Immediate versus conventional loading of mandibular implant-retained overdentures: a 3-year follow-up of a randomized controlled trial.

OBJECTIVES: There is a scarcity of randomized clinical trials (RCT) that report medium- and long-term results and a lack of consensus in the literature on the predictability of immediately loaded unsplinted narrow diameter implants supporting mandibular overdentures. This RCT compared the performance of conventional (CL) and immediate loading (IL) of mandibular overdentures retained by two narrow-diameter implants for 3 years. MATERIALS AND METHODS: Patients from an RCT treated with CL or IL were invited to attend to 2- and 3-year follow-ups. Clinical, radiographic, functional, and oral health-related quality of life parameters were evaluated. Prosthetic maintenance events, biological complications, and success and survival rates were also recorded. The data were tested by multilevel mixed-effects linear regression analysis and chi-squared tests. RESULTS: The 1-year survival rates of 90% in the CL group and 85% in the IL group were maintained as no implants were lost between 1 and 3 years. The marginal bone loss (MBL) in the IL group was significantly lower after year 3 (-0.04; p < 0.01). Significant changes were found only for the intra-group comparisons in the third year of function: (i) CL and IL presented similar progression of implant stability, MBL, and posterior bone area resorption; (ii) while CL started deteriorating of masticatory function, IL still exhibited functional evolution and (iii) oral comfort domain in the CL and pain domain in the IL were improved. CONCLUSION: Although IL experienced the lowest MBL after 3 years, the outcomes showed that both loading protocols result in predictable medium-term rehabilitation when monitored annually. CLINICAL RELEVANCE: It can be expected that in the third year of function, patients with immediate loading may present more complaints related to general performance even with acceptable masticatory function and self-reported improvements in oral comfort.

Effect of mandibular bone atrophy on maxillary and mandibular bone remodeling and quality of life with an implant-retained mandibular overdenture after 3 years.

STATEMENT OF PROBLEM: The medium-term effect of an implant-retained mandibular overdenture on bone remodeling in the maxilla and posterior mandible of edentulous patients and the effects on quality of life have not been established. PURPOSE: The purpose of this prospective observational clinical study was to evaluate the 3-year effects of implant-retained mandibular overdentures on oral-health-related quality of life (OHRQoL) and bone remodeling in different regions of the maxilla and mandible in participants with atrophic or nonatrophic mandibles. MATERIAL AND METHODS: Twenty-six edentulous participants received 2 narrow-diameter implants in the anterior mandible. Mandibular bone atrophy was categorized from presurgical panoramic radiographs according to the Cawood and Howell criteria. OHRQoL was assessed by using the OHIP-EDENT questionnaire. Participants were evaluated annually for 3 years to measure the marginal bone loss and bone area of the posterior mandible, and the anterior and posterior regions of the maxilla were assessed annually through panoramic radiographs. The data were analyzed by using a mixed-effects linear regression to estimate time-dependent trends and a mixed-effect linear regression model to verify differences between groups. The Pearson correlation coefficients between bone variables and 3-year OHIP-EDENT outcomes were calculated. RESULTS: In the third year, atrophic participants had a significantly lower marginal bone loss (0.02 mm) than nonatrophic participants (-0.39 mm) (P=.030). Differences were also found in the functional limitation (nonatrophic=1.82 ±1.75, atrophic participants=1.92 ±1.54; P=.018) and handicap domains (nonatrophic=0.36 ±0.54, atrophic participants=0.08 ±0.27; P=.003). For nonatrophic participants, comparisons between baseline and 3-year outcomes showed significant bone resorption as indicated by the area ratio in the anterior maxilla (P=.035), posterior maxilla (P=.022), and posterior mandible (P=.009). Conversely, the bone area of the anterior maxilla (P=.019) decreased in atrophic participants between baseline and year 1, while the bone area of the anterior maxilla and posterior mandible increased (P<.001) between years 1 and 3. Higher effect sizes were observed in the OHRQoL domains of the atrophic participants. CONCLUSIONS: Bone atrophy influenced both the OHRQoL profile and bone remodeling profile in different regions of the mandible and maxilla in mandibular overdenture users. In atrophic participants, bone tissue in both jaws responded positively to overdenture use, with bone apposition after the first year and bone area preservation in the anterior maxilla, posterior mandible, and peri-implant regions after 3 years of follow-up.

Clinical performance of narrow-diameter implants with hydrophobic and hydrophilic surfaces with mandibular implant overdentures: 1-year results of a randomized clinical trial.

