Department Of Prosthetic Dentistry Research Articles

Comparative Evaluation of the Effectiveness of Conventional vs Disposable Dental Unit Waterline in Limiting the Contamination of Microorganisms in the Waterline System

Context: Cross infection from contaminated dental instruments is a matter of great concern. On sudden stoppage of an air-rotor, the airflow is cut off creating negative pressure in the unit leading to suck-back of saliva from the patient’s mouth. Aims: To detect the presence of microorganisms in the waterline of air rotor units with time. The effect of using disposable waterline on the microbial load was also investigated. Methods and Material: The study was conducted on randomly selected patients having age range of 20 to 30 years, with indication for single or multiple units fixed partial denture fabrication in the Department of Prosthetic Dentistry. In Group A, the existing waterline system after treatment on each patient was examined for determining the influence of time over the degree of microbial contamination. In Group B, the air-rotor handpiece-coupling joint was attached with sterilised disposable plastic tubelines instead of existing tubeline. Water samples collected from air rotor units and watercan of both Group A and B before and during use for 15,30 & 45 minutes were subjected to microbiological study. Statistical analysis used: Chi-square test was used to assess the effect of time on the microbial load from the data obtained. Results: After 45 minutes of use, 50% of the samples in group A were positively related to microbial contamination and the result obtained from Group B were negative. Conclusions: Air-rotor with existing tube line after 45 minutes of use is significantly responsible for the contamination. Air-rotor with disposable tube line on the contrary could be used without risk of contamination on the next patient even after 45 minutes. Keywords: Air rotor handpiece, Source of bacterial infection, Biofilm, Disinfection.

FEATURES OF TROPHISM OF BONE TISSUE AFTER THE INSTALLATION OF DENTAL IMPLANTS

Relevance. The most important condition for a successful result of dental implantation is high-quality osseointegration of dental implants. In the literature, the issue of the quality of osseointegration is widely covered, which directly depends on the primary stability of dental implants. In the area of bone tissue remodeling, surrounding the installed dental implants, there are permanent processes of bone resorption and its restoration [1][2].The aim is to reveal the reactivity of alkaline phosphatase and osteocalcin in the biological fluid (saliva) in patients after dental implants.Materials and methods. The collection and analysis of clinical material was carried out on the basis of the Clinics of the Samara State Medical University of the Ministry of Health of Russia. Dental implantation surgery was performed in 184 patients aged 32 to 65 years. The gender ratio was 2:3 (40 men and 60 women). The teeth were lost due to poor oral hygiene and caries complications.Results and discussion. At the time of admission of patients to the department of the Department of Prosthetic Dentistry of the Clinics of the Samara State Medical University of the Ministry of Health of Russia, the bulk of the patients had a low hygienic status. The OHI-S index averaged 2.74 ± 0.33 conventional units. (control – 0.50 ± 0.07 c.u.). In order to reduce the negative influence of microorganisms in the supra- and subgingival dental deposits, all patients underwent professional oral hygiene, as well as antimicrobial therapy. At the time of installation of dental implants, the average OHI-S and Müllemann-Cowell index was 0.72 ± 0.06 and 0.57 ± 0.06 conventional units, respectively.Conclusions. 1. The increase in the titer of alkaline phosphatase and osteocalcin during dental implantation is not statistically significant. 2. TCRF in the oral fluid (saliva) exhibits maximum activity by the 14th day, exceeding the initial three times. This indicator remains at an increased level in the period up to six months from the beginning of the operation. 3. Revealing the values of the TRKF titer after the operation of dental implantation is advisable to use as an assessment of the state of trophic processes occurring in the bone tissue.

