Influence of denture-bearing conditions on masticatory function and patient-reported outcomes measures.

PURPOSE: To investigate the influence of different denture-bearing conditions on the masticatory function and patient-reported outcome measures (PROMs) of complete denture wearers. METHODS: Sixty edentulous patients were selected and allocated into two groups according to the American College of Prosthodontics' (ACP) classification: non-atrophic (NAT) (Classes I and II) (n = 24) and atrophic (AT) (Classes III and IV) (n = 36). All patients received new complete dentures (CDs). The objective variables (masticatory performance and swallowing threshold) were assessed as well as the PROMs (oral health-related quality of life (OHIP-EDENT), patient satisfaction) and quality of the prosthesis, at baseline (using the old CD) and after 4 months new prostheses use. Data were analyzed by Mann-Whitney test followed by the Generalized Equations Estimation (GEE), linear regression and Chi-square test. RESULTS: Higher masticatory performance was observed in the NAT group (p < .05) for both time points, baseline and after 4 months. However, compared to baseline, both groups showed significant masticatory improvement after 4 months (p < .05). Satisfaction and overall quality of life improved after 4 months with no difference between groups (p > .05). Regarding the quality of the CD, baseline results were significantly (p < .05) lower in the AT group, but after 4 months, no significant differences were found between groups and in intragroup analysis (p > .05). CONCLUSIONS: The denture-bearing conditions seems to impact masticatory function, but the PROMs are barely affected.

Four-year assessment of masticatory function in mandibular overdenture wearers: A randomised clinical trial comparing two to four implants to retain the prosthesis.

BACKGROUND: Limited data exist on the mid- to long-term masticatory capacity of mandibular overdenture (IOD) wearers, particularly regarding the use of posterior implants to retention. OBJECTIVES: To periodically evaluate mastication of IOD wearers, comparing the effectiveness of two to four implants to retain the prosthesis. METHODS: In a randomised controlled clinical trial, 20 complete edentulous patients (14 women), aged 51-84 years (mean age 69.1 ± 9.6), received new bimaxillary complete dentures (CD). After adaptation, baseline measurements of masticatory performance (X50) and swallowing threshold were conducted using the sieving method. Patients were then randomly assigned to groups: control (two intra-foraminal regular implants) and experimental (two intra-foraminal regular implants and two extra-short posterior implants) (n = 10 each). After 4 months, implants were splinted, and a new mandibular IOD was fabricated with bar/clip retention. Mastication was reassessed after 6, 12, and 48 months, and data analysed with repeated measures ANOVA and Sidak's post hoc (α = 0.05). RESULTS: Despite a loss of two patients per group, masticatory performance significantly improved after mandibular IOD installation (p = .031) in both groups (p = .670). A second improvement was observed after 6 months (p = .027), with no subsequent changes (p > .05). Swallowing threshold improvements were noted with IOD, and no discernible differences between groups were observed (p > .05). CONCLUSION: Masticatory function significantly improved after mandibular IOD installation, with the number of implants demonstrating minimal influence. CLINICAL TRIAL REGISTRATION: The present study was not registered in a public database, as mandated. It is important to note that the recommendation for registration was initiated in 2017 by the Committee of Medical Journal Editors, while patient inclusion in the research took place in 2016. Given that the data presented in this manuscript cover a follow-up period of up to 4 years post-surgical intervention, delayed registration was not feasible.

Long-term assessment of the periodontal health of removable partial denture wearers: A systematic review and meta-analysis.