OBJECTIVE: To compare peri-implant clinical and radiographic parameters between hydrophilic and hydrophobic narrow dental implants in patients with mandibular implant overdentures for 1 year. MATERIALS AND METHODS: In a randomized, double-blind, split-mouth study with a 1-year follow-up, sixteen edentulous participants received two narrow-diameter implants in the anterior mandibular region with 2 types of surfaces: hydrophobic (Neoporos surface, NS) and hydrophilic (Acqua surface, AS). During the osseointegration period and after loading with mandibular implant overdentures, the outcomes monitored were (i) peri-implant health: early healing index (EHI), visible plaque index (VPI), calculus presence (CP), peri-implant inflammation (PI), probing depth (PD), and bleeding on probing (BOP); (ii) implant stability quotient (ISQ), (iii) crestal bone loss (CBL) and bone level change (BLC); and (iv) implant success and survival rates. RESULTS: The PD in NS implants decreased by 31.78% between 15 and 30 days, while a similar reduction (-31.28%) occurred in the 3rd month in the AS group. The ISQ also decreased significantly during the 1st month in both groups: -10.95% after 7 days in the NS group and -7.46% after 15 days in the AS group. At 12 months, statistically significant differences were not observed; however, the AS surface presented 50.6% smaller CBL and 41.3% smaller BLC values. The success and survival rates were 62.5% for AS implants and 87.5% for NS implants. CONCLUSION: Narrow-diameter implants with hydrophilic and hydrophobic surfaces loaded with mandibular implant overdentures showed no differences in peri-implant healing, stability, and peri-implant bone remodeling in the 1st year of follow-up.

Circumferential bone level and bone remodeling in the posterior mandible of edentulous mandibular overdenture wearers: influence of mandibular bone atrophy in a 3-year cohort study.

OBJECTIVES: Evaluate circumferential bone level and morphological alterations in the posterior mandibular ridge of atrophic (AP) and non-atrophic (NAP) patients using implant-retained mandibular overdentures (MO) over 3 years. MATERIALS AND METHODS: Twenty-six edentulous patients categorized according to mandibular atrophy (AP = 13/NAP = 13) received two narrow diameter implants (Facility, 2.9 × 10 mm) in the anterior region of mandible. The vertical and horizontal bone level was measured along with bone remodeling at 4 distances from the mental foramen in the posterior region of the mandible (L1-L4) via CBCT. RESULTS: NAP showed significantly higher total height and medullary height in all posterior regions at 1 and 3 years (p ≤ 0.01). Cortical height and width were significantly higher (p ≤ 0.05) in this group at distances L1 and L4, respectively, in year 1. NAP shows a significantly higher % of medullary height at distances L1 (p ≤ 0.05), L2 (p ≤ 0.01), and L3 (p ≤ 0.05) after 1 year, and at all distances (p ≤ 0.05) after 3 years. Bone remodeling in the groups differed significantly (p ≤ 0.05) in terms of cortical width and % medullary width at L3. CONCLUSION: AP and NAP showed similar vertical and horizontal bone level. Bone resorption in the posterior ridge was stabilized by MO over 3 years; however, AP are more susceptible to the long-term substitution of medullary bone by cortical bone. CLINICAL RELEVANCE: This study is the first to longitudinally evaluate bone dimensions in atrophic and non-atrophic two-implant MO users by CBCT and revealed that MO is a predictable treatment based on the stabilization of the posterior bone resorption.

Effect of mandibular residual ridge regularization on peri-implant wound healing when narrow diameter implants are used as overdenture retainers.

STATEMENT OF PROBLEM: Alveolar ridge regularization involves the smoothing and minimal reduction of rough alveolar bone ridge to achieve adequate bone thickness around the implant. The effect of this procedure on peri-implant health is unclear. PURPOSE: The purpose of this clinical study was to evaluate whether bone regularization affects the clinical and biological parameters of peri-implant health when narrow diameter implants are placed as mandibular implant overdenture retainers during initial healing and after occlusal loading. MATERIAL AND METHODS: The need for mandibular ridge regularization in the anterior mandibular region was analyzed before the placement of 2 implants (2.9×10 mm, Facility; Neodent) in 21 participants provided with mandibular overdentures. Primary stability was measured by the insertion torque and implant stability quotient (ISQ). Clinical and biological evaluations measuring the plaque index, presence of calculus, probing depth, bleeding on probing index, gingival index, secondary stability (ISQ), and interleukine-1ß (IL-1ß) and tumor necrosis factor-α (TNF-α) concentrations in peri-implant crevicular fluid were measured during osseointegration on days 7, 15, 30, 60, and 90 and after loading on day 180 after implant placement. Multilevel mixed-effects linear regression analysis and the Kaplan-Meier test were used to analyze the data (α=.05). RESULTS: The ISQ values showed significant differences on days 7 (P<.001) and 15 (P=.002) with higher values and on day 180 (P=.008) with a lower value compared with the baseline value in the ridge regularization group. Additionally, a significant decrease in probing depth was observed on days 60 (P=.008) and 180 (P=.027) compared with that on day 15 after implant placement. In the nonridge regularization group, significant decreases in probing depth were observed on days 30 and 180. Moreover, TNF-α levels in this group were significantly lower on days 30 (P=.001), 60, 90, and 180 (P<.001) when compared with the value on day 7 (P<.001). The ridge regularization group presented with significant differences in TNF-α and IL-1ß levels on days 60 (P=.004) and 30 (P=.007), respectively, when compared with the values on day 7. The ISQ and probing depth in the ridge regularization group were associated with changes in TNF-α and IL-1ß levels; furthermore, bone type, duration of edentulism, and mandibular bone atrophy were correlated with the clinical outcomes and TNF-α release. The implant survival rate was 67% in the nonridge regularization group and 100% in the ridge regularization group. CONCLUSIONS: Mandibular ridge regularization appeared to be beneficial for peri-implant healing during the early stages and after 3 months of occlusal loading in patients with an atrophic ridge, prolonged time since edentulism, and poor bone quality.

