With the increased life expectancy, complete dentures have been used in the treatment of edentulism<span> </span><span>progressively. It restores stomatognathic system functions, providing improvemen...With the increased life expectancy, complete dentures have been used in the treatment of edentulism<span> </span><span>progressively. It restores stomatognathic system functions, providing improvements in chewing, aesthetics, and phonetics. The aim was to report an oral rehabilitation of a patient with severe aesthetic and functional impairment, with Angle’s class III malocclusion. The patient sought the extension project of the School of Dentistry of the Federal University of Minas Gerais with aesthetic complaints. After clinical and radiographic evaluation, the proposed planning was immediate complete denture maxilla and immediate implant-retained overdenture in mandible. During clinical evaluation it was observed that the patient was Angle</span><span>’</span><span>s III. The rehabilitation was performed as proposed and at the end of the treatment, it was possible to revert the class III occlusal pattern to Angle’s I. The excellent maxillomandibular relationship was achieved, which ensured optimal facial aesthetics and functional condition. It was concluded that the immediate complete dentures and immediate implant-retained overdenture might be beneficial for restoring the aesthetics and function of patients with Angle’s class III malocclusion.</span>展开更多
Previously, the choice of prosthetic implant-retained overdentures has depended on data from previous studies about the retention-fatigue strength of the attachment system selected. Little or no data have been availab...Previously, the choice of prosthetic implant-retained overdentures has depended on data from previous studies about the retention-fatigue strength of the attachment system selected. Little or no data have been available on the correlation between the attachment system selected and the overdenture support configuration. The purpose of the present study was to evaluate the retention force and fatigue resistance of three attachment systems and four support designs of overdenture prosthesis. Four lower edentulous acrylic models were prepared and eight combinations of attachments groups were investigated in the study. These included: O-Rings with mini-dental implants (MDIs), Dalbo elliptic with Dalbo Rotex and fabricated flexible acrylic attachments with both MDI and Dalbo Rotex. The study was divided into four test groups: groups A and B, controls, and groups C and D, experimental groups. Control group A contained three overdenture supports: two free standing MDIs in the canine region and at the midline, and one simulated tooth root with Dalbo Rotex screwed in. Control group B contained four overdenture support foundations: two free standing MDIs in the right canine region and the first premolar region, and two simulated tooth roots with Dalbo Rotex screwed in at the same MDI position, but on the left side of the model. Experimental group C contained three overdenture support foundations: two free standing MDIs in the canine region and at the midline, and one simulated tooth root with MDI screwed in. Experimental group D contained four overdenture support foundations: two free standing MDIs in the right canine region and the first premolar region, and two simulated tooth roots with MDIs screwed in at the same MDI position, but on the left side of the model. Each group was further divided into two subgroups according to attachment type used. Five samples were prepared for each group. Retention force (N) values were recorded initially (0 cycles) and after 360, 720, 1440 and 2880 insertion and removal cycles. During the tensile test a cross-head speed of 10 mm/min was applied. Values of absolute force (AF) and relative force (RF) were statistically analyzed by two-way ANOVA and multiple comparison Tukey’s tests between groups and cycles periods. The results of fatigue tests showed a 50% reduction in retention force in the subgroups with flexible attachments. A triangular design of overdenture support foundations with O-Ring attachments revealed the lowest value of AF and a relatively high reduction in RF. The four overdenture support designs with flexible acrylic attachments improved the retention force and reduced the fatigue retention. Furthermore, the results of the investigation demonstrate that flexible acrylic attachments for both teeth and implant-supported overdentures offer a wide range of retention forces.展开更多
Mandibular single denture opposed by maxillary natural dentition showed a great problem. However, mandibular implant overdenture treatment has gained considerable recognition. Ten male patients with complete mandibula...Mandibular single denture opposed by maxillary natural dentition showed a great problem. However, mandibular implant overdenture treatment has gained considerable recognition. Ten male patients with complete mandibular edentulous arch and opposing arch have full natural dentition. Patients were divided into two groups. All patients received two endosseous titanium implants. In Group I, patients were rehabilitated with conventional implant retained overdentures. While in Group II, Patients were rehabilitated with occlusal reactive implant overdentures. A Novel proposed biosensor was used to measure the amount of biting force on the implant retained overdenture. Quantitative electromyographic (EMG) signals of the masseter and anterior fibers of temporalis muscles were recorded, filtered and directly interfaced with a computer to represent the data graphically. The mean amplitude (μV), turn, and activity were recorded at the baseline and after three months. The results revealed an increase in the muscle activity in group II after three months as compared to group I. Significant difference in bilateral biting force at the premolar-molar area was found between group I and group II after three months. This study concluded that a resilient implant overdenture denture could be a desirable treatment in mandibular overdenture supported by two implants with resilient attachment and opposing natural dentition due to its easy fabrication and durability in use and increased muscle activity.展开更多
