Raissa Micaella Marcello-Machado

Masticatory function parameters in patients with varying degree of mandibular bone resorption.

PURPOSE This cross-sectional study analyzes how bone resorption affects the masticatory function and investigates the relation between perceived and measured masticatory function. METHODS Thirty complete dentures wearers were divided in two groups according to mandible bone atrophy based on the classification criteria from Cawood & Howell. Retention and stability of the mandibular complete denture, masticatory performance (MP) indexes (X_50 and B) and masticatory efficiency (ME, sieves 4 and 2.8) were evaluated. Geriatric Oral Health Assessment Index (GOHAI) and Dental Impact on Daily Living (DIDL) questionnaires were completed by the patients. RESULTS A strong correlation between bone atrophy and poor retention was found (P=0.0132). Neither masticatory performance indexes nor GOHAI and DIDL domains showed statistical differences (P>0.05) when patients were compared according to the atrophy criteria. Mandibular length showed a negative correlation with ME4, showing a positive association (R2=0.17, β=-0.67, P=0.029). Mandibular denture retention was significantly correlated with MPB (P=0.01) and ME2.8 (P=0.01). GOHAI showed a positive association between the physical and the functional domains and ME2.8 (R2=0.17; β=1.22; P=0.02). DIDL showed a negative association between ME4 and oral comfort domain (R2=0.16; β=-2.94; P=0.02). CONCLUSION Mandibular bone height does not directly affect the masticatory function and is inversely correlated with the self-perceived masticatory ability.

Masticatory function of conventional complete denture wearers changing to 2-implant retained mandibular overdentures: clinical factor influences after 1 year of function

PURPOSE Evaluate how clinical factors related to conventional complete denture (CCD) wearers, can influence masticatory function (MF) of totally edentulous patients before and after one-year transitioning to implant-retained mandibular overdentures (IMO). METHODS Forty patients using CCD were rehabilitated with IMO and their MF was evaluated by: (i) ST_X50: theoretical aperture through which 50% of the weight of the particles would pass; (ii) STB: distribution homogeneity of the crushed particles. The clinical parameters analyzed were: atrophy, retention, stability, facial type, anteroposterior skeletal discrepancy, and type of loading. The statistical association was tested through crude and adjusted logistic regression. RESULTS IMO promoted improvements in the MF, irrespective of the clinical parameters. CCD wearers with poor retention had 86% less chance of achieving a good ST_X50. STB was associated with stability, facial type, and anteroposterior discrepancy. Subjects with poor mandibular CCD stability had a 76% lower chance of achieving a good test food homogenization, whereas brachyfacial individuals were 1.3 times more likely to have a good STB. Class II patients had an 89% lower chance of having a good homogenization of the particles as CCD users and after transition to IMO. CONCLUSIONS CCD users with poor retention achieved an inferior ST_X50. The STB performance can be compromised by poor stability or Class II characteristics, while brachyfacial individuals achieve better homogenezation of the food bolus. Although the transition to IMO improved the masticatory function, the anteroposterior discrepancy still maintained an association with STB, as Class II individuals still presented difficulties homogenizing food.

One-year clinical outcomes of locking taper Equator attachments retaining mandibular overdentures to narrow diameter implants

BACKGROUND Narrow diameter implants (NDI) are recommended to retain mandibular overdentures (MOs) in cases of limited bone thickness. It is necessary to evaluate the clinical behavior of NDI as MO retainers connected to a new screwless locking taper abutments, their predictability and maintenance problems. OBJECTIVES To evaluate the peri-implant tissue behavior around NDI and the performance of locking taper stud abutments as MO retainers. METHODOLOGY Thirty patients (average age of 67.5 years) received 2 NDI implants (2.9 × 10 mm) loaded after 12 weeks using Equator stud attachments. The plaque index (PI), calculus index (CI), gingival index (GI), probing depth (PD), bleeding on probing (BOP), and implant stability quotient (ISQ) were monitored during osseointegration at 0, 4, 8, and 12 weeks and postloading at 24, 48, and 60 weeks. The marginal bone level (MBL) and bone level changes (BLC) were determined at baseline and 60 weeks. RESULTS The cumulative success rate was 83.3%. The PI oscillated in the first 24 weeks and decreased from 48 weeks onward, while the CI score showed significantly higher values at week 8 (22%). The GI also peaked at week 8 (18.6%) and decreased from week 12 onward. The PD decreased gradually over time, but no significant differences were found between weeks 8 and 12. The ISQ decreased significantly between 0 and 12 weeks. After MO loading, the ISQ values increased linearly and significantly between 12 and 24, 24 and 48, and 48 and 60 weeks and reached values similar to the primary stability after 60 weeks [56.1(42.0-65.3)]. No significant MBL was observed at 60 weeks, with an average BLC of -0.06 ± 0.64 mm. CONCLUSION NDI connected to locking taper Equator attachments showed a stable clinical behavior as an MO retainer for edentulous patients with clinical mandibular atrophy.