Histomorphometric analysis of implant osseointegration using hydrophilic implants in diabetic rats.

OBJECTIVES: To evaluate peri-implant bone formation of titanium implants using an in vivo rat model with and without uncontrolled diabetes mellitus (DM) to evaluate osseointegration of hydrophobic (Neoporos®) and hydrophilic (Acqua®) surfaces. MATERIALS AND METHODS: 54 rats were divided into two groups: DM group (DMG) (streptozotocin-induced diabetes) and a control group (CG). Implants with hydrophobic (Neoporos®) and hydrophilic surfaces (Acqua®) were placed in the left or right tibia of animals. Animals were further divided into three groups (n = 9) euthanized after 7, 14, or 28 days. Bone-to-implant contact (BIC) and bone area fraction occupancy (BAFO) were assessed in total, cortical, and medullary areas. RESULTS: The DMG group, after a 7-day healing period, yielded with the Acqua implants presented significantly higher total BIC (+37.9%; p=0.03) and trabecular BIC (%) (+46.3%; p=0.02) values in comparison to the Neoporos implants. After 28 days of healing, the CG yielded that the cortical BAFO of Acqua implants to be significantly, 14%, higher (p=0.04) than Neoporos implants. CONCLUSION: The positive effects of the Acqua surface were able to counteract the adverse impact of uncontrolled DM at early osseointegration periods. After 28 days in vivo, the metabolic systemic impairment caused by DM overcame the surface treatment effect, leading to impaired osseointegration in both hydrophilic and hydrophobic implants. CLINICAL RELEVANCE: The adverse effects of diabetes mellitus with respect to bone healing may be minimized by deploying implants with strategically modified surfaces. This study evaluated the effects of implants with Acqua® and Neoporos® surfaces in both diabetic and healthy animals. During the initial healing period in diabetic animals, the hydrophilic surface was demonstrated to have beneficial effect on osseointegration in comparison to the hydrophobic surface. The results provide an insight into early healing, but the authors suggest that a future short-term and long-term clinical study is needed to assess the possible benefit of the Acqua® implant as well as in increasing the predictability of implant osseointegration.

Do implant-retained mandibular overdentures maintain radiographic, functional, and patient-centered outcomes after 3 years of loading?

OBJECTIVES: Analyzing whether radiographic, functional, and oral health-related quality of life (OHRQoL) outcomes are maintained over 3 years of implant-retained mandibular overdenture (IMO) function and investigating the bite force associations in the 3rd year of function. MATERIAL AND METHODS: A longitudinal clinical study in which 24 IMO users were evaluated during a 3-year follow-up period. Patients' posterior area index, masticatory function, OHRQoL and bite force were assessed. The masticatory function parameter ST_X50 reflects the opening through which 50% of the crushed particles would pass, ST_B describes the homogeneity of the bolus, and the masticatory efficiency parameters ME_5.6 and ME_2.8 represent the % of material retained in the 5.6 and 2.8 mm sieves, respectively. RESULTS: A significant increase in posterior area index (p ≤ .01) was found in all evaluated periods. Minor deteriorations in ST_X50 (p ≤ .01) and ME_5.6 (p ≤ .01) between the 2nd and the 3rd year coincided with improvements in ST_B (p ≤ .01), number of cycles (p ≤ .01), and cycle time (p = .02). The global OHIP-Edent score (p = .02) and the scores in the functional limitation (p = .02), psychological discomfort (p ≤ .01), and handicap domains (p ≤ .01) increased significantly between the 2nd and the 3rd year. Correlations between bite force and cycle time (p = .03) and between posterior area index and ST_X50 (p ≤ .01) and ME_2.8 (p = .02) were also found. CONCLUSION: Changes in posterior area index, masticatory function, and OHRQoL are still ongoing during the 3rd year of IMO function. Bite force and posterior area index influence the masticatory function outcomes in the 3rd year of IMO function.

Mapping of inflammatory biomarkers in the peri-implant crevicular fluid before and after the occlusal loading of narrow diameter implants.

