Conventional Removable Partial Dentures Research Articles

COMPARISON BETWEEN THE EFFECT OF CONVENTIONAL REMOVABLE PARTIAL DENTURES AND TELESCOPIC REMOVABLE PARTIAL DENTURES ON POCKET DEPTHS AND ALVEOLAR BONE HEIGHT OF ABUTMENT TEETH

Objective: this study was conducted to compare the effect of the conventional removable partial dentures (RPDs) and telescopic partial dentures on pocket depths and alveolar bone height of abutment teeth after a follow-up period of one year.Materials and Methods: twenty eight patients with mandibular bilateral free-end saddle were selected for this study, with canines and first premolars as last standing abutments on both sides and an opposing maxillary dentulous arch. They were randomly divided into two groups, group I receiving a conventional RPD, and group II receiving a telescopic partial denture. CAD/CAM technology was used for the fabrication of Polymethylmethacrylate patterns for both copings and frameworks for the two groups followed by casting in the conventional manner. Radiographic bone height measurements and pocket depth measurements were performed for the two groups at denture delivery and after one year.Results: there was no significant difference in percentage bone loss and pocket depth between the two groups after one year. However, only group II showed a significant increase in pocket depth after one year of follow-up. There was also an increase in bone loss in both groups after one year but it was not significant. Conclusion: Minor changes in pocket depths and alveolar bone height were observed in both groups. However, the telescopic partial denture showed signs of gingival inflammation and increased pocket depths, while the conventional removable partial denture showed more favorable results.

DİŞ ÜSTÜ PROTEZLERDE SCHUBİGER ATAŞMAN DİZAYNININ MODİFİYE KULLANIMI: OLGU SUNUMU

Diş üstü protez, protezin mukozal yüzeyinin bir veya daha fazla destek dişin üzerini sararak destek aldığı protezlerdir. Protezin tutuculuk ve stabilitesini arttırmak amacıyla, kalan destek dişler üzerine inşa edilebilen farklı ataşman çeşitleri kullanılmaktadır. Schubiger ataşman dizaynı da destek dişleri bar tutuculara bağlayan prefabrike vidalardan oluşur. Bu rapor prefabrike formu yerine modifiye Schubiger ataşman dizaynının kullanıldığı diş üstü protezlerle tedavi edilmiş kısmı dişsiz bir vakayı anlatmaktadır. Otuzbir yaşındaki erkek hasta çok sayıda diş eksikliği şikâyeti ile Protetik Diş Tedavisi departmanımıza başvurmuştur. Hastanın periodontal hastalığa bağlı olarak birçok dişini kaybettiği anlaşılmıştır. Hastanın ağız içi muayenesinde geri kalan dişlerinin (#13, #21, #23, #26, #27, #33, #37, #43, #45) stabilizasyonda avantajlı bir şekilde çapraz ark konumunda bulunduğu ancak konvansiyonel hareketli bölümlü protez için klinik kron boylarının çok yüksek olduğu görülmüştür. Tüm olası tedavi seçenekleri hasta ile görüşülüp, hem ideal estetik ve fonksiyonun sağlandığı hem de ileride uygulanması düşünülebilecek implant destekli sabit protetik tedavi amacıyla kemik kaybını engelleyecek bir diş üstü protez yapılması yönünde seçim yapılmıştır. Bu sayede, hastanın geri kalan kemik dokusunun korunabileceği ve prefabrike ataşmanlara göre maliyeti uygun bir tedavi sağlanmıştır. Uygulanan tedavi ile hastanın estetik ve fonksiyon ihtiyacı karşılanmıştır. Anahtar Kelimeler : Diş üstü protez, Kısmi dişsizlik, Schubiger bağlant ı THE MODIFIED USAGE OF SCHUBIGER ATTACHMENT DESIGN IN OVERDENTURES: A CASE REPORT ABSTRACT An overdenture is a prosthesis that supplies support from one or more abutment teeth by covering them beneath its mucosal surface. Different kinds of attachment systems, which are constructed on existed abutment teeth are used to increase the retention and stability of the denture. Schubiger attachment design is one of the attachments, which consists of prefabri- cated screws to connect the abutment teeth to bar retainers. This report presents the rehabilitation of a partially edentulous case with teeth supported over- dentures in which modified Schubiger attachment design was used instead of its prefabricated form. A 31-year-old male patient reported with the chief complaint of many missing teeth in our Department of Prosthodontics. The patient’s history revealed missing teeth due to periodontal disease. Intraoral examina- tion revealed that remaining teeth were located in cross arch as an advantage in stabilization (#13, #21, #23, #26, #27, #33, #37, #43, #45), but the height of the clinical crowns were so high to rehabilitate by a conventional removable partial denture. All situations were discussed with the patient and an overdenture treatment plan was choosen for both having the ideal esthetic, function and preventing the loss of alveolar bone for possible implant supported fixed prosthesis rehabilitation in the future. Thus, both preventive treatment on existing bone and cost effective treatment to the use of prefabricated attachments were obtained. The applied treatment met the patient’s needs such as esthetic and function. Keywords: Overdenture, Partially edentulous, Schubiger attachment