Aim: To compare the chewing process and swallowing threshold parameters of subjects with complete dentures and overdentures with data obtained from subjects with complete natural dentitions. Metho-dology: The chewing ...Aim: To compare the chewing process and swallowing threshold parameters of subjects with complete dentures and overdentures with data obtained from subjects with complete natural dentitions. Metho-dology: The chewing process in terms of swallowing threshold parameters of four groups of subjects with complete dentures (all females) was quantified by sieving particles after chewing of an artificial test ‘food’ and compared with that of subjects with com-plete natural dentitions as a reference group (33 sub-jects). All subjects (except those of the reference group) had a complete denture in the upper jaw. Regarding the lower jaw two groups with complete dentures (with high (24 subjects), respectively low mandible (12 subjects)) and two groups with overdentures (implant-retained (22 subjects), respectively natural root supported (19 subjects)) were composed. Results: The ‘overdenture-implants’ group needed significantly more chewing cycles and time (mean: 45 cycles in 32 seconds) until ‘swallowing’ compared to the group with complete natural dentitions (mean: 26 cycles in 19 seconds until ‘swallowing’). Also the ‘complete denture-low mandible’ group needed sig-nificantly more cycles and time (mean: 52 cycles in 44 seconds) until ‘swallowing’ than the complete dentition group. In the ‘overdenture-natural roots’ group these outcomes (33 cycles in 24 seconds) were not significantly different compared with the complete dentition group. The ‘complete denture-high mandi-ble’ group (32 cycles in 26 seconds) needed not sig-nificantly more cycles until ‘swallowing’, however time until ‘swallowing’ was significantly longer com-pared to the complete dentition group. All denture groups had significantly larger mean particle sizes when ‘swallowing’ (sizes in the order of 3 mm) than the natural dentition group (about 2 mm). Conclusion: Despite efforts to compensate for a reduced chewing efficiency, subjects with complete dentures (including overdentures) had 50% larger median particle sizes when ‘swallowing’ compared to subjects with complete natural dentitions.展开更多
The aim of this study was to assess the stress patterns on the peri-implant zone and residual alveolar ridge in different overdenture attachment system designs by the photoelasticity method. Four attachments systems w...The aim of this study was to assess the stress patterns on the peri-implant zone and residual alveolar ridge in different overdenture attachment system designs by the photoelasticity method. Four attachments systems were tested: O-ring, ERA, Bar-clip, and Bar-clip/O-ring association. The prostheses were loaded with 100 N in five pre-determined points and the photoelastic model was evaluated by a circular polariscope. The anterior load, O-ring, and ERA showed better stress distribution in relation to the bars systems, which presented stress levels surrounding implants. The molar load, Bar-clip/O-ring association, presented the biggest stress concentration on the peri-implant region in relation to the others. When the second molar was loaded, there was a concentration of stress in the alveolar ridge in all situations analyzed. Within the limitation of this “in vitro” study, it could be concluded that there were biomechanical differences among the attachments systems analyzed, principally between isolated and the bars systems. The O-ring showed better stress distribution and the Bar-clip/O-ring showed higher stress concentration.展开更多
文摘With the increased life expectancy, complete dentures have been used in the treatment of edentulism<span> </span><span>progressively. It restores stomatognathic system functions, providing improvements in chewing, aesthetics, and phonetics. The aim was to report an oral rehabilitation of a patient with severe aesthetic and functional impairment, with Angle’s class III malocclusion. The patient sought the extension project of the School of Dentistry of the Federal University of Minas Gerais with aesthetic complaints. After clinical and radiographic evaluation, the proposed planning was immediate complete denture maxilla and immediate implant-retained overdenture in mandible. During clinical evaluation it was observed that the patient was Angle</span><span>’</span><span>s III. The rehabilitation was performed as proposed and at the end of the treatment, it was possible to revert the class III occlusal pattern to Angle’s I. The excellent maxillomandibular relationship was achieved, which ensured optimal facial aesthetics and functional condition. It was concluded that the immediate complete dentures and immediate implant-retained overdenture might be beneficial for restoring the aesthetics and function of patients with Angle’s class III malocclusion.</span>
文摘Previously, the choice of prosthetic implant-retained overdentures has depended on data from previous studies about the retention-fatigue strength of the attachment system selected. Little or no data have been available on the correlation between the attachment system selected and the overdenture support configuration. The purpose of the present study was to evaluate the retention force and fatigue resistance of three attachment systems and four support designs of overdenture prosthesis. Four lower edentulous acrylic models were prepared and eight combinations of attachments groups were investigated in the study. These included: O-Rings with mini-dental implants (MDIs), Dalbo elliptic with Dalbo Rotex and fabricated flexible acrylic attachments with both MDI and Dalbo Rotex. The study was divided into four test groups: groups A and B, controls, and groups C and D, experimental groups. Control group A contained three overdenture supports: two free standing MDIs in the canine region and at the midline, and one simulated tooth root with Dalbo Rotex screwed in. Control group B contained four overdenture support foundations: two free standing MDIs in the right canine region and the first premolar region, and two simulated tooth roots with Dalbo Rotex screwed in at the same MDI position, but on the left side of the model. Experimental group C contained three overdenture support foundations: two free standing MDIs in the canine region and at the midline, and one simulated tooth root with MDI screwed in. Experimental group D contained four overdenture support foundations: two free standing MDIs in the right canine region and the first premolar region, and two simulated tooth roots with MDIs screwed in at the same MDI position, but on the left side of the model. Each group was further divided into two subgroups according to attachment type used. Five samples were prepared for each group. Retention force (N) values were recorded initially (0 cycles) and after 360, 720, 1440 and 2880 insertion and removal cycles. During the tensile test a cross-head speed of 10 mm/min was applied. Values of absolute force (AF) and relative force (RF) were statistically analyzed by two-way ANOVA and multiple comparison Tukey’s tests between groups and cycles periods. The results of fatigue tests showed a 50% reduction in retention force in the subgroups with flexible attachments. A triangular design of overdenture support foundations with O-Ring attachments revealed the lowest value of AF and a relatively high reduction in RF. The four overdenture support designs with flexible acrylic attachments improved the retention force and reduced the fatigue retention. Furthermore, the results of the investigation demonstrate that flexible acrylic attachments for both teeth and implant-supported overdentures offer a wide range of retention forces.