OBJECTIVE: To monitor the cytokine release patterns in the peri-implant crevicular fluid (PICF) and to investigate which factors affect the success rate of narrow diameter implants (NDI) during the first year. MATERIAL AND METHODS: Mandibular implant overdentures (IOD) retained by 2 NDI were installed in 16 clinically atrophic edentulous patients. The following parameters were monitored during the first year: (i) peri-implant health parameters (plaque index (PI), calculus presence (CP), gingival index (GI), probing depth (PD) and bleeding on probing (BoP); (ii) cytokine concentrations in the PICF (TNF-α, IL-1ß, IL-6, IL-10); (iii) implant stability quotient (ISQ); (iv) marginal bone level (MBL) and bone level change (BLC); (v) implant success. The insertion torque, bone type, mandibular atrophy, time since edentulism, and smoking habits were also recorded. All data were analyzed using multivariable multilevel mixed-effects regression models. RESULTS: The variability in the TNF-α release patterns temporarily reduced at weeks (w) 8-12, while the IL-1ß concentrations remained low until they peaked at w48 [p < 0.05; + 177.55 pg/µl (+ 96.13 - + 258.97)]. Conversely, IL-10 release decreased significantly at w48 [p < 0.05; - 456.24 pg/µl (- 644.41 - - 268.07)]. The PD and ISQ decreased significantly (p < 0.05) over the follow-up period, while the MBL was stable after w48 with a BLC of 0.12 ± 0.71 mm. The overall success rate was 81.3%, and was influenced by TNF-α, IL-1ß, IL-10, PI, GI, PD, smoking, and time since edentulism. CONCLUSION: Pro- and anti-inflammatory cytokine release was balanced during the first 24 weeks. The GI, smoking, and time since edentulism are the most important factors determining the implant success. CLINICAL RELEVANCE: The study contributes to the understanding of the osseointegration process in a clinically atrophic population rehabilitated with IOD, and highlights the importance of monitoring clinical peri-implant health-related parameters, smoking habit, and time since edentulism to predict implant success rates.

Masticatory function and oral health-related quality of life of patients with atrophic and non-atrophic mandibles using implant-retained mandibular overdentures: 3-year results of a prospective clinical study.

BACKGROUND: Long-term changes in masticatory function, oral health-related quality of life (OHRQoL) and prosthetic complications in implant-retained mandibular overdenture (IMO) wearers as a function of bone atrophy require detailed investigations. OBJECTIVE: Investigating the evolution of masticatory function, OHRQoL and prosthetic occurrences of IMO wearers according to mandibular bone atrophy over 3 years of usage. METHODS: This study evaluated 26 IMO wearers after 2 and 3 years of IMO loading categorised according to mandibular resorption degree into atrophic mandible (AM) and a non-atrophic mandible (NAM) group. Masticatory function was assessed by the Masticatory Performance (MP) and Swallowing Threshold (ST) tests; OHRQoL and satisfaction via the Dental Impact on Daily Living (DIDL) questionnaire; and the prosthetic maintenance requirements and complications were monitored. RESULTS: After the second year, the AM Group performed 32% more cycles (P = .047) than the NAM Group during the ST test. The DIDL questionnaire showed no significant difference for all domains, except for a moderate effect size in the General Performance domain after the third year. AM Group had more prosthetic occurrences (n = 109) than NAM Group (n = 60) in the first year, mainly due to Equator attachment dislodgment. During the third year, NAM Group presented a greater number of events (n = 45) than AM Group (n = 21) due to the greater number of O-ring exchanges. CONCLUSION: Masticatory function and OHRQoL are not related to mandibular bone atrophy until 3 years after IMO rehabilitation. The prosthetic complications profile differs between groups, mainly in the first year.

Healing differences in narrow diameter implants submitted to immediate and conventional loading in mandibular overdentures: A randomized clinical trial.

BACKGROUND: Biological responses to different loading protocols during the bone healing phase in subjects with long time since edentulism, rehabilitated with narrow diameter implants (NDIs) to retain mandibular overdentures (MOs), are still unavailable. OBJECTIVE: This randomized clinical trial compared the peri-implant health, implant stability, and concentrations of pro- and anti-inflammatory cytokines in the peri-implant crevicular fluid (PICF) in mandibular edentulous patients under conventional (CL) and immediate loading (IML) during healing. METHODOLOGY: Twenty totally edentulous patients received two NDIs (2.9 × 10 mm, Facility NeoPoros) placed in mandible anterior region and were randomly assigned to two loading protocols: CL (n = 10) and IML (n = 10). The following clinical outcomes were evaluated 1, 2, 4, 8, and 12 weeks after surgery: (a) peri-implant tissue health (gingival index-GI, plaque index-PI, calculus-presence CP, probing depth-PD, and bleeding on probing-BOP); (b) implant stability quotient (ISQ); and (c) IL-1ß, IL-6, IL-10, and TNF-α levels in the PICF analyzed by ELISA. RESULTS: The CL group showed significantly higher CP scores at weeks 8 and 12. The IML group showed significantly higher GI from the first week onwards. The IML group presented significantly lower PD at all follow-up times, and higher BOP rates than CL at week 12. The ISQ values of the CL group were higher than those of the IML group, except at week 4. The IML group released significantly more TNF-α between weeks 1 and 4 and more IL-1ß during week 4-12, while releasing less IL-6 until week 8, mainly at week 2 (-47.6%). The release of IL-10 was similar for both groups and increased progressively over time. At week 12, the IML group released 45.74% more IL-10 than the CL group. The survival rates were 95% and 90% for CL and IML, respectively. CONCLUSION: The IML group presented more favorable PD at all evaluation times; the differences between the other clinical parameters were less systematic. The implant stability and the inflammatory marker concentrations were more stable in the CL group.