Tooth replacement for partially dentate elders: A willingness-to-pay analysis

ObjectivesThe primary aim of this study was to investigate partially dentate elders’ willingness-to-pay (WTP) for two different tooth replacement strategies: Removable Partial Dentures (RPDs) and, functionally orientated treatment according to the principles of the Shortened Dental Arch (SDA). The secondary aim was to measure the same patient groups’ WTP for dental implant treatment. Methods55 patients who had completed a previous RCT comparing two tooth replacement strategies (RPDs (n=27) and SDA (n=28)) were recruited (Trial Registration no. ISRCTN26302774). Patients were asked to indicate their WTP for treatment to replace missing teeth in a number of hypothetical scenarios using the payment card method of contingency evaluation coupled to different costs. Data were collected on patients’ social class, income levels and other social circumstances. A Mann-Whitney U Test was used to compare differences in WTP between the two treatment groups. To investigate predictive factors for WTP, multiple linear regression analyses were conducted. ResultsThe median age for the patient sample was 72.0 years (IQR: 71–75 years). Patients who had been provided with RPDs indicated that their WTP for this treatment strategy was significantly higher (€550; IQR: 500–650) than those patients who had received SDA treatment (€500; IQR: 450–550) (p=0.003). However patients provided with RPDs indicated that their WTP for SDA treatment (€650; IQR: 600–650) was also significantly higher than those patients who had actually received functionally orientated treatment (€550; IQR: 500–600) (p<0.001). The results indicated that both current income levels and previous treatment allocation were significantly correlated to WTP for both the RPD and the SDA groups. Patients in both treatment groups exhibited little WTP for dental implant treatment with a median value recorded which was half the market value for this treatment (€1000; IQR: 500–1000). ConclusionsAmongst this patient cohort previous treatment experience had a strong influence on WTP as did current income levels. Both treatment groups indicated a very strong WTP for simpler, functionally orientated care using adhesive fixed prostheses (SDA) over conventional RPDs. Clinical significancePartially dentate older patients expressed a strong preference for functionally orientated tooth replacement as an alternative to conventional RPDs.

Implant supported dental rehabilitation following segmental mandibular reconstruction- quality of life outcomes of a prospective randomized trial

The primary objective of this study was to assess the difference in quality of life (QoL) in patients with dental rehabilitation using two or four implant-supported overdentures following segmental mandibulectomy defect reconstruction with fibula free flap. This prospective, parallel designed, randomized clinical study was conducted with a 1:1 ratio. At baseline, all participants already had fibula flap reconstruction for segmental defects of the mandible and rehabilitation with conventional (non-implant supported) removable partial dentures. The participants were then randomized into two groups. Group I received implant supported overdentures on two implants, and Group II received four implants. QoL outcomes were evaluated using standardized questionnaires (EORTC_QLQ c30, H&N35, OHIP, DSI). Outcomes of treatment were evaluated at 6 months (T1) and 1 year (T2) following rehabilitation. A total of 52 patients were randomized into two treatment groups (26 each). After accounting for the loss to lack of follow-up, 22 patients in Group I and 24 patients in Group II were evaluated for QoL at the end of the study. There was a significant improvement in QoL with implant-assisted dental rehabilitation. However there were no significant differences in QoL between the two-implant and four-implant groups. Implant-supported removable overdentures improve QoL outcomes in patients with reconstructed mandibles. This study showed no significant difference in QoL outcomes in patients with two- or four-implant supported removable prostheses.

Cost-effectiveness of implant-supported mandibular removable partial dentures.