文摘Mandibular single denture opposed by maxillary natural dentition showed a great problem. However, mandibular implant overdenture treatment has gained considerable recognition. Ten male patients with complete mandibular edentulous arch and opposing arch have full natural dentition. Patients were divided into two groups. All patients received two endosseous titanium implants. In Group I, patients were rehabilitated with conventional implant retained overdentures. While in Group II, Patients were rehabilitated with occlusal reactive implant overdentures. A Novel proposed biosensor was used to measure the amount of biting force on the implant retained overdenture. Quantitative electromyographic (EMG) signals of the masseter and anterior fibers of temporalis muscles were recorded, filtered and directly interfaced with a computer to represent the data graphically. The mean amplitude (μV), turn, and activity were recorded at the baseline and after three months. The results revealed an increase in the muscle activity in group II after three months as compared to group I. Significant difference in bilateral biting force at the premolar-molar area was found between group I and group II after three months. This study concluded that a resilient implant overdenture denture could be a desirable treatment in mandibular overdenture supported by two implants with resilient attachment and opposing natural dentition due to its easy fabrication and durability in use and increased muscle activity.
文摘Aim: To compare the chewing process and swallowing threshold parameters of subjects with complete dentures and overdentures with data obtained from subjects with complete natural dentitions. Metho-dology: The chewing process in terms of swallowing threshold parameters of four groups of subjects with complete dentures (all females) was quantified by sieving particles after chewing of an artificial test ‘food’ and compared with that of subjects with com-plete natural dentitions as a reference group (33 sub-jects). All subjects (except those of the reference group) had a complete denture in the upper jaw. Regarding the lower jaw two groups with complete dentures (with high (24 subjects), respectively low mandible (12 subjects)) and two groups with overdentures (implant-retained (22 subjects), respectively natural root supported (19 subjects)) were composed. Results: The ‘overdenture-implants’ group needed significantly more chewing cycles and time (mean: 45 cycles in 32 seconds) until ‘swallowing’ compared to the group with complete natural dentitions (mean: 26 cycles in 19 seconds until ‘swallowing’). Also the ‘complete denture-low mandible’ group needed sig-nificantly more cycles and time (mean: 52 cycles in 44 seconds) until ‘swallowing’ than the complete dentition group. In the ‘overdenture-natural roots’ group these outcomes (33 cycles in 24 seconds) were not significantly different compared with the complete dentition group. The ‘complete denture-high mandi-ble’ group (32 cycles in 26 seconds) needed not sig-nificantly more cycles until ‘swallowing’, however time until ‘swallowing’ was significantly longer com-pared to the complete dentition group. All denture groups had significantly larger mean particle sizes when ‘swallowing’ (sizes in the order of 3 mm) than the natural dentition group (about 2 mm). Conclusion: Despite efforts to compensate for a reduced chewing efficiency, subjects with complete dentures (including overdentures) had 50% larger median particle sizes when ‘swallowing’ compared to subjects with complete natural dentitions.
文摘The aim of this study was to assess the stress patterns on the peri-implant zone and residual alveolar ridge in different overdenture attachment system designs by the photoelasticity method. Four attachments systems were tested: O-ring, ERA, Bar-clip, and Bar-clip/O-ring association. The prostheses were loaded with 100 N in five pre-determined points and the photoelastic model was evaluated by a circular polariscope. The anterior load, O-ring, and ERA showed better stress distribution in relation to the bars systems, which presented stress levels surrounding implants. The molar load, Bar-clip/O-ring association, presented the biggest stress concentration on the peri-implant region in relation to the others. When the second molar was loaded, there was a concentration of stress in the alveolar ridge in all situations analyzed. Within the limitation of this “in vitro” study, it could be concluded that there were biomechanical differences among the attachments systems analyzed, principally between isolated and the bars systems. The O-ring showed better stress distribution and the Bar-clip/O-ring showed higher stress concentration.