Is predicting masticatory function based on mandibular bone atrophy as defined by clinical and radiographic parameters possible? A clinical study.

STATEMENT OF PROBLEM: The degree of mandibular bone atrophy can guide and determine the choice of prosthetic treatment. Although several methodologies have been proposed for classifying atrophy, the clinical and radiographic parameters considered for the classification of mandibular bone atrophy should be standardized. PURPOSE: The purpose of this clinical study was to evaluate the influence of methodologies of mandibular bone atrophy categorization on the masticatory function in complete denture (CD) wearers and to verify the relationship between these parameters according to the retention and stability of the mandibular CD. MATERIAL AND METHODS: CD wearers were radiographically and clinically evaluated to determine the mandibular bone atrophy levels. Three classifications were adopted: the Cawood and Howell criteria, the Wical and Swoope criteria, and the Kapur classification. CD retention and stability were scored based on the Sato et al method. The masticatory function was evaluated by the multiple sieve method using optical test food to determine the masticatory performance (MP) indexes (median particle size, MP X50; homogeneity index, MP B) and the masticatory efficiency (sieves 4 and 2.8). RESULTS: In this sample of 63 individuals (mean age of 67.4 years), atrophic participants presented significant differences in all radiographic parameters (Mann-Whitney test, P<.05) with both the Cawood and Howell and Wical and Swoope methodologies. No differences in masticatory function were found, except for atrophic participants classified by Wical and Swoope criteria, who had worse MP X50 (P=.047) than nonatrophic participants, with a medium effect size of 0.7. The retention of the mandibular CD significantly affected the masticatory outcomes, with higher values for MP X50 (P=.012) and MP B (P=.040) and lower values for masticatory efficiency, 2.8 (P=.008) for atrophic participants. The presence of mandibular bone atrophy showed an association with poor retention (P=.04) and poor stability (P=.002) when the Cawood and Howell criteria were adopted (Fisher exact test, P<.05). CONCLUSIONS: The Kapur classification confirmed the clinical condition of the participants' atrophy, and the most clinically atrophic participants showed poor retention and stability of the mandibular CD. Only the poor retention directly affected the masticatory function. Radiographic evaluations alone did not provide sufficient data to determine the predictability of CD treatment regarding the participants' masticatory function. Radiographically, atrophic participants with poor retention had impaired mastication.

Influence of facial patterns on the masticatory function and quality of life of completely edentulous patients during the transition to implant-retained mandibular overdentures.

STATEMENT OF PROBLEM: Although implant-retained mandibular overdentures (IMOs) provide functional benefits, the influence of the vertical facial pattern (FP) and the anteroposterior skeletal discrepancy (ASD) on the masticatory function and patient-centered outcomes during the transition to IMOs is still uncertain. PURPOSE: The purpose of this interventional clinical study was to evaluate the influence of the FP and ASD on the masticatory function, oral health-related quality of life (OHRQoL), and satisfaction of completely edentulous patients before and after transition to IMOs. MATERIAL AND METHODS: Cephalometric analysis was performed on 42 participants before treatment. Ricketts analysis was used to classify the FP, and the maxillomandibular relationship to the base of the skull determined the ASD. Masticatory performance (MP) and swallowing threshold (ST) test results were evaluated by the multiple sieve method by using artificial test food (Optocal cubes) to determine the median particle size (×50), homogenization index (B), and masticatory efficiency based on sieves 5.6 (ME: 5.6) and 2.8 (ME: 2.8). OHRQoL and satisfaction were evaluated by using the Dental Impact on Daily Living questionnaire. The data were analyzed using mixed-effects linear regression models to estimate the effect of time, FP, ASD, age, and sex on MP, ST, and OHRQoL. RESULTS: The MP, ST, OHRQoL, and satisfaction improved significantly after IMO loading, irrespective of FP and ASD. However, MP outcomes were most negatively affected mainly among dolichofacial (B and ME: 2.8), class II, and class III (×50, B, and ME: 2.8) participants. The ST test showed that class II participants still showed inferior ×50 values and performed a lower number of cycles than class I and class III participants. Women presented reduced masticatory function for all MP and ST outcomes and reported lower coefficients for appearance and general performance domains than men. CONCLUSIONS: The MP test detected more subtle improvements than the ST test, especially in class III participants. The class II participants benefited the least from the IMO installation according to the ST test. The IMO treatment improved the OHRQoL and satisfaction of edentulous patients, irrespective of the FP or ASD.