The aim of this study was to conduct a cost-effectiveness analysis comparing conventional removable partial dentures (RPDs) and implant-supported RPDs (ISRPDs) treatment in patients with an edentulous maxilla and a bilateral free-ending situation in the mandible. Thirty subjects were included. A new RPD was made and implant support was provided 3months later. Treatment costs (opportunity costs and costs based on tariffs) were calculated. Treatment effect was expressed by means of the Dutch Oral Health Impact Profile questionnaire (OHIP-NL49), a chewing ability test (Mixing Ability Index, MAI) and a short-form health survey measuring perceived general health (SF-36), which was subsequently converted into quality-adjusted-life-years (QALYs). The incremental cost-effectiveness ratio (ICER) was the primary outcome measure of cost-effectiveness, comparing both treatment strategies. The mean total opportunity costs were €981 (95% CI €971-€991) for the RPD treatment and €2.480 (95% CI €2.461-€2.500) for the ISRPD treatment. The total costs derived from the national tariff structure were €850 for the RPD treatment and €2.610 for the ISRPD treatment. The ICER for OHIP-NL49 and MAI using the opportunity costs was €80 and €786, respectively. When using the tariff structure, corresponding ICERs were €94 and €921. The effect of supporting an RPD with implants when expressed in QALYs was negligible; hence an ICER was not determined. It is concluded that depending on the choice of outcome measure and monetary threshold, supporting an RPD with implants is cost-effective when payers are willing to pay more than €80 per OHIP point gained. Per MAI point gained, an additional €786 has to be invested.

Load distribution on abutment tooth, implant and residual ridge with distal-extension implant-supported removable partial denture

PurposeThe aim of this study was to evaluate the effect of implant location on load distribution in the abutment tooth, implant and residual ridge with a distal-extension implant-supported removable partial denture (ISRPD). MethodsA mandibular unilateral distal-extension edentulous simulation model was used. Implants were inserted at the second premolar (mesial implant) and second molar (distal implant) positions in the edentulous area. An experimental ISRPD was fabricated of acrylic resin with a cobalt-chromium alloy framework. Loads on the implants and abutment tooth were measured with piezoelectric force transducers. The load on the residual ridge was measured with pressure-sensitive film. A vertical load of 100N was applied at the first molar region. Measurements were made under the following three conditions: with conventional removable partial denture (CRPD), with mesial-implant-supported removable partial denture (MISRPD), and with distal-implant-supported removable partial denture (DISRPD). In each condition, the unused implants were made inactive by eliminating contact with the inner surface of the denture. ResultsThe load on the abutment tooth was greatest with DISRPD, followed by CRPD and MISRPD (P<0.01). The load on the implant was greater with DISRPD than with MISRPD (P<0.01). The load on the residual ridge was lowest with DISRPD, followed by MISRPD and CRPD (P<0.01). ConclusionsThis experimental study provided quantitative data regarding the effect of implant location on load distribution with ISRPDs. Further investigation regarding the effect of denture design on the load distribution is needed for determining the proper implant location of ISRPD.

Implant-Supported Removable Partial Denture Improves the Quality of Life of Patients with Extreme Tooth Loss.

This study aimed to evaluate oral health-related quality of life (OHRQoL) in partially dentate subjects, presenting extreme tooth loss in posterior region with missing post-canines, comparing the use of conventional removable partial dentures (RPDs) and implant-supported RPDs. OHRQoL was measured using the Brazilian version of the Oral Health Impact Profile. Twelve subjects presenting maxillary total and mandibular Kennedy Class I edentulism (mean age 62.6±7.8 years) first received complete maxillary dentures and conventional mandibular free-end RPDs. After two months, the subjects had their OHRQoL assessed. Osseointegrated implants were inserted bilaterally in the mandibular first molar regions, and after four months ball abutments were placed to support the free-end RPD. Two months later, the patients had their OHRQoL reassessed. Wilcoxon signed-rank test was used to evaluate differences in OHRQoL (α=0.05). Results showed improvement in all OHIP-49 domains (p<0.05) after associating implants to the RPD. The mandibular implant-supported free-end RPD significantly improved OHRQoL.