The Use of Digital Technologies for Teaching Dentistry

The study considers the possibilities of using advanced digital technologies in dental practice and training. The Digital Smile Design methodology has been characterized; this is an innovative technological solution used to perform an aesthetic analysis, plan the virtual treatment tactics, draw up a plan of necessary dental procedures, as well as visualize the preliminary therapy result. As part of the "Aesthetic Dentistry" course, the technological capabilities of the Digital Smile Design software have been studied. The study involved 25 four-year students of the Department of Prosthetic Dentistry, Sechenov First Moscow State Medical University. At the initial stage of the research, the students were provided with digital photos, including a 3D model of the dental arcade and surrounding soft tissue and video materials of the clinical case, on the basis of which a smile in accordance with the morpho-psychological characteristics of the patient was designed. The students tested the technological capabilities of the Digital Smile Design software, in particular SmileDesignerPro, AestheticDigitalSmileDesign, Cerec SW 4.2, PlanmecaRomexisSmileDesign, VisagiSMile, DSD AppbyCoachman, 3Shape SmileDesign, ExocadSmileCreator, DentalTreatmentSimulation ™ PRO. Based on the results obtained, the key advantages of the Digital Smile Design methodology in aesthetic and orthopedic dentistry have been identified. Having studied the process of designing a digital smile within the framework of the "Aesthetic Dentistry" course and conducted a survey of students to determine the practical convenience of the technologies, the Digital Smile Design software was ranked according to its advantages in dental practice and training.

Assessing decision-making in education of restorative and prosthetic dentistry: a pilot study.

To evaluate whether a concordance assessment (CA) software application is able to assess decision-making in restorative and prosthetic dentistry. Vignettes representing 10 different clinical situations were integrated into a software application. Each vignette included 3D digital models and a short case, as well as 5 therapeutic options rated on a 4-point Likert scale (-2 = strongly contraindicated; -1 = contraindicated; +1 = indicated; +2 = strongly indicated). A panel of 15 dental educators (9 educators from the prosthetic department [PD] and 6 from the conservative department [CD]) had to evaluate the indication of each of the 5 therapies for the 10 vignettes. This pilot questionnaire showed good internal consistency on most therapies (Cronbach's α = 0.86), with the exception of more recently introduced therapies (overlay/veneerlay and endocrown). On a maximum score out of 100, the average of CD educators (79.2 ± 3.2) was not significantly different (P = .73) from that of a PD educator (77.8 ± 3.5). Scores ranged from 66.8 to 89.6. Analysis of the expert panel's responses also reported mostly (34/50) a distribution of responses that was characteristic of CA and uncertain situations. The present software application was able to reproduce and assess decision-making in dentistry with satisfying internal consistency of educators.

Changes in the oral mucosa in patients with bruxism

The aim of the study was to determine changes in the oral mucosa in patients with bruxism using the method of autofluorescence stomatoscopy.50 patients with bruxism aged 35-65 years were examined at the Department of Prosthetic Dentistry, Faculty of Dental Medicine, Medical University - Sofia, Bulgaria. Using the digital diagnostic system OccluSense (Bausch, Germany), deviations in static and dynamic occlusion were determined. For the diagnosis of precancerous diseases and early stages of malignant neoplasms of the oral mucosa, we used the method of autofluorescent stomatoscopy using a LED stomatoscope «AFS» made in Russia with radiation in the spectral range of 400 nm.The normal mucous membrane of the mouth at this frequency of the spectrum has a green glow. Metabolic and/or structural changes occurring at the cellular and/or tissue level of the oral mucosa lead to a change in its optical properties.Analysis of occlusion in 50 patients with bruxism showed uneven distribution of the chewing load. In 60% of patients, the presence of supercontacts was revealed, and in 76% of cases, occlusion disorders were detected, in 88% of patients, hyperkeratosis of the buccal mucosa was noted, and in 77.3% they were localized along the line of closing of the teeth.Examination of the oral mucosa using the autofluorescent stomatoscopy method allows visualizing and, accordingly, objectifying the presence of hyperkeratotic changes in the buccal mucosa in patients with bruxism. The APS apparatus allows for a reliable and effective assessment of non-inflammatory and inflammatory changes, precancerous and cancerous lesions, which makes it indispensable for the manifestation of oncological alertness in the daily clinical practice of dentists.Определить изменения слизистой оболочки рта (СОР) у пациентов, страдающих бруксизмом, с помощью метода аутофлюоресцентной стоматоскопии.Обследованы 50 пациентов с бруксизмом в возрасте 35—65 лет на кафедре ортопедической стоматологии факультета дентальной медицины Медицинского университета (София, Болгария). С помощью цифровой диагностической системы OccluSense (Bausch, Германия) определены отклонения в статической и динамической окклюзии. Для диагностики предраковых заболеваний и ранних стадий злокачественных новообразований СОР использовали метод аутофлюоресцентной стоматоскопии с применением светодиодного аппарата стоматоскоп АФС производства РФ с излучением в спектральном диапазоне 400 нм.Нормальная СОР при этой частоте спектра имеет зеленое свечение. Метаболические и/или структурные изменения на клеточном и/или тканевом уровне СОР приводят к изменению ее оптических свойств. Анализ окклюзии у 50 пациентов с бруксизмом показал неравномерное распределение жевательной нагрузки. У 60% пациентов выявлены супраконтакты и в 76% случаев — нарушения окклюзии, у 88% пациентов отмечены явления гиперкератоза слизистой оболочки щек, причем в 77,3% локализующиеся вдоль линии смыкания зубов.Исследование СОР с помощью метода аутофлюоресцентной стоматоскопии позволяет визуализировать и, соответственно, обективизировать наличие гиперкератотических изменений слизистой оболочки щек у пациентов с бруксизмом. Аппарат АФС позволяет осуществить достоверную и эффективную оценку невоспалительных и воспалительных изменений, предраковых и раковых поражений, что делает его незаменимым для проявления онкологической настороженности в ежедневной клинической практике стоматолога.