Can implant surfaces affect implant stability during osseointegration? A randomized clinical trial

This randomized clinical trial evaluated the insertion torque (IT), primary, and secondary stability of dental implants with different surface treatments during the osseointegration period. Nineteen patients with bilateral partial edentulism in the posterior mandibular region were randomly allocated to two implant brand groups and received implants with different surface treatments in the opposite site of the arch: Osseotite and Nanotite or SLA and SLActive. During implant placement, the maximum IT was recorded using a surgical motor equipped with a graphical user interface. The implant stability quotient (ISQ) was assessed immediately after the IT, and was measured weekly via resonance frequency analysis during 3 months. The data were analyzed by a one-way ANOVA, the Bonferroni test, paired t tests and Pearsons correlation coefficient. The IT values were similar (p > 0.05) for all implant types ranging from 43.82 ± 6.50 to 46.84 ± 5.06. All implant types behaved similarly until the 28th day (p > 0.05). Between 35 and 56 days, Osseotite and SLActive showed lower ISQ values (p < 0.001) compared to Nanotite and SLA implants. After 56 days, only Osseotite maintained significantly lower ISQ values than the other implants (p < 0.05). After 91 days the ISQ values were significantly higher than the baseline for all four implant types (p < 0.001). The ISQ and IT values were significantly correlated at the baseline and at the final evaluation for Osseotite, Nanotite, and SLActive implants (p < 0.001). After 91 days, ISQ and IT values were only significantly correlated for the Osseotite implants (p < 0.05). All implants types exhibited acceptable primary and secondary stability.

Systematic review of wound healing biomarkers in peri-implant crevicular fluid during osseointegration

OBJECTIVE To quantify and characterize the role of biomarkers in peri-implant crevicular fluid (PICF) at each stage of healing during osseointegration. DESIGN This systematic review was performed in accordance with PRISMA guidelines using several databases: MedLine (PubMed), Embase, ISI Web of Science, Scopus, and Cochrane Library. Medical subject headings and their indexers were used with no other limitations until December 2017. The dataset was extended with relevant papers from the reference lists of selected papers and from the gray literature. Data was summarized for study objectives, patient demographics, methods used to analyze PICF, biomarker concentrations, results and main findings. Methodologic quality of each included study was assessed using the checklist created by Downs and Black. RESULTS Electronic search resulted in 1698 articles. After excluding the duplicates, reading titles, abstracts and reference list reviews 30 prospective studies with longitudinal follow-up were selected. In total, 52 different biomarkers were identified. The most studied cytokines were interleukin (IL)-1, IL-1β, tumor necrosis factor alpha (TNF-α), and nitric oxide (NO). The earliest PICF specimens were collected immediately after implantation, and the latest at 16 weeks prior to occlusal loading. 36 biomarkers were quantified during week 1, 49 between day 10 and week 6, and 49 between weeks 8 and 12. Only 5 articles received good quality ratings. CONCLUSION The mechanism by which inflammatory and bone biomarkers are released during osseointegration has not yet been identified. However, some hypotheses based on immune-modulated reactions are being explored to investigate early and asymptomatic implant failures. Given the available clinical studies, it was not possible to further explore the performance of all biomarkers already analyzed and to extrapolate their results to propose a consultable data system based on release volume or concentration because of clinical study and data heterogeneity.