Flexible resins: an esthetic option for partially edentulous patients

Flexible thermoplastic resins have been used as an alternative to partially edentulous patients for decades in the USA. However, they are neither popular nor widespread in Brazil. This material represents an excellent treatment option to solve clinical problems such as compromised esthetics caused by visible metal clasps, and fall fracture of dentures made of conventional resins. Additionally, there is little researching and no controlled clinical studies about the use of flexible resins in prosthodontics. For these reasons, this study presents a case report of a dissatisfied patient treated with a conventional removable partial denture, which was replaced by a modified metal framework without metal clasps in combination with flexible resin, and a literature review about this material focusing on the dental practitioner. The study also reports how these polymers can be used, their indications, and their clinical and laboratory considerations.

One Year Clinical Follow-Up of Oral Health Status in Cobalt-Chromium Removable Partial Denture Wearers

Objective: To investigate the effect of conventional removable partial dentures (RPDs) on oral tissue in terms of periodontal condition and caries incidence for Saudi female patients in Riyadh. Methods: This is a clinical trial in which 61 female patients were treated with conventional RPDs in College of Dentistry, Riyadh, Saudi Arabia. A base line examination was done one week after denture insertion which included plaque index, probing depth, tooth mobility, and caries. The same examination was performed in a recall visit one year later. Data were statically analyzed and significance level was set to 0.05. Results: A statistically significant difference was detected between base line examination and the recall in plaque index, probing depth, mobility, and caries incidence (p<0.05). Conclusion: Plaque index, probing depth, tooth mobility, and caries increased after one year of wearing Cobalt Chromium RPDs.

Magnet supported cast based complete denture

Magnets have been used widely in the field of dentistry for many years with some success, as they can be manufactured in small dimensions as retentive devices in overdenture technique, maxillofacial prosthesis, and obturators. Unlike mechanical attachments, magnets have potential for unlimited durability and might, therefore, be superior to mechanical ball or bar attachments for the retention of removable prostheses. The present article demonstrates the rehabilitation of a partially edentulous patient with the help of magnetic assembly mandibular overdenture and maxillary conventional removable partial denture. A multidisciplinary approach was adopted to retain the remaining teeth in the mandibular arch with the help of endodontic treatment (root canal treatment) followed by prosthetic rehabilitation.

Influence of different prosthodontic rehabilitation options on oral health-related quality of life, orofacial esthetics and chewing function based on patient-reported outcomes.

The aim was to assess influence of different prosthodontic rehabilitation options on improvement of orofacial esthetics, chewing function (CF) and oral health-related quality of life. Patients treated with 70 conventional complete dentures (CDs), 38 implant-supported mandibular complete dentures opposed to maxillary CDs, 56 conventional removable partial dentures, 15 implant-supported removable partial dentures, 25 conventional fixed partial dentures (FPDs) and 59 implant-supported fixed partial dentures (IFPDs) were included. The survey was conducted using the three questionnaires: the OHIP-CRO14, the Orofacial Esthetic Scale (OES-CRO) and the Chewing Function Questionnaire (CFQ), and administrated twice: at the baseline prior the therapy and 3 months after prosthodontic rehabilitation had been finished. The after-treatment scores were significantly better than the baseline scores (p < 0.001) for the OES, OHIP14 and CF questionnaires in all types of treatments. The two-factor ANOVA showed no significant difference for the OES after-treatment scores between different rehabilitation options and implant presence, but the OHIP14 and CFQ after-treatment scores were significantly better in FPD and IFPDs than in removable implant and conventional denture wearers. The score change was significantly higher in all implant removable denture patients for the OES, OHIP and CFQ. The lowest score change was registered in the FPD wearers. (p < 0.01). Removable denture implant patients most benefited from implant support, but IFPD and FPD had the best after-treatment scores. The assessed clinical parameters may help dentists in choice of the best rehabilitation option with the highest treatment effect.