ПРОФИЛАКТИКА ТОКСИКО-АЛЛЕРГИЧЕСКИХ РЕАКЦИЙ ПРИ ИСПОЛЬЗОВАНИИ СЛОЖНОЧЕЛЮСТНЫХ ПРОТЕЗОВ И АППАРАТОВ

Subject. Today, nanoparticles of chemical elements that make up the body are of particular interest. Such nanomaterials usually do not cause allergic reactions, they can potentially be broken down and removed from it, and, for example, drugs can be placed in the pores of these materials. At the Department of Prosthetic Dentistry of V.G. N.N. Burdenko together with Voronezh State University developed a polymer modified with nanosized silver particles, which was successfully tested on patients in the manufacture of removable plate prostheses. However, there is no data on the effect of this polymer in patients with complex jaw pathology in combination with somatic pathology, in which visible changes occur in the oral cavity. 
 Goal ― to consider the problem of prevention of toxic-allergic reactions when using complex-jaw prostheses and devices. To study the state of the oral microbiocenosis and the cytological characteristics of the mucous membrane in patients with apparatus bases made of a polymer modified with nanoscale silver. Materials and methods. 80 people were examined and 60 patients were treated for complete absence of teeth with various degrees of atrophy according to A.I.Doynikov (1967) I, II, III, IV, V, with a uniform quantitative distribution in groups. 
 Methodology. 80 people were examined and 60 patients were treated for complete absence of teeth with various degrees of atrophy according to A.I.Doynikov (1967) I, II, III, IV, V, with a uniform quantitative distribution in groups. 
 Results. The dynamics of the inflammatory processes of the mucous membrane of the prosthetic bed under the bases of removable jaw devices made by the known method and with bases from modified materials was studied. A complex of personalized prevention of complications associated with the action of basic polymers has been developed. 
 Conclusion. Obtained by analyzing the results of the study, it was possible to create, on the basis of the use of modified acrylic polymer as the material of the bases of removable prostheses and devices, a program for individual prevention of the inflammatory complications induced by them from the mucosa of the prosthetic bed, the efficiency level of which is at least 60 %. This predisposes to recommendations for the further implementation of the modified nanosilver acrylic polymer in practical dentistry.

Distribution of temporomandibular disorders among sleep bruxers and non-bruxers-A polysomnographic study.

Bruxism is often indicated as a risk factor for the occurrence of temporomandibular disorders (TMD). Despite the frequent co-occurrence of bruxism and TMD, the exact relationship between these phenomena has not been thoroughly explained, and their causal relationship is still considered controversial. The aim of this study was to evaluate the distribution of TMD among sleep bruxers and non-bruxers. The participants of this study were 77 patients of the Clinic of Prosthetic Dentistry operating at the Department of Prosthetic Dentistry, Wroclaw Medical University who had been diagnosed with TMD and probable sleep bruxism. Patients underwent video-polysomnography to assess the intensity of sleep bruxism using the Bruxism Episode Index (BEI). The following TMD diagnoses were made: local myalgia, temporal tendonitis, myofascial pain, myofascial pain with referral, hypertrophy, osteoarthrosis, disc displacement with reduction, disc displacement without reduction with limited opening, subluxation, adhesions/adherence, arthralgia, headache attributed to TMD and oromandibular dystonia. None of these occurred statistically significantly more often in the studied group (bruxers; BEI≥2) than in the control group (non-bruxers; BEI<2); (P>.05 for all comparisons). The distribution of TMD among sleep bruxers and non-bruxers is similar. Therefore, the prevalence of sleep bruxism seems not to be a certain risk factor for TMD occurrence.

