| 1. |
- Kronström, Mats, et al.
(author)
-
Patient evaluation of treatment with fixed prosthodontics supported by implants or a combination of teeth and implants
- 2004
-
In: Journal of Prosthodontics. - 1059-941X .- 1532-849X. ; 13:3, s. 160-165
-
Journal article (other academic/artistic)abstract
- PURPOSE: The objective of this study was to compare treatment outcomes among subjects with complete arch fixed prostheses in the maxilla, supported by implants or a combination of natural teeth and dental implants. MATERIALS AND METHODS: Twenty-one subjects with maxillary tooth- and implant-supported fixed prostheses and 21 subjects with maxillary implant-supported fixed prostheses were identified and included in the study. All abutment teefh in the group with tooth- and implant-supported prostheses were provided with cemented copings that incorporated threads for vertical locking screws. Frameworks were fabricated with a gold alloy that was veneered with acrylic resin or ceramic materials. All frameworks were screw-retained to implants and copings. Frameworks in the group with implant-supported prostheses were fabricated with milled titanium or gold alloy to which denture teeth and resin base material were applied. All prostheses had a minimum of 8 units, at least 4 of which were in one quadrant. Subjects in both groups were mailed a questionnaire consisting of 15 questions focused on various factors related to treatment outcome, such as oral function and patient satisfaction. RESULTS: The response rate was 86%. Both groups reported a high satisfaction rate for most items with few regretting their choice of treatment. Most individuals in both groups reported great improvement in chewing ability and few reported phonetic disturbances. No statistically significant differences were found between the groups. CONCLUSION: The results of the present study showed similarity in questionnaire responses between the 2 groups of participants. High satisfaction was repoited both among subjects who received a complete arch fixed prosthesis in the maxilla supported by dental implants only, as wdl as among those whose prostheses were supported by a combination of natural teeth and dental implants.
|
|
| 2. |
|
|
| 3. |
|
|
| 4. |
- Edin, Benoni B, et al.
(author)
-
Neural network analysis of the information content in population responses from human periodontal receptors
- 1992
-
In: Proceedings of SPIE, the International Society for Optical Engineering. - : SPIE. - 0277-786X .- 1996-756X. ; 1710, s. 257-266
-
Journal article (peer-reviewed)abstract
- Understanding of the information processing in some sensory systems is hampered for several reasons. First, some of these systems may depend on several receptor types with different characteristics, and the crucial features of natural stimuli encoded by the receptors are rarely known with certainty. Second, the functional output of sensory processing is often not well defined. The human tooth is endowed with several types of sensory receptors. Among these, the mechanoreceptors located in the periodontal ligaments have been implicated in force encoding during chewing and biting. Individual receptors cannot, however, code unambiguously either the direction or the magnitude of the applied forces. Neuronal responses recorded in single human nerve fibers from periodontal receptors were fed to multi-layered feed-forward networks. The networks were trained with error back-propagation to identify specific features of the force stimuli that evoked the receptor responses. It was demonstrated that population responses in periodontal receptors contain information about both the point of attack and the direction of applied forces. It is concluded that networks may provide a powerful tool to investigate the information content in responses from biological receptor populations. As such, specific hypotheses with respect to information processing may be tested using neural networks also in sensory systems less well understood than, for instance, the visual system.
|
|
| 5. |
- Edin, Benoni B, et al.
(author)
-
Receptor encoding of moving tactile stimuli in humans. I. Temporal pattern of discharge of individual low-threshold mechanoreceptors.
- 1995
-
In: Journal of Neuroscience. - 0270-6474 .- 1529-2401. ; 15:1 Pt 2, s. 830-847
-
Journal article (peer-reviewed)abstract
- The response of 70 cutaneous, low-threshold mechanoreceptors in the human median, radial and inferior alveolar nerves to well controlled brush stimuli moving across the receptive field was quantitatively studied. Microneurography was used to obtain the response of each to multiple velocities from 0.5 to 32 cm/sec in at least two opposing directions. A high degree of response consistency was observed from the slowly adapting receptors to replication of the same stimulus and to a lesser, but significant degree from the fast adapting receptors. The evoked discharge reflected up to three partially overlapping phases of the moving stimulus: skin compression, indentation, and stretch. Although the overall discharge rate increased with both stimulus velocity and force, the spatial discharge pattern was preserved to a high degrees. In contrast, the discharge patterns differed for opposing and orthogonal directions. Reducing the area of skin surrounding the receptive field that was contacted by the moving stimuli had little effect on the evoked response. Individual mechanoreceptors display highly reliable differences to brush stimuli moving at different velocities. to brush stimuli moving at different velocities. Moreover, different directions of movement evoke differences in the discharge that are consistently observed upon replication of the same stimuli. Despite the richness and consistency in the spatial discharge pattern displayed by individual receptors, it is argued that the details of the patterns are not likely used by the CNS to infer information about direction and velocity of movement across the skin. Rather, the intensity of discharge is proposed as a plausible information-bearing attribute of the stimulus-evoked response.
|
|
| 6. |
- Grigoriadis, Anastasios, et al.