STATEMENT OF PROBLEM: The long-term effects of wearing removable partial dentures (RPDs) remain unclear. PURPOSE: This systematic review addressed the question "Is the long-term use of RPDs deleterious to the remaining teeth?" MATERIAL AND METHODS: This review was guided by the preferred reporting items for systematic reviews and meta-analyses (PRISMA) checklist. Six databases and nonpeer-reviewed literature were searched in April 2024 without language or follow-up restrictions. Only clinical studies evaluating RPD long-term use were included. The risk of bias and evidence certainty were assessed (RoB 2.0; ROBINS-I; GRADE), and meta-analyses were conducted for survival rate and periodontal health (α=.05). RESULTS: A total of 5577 records were identified, and 46 studies covering data from 4359 prostheses and 4072 participants (mean age 60 ±5.2 years) were included. A low to moderate risk of bias was found. A 5-year survival rate of 95.1% (ER=0.951; 95% CI=0.900 to 0.977; P<.001) and 91.7% (ER=0.917; 95% CI=0.870 to 0.948; P<.001) was found for cast-clasp RPD and RPDs retained by telescopic crowns respectively, with no difference between them (P=.71). Abutments (OR=1.99, 95% CI=1.32 to 3.01; P=.001) and nonvital teeth (HR=2.961; 95% CI=2.023 to 4.335; P<.001) presented a higher risk of extraction after 5 years. Tooth mobility (P=.98) and probing depth (P=.50) remained unchanged, while the gingival index increased (MD=0.477 (95% CI=0.12 to 0.83; P=.008). CONCLUSIONS: A high survival rate was found for both cast-clasp RPD and RPDs retained by telescopic crowns, with few periodontal changes to the remaining teeth.

Digital workflow to produce 3D-printed incisal facial indirect restoration with lingual rest seats to support a removable partial denture.

A technique for fabricating lingual rest seats and indirect incisal restorations using a digital workflow is described. After intraoral scanning, the incisal edge position of the restoration and lingual rest seats for a subsequent removable partial denture (RPD) were designed digitally. Adaptation was evaluated with trial restorations, and definitive restorations were printed from a 3-dimensional resin (Varseo Smile Crown Plus Bego; Wilcos). The restorations were cemented with a heated composite resin (Tetric N; Ivoclar AG) polymerized for 40 seconds. The RPD was fabricated and delivered following a conventional technique. This standard, rapid, cost-effective, and straightforward approach allows a controlled and standardized process to obtain lingual rest seats and incisal restorations simultaneously, providing support for a successful Kennedy Class I RPD.

Performance of complete dentures fabricated with the simplified and the traditional technique: A randomized clinical trial.

STATEMENT OF PROBLEM: The simplified technique has been recommended for the fabrication of removable complete dentures. However, a consensus regarding the performance of the simplified and the traditional techniques is lacking. PURPOSE: The purpose of this randomized clinical trial was to compare the performance of prostheses fabricated with the simplified and the traditional techniques. MATERIAL AND METHODS: Sixty participants were recruited and randomized into 2 groups: traditional technique (control group) and simplified technique (experimental group). The assessments were performed before treatment (baseline) and 2 and 4 months after adaptation to the new complete dentures. The variables evaluated were satisfaction, oral health-related quality of life (OHRQoL) by using the Brazilian version of the OHIP-EDENT, the quality of the prostheses, and, for the functional assessment, the masticatory performance and swallowing threshold. The data were analyzed by the Fisher exact test, the Mann-Whitney test, and the generalized equations estimating (GEE) method. RESULTS: At baseline, the mean ±standard deviation quality of the prostheses was 5.3 ±2.3 for the traditional technique and 4.9 ±2.3 for the simplified technique, and at 4 months, it was 9.3 ±0.9 and 9.1 ±0.9, respectively. For masticatory performance, the mean ±standard deviation X50 at baseline was 5.7 ±1.4 for the traditional technique and 5.7 ±0.9 for the simplified technique, and at 4 months, it was 3.8 ±1.2 and 3.7 ±0.9, respectively. The mean ±standard deviation OHRQoL at baseline was 14.1 ±8.6 for the traditional technique and 12.5 ±9.4 for the simplified technique, and at 4 months, it was 3.2 ±4.3 and 2.6 ±5.1, respectively. The mean ±standard deviation satisfaction at baseline was 9.5 ±3.9 for the traditional technique and 9.3 ±4.2 for the simplified technique; after 4 months, it was 14.8 ±2.0 for both techniques. There was a significant improvement (P<.05) for all variables in the study when comparing them at the baseline to those at the evaluation after provision of new complete dentures. There was no significant difference in all analyzed variables (P>.05) between the 2 techniques for prosthesis fabrication. CONCLUSIONS: The simplified technique appears to be a suitable alternative to the traditional technique for the fabrication of complete dentures, with similar performance.

Influence of different presentations of denture adhesives on masticatory function of complete denture wearers: A systematic review and meta-analysis.

STATEMENT OF PROBLEM: Denture adhesives improve the mastication of complete denture wearers. However, the impact of denture adhesives with different presentations on mastication remains unclear. PURPOSE: The purpose of this systematic review was to answer the focused question, "Do different presentations of denture adhesives affect the masticatory function of complete denture wearers?". MATERIAL AND METHODS: This review was guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Six databases and the non-peer-reviewed literature were searched up to July 2021. Only clinical studies (randomized clinical trials and nonrandomized clinical trials) comparing the use of different denture adhesive presentations (cream, powder, or strips) were included, without language or follow-up restrictions. The risk of bias was assessed by using the Cochrane tools (RoB 2.0 and ROBINS-I). Masticatory performance, by using single and multiple sieves, masticatory performance with color-changing chewing gum (mixing ability), swallowing threshold (particle size and number of cycles), jaw kinematics, and occlusal force were considered. Meta-analyses were conducted to evaluate masticatory performance (single sieve) and occlusal force outcomes (α=.05), and the certainty of the evidence was determined with the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) evaluations. RESULTS: Nine studies (6 randomized and 3 nonrandomized clinical trials) were included. The risk of bias was considered moderate. Meta-analyses showed no differences between cream and powder denture adhesives for masticatory performance (standard mean difference=0.02; 95% CI=-0.46 to 0.50, P=.93) or between cream and strip denture adhesives for occlusal force (mean difference=14.35; 95% CI=-11.14 to 39.84, P=.27). Similarly, in qualitative analysis, cream and powder denture adhesives' performances were similar regarding masticatory performance with color-changing chewing gum (mixing ability), occlusal force, swallowing threshold (particle size and number of cycles), and jaw kinematics (P>.05). However, for resorbed ridges, cream denture adhesive resulted in a higher masticatory performance than strip (P<.05). When comparing powder to strip denture adhesives, the occlusal force was higher in the powder group (P<.05). The certainty of evidence was very low for all evaluated outcomes. CONCLUSIONS: Different presentations of denture adhesives seem to improve the masticatory function of complete denture wearers in a similar way. However, the qualitative analysis showed that, in patients with a resorbed ridge, a cream denture adhesive may be better than strips to improve mastication, although the certainty of evidence was very low.

Clinical performance of polymer frameworks in dental prostheses: A systematic review.

STATEMENT OF PROBLEM: High-performance polymers including polyetheretherketone (PEEK) and polyetherketoneketone (PEKK) have been used as substitutes for metal frameworks in dental prostheses. However, the clinical performance of polymer-based frameworks is still uncertain. PURPOSE: The purpose of this systematic review was to compare the clinical performance of PEEK and PEKK with that of metal frameworks for different dental prostheses. MATERIAL AND METHODS: This review follows the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Six databases and non-peer-reviewed literature (without language or follow-up restrictions) were searched for studies conducted before February 2022. Only clinical studies, either randomized clinical trials (RCTs) or nonrandomized clinical trials (N-RCTs), comparing the clinical performance of polymer and metal frameworks were included. The risk of bias and certainty of the evidence were assessed with the RoB 2.0, ROBINS-I, and GRADE. Biologic (plaque and gingival indices, probing depth, bleeding scores, implant stability quotient, marginal bone loss) and mechanical outcomes (ridge base relation, prosthetic marginal gap, and fracture) were assessed. RESULTS: Only 9 studies (7 RCTs and 2 N-RCTs) were included, all with moderate to serious risk of bias and low to very low certainty of evidence. No meta-analysis was possible, but qualitative analysis revealed lower plaque and gingival indices, probing depth, and marginal bone loss, with higher survival rates for implant-supported fixed prostheses and overdentures fabricated with PEEK than for metal frameworks. No significant differences were found between groups for removable partial dentures. The marginal fit of PEEK frameworks was also better for single crowns. Three fractures were reported in the 3 PEKK fixed dental prostheses with cantilevers. CONCLUSIONS: PEEK and PEKK seem to be promising materials for dental prostheses, with acceptable response from the periodontal tissue. However, further well-designed studies are necessary to better understand their clinical and long-term limitations.

Consensus on the terminologies and methodologies for masticatory assessment.

A large number of methodological procedures and experimental conditions are reported to describe the masticatory process. However, similar terms are sometimes employed to describe different methodologies. Standardisation of terms is essential to allow comparisons among different studies. This article was aimed to provide a consensus concerning the terms, definitions and technical methods generally reported when evaluating masticatory function objectively and subjectively. The consