Ehab Elsaih

Purpose: This invitro study investigated and compared the effect of different retainer design on load transmission to abutments in asymmetrical distal extension removable partial denture (RPD) cases to verify the null hypothesis that; the use of different clasps in asymmetrical design has no effect on abutment teeth. Materials and methods: A simulated Mandibular arch model with six-anterior teeth, two-first premolars and a left-second-premolar was fabricated. Six RPDs were constructed as follows; three RPDs designed with RPI clasp (mesial occlusal rest, proximal plate and I-bar retainer arm) on both sides (Group I) and the other three RPDs designed with RPI clasp on the longer side and a distal half T clasp (mesial occlusal rest, proximal plate and half T-bar retainer arm) on the shorter side. Linea strain gauges were bonded buccal, lingual and distal to the abutment teeth. Unilateral and central loading was applied and micro strains readings were collected, tabulated, and statistically analyzed Results: The use of a distal half T clasp retainer decreases the micro strains on abutment of the shorter saddle in asymmetrical distal extension partial edentulous model. The use of RPI clasp in the shorter saddle increase strain of abutments (especially distal) upon central loading. Also thi increase strain of abutments (especially lingual) upon unilateral loading of longer RPD saddle. Conclusion: The RPI clasp assembly was found to increase micro-strain versus the distal half T clasp under unilateral load and central loading conditions of asymmetrical bilateral distal extension RDPs.

Objective: The Purpose of this study was to investigate and compare the effect of different mandibular prosthesis; non-splinted implant overdenture (NSIOD), splinted implant overdenture (SIOD) with bar, distal extension removable partial denture (DERPD) and conventional complete denture (CCD) on the antagonist maxillary edentulous arch anterior bone resorption. Materials and methods: Twenty four patients were selected with maxillary edentulous arches against different mandibular prosthesis. According to the mandibular prosthesis the patients were grouped as follows; six patients had NSIOD, six patients had SIOD, six patients had bilateral DERPD and six patients had CCD. Standardized digital panoramic radiographs for each patient at prosthetic delivery and five years later were traced and compared for bone resorption ratio in the anterior maxilla. Results: The mean anterior maxillary bone resorption ratio (AMaxRR) results revealed that in the NSIOD, SIOD, DERPD and CCD groups ongoing resorption of the anterior maxilla had occurred during the 5-years evaluation period, which was significant for DERPD compared to all groups and both SIOD and NSIOD groups compared to CCD group. However, between NSIOD and SIOD groups the results showed insignificant difference. Conclusions: Within the limitation of this study it could be concluded that; 1) maxillary bone resorption continue through time especially anteriorly, 2) absence of clinical evidence that maxillary ridge resorption is accelerated with certain types of two-implant supported mandibular overdenture attachments; 3) for edentulous maxilla the AMaxRR s​h​o​

Maxillary four implants retained palate-less overdenture with two arch distributions (preliminary report) Abstract Statement of problem: The effect of different arch distribution of four implants retaining palate-less complete maxillary overdenture on dental implant has not been sufficiently assessed. Purpose: The purpose of this study was to compare the effect of palate-less maxillary overdenture retained by four implants with different arch distributions on implant survival, marginal bone height changes and periotest values over the study period. Material and methods: Six edentulous male patients, having problems with their maxillary complete denture, were selected to participate in this study. Every participant had four implants installed in maxilla. According to arch configuration of implants patients were grouped into; group I, where implants configured in canine and second premolar bilaterally and group II, where implants configured in canine and first molar bilaterally. After six month the palate-less implant overdenture was constructed and delivered to the patients. Follow-up were doneat 12 and 18 months periods. Effect of prosthesis on implants, with different arch distributions, was studied in terms of; implant survival, marginal bone loss, periotest values and patient satisfaction were carried-out. Data were collected and statistically analyzed. Results: Along the period of this study, both groups; all implant survived with acceptable periotest values, marginal bone level and reported patient satisfaction. Group II showed a statistically significant less marginal bone loss in the posterior i​m​p​l​a​

SummaryThe aim of this 1‐year study was to evaluate and compare crestal bone loss and clinical outcomes of immediate and delayed loaded implants supporting mandibular overdentures with Locator attachments. In a randomised controlled clinical trial, 36 completely edentulous patients (mean age 59·6 years) who desired to improve the stability of their mandibular dentures were randomly assigned into two groups. Each patient received two implants in the canine area of the mandible after a minimal flap reflection. Implants were loaded by mandibular overdentures either 3 months (delayed loading group, G1) or the same day (immediate loading group, G2) after implant placement. Locator attachments were used to retain all overdentures to the implants. Peri‐implant vertical (VBL) and horizontal (HBLO) bone losses and clinical parameters [plaque scores (PI), gingival scores (GI), probing depths (PD) and implant stability (ISQ)] were assessed at time of overdenture insertion (T0), 6 months (T6) and 12 months (T12) after overdenture insertion. After 12 months of overdenture insertion, two implants (5·5%) failed in G2. Vertical bone loss was significantly higher in G2 compared with G1, while HBLO demonstrated insignificant differences between groups. All clinical parameters (PI, GI, PD and ISQ) did not differ significantly between groups. Vertical bone loss was significantly correlated with PD and HBLO. Immediately loaded two implants supporting a Locator‐retained mandibular overdenture are associated with more vertical bone resorption when compared to delayed loaded implants after 1 year. Clinical outcomes do not differ significantly between loading protocols.