(author)
-
Adaptability of mastication in people with implant-supported bridges
- 2011
-
In: Journal of Clinical Periodontology. - 0303-6979 .- 1600-051X. ; 38:4, s. 395-404
-
Journal article (peer-reviewed)abstract
- Objectives: We aimed to determine whether people with implant-supported bridges in both jaws, thus lacking periodontal receptors, adjust jaw muscle activity to food hardness during mastication.Materials and Methods: Thirteen participants with implant-supported bridges in both jaws and 13 with natural dentition chewed and swallowed soft and hard gelatine-based model foods, while electromyographic (EMG) activity of the masseter and temporal muscles was recorded bilaterally together with the position of the mandible. Data were compared by using a mixed-design anova model and a P-value<0.05 was considered statistically significant.Results: The number of chewing cycles and the duration of the masticatory sequence increased with food hardness in both groups, whereas vertical and lateral amplitude of the jaw movements, and the jaw-opening velocity, increased significantly with food hardness only for the dentate group. Although both groups adapted the EMG activity to the hardness of the food, the implant participants showed a significantly weaker increase in EMG activity with increased food hardness early during the masticatory sequence than the dentate participants did. In addition, the implant group showed significantly less reduction of muscle activity during the progression of the masticatory sequence than the dentate group.Conclusions: People with implant-supported bridges show an impaired adaptation of the muscle activity to food hardness during mastication. We suggest that a lack of sensory signals from periodontal mechanoreceptors accounts for the impairment.
|
|
| 7. |
- Grigoriadis, Anastasios, et al.
(author)
-
Effect of Sudden Deprivation of Sensory Inputs From Periodontium on Mastication
- 2019
-
In: Frontiers in Neuroscience. - : Frontiers Media SA. - 1662-4548 .- 1662-453X. ; 13
-
Journal article (peer-reviewed)abstract
- Objective: To investigate the effect of sudden deprivation of sensory inputs from the periodontium on jaw kinematics and time-varying activation profile of the masseter muscle.Methods: Fourteen (age range: 22-26 years; four men) healthy and natural dentate volunteers participated in a single experimental session. During the experiment, the participants were asked to eat six hard visco-elastic test food models, three each before and after an anesthetic intervention. The movements of the jaw in three dimensions and electromyographic (EMG) activity of the masseter muscle on the chewing side were recorded.Results: The results of the study showed no significant differences in the number of chewing cycles (P = 0.233) and the duration of chewing sequence (P = 0.198) due to sudden deprivation of sensory inputs from the periodontium. However, there was a significant increase in the jaw opening velocity (P = 0.030) and a significant increase in the duration of occlusal phase (P = 0.004) during the anesthetized condition. The EMG activity of the jaw closing phase was significantly higher during the control condition [116.5 arbitrary units (AU)] than anesthetized condition (93.9 AU). The temporal profile of the masseter muscle showed a biphasic increase in the excitatory muscle drive in the control condition but this increase was virtually absent during the anesthetized condition.Conclusion: Sudden deprivation of sensory inputs from the periodontium affects the jaw kinematics and jaw muscle activity, with a clear difference in the time-varying activation profile of the masseter muscle. The activation profile of the masseter muscle shows that periodontal mechanoreceptors contribute to approximately 20% of the EMG activity during the jaw closing phase.
|
|
| 8. |
- Hammoudi, Wedad, et al.
(author)
-
Long-term results of a randomized clinical trial of 2 types of ceramic crowns in participants with extensive tooth wear
- 2022
-
In: The Journal of prosthetic dentistry (Print). - : Elsevier. - 0022-3913 .- 1097-6841. ; 127:2, s. 248-257
-
Journal article (peer-reviewed)abstract
- STATEMENT OF PROBLEM: Evidence is sparse regarding the long-term outcomes of restorative treatment of patients with extensive tooth wear.PURPOSE: The purpose of this long-term prospective randomized clinical trial was to evaluate the performance and success rate of pressed lithium disilicate (LD) and translucent zirconia (TZ) crowns in participants with extensive tooth wear.MATERIAL AND METHODS: A total of 62 participants with extensive tooth wear (17 women, 45 men; mean age 44.8 years; range 25-63 years) received a total of 713 crowns, LD=362 and TZ=351. Both types of crowns had chamfer preparations and were adhesively luted with dual-polymerizing composite resin cement (PANAVIA F 2.0; Kuraray Noritake Dental Inc). The restorations were clinically reevaluated on average 14, 31, 39, 54, and 65 months after insertion of the crowns according to the modified United States Public Health Service (USPHS) criteria.RESULTS: After an observation period of up to 6 years, the survival rate for both types of crowns was 99.7%, with 1 lost LD crown after 1 year as a result of loss of retention and 1 lost TZ crown after 3 years because of tooth fracture at the cemento-enamel junction. The success rates were similar for both types of crowns: 98.6% for LD and 99.1% for TZ. Reasons for failures were that 3 participants in each group developed apical lesions, minimal ceramic fractures, or their crowns were rebonded after loss of adhesion. Assessment of color at baseline was significantly different with a better match for LD (84.8% Alfa, 15.2% Bravo) than for TZ crowns (36.5% Alfa, 63.5% Bravo), including TZ crowns with veneered porcelain (P<.001). Secondary caries and cracks did not occur. A post hoc analysis of clinical performance did not indicate any significant differences between extensive tooth wear with primarily mechanical or chemical factors.CONCLUSIONS: No differences were found between the 2 types of ceramic materials concerning the long-term success and clinical performance, except that TZ crowns were rated by a blinded clinician as less esthetic than LD crowns. The use of high-strength ceramic materials, as well as reliable adhesive bonding, are probably the key factors in the long-term success of ceramic crowns in participants with extensive tooth wear independent of the specific etiology.