Correlation between Sleep Bruxism, Stress, and Depression-A Polysomnographic Study.

Background and objectives: Sleep bruxism is a common phenomenon that can affect approximately 13% of adult population. It is estimated that bruxism can be caused by three types of factors: biological, psychological, and exogenous. There are many scientific reports about the coexistence of bruxism, stress, and psychoemotional disorders. The aim of this study is to evaluate the possible correlation between occurrence of sleep bruxism and perceived stress and depressive symptoms. Material and methods: The material of this study consisted of 77 patients of Clinic of Prosthetic Dentistry operating at the Department of Prosthetic Dentistry, Wroclaw Medical University, Poland in which after using guidelines of the American Academy of Sleep Medicine probable sleep bruxism was fund. Patients then underwent video-polysomnography. Exposure to perceived stress was evaluated with Perceived Stress Scale-10 (PSS-10). Occurrence of depressive symptoms was evaluated with Beck’s Depression Inventory (BDI). Results: The analysis showed lack of statistically significant correlation between Bruxism Episodes Index (BEI) and Perceived Stress Scale–10 and Beck’s Depression Inventory scores (p = 0.64, p = 0.65; respectively), also when comparing study group (bruxers) and control group (non-bruxers) (p = 0.88, p = 0.77; respectively). Conclusion: Intensity of sleep bruxism was not statistically significantly correlated with self-reported perceived stress and depression. This issue requires further research.

Sleep Bruxism and Occurrence of Temporomandibular Disorders-Related Pain: A Polysomnographic Study.

Introduction: The diagnosis of sleep bruxism is challenging due to the difficulties involved. Sleep bruxism can lead to clinical consequences, including pain in masticatory muscles, limitation of jaw mobility, headache, and the spectrum of symptoms associated with damage to the teeth and oral mucosa. Currently, only video-polysomnography can definitely diagnose sleep bruxism. Due to the risk of painful temporomandibular disorders (TMD) in sleep bruxers, early diagnosis of pain in the temporomandibular region using questionnaires is recommended. Therefore, this study aimed to assess the relationship between the intensity of sleep bruxism and the occurrence of pain related to TMD.Materials and Methods: This study was conducted on the patients of the Clinic of Prosthetic Dentistry operating at the Department of Prosthetic Dentistry at the Wroclaw Medical University. Based on a positive medical history, a thorough examination for the diagnosis of probable sleep bruxism was carried out in the enrolled patients. Eligible patients were then subjected to a video-polysomnographic study. Each patient was asked to complete the TMD Pain Screener questionnaire to assess the occurrence of pain in jaw and temple area.Results: The results of the study showed that increased bruxism episode index (BEI) was statistically significantly correlated with increase of all types of bruxism episodes—phasic, tonic, and mixed—in all the studied patients; a significant correlation was also found with respect to division of patients into studied and control groups. The study also showed that there was no statistically significant difference between BEI values and scores of TMD Pain Screener. In all the studied patients, a higher BEI was not found to be correlated with the occurrence of TMD-related pain assessed by TMD Pain Screener; similarly, no correlation was found with respect to division of patients into studied and control groups.Conclusions: The occurrence of TMD-related pain is not related to the intensity of sleep bruxism. TMD Pain Screener may be used as an auxiliary tool in the diagnosis or risk of occurrence of TMD-related pain, whereas in the case of sleep bruxism, it has only limited diagnostic value.Clinical Trial Registration: www.ClinicalTrials.gov, identifier NCT03083405

Clinical assessment of Citrosept Dental effectiveness in treatment of Candida-associated denture stomatitis, in patients using removable acrylic dentures