다수의 임플란트발거로 임플란트 고정성 보철이 실패한 환자에서의 잔존 임플란트를 이용한 부분 가철성 국소의치 수복증례

부분 무치악을 수복하는 데 있어서 선택할 수 있는 치료의 옵션으로는 전통적인 국소의치와 임플란트 지지-고정성 보철물 등이 있다. 하지만, 환자의 전신적 또는 구강의 상태(수술적인 술식이 제한되는 전신병력, 지지조직의 부족 그리고 골유착에 실패한 임플란트)와 치료비용에 대한 허용 정도에 따라 모든 옵션이 항상 가능한 것은 아니다. 가철성 국소의치는 임플란트 고정성 보철물에 비해 구강위생 관리 및 상,하악 악간관계의 부조화를 수정하기에 편리한 장점이 있다. 최근에는 전략적 위치에 임플란트를 식립하여 기존 악궁 형태에서는 제한되는 국소의치 디자인의 한계를 개선할 수 있는 임플란트지지형 RPD(Implant Supported Removable Partial Denture)가 새로운 방안으로 대두되고 있다. ISRPD는 전략적 위치에 임플란트를 식립하여 역학적인 한계를 극복할 수 있을 뿐 만 아니라 전악의 임플란트지지형 고정성 보철이 제한되는 환자에서 보다 경제적이고 현실적인 보철적 해결책이 될 수 있다. 따라서, RPD를 이용한 보철계획 수립시 전략적 위치에서의 임플란트의 사용은 고전적인 가철성 국소 의치에서보다 유지력과 안정성을 증진시키고 구강위생관리 또한 용이하여 환자의 적응도를 높이는 방안으로 고려될 수 있다. 본 증례는 상악 양측 구치부의 임플란트 고정성 보철,하악의 bar-type overdenture를 사용중이던 59세 남성환자에서 상악 #15i임플란트의 abutment screw fracture와 임플란트의 골유착 실패로 인한 다수 임플란트를 발거 후 남은 #15i,24i,25,26,i의 잔존 임플란트와 #23 자연치를 활용해 상악에 ISRPD를 적용한 경우이다. #23 surveyed crown, #24i=25i=26i surveyed bridge 및 #15i에 gold coping을 제작하여 국소의치의 지지와 유지,안정을 도모하였다.최종 보철물을 장착하고 2년간 주기적인 follow up 통해 예후를 관찰중이며 지대치로 사용한 임플란트에서 screw loosening이나 파절, 골흡수 등의 증상은 현재까지 관찰되지 않았다. There are several treatment options for rehabilitation of partial edentulism including the use of conventional or implant-retained fixed prostheses. However, such prosthetic options cannot always be possible because of compromised general and oral health (i.e. loss of supporting tissues, medical reasons, extensive surgical protocol and osseointegration failure of dental implant) as well as the affordability of patients. In some cases, removable partial denture provides easier access for oral hygiene procedures and the ability to correct discrepancies in dental arch relationships than implant fixed prosthesis. Recently, Implant Supported Removable Partial Denture (ISRPD) where to place dental implant in strategic position has been suggested to improve the limitation and shortcomings of conventional RPD. ISPRD can overcome mechanical limition of conventional RPD by placing implant in a favorable position and can be cost-effective, prosthetic solution for partially edentulous patients who are not immediate candidates for extensive, fixed implant supported restorations. Incorporation of dental implants to improve the RPD support and retention and to enhance patient acceptance should be considered when treatment planning for RPD. In this case, 59 years old male patient who received dental treatment of implant fixed prosthesis on both side of the upper jaw and implant overdenture on lower jaw showed implant abutment screw fracture on #15i and osseointegration failure on multiple number of implants. After removing failed implants, we planned ISRPD using #15i,24i,25i,26i and #23 natural tooth for RPD abutment. We fabricated #23 surveyed crown,#24i=25i=26i surveyed bridge and #15i gold coping for support,retention and stability for RPD. Periodic follow up check for 2years has been performed since the ISRPD delivery to the patient. No sign of screw loosening, fracture or bone resorption around abutment implants were detected.

Comparison of functionally orientated tooth replacement and removable partial dentures on the nutritional status of partially dentate older patients: A randomised controlled clinical trial

ObjectivesThe aims of this study were to conduct a randomised controlled clinical trial (RCT) of partially dentate older adults comparing functionally orientated treatment based on the SDA concept with conventional treatment using RPDs to replace missing natural teeth. The two treatment strategies were evaluated according to their impact on nutritional status measured using haematological biomarkers. MethodsA randomised controlled clinical trial (RCT) was conducted of partially dentate patients aged 65 years and older (Trial Registration no. ISRCTN26302774). Each patient provided haematological samples which were screened for biochemical markers of nutritional status. Each sample was tested in Cork University Hospital for serum Albumin, serum Cholesterol, Ferritin, Folate, Vitamin B12 and 25-hydroxycholecalciferol (Vitamin D). ResultsA mixed model analysis of covariance (ANCOVA) indicated that for Vitamin B12 (p=0.9392), serum Folate (p=0.5827), Ferritin (p=0.6964), Albumin (p=0.8179), Serum Total Cholesterol (p=0.3670) and Vitamin D (p=0.7666) there were no statistically significant differences recorded between the two treatment groups. According to the mixed model analysis of covariance (ANCOVA) for Vitamin D there was a significant difference between levels recorded at post-operative time points after treatment intervention (p=0.0470). There was an increase of 7% in 25-hydroxycholecalciferol levels recorded at 6 months compared to baseline (p=0.0172). There was no further change in recorded levels at 12 months (p=0.6482) and these increases were similar within the two treatment groups (p>0.05). ConclusionsThe only measure which illustrated consistent significant improvements in nutritional status for either group were Vitamin D levels. However no significant difference was recorded between the two treatment groups. Clinical significanceFunctionally orientated prosthodontic rehabilitation for partially dentate older patients was no worse than conventional removable partial dentures in terms of impact on nutritional status.