|
|
| 9. |
- Hedberg, Linn, et al.
(author)
-
White matter abnormalities mediate the association between masticatory dysfunction and cognition among older adults
- 2023
-
In: Journal of Oral Rehabilitation. - : John Wiley & Sons. - 1365-2842. ; 50:12, s. 1422-1431
-
Journal article (peer-reviewed)abstract
- Background: Masticatory parameters, such as reduced number of teeth and posterior contacts, have been shown to be associated with reduced cognitive status. The underlying mechanisms that affect these associations, are however, not well understood. Objectives: The study aims to investigate the association between masticatory dysfunction and cognition and explore the mediating effect of brain structure. Methods: In this cross-sectional study, 45 older adults with subjective masticatory dysfunction (mean age 72.3 +/- 4.0 years) were included. Mini-Mental State Examination score <25, brain trauma, neurological disease, neurodegenerative disorders, depression or poor Swedish language skills were criteria for exclusion. Cognitive functions (executive function and episodic memory) and masticatory dysfunction defined by functional occluding status (FOS; the number of occluding units and number of remaining teeth) were analysed with partial correlation models. Structural magnetic resonance imaging was performed on 28 feasible participants. Multiple regression analyses were performed to evaluate the predictive value of brain structure and white matter hypointensities (WM-hypo) on cognitive functions. A mediation analysis was applied to assess significant predictor/s of the association between FOS and cognition. Results: Both episodic memory and executive functions were positively correlated with FOS. WM-hypo predicted cognitive status (executive function, p = .01). WM-hypo mediated 66.6% (p = 0.06) of the association between FOS and executive functions. Conclusion: Associations between FOS and cognitive functions are reported, where FOS, a potential modifiable risk factor, was related to both episodic memory and executive functions. The mediating effect of WM-hypo on the association between FOS and executive functions highlights the impact of the vascularisation of the brain on the link between mastication and cognition. The present study provides increased knowledge that bridges the gap between masticatory dysfunction and cognition.
|
|
| 10. |
- Johansson, Anders S, et al.
(author)
-
Impaired masticatory behavior in subjects with reduced periodontal tissue support.
- 2006
-
In: Journal of Periodontology. - : Wiley. - 0022-3492 .- 1943-3670. ; 77:9, s. 1491-7
-
Journal article (peer-reviewed)abstract
- BACKGROUND: Mechanoreceptors situated in the periodontal ligament provide detailed information about intensive and spatial aspects of tooth loads, which support the neural control of masticatory forces. We asked whether a reduced periodontal ligament due to periodontitis, and, thus, an altered mechanoreceptive innervation of the teeth, would affect masticatory behavior when subjects used incisors to hold and split food. METHODS: We tested 11 subjects with reduced periodontal tissue support that rendered 30% to 70% alveolar bone loss for at least one pair of opposing anterior incisors. Forces were recorded when subjects used their affected incisors to hold half of a peanut for approximately 4 seconds and then split it. Age- and gender-matched healthy subjects served as the control group. None of the participants showed acute oral symptoms or massive periodontal inflammation. RESULTS: The test group used greater force when holding food between the teeth (1.1+/-0.4 N [ mean+/-1 SD]) compared to the control group (0.4+/-0.2 N). Hold forces used by subjects in the test group were also more variable, both within and between trials. The increase in bite force applied to split the peanut was slower and more hesitant for subjects in the test group compared to the control group. CONCLUSIONS: Reduced periodontal tissue support accompanies impaired regulation of masticatory forces. Faulty mechanoreceptive innervation of the periodontal ligament explains the elevated hold force, whereas a change in biting strategy due to the weakened support of the teeth may account for the more defensive food-splitting behavior.
|
|