Introduction. For patients using removable dentures the level of comfort and thus the life quality has substantially increased with the development of prosthetic dentistry. However, denture stomatitis, especially accompanied by fungal infections, remains a problem and affects many patients using prosthetic restorations. It is mainly caused by an increasing resistance of fungi to antifungal medications. Aim of the study. To assess clinically the effectiveness of a herbal grapefruit seed extract product called Citrosept Dental in treating Candida-associated denture stomatitis, in patients using acrylic removable dentures. Materials and methods. The studied group included 32 patients (18 women and 14 men) of the Department of Prosthetic Dentistry, Medical University of Warsaw, aged 41 to 83 years (average age 62 years), with symptoms of denture stomatitis accompanied by fungal infections, which were confirmed by a mycological test (group 1). Patients with a positive mycological test result used 1% Citrosept Dental gel on mucosal lesions three times a day after meals, for three weeks. Results. The lesions disappeared completely in 24 patients (75%) after three weeks of Citrosept Dental application. The mucosa of 13 patients with type 1 stomatitis (81.25%) was pink and healthy; that was also the case of 78.57% patients with diffuse erythema. In the three remaining patients with type 2 stomatitis lesions healed after using Citrosept Dental and only had single pinpoints of hyperaemia. There was no change in the oral mucosa of the patient with type 3 stomatitis. Conclusions. Citrosept Dental in in vivo studies reduced denture-associated mucosal inflammations in patients with denture stomatitis accompanied by fungal infections, and also produced resolution of subjective symptoms in a significant majority of patients.

THE STUDY OF NANOSTRUCTURED ANATASE COATINGS ON THE SURFACE OF RUTILE

Nanosized titanium dioxide allows solving complex engineering problems. One of such tasks is the creation of materials and coatings that reduce the likelihood of nosocomial infections on the surface of orthopedic structures including implant systems. The paper presents the results of the Raman spectroscopy, X-ray diffraction analysis and scanning electron microscopy of anatase ceramic coatings deposited by sol-gel technology on a sintered material based on a nanosized titanium dioxide powder (rutile modification). The resulting coating has a complex layered structure, which is almost completely represented by titanium dioxide in the anatase phase according to the Raman spectroscopy data. The simultaneous existence of both phases in the coating was recorded. The identification of rutile on diffractograms seems to be due to the fact that modified peak intensity rutile is mainly formed during the first stages of coating application on the polycrystalline rutile surface. The fact that non-stoichiometric phases also present in the diffractograms suggests that coating phase composition is not the same in thickness and is represented by a gradual layerwise transition from rutile to anatase. The coating thickness is 60 ± 15 μm. The coating is represented by lamellar blocks of various sizes. The thickness of a single plate in the coating is 60–80 nm. The developed technique makes it possible to apply the anatase coating not only on samples of titanium dioxide ceramics but also on the surface of titanium implants with the preliminary formation of a titanium dioxide layer in the form of rutile on the metal surface. Experiments on the study of antibacterial properties and morphological characteristics of bone tissue in contact with the implant were carried out at the Department of Prosthetic Dentistry at the PSMU.

WHO-5 well-being index as screening instrument for psychological comorbidity in patients with temporomandibular disorder

Objectives: The aim of the study was to compare the WHO-Five Well-Being Index (WHO-5) with the Oral Health Impact Profile-49 (OHIP-49) questionnaire as screening tools to detect psychological comorbidity in TMDs.Methods: A TMD group (92 patients, 42.8 ± 17.1 yrs) and a control group (90 patients of the Department of Prosthetic Dentistry, 38.9 ± 10.1 yrs) completed the WHO-5 and the OHIP-49 questionnaire.Results: The patients with TMD reported significantly greater OHIP-49 sum scores than controls (47.5 ± 34.7 vs. 7.7 ± 12.1; p < 0.001). The mean raw score of the WHO-5 was significantly less, with 45.6 ± 20.6 points for patients with TMD than the 73.2 ± 15.6 points found for controls (p < 0.001). The OHIP sum score and the WHO-5 raw score were significantly associated (r = 0.705, p < 0.001). Both instruments exhibited excellent internal consistency (Cronbach’s α = 0.967 and 0.883, respectively).Conclusions: WHO-5 proved to be an effective and economic screening instrument to detect psychological comorbidity in TMDs. Implementing WHO-5 in standard care could contribute to more individualized interdisciplinary psychotherapy and/or functional therapy.