Strain Distribution in a Kennedy Class I Implant Assisted Removable Partial Denture under Various Loading Conditions

Purpose. This in vitro study investigates how unilateral and bilateral occlusal loads are transferred to an implant assisted removable partial denture (IARPD). Materials and Methods. A duplicate model of a Kennedy class I edentulous mandibular arch was made and then a conventional removable partial denture (RPD) fabricated. Two Straumann implants were placed in the second molar region, and the prosthesis was modified to accommodate implant retained ball attachments. Strain gages were incorporated into the fitting surface of both the framework and acrylic to measure microstrain (μStrain). The IARPD was loaded to 120Ns unilaterally and bilaterally in three different loading positions. Statistical analysis was carried out using SPSS version 18.0 (SPSS, Inc., Chicago, IL, USA) with an alpha level of 0.05 to compare the maximum μStrain values of the different loading conditions. Results. During unilateral and bilateral loading the maximum μStrain was predominantly observed in a buccal direction. As the load was moved anteriorly the μStrain increased in the mesial area. Unilateral loading resulted in a twisting of the structure and generated a strain mismatch between the metal and acrylic surfaces. Conclusions. Unilateral loading created lateral and vertical displacement of the IARPD. The curvature of the dental arch resulted in a twisting action which intensified as the unilateral load was moved anteriorly.

Magnet retained mandibular overdenture: A multidisciplinary approach

Magnets have been used widely in the field of dentistry for many years with some success, as they can be manufactured in small dimensions as retentive devices in overdenture technique, maxillofacial prosthesis, and obturators. These magnets are attached with remaining root structure or osseointegrated implants which transfer the occlusal load to the bone through the periodontal ligament of the retained roots, thereby prevent resorption of remaining alveolar bone proper and inter-radicular bone present around the roots. In this article, the use of magnetic assembly in fabrication of mandibular overdenture on retained roots and a conventional maxillary removable partial denture is discussed. Magnetic assembly consists of magnet and coping with a keeper on the remaining tooth structure since magnetic attachments can provide support, stability, and retention.Clinical Relevance to Interdisciplinary DentistryThe present article demonstrates the rehabilitation of partially edentulous patient with the help of magnetic assembly mandibular overdenture and maxillary conventional removable partial denture. Clinical presentation showed few remaining teeth in relation to the mandibular ridge. A multidisciplinary approach was adopted to retain the remaining teeth in the mandibular arch with the help of endodontic treatment (root canal treatment) followed by prosthetic rehabilitation.

The effect of implant‐supported removable partial dentures on oral health quality of life

Removable partial dentures (RPDs) represent standard treatment for partial edentulism despite major shortcomings. To alleviate these shortcomings, endosseous implants provide support and stability as well as contribute to maintenance of alveolar bone. This prospective, within subject, time series study evaluated patient-based outcomes of RPDs compared to implant-supported removable partial dentures (ISRPDs). The study hypothesis was that the ISRPD would substantially improve oral health quality of life for patients. Seventeen patients requesting new mandibular Kennedy I or II RPDs received one 6-mm dental implant in one or both of the posterior edentulous areas. After healing, conventional RPDs were fabricated and delivered. Twelve weeks later, second-stage surgery was performed, and ball abutments with Clix attachments were inserted, thereby converting the prostheses to ISRPDs. Oral health quality of life was evaluated using the 49-item Oral Health Impact Profile (OHIP-49) questionnaire. The OHIP-49 was administered prior to treatment (baseline), at 6 and 12 weeks following RPD delivery and at 6 and 12 weeks following ISRPD conversion. Radiographic evaluation was performed at 6 and 12 weeks following ISRPD conversion. In statistical analysis, a fixed-slope random intercept variance components model took account of the multiple observations per person over time. In 17 subjects, 29 of 30 implants survived. The failed implant was replaced without complications. Abutment complications were limited to one abutment loosening and one attachment replacement. Minor prosthodontic complications were recorded. The OHIP-49 score reduced by 11.8 points, on average, at 12 weeks following ISRPD conversion (P = 0.011). Patients reported improved oral health following conversion to an ISRPD from RPD. The ISRPD involving short implants is one treatment option that should be considered when treatment planning Kennedy Class I and II patients.

