiple teeth following the surgical treatment. Medical history revealed COVID-19-associated mucormycosis, following which exenteration of the left eye along with the segmental maxillectomy was carried out. Patient opted for prosthetic rehabilitation due to the invasiveness of any implant or surgical procedure. This presentation describes the prosthetic rehabilitation of an orbital defect with an assembly of intraoral and extra-oral prosthesis coupled with using intraoral magnets. The poster presentation aims to highlight the fabrication of a hollow orbital conformer to retain the orbital prosthesis with the purpose of reducing its weight. Iris positioning has been performed using a printed millimetre graph grid attached to the spectacles for better orientation in contrast to the contralateral eye. For a life-like appearance of the extra oral prosthesis, instead of artificial hair attachment, utilisation of patient’s own natural hair for weaving of eyebrows and eyelashes was carried out. Satisfactory functional and aesthetic outcomes were achieved leading to gain in confidence of the patient to face the everyday social dilemmas.
Keywords: Exenteration, hollow, magnets, mucormycosis, orbital prosthesis, segmental maxillectomy
Poster 2506, Language: English
Introduction: Pyogenic granuloma is one of the inflammatory hyperplasias seen in the oral cavity. It arises in response to various stimuli, such as low grade local irritation, traumatic injury, sex hormones, and certain kinds of drugs such as cyclosporine. Clinically, oral pyogenic granuloma is a smooth or lobulated exophytic lesion manifesting as small, red erythematous papule on a pedunculate or sometimes sessile base, which is usually haemorrhagic and compressible. Oral pyogenic granuloma shows a striking predilection for the gingiva, followed by lips, tongue, and buccal mucosa. Lesions are more common on the maxillary gingiva than the mandibular gingiva.
Objective: To prevent the recurrence of pyogenic granuloma.
Methodology: A 42-year-old female patient reported to our department of periodontology in PGIDS Rohtak, with a chief complaint of swelling in the upper front teeth which bleeds during tooth brushing and on slight provocation. The patient gave a history of treatment of this lesion in a private clinical setting twice 6 months ago. Clinical examination revealed a smooth, red, painless erythematous swelling on the interdental papilla between maxillary central incisors extending to involve palatal side. Differential diagnosis of pyogenic granuloma was made. Excisional biopsy was then performed under LA to remove the lesion; open flap debridement was carried out in relation to maxillary central incisors, and tissue was sent for histopathologic examination. Postoperative instructions were given and the patient recalled for suture removal after a week.
Result: The histopathologic report confirmed the diagnosis of pyogenic granuloma. The lesion was completely resolved and followed up for 6 months.
Discussion and conclusion: Excisional surgery is the treatment of choice for this condition; other treatment protocols such as the use of Nd:YAG laser, cryosurgery, intralesional injection of corticosteroids and sodium tetradecyl sulfate sclerotherapy have been proposed. To prevent the recurrence of pyogenic granuloma, excisional biopsy along with open flap debridement should be carried out to remove granulation tissue and subgingival deposits. Private practitioners should emphasise the need of complete debridement to remove local irritant factors present subgingivally.
Keywords: granuloma, hyperplasia, periodontitis