Relationship Between Masticatory Function Impairment and Oral Health-Related Quality of Life of Edentulous Patients: An Interventional Study.

PURPOSE: To investigate the influence of impaired masticatory function on the oral health-related quality of life of conventional complete denture wearers before and after the transition to implant-retained mandibular overdentures. MATERIALS AND METHODS: Masticatory function and oral health-related quality of life were evaluated in 40 edentulous patients after 3 months of adaptation to complete dentures and after transition to implant-retained mandibular overdentures. Masticatory function was evaluated through the swallowing threshold test with a standardized portion of an artificial test food (Optocal) to determine median particle size (×50) and homogenization index (B). After the test, the masticatory function outcomes were used to categorize patients in 2 groups according to chewing performance: (i) satisfactory or (ii) unsatisfactory. The cutoff value for ×50 was based on a preestablished value of 3.68 mm, whereas for the B index, median values were adopted for categorization. The oral health-related quality of life was analyzed via the Oral Health Impact Profile for Edentulous Adults (OHIP-EDENT) questionnaire. The Mann-Whitney test was used to compare masticatory function outcomes and OHIP-EDENT scores, and associations were checked using the Spearman correlation test and multiple linear regression. RESULTS: Masticatory function was significantly correlated with functional limitation (p = 0.02) and physical disability (p = 0.04) for complete denture wearers with unsatisfactory masticatory function. After the transition to implant-retained mandibular overdentures, only the psychological discomfort domain (p = 0.02) was influenced by the masticatory function category. Multiple linear regression analysis revealed that only the functional limitation domain (p < 0.001) of the complete denture wearers was associated with masticatory function outcomes. CONCLUSIONS: Implant-retained mandibular overdentures eliminate the problems that lead to functional limitations, consequently improving masticatory function and oral health-related quality of life of these individuals; however, patients with unsatisfactory masticatory function after transition to implant-retained mandibular overdentures still experience more psychological discomfort.

How fast can treatment with overdentures improve the masticatory function and OHRQoL of atrophic edentulous patients? A 1-year longitudinal clinical study.

OBJECTIVES: The aim of this prospective clinical study was to evaluate the masticatory function (MF) and subjective perception of patients with poor denture-bearing tissue in relation to change and the time required to identify an improvement in these parameters after rehabilitation with mandibular overdentures (MO) by two narrow-diameter two-piece implants. MATERIAL AND METHODS: Twenty-three edentulous patients were selected for MO installation. The masticatory function (MF) was evaluated with the masticatory performance (MP) and swallowing threshold (ST) tests. In the MP test, each volunteer was instructed to masticate a portion of Optocal (standardized artificial test food) for 40 masticatory cycles. During the swallowing threshold test, the patients were instructed to chew a new portion of Optocal cubes until they felt the desire to swallow. The MF tests were performed while complete denture (CD) wearers (baseline) and 1, 3, 6, and 12 months after MO loading. In addition, the subjective perception was assessed through the questionnaires Dental Impact on Daily Living (DIDL), Geriatric Oral Health Assessment Index (GOHAI), and Oral Health Impact Profile in Edentulous (OHIP- EDENT) at the baseline and 3, 6, and 12 months after MO loading. RESULTS: A significant improvement in masticatory function (p < .05) was observed already in the first month of loading. Three months after MO loading, a significant improvement (p < .05) was found in the subjective perception of patients. The effect size indicates that the MO had the greatest impact on the domains related to function and comfort of all questionnaires and in relation to psychosocial domain of the GOHAI. The level of patient satisfaction increased significantly after the MO loading and reached >90% satisfied patients at 12 months. CONCLUSION: The MO improved both the MF of the patient and their oral health-related quality of life and satisfaction regarding the prosthesis in a short time period.

3-Year Bone Remodeling in Mandibular Overdenture Wearers: Results from an RCT Comparing Immediate vs Conventional Loading Using Cone Beam Computed Tomography.