Mandibular Overdenture Retained by Magnetic Assembly: A Clinical tip.

The preservation of remaining root structure and alveolar bone covering them with denture has been used since many years. Tooth-retained overdentures transfer occlusal forces to the alveolar bone through the periodontal ligament of the retained tooth roots and thereby prevent bone resorption. Applications of magnets in overdenture technique has been widely used in dentistry in the field of prosthodontics, as they can be manufactured in small dimensions as retentive devices for complete denture, removable partial dentures, obturators and maxillofacial prosthesis. This article presents a simple and efficient method of fabrication of mandibular over denture retained by magnets in a patient whose mandibular residual ridge is severely resorbed with few remaining teeth and maxillary conventional removable partial denture. Mandibular over denture retained by magnets assembly consist of magnet and coping with keeper on remaining tooth structure to rehabilitate the patient since magnetic attachments can provide support, stability and retention.

Periodontal ligament influence on the stress distribution in a removable partial denture supported by implant: a finite element analysis

ABSTRACTObjectiveThe non-homogenous aspect of periodontal ligament (PDL) has been examined using finite element analysis (FEA) to better simulate PDL behavior. The aim of this study was to assess, by 2-D FEA, the influence of non-homogenous PDL on the stress distribution when the free-end saddle removable partial denture (RPD) is partially supported by an osseointegrated implant. Material and MethodsSix finite element (FE) models of a partially edentulous mandible were created to represent two types of PDL (non-homogenous and homogenous) and two types of RPD (conventional RPD, supported by tooth and fibromucosa; and modified RPD, supported by tooth and implant [10.00x3.75 mm]). Two additional FE models without RPD were used as control models. The non-homogenous PDL was modeled using beam elements to simulate the crest, horizontal, oblique and apical fibers. The load (50 N) was applied in each cusp simultaneously. Regarding boundary conditions the border of alveolar ridge was fixed along the x axis. The FE software (Ansys 10.0) was used to compute the stress fields, and the von Mises stress criterion (σvM) was applied to analyze the results. ResultsThe peak of σvM in non-homogenous PDL was higher than that for the homogenous condition. The benefits of implants were enhanced for the non-homogenous PDL condition, with drastic σvM reduction on the posterior half of the alveolar ridge. The implant did not reduce the stress on the support tooth for both PDL conditions. ConclusionThe PDL modeled in the non-homogeneous form increased the benefits of the osseointegrated implant in comparison with the homogeneous condition. Using the non-homogenous PDL, the presence of osseointegrated implant did not reduce the stress on the supporting tooth.

Acetal resin as an esthetic clasp material

Removable partial dentures (RPDs) are an effective and affordable treatment option for partial edentulism. Restoration of esthetics is an important function of RPD and it determines the success of the treatment. The goal of achieving optimal esthetics - while maintaining retentive integrity, stability, and protecting the health of the tooth - is the most difficult task. The traditional use of the metal clasp like cobalt chromium (Co-Cr), gold, stainless steel, and titanium hampers esthetics, since its obvious display conflicts with patient's prosthetic confidentiality. Acetal resin (polyoxymethylene or POM), a thermoplastic resin, may be used as an alternative denture clasp material. This material was promoted primarily on the basis of superior esthetics, which allowed the clasps to better match the color of abutment tooth. PubMed and Google Scholar were used to search original research articles, case reports, and other reviews about acetal resin. The keywords used were acetal resin, esthetic, clasp, removable partial denture, thermoplastic, metal free framework. This article is the result of a literature study on acetal resin clasp material for conventional RPD.

Mucosal Thickness Changes in Flexible and Conventional Cobalt Chrome Removable Partial Dentures Wearers

Mucosal Thickness Changes in Flexible and Conventional Cobalt Chrome Removable Partial Dentures Wearers