Purpose: The aim of this study was to evaluate the effect of cantilevered bar length on strain produced around two implants supporting a mandibular overdenture. Materials and methods: Two root-form implants were placed bilaterally in the canine region of an edentulous acrylic resin mandibular cast and connected with a resilient bar/clip attachment. Four linear strain gauges were bonded to the acrylic resin at the mesial and distal surfaces of each implant. Each gauge was wired separately into a 1/4 Wheatstone bridge of a multichannel digital bridge amplifier. Strains were measured without cantilevered bar extensions (control group) and with the following lengths of cantilevered bars: 11 mm (group 1), 9 mm (group 2), and 7 mm (group 3). For each cantilevered bar length, strains were measured using clips placed on the cantilevers and attached to the overdenture (bar-clip contact) and without clips (bar-acrylic resin contact). Strain measurements were performed under central and unilateral loading using a loading device. Results: The bar with cantilevers (either with or without clips) demonstrated a significant increase in strain compared to the bar without cantilevers. The 11-mm cantilever length generated the highest peri-implant strain values, while the 7-mm length recorded the lowest. For all cantilevered bar lengths, the strains significantly decreased with bar-clip contact compared to bar-acrylic resin contact. Under central loading, distal and mesial peri-implant strains were the highest and the lowest values, respectively, while under unilateral loading, the highest strain was recorded at distal sites of t​

ABSTRACT Background: metal bar splinted implants provide overdenture with good support and retentive quality. Besides, it is known to preserve marginal bone of corresponding dental implants. Reinforced composite bars offer less cost, time preserve, easy to construct and repair alternative. Objective: Till now there is no clear research data comparing reinforced composite bar modality to conventional metal splinting in terms of implant marginal bone height changes. Material and methods: twelve edentulous male patients were selected and assigned into two equal groups using balanced randomization. All patients received lower implant supported overdenture with either cast bar (group I) or infibra ribbon bar (group II). Radiographic evaluations were performed at the time of overdenture insertion then at 6, 12 and 18 months after overdenture insertion. Results: The results were significant for all periods of study. (P=.006*, .039* and .000* for each period respectively) for group I compared to group II. Conclusion: Within the limitation of this short clinical study it could be concluded that; mandibular two implant retained overdenture splinted with infibra ribbon bar reduces stress concentration in implant marginal bone compared to cast bar. As a consequence, bone level is better preserved, and implant survival is expected to be improved if all other clinical conditions were constant.

Purpose: This work was aimed to evaluate and compare the effect of early progressive and delayed loading of two implants retained mandibular overdentures regarding marginal bone changes and periotest values of implants supporting mandibular overdenture. Material and Methods: 24 completely edentulous male patients were selected from department of prosthodontics, Faculty of dentistry, Mansoura University. All systemic and radiographic examinations needed for implant planning and placement were performed. All patients received two implants at the mandibular canine regions. Directly after implant placement, the patients were divided equally into two equal groups as follows; Group I: after 3 months submerging period, implants were exposed and overdentures were attached to ball abutments via direct pick-up technique of female socket attachments (delayed loading), Group II: after 4 weeks of implant installation the mandibular overdenture was attached to implant ball abutment via resilient liner and replaced after another 4 weeks by direct pick-up technique of female socket attachments (early progressive Loading). Follow-up records were done at 6, 12 and 18 months intervals after implant loading with overdentures. Study parameters were radiographic evaluation of marginal bone height changes and implant mobility using periotest. Results: All implants were successful with respect to mobility test with no significant difference between both groups. Generally the mean marginal bone loss and heights changes, both vertically and horizontally, were comparable to the worldwide accepted range. In c​

Background and Purpose: Implant-retained mandibular overdentures have recently become a popular treatment alternative for edentulous patients desiring increased retention of complete dentures. Smoker patient’s are routinely excluded from this benefit, therefore the goal of this study was to evaluate marginal bone changes radiographically around implants placed in mandibular canine region for implant retained overdenture patients (smokers and non smokers) 18 months after loading. Methods: Forty patients received two implants in the mandibular canine region. 13 were nonsmokers and 27 were smokers and subdivided according to smoking ratio to smokers≤ 10cigaretts and smokers >10cigaretts. After three month submerging period healing abutments were connected. Ball abutments were mounted 4–6 weeks afterwards and the complete overdenture was constructed and delivered. Marginal bone level was assessed radio-graphically at time of loading, 6 month, 12 month and 18 month after overdenture insertion. Results: Two patients had unilateral implants were judged as failures at the second surgical appointment. Three patients with clinically successful implants were blindly selected for exclusion from the grouping for balancing the statistical analysis. After the drop outs, seventy two implants were evaluated. A statistically significant vertical bone loss was seen in the three groups after the first 6 months (average 0.733mm ) and after the 2nd 6 months (average .618mm), and after the 3rd 6 months (average .05 mm), with statistically significant differences among the three groups for all p​e​

purpose: This study was aimed to investigate and compare the effect of implant supported versus retained mandibular distal extension removable partial overdenture (RPOD) on the abutment and implant marginal bone height changes. materials and methods: 20 healthy male patients were selected with mandibular bilateral distal extension ridges against edentulous maxilla .One osseointegerated self taping implants was installed distally in the area of the second mandibular molar of each side. Patients were divided into two equal groups; Group I: received maxillary complete denture against implant supported RPOD, and Group II : received maxillary complete denture against implant retained RPOD. Digital panoramic radiographs were recorded for each patient immediately, 6 and 12 months after denture insertion to measure the abutment and implant marginal bone height changes. results: The mean tooth abutments marginal bone loss was statistically significant in both groups after 6 and 12 months of the study. However, this marginal bone loss was statistically significant between both groups after 12 months of the study. The mean implant marginal bone loss was statistically significant within and between both groups along the periods of the study. Conclusion: Regardless the implant RPOD designs concept (supported or retained), abutment tooth and implant marginal bone were significantly reduced. However, this study recommended periodic monitoring of ridge base relation to preserve the supporting structures.