PURPOSE: To evaluate the circumferential bone level and the morphological changes in posterior mandibular ridge of mandibular overdenture wearers submitted to conventional and immediate loading through cone beam computed tomography (CBCT) at 1 and 3 years. MATERIAL AND METHODS: Twenty participants who received 2 NDI (Facility - 2.9x10 mm) were randomly allocated to the conventional loading (CL: n=10) or immediate loading (IL: n=10) groups. CBCT scans were performed in each group to analyze the vertical (VBL) and horizontal (HBL) bone level around the implants, analyzed together with the posterior bone remodeling of the mandible measured at distances of 5, 10, 15, and 20 mm from the mental foramen (L1-L4). Differences between groups were verified using the student t test at a significance level of 5%. RESULTS: The IL group showed a significantly higher HBL in the first year (P=.028) and a significantly higher VBL in the third year (P=.032), with HBL of -0.22 mm and VBL of -0.59 mm, respectively. After the third year, measurements of the percentage of cortical and medullar height indicated that the IL group presented a significantly higher percentage of cortical bone height (40.1 ± 9.3) compared to the CL group (31.8 ± 5.8) at position L1 (P=.05). No difference was found for posterior ridge remodeling (P>.05). CONCLUSIONS: IL group showed slightly higher values of HBL and VBL, and locally displayed more replacement of medullary by cortical bone. However, circumferential bone level values in the IL group are still clinically acceptable and the posterior resorption rate remained stable after 3 years of function, irrespective of the loading type.

Prosthetic complications and quality of life among wearers of mandibular overdenture with the Facility-Equator system.

This longitudinal study aimed to assess the performance of the Facility-Equator system as mandibular overdenture (MO) retainers from a prosthetic perspective during 2 years of loading and to investigate the oral health-related quality of life (OHRQoL) and whether prosthetic events can affect the OHRQoL. Twenty-four patients (68.1 ± 7.51 years) reported their OHRQoL through the Geriatric Oral Health Assessment Index (GOHAI) and Oral Health Impact Profile (OHIP-EDENT) questionnaires before MO loading and after 1 and 2 years of usage. Prosthetic occurrences were recorded during this period. Data were analyzed using the Wilcoxon test, Mann-Whitney test, and Spearman correlation coefficients. Of the 127 prosthetic events that occurred in the first year, the most frequent events were prosthesis adjustments (16.5%), dislodgement of the Equator attachment (14.17%), and O-ring replacement (11.8%). Eighty-seven prosthetic events were recorded in the second year, the most frequent events being prosthesis adjustments (27.6%), O-ring replacement (20.7%), and recapturing the female matrix (11.5%). All domains of the GOHAI and OHIP-EDENT questionnaires exhibited a significant difference (p < 0.05) between the baseline and 1- and 2-year evaluations, except in the Social Disability and Psychological Discomfort domains (p > 0.05) of OHIP-EDENT after 1 year. Complications related to prosthetic maintenance, such as fracturing of the prosthesis, Equator dislodgement, prosthesis rebasing, and new overdenture confection, affect the OHRQoL (p < 0.05), primarily the Physical Pain and Discomfort domains, especially in the first year of MO loading.

Prosthetic aftercare, mastication, and quality of life in mandibular overdenture wearers with narrow implants: A 3-year cohort study.

OBJECTIVES: This cohort study investigated clinical, functional, and quality of life outcomes, along with prosthetic maintenance events in mandibular overdenture (MO) wearers for 3 years. METHODS: Thirty MO wearers with narrow diameter implants (NDIs) and locking taper stud abutments (Facility-Equator system) were annually monitored by registering the visible plaque index (VPI), peri­implant inflammation (PI), calculus presence (CP), probing depth (PD), bleeding on probing (BOP), secondary implant stability (ISQ), marginal bone loss (MBL), masticatory performance and dental impact in daily life (DIDL) questionnaire domains. Multilevel mixed-effects linear regression was performed to analyse changes over time. Chi-square tests were performed to analyse the relationship between the appearance of prosthetic complications and maintenance occurrences. The survival rate of patients with NDIs was calculated using the Kaplan-Meier test. RESULTS: Twenty-six individuals attended all follow-ups, the survival rate of 83.3% in the first year was maintained, and no one implant was lost over the 3-year period. There were significant differences for PD between 1 and 3 years (p ≤ 0.01) and between 2 and 3 years for PI (p ≤ 0.01), GI (p ≤ 0.01), ISQ (p = 0.02), and MBL (p ≤ 0.01). All masticatory performance outcomes showed significant differences (p ≤.01). Prosthetic maintenance events decreased significantly over time. Appearance, general performance, and eating and chewing domains presented high effect sizes. CONCLUSION: Continued changes were observed in the clinical parameters of MO users over the 3-year period. In addition, most functional parameters, except for particle homogenization, improved significantly over time. The positive impact on quality of life is likely related to the significant reduction in prosthetic maintenance events. CLINICAL SIGNIFICANCE: Periodic returns to assess peri­implant tissues and MO maintenance should be performed to ensure the success of rehabilitation to assure improvements in masticatory function and oral health-related quality of life.

Influence of Facial Morphology on Masticatory Function and Quality of Life in Elders Using Mandibular Overdentures: 3-Year Results.

Background: Facial types may interfere in the oral health-related quality of life (OHRQoL) and masticatory performance of implant-retained mandibular overdenture (IMO) wearers. Purpose: Investigate the medium-term changes in the masticatory function (MF) and OHRQoL parameters of IMO users, as a function of facial pattern, anteroposterior skeletal discrepancy, and sex. Methods: Forty IMO users, most of them Caucasian (90%) with average age of 69.17 years were classified according to their facial pattern and antero-posterior discrepancy prior to rehabilitation. MF was evaluated by the multiple sieves method to determine the average particle size (X50), heterogeneity (B) and masticatory efficiency (ME, calculated as the percentage of material retained in the 5.6 and 2.8 mm sieves), using Masticatory performance (MP) and swallowing threshold (ST) tests. OHRQoL was measured by applying the dental impact on daily life (DIDL) questionnaire. The data were analyzed by Wilcoxon-paired tests to analyze changes in MF parameters over time, and mixed-effect multilevel regression models were employed to verify differences between groups. Results: Significant changes were still observed in the 3rd year for the ST test with improvements in B for Mesofacial and in time for Dolichofacial individuals, while ME_2.8 deteriorated for Brachyfacial participants. B values of Class I and male individuals improved and brachyfacial individuals still presented worse homogenization (B) than Mesofacial participants in both masticatory tests. Class II and III participants still showed improvements in ME_5.6 and time compared to Class I despite increases in X50. Class II individuals needed less cycles than Class I in the 3rd year. Brachyfacial participants scored lower in the Appearance domain than Mesofacial ones in the 3rd year. Dolichofacial participants and Class III patients scored lower in the Oral Comfort domain than Mesofacial and Class I, respectively. In addition, age influenced the Pain, Oral Comfort and General Performance domains in the 3rd year. Conclusions: Differences in facial morphology continue to influence the MF and OHRQoL outcomes in the 3rd year, and age influenced some OHRQoL domains. Brachyfacial individuals continue to benefit least from rehabilitation with IMO according to masticatory parameters.

Evaluation of Bite Force and Masticatory Performance: Complete Denture vs Mandibular Overdenture Users.

This cross-sectional observational study with 24 patients evaluated differences in bite force (BF) and masticatory performance (MP) between conventional complete denture (CCD) and implant mandibular overdenture (IMO) users and the correlation between these variables. The BF test was performed bilaterally with an occlusal force device. During the MP test, patients were asked to chew Optocal particles for 40 cycles. The Shapiro Wilk test was employed to verify the normality of the data, the student t test to identify differences between groups, and Pearson's correlation to investigate interrelationships between variables. A multiple linear regression was subsequently performed via the stepwise method. P values ≤0.05 were considered statistically significant. Unlike IMO users, CCD users presented a significant difference (25.6%) in BF between the dominant and non-dominant chewing side (p=0.04). IMO users presented significantly higher BF (p=0.01) without presenting a dominant side (p=0.38), and also performed significantly better for the following MP parameters: MPX50 values decreased by 27.25% in IMO users (p=0.01), MPB decreased by 48.38% (p=0.01), and ME 5.6 decreased by 53.25% (p=0.02), while ME2.8 increased by 151.57% (p=0.01). The BF and MPX50 in the IMO wearers group were negatively correlated (-0.57; p=0.05); this correlation coefficient was the only parameter included in the multivariate regression model. IMO users have higher BF and better masticatory performance than CCD users, especially in terms of chewed particles size reduction. MP is correlated with a higher BF in IMO users through better particle trituration.

Clinical Versatility of the Facility-Equator Implant System as Mandibular Overdenture Retainers.

The use of mandibular overdentures (MO) for the rehabilitation of totally edentulous individuals with limited bone availability is widespread and has proven clinical success. Narrow diameter implants (NDI) are available on the market as MO retainers to solve problems related to limited bone availability and bone thickness, providing a low-cost, minimally invasive treatment option. This technique evolved over the years, and changes frequently involved the number of implants used as MO retainers, as the adoption of a smaller number of implants can generate biomechanical disadvantages, contributing to the increased stress in peri-implant tissues, which may accelerate marginal bone loss (MBL), in addition to reducing masticatory capacity and satisfaction with rehabilitation. Some studies pointed out that the use of 3 or more implants as MO retainers improves the biomechanics. Thus, the objective of this study was to report 3 different clinical cases where 3 or more NDI were adopted to retain mandibular overdentures in association with diverse loading protocols: (i) 3 implants adopting conventional loading, (ii) 4 implants using progressive loading, and (iii) 4 implants with hybrid loading. The case with 4 implants and progressive loading showed a slight worsening of masticatory function at 1 year, in addition to a more pronounced MBL compared to other cases, but with improvements in satisfaction and oral health-related quality of life. Thus, NDI can be used as MO retainers with predictability and clinical success, using different numbers of implants and loading protocols.