MICHAEL NAUMANN, DR MED DENT, Professor, Department of Prosthetic Dentistry, Center of Dentistry, University of Ulm, Ulm, Germany

MICHAEL NAUMANN, DR MED DENT, Professor, Department of Prosthetic Dentistry, Center of Dentistry, University of Ulm, Ulm, Germany

Is there a link between tinnitus and temporomandibular disorders?

The frequent concurrence of tinnitus and temporomandibular joint and masticatory muscle disorders (TMD) has led to the assumption that a possible relationship exists between these 2 conditions. The present prospective clinical study was conducted to assess the possible association between tinnitus and TMD and to investigate the effect of stomatognathic therapy on tinnitus distress. The prevalence of TMD and tinnitus was investigated in a consecutive series of 951 patients at the Department of Prosthetic Dentistry at the University Medical Center Regensburg, Germany. Patients with TMD and simultaneous tinnitus were included in the prospective clinical trial (n=25). Baseline examination comprised a detailed functional analysis, diagnosis of temporomandibular joint and masticatory muscle disorder, and a tinnitus questionnaire. All the participants received individual dental functional therapy (oral splints, physiotherapy). The effects of functional therapy on TMD and tinnitus symptoms were examined 3 to 5 months after the initiation of dental functional therapy. Means (standard deviations) were calculated, and 1-way ANOVA was used to investigate statistical differences (α=.05). The differences of the 2 binary outcomes were compared with the Pearson χ(2) test, and the relative risk was calculated. Prevalence of tinnitus was found to be 8 times higher in participants with TMD (30 of 82 [36.6%]) than in participants without TMD (38 of 869 [4.4%]). All the participants with unilateral TMD and unilateral tinnitus showed theseconditions on the same side. Stomatognathic therapy improved tinnitus symptoms in 11 of 25 participants (44%). The results of this study and the prospective clinical trial showed a significant correlation between tinnitus and TMD. The observed treatment outcome suggests that dental functional therapy may have a positive effect on TMD-related tinnitus.

Tinnitus with Temporomandibular Joint Disorders

Tinnitus is frequently associated with temporomandibular joint (TMJ) dysfunction. However, the nature of the relationship is not fully understood. Here the authors compared 30 patients with a confirmed diagnosis of temporomandibular joint dysfunction and tinnitus to a group of 61 patients with tinnitus but without any subjective complaints of TMJ dysfunction with respect to clinical and demographic characteristics. Case-control study. Tertiary referral center. Tinnitus patients with and without TMJ dysfunction presenting at the Department of Prosthetic Dentistry and th: Tinnitus Clinic at the University of Regensburg. Tinnitus patients with TMJ disorder had better hearing function (P < .0005), lower age (P = .001), and lower age at tinnitus onset (P = .002) and were more frequently female (P = .003). Their subjectively perceived tinnitus loudness was lower (P = .01), and more of them could modulate their tinnitus by jaw or neck movements (P = .001). Classical risk factors for tinnitus (age, male gender, hearing loss) are less relevant in tinnitus patients with TMJ disorder, suggesting a causal role of TMJ pathology in the generation and maintenance of tinnitus. Based on this finding, treatment of TMJ disorder may represent a causally oriented treatment strategy for tinnitus.

Patient Evaluation after Treatment with Maxillary Implant‐Supported Overdentures

To evaluate and compare outcome among patients after implant overdenture treatment in the maxilla. The study sample comprised two groups of patients: group 1, in which the patients were planned for overdenture treatment, and group 2, in which the patients originally were planned for a fixed prosthesis in the maxilla but had overdenture treatment owing to implant failures, resulting in an insufficient number of implants to support a fixed prosthesis. All patients treated with maxillary implant-supported overdentures in the Department of Prosthetic Dentistry, Central Hospital, Skövde, Sweden, between 1993 and 2002 received a questionnaire at their yearly follow-up visit with nine questions related to their treatment. All questions had visual analogue scale response alternatives ranging from a negative to a positive opinion. Nineteen patients, 10 in group 1 and 9 in group 2, completed the questionnaire, yielding a response rate of 86%. Both groups expressed a high satisfaction rate, and few regretted their choice of treatment. Patients planned for overdenture treatment (group 1) reported significantly fewer speech problems after treatment compared with those originally planned for a fixed prosthesis (group 2, p < .05). No other significant differences between the two groups were seen. Within the limitations of the present study, it can be concluded that maxillary implant overdenture treatment may be considered a viable option among patients with an insufficient number of implants for a fixed prosthesis.

A Retrospective Evaluation of Treatments with Implant-Supported Maxillary Overdentures

Considerably lower success rates have been presented for implant-supported overdentures in the maxilla compared with the mandible. The aim of the study was to report the outcome of implant-supported maxillary overdentures from one clinic. All patients treated with implant-supported maxillary overdentures in the Department of Prosthetic Dentistry, Central Hospital, Skövde, Sweden, between 1993 and 2002 were identified from patient charts and included in the study. All patients had a rigid cast gold alloy bar designed with ball attachments retaining an overdenture. Twenty-seven subjects were included, of whom 13 were originally planned for overdenture treatment (group 1) and the other 14 for a fixed prosthesis (group 2). The mean observation period was 5.7 years for subjects in group 1 and 5.5 years for those in group 2. One hundred forty-five implants were placed, and the majority of the failures were diagnosed as early ones and were found in group 2. The cumulative implant survival rate after 5 years was 77% in group 1 and 46% in group 2. The probability of having implant failure was almost three times higher among subjects in group 2 compared with subjects in group 1. Most technical and biologic complications were related to the retention system. Maxillary implant-supported overdentures show a high implant failure rate, but fewer implant failures occurred for patients originally planned for overdenture treatment.

Single tooth crowns supported on hydroxyapatite coated endosseous dental implants: a prospective 5-year study on twenty subjects.

To evaluate the success and maintenance requirements of cylindrical, hydroxyapatite coated implants used as single-tooth implants. A five-year prospective trial. Twenty patients, attending the Department of Prosthetic Dentistry at GKT Dental Institute, London, were provided with 23 Calcitek, Integral Omniloc single tooth implants. Annual reviews were undertaken for five years. Assessment criteria included implant survival; abutment or crown looseness; radiographic evidence of bone loss; evidence of plaque and inflammation of the mucosal cuff; the patient's perception of the restoration. All implants integrated. Two subjects, with three crowns, dropped out giving a known cumulative survival rate of 87%. Twelve implants exhibited no measurable bone loss and six demonstrated funnel formation up to 2mm in depth which, at five years, appeared to be stable; three implants exhibited continuing bone loss and their inclusion as failures gives a known success rate of 74%. The abutments came loose on four occasions; the crowns decemented on 12 occasions; two crowns were repaired and one remade. The appearance was judged to be good or very good. The prospective study indicated that hydroxyapatite coated implants can be successful as single tooth implants, over a five-year period.

The immediate rehabilitation by means of a ready-made final fixed prosthesis in the edentulous mandible: a 1-year follow-up study on 50 consecutive patients.

Although a two-stage procedure with symphyseal oral implants can lead to a long-term (15 years) 99% cumulative survival rate, a one-stage approach with immediate loading via prefabricated elements seems to offer a short-term acceptable outcome with significantly lower costs. A series of 50 consecutive patients, not eliminated for any systemic or smoking condition, received at the department of periodontology three implants in the symphyseal area, connected by a very rigid horse shoe-shaped titanium bar. A final screw retained prosthetic framework was placed on top of it at the department of prosthetic dentistry within 2 days after surgery (44) or after a delay, due to purely external factors, of up to 10 days (6). Forty-five patients were followed for 1 year. In one patient, all three implants failed and another four patients were lost to follow-up. The cumulative failure rates for implants and prostheses at 1 year were, respectively, 7.3% and 5%. The mean marginal bone loss at 1 year was 1.08 mm (SD: 1.62; range -5.68 to +2.55). This study shows that stable marginal bone levels can be maintained around immediately loaded implants in the lower jaw in an average patient population for at least 1 year. The survival rate is, however, lower than for a staged approach.

5. 九州歯科大学附属病院第1義歯科における高齢患者の動向 : 2年間の調査報告(口頭発表,第64回九州歯科学会総会講演抄録)

5. 九州歯科大学附属病院第1義歯科における高齢患者の動向 : 2年間の調査報告(口頭発表,第64回九州歯科学会総会講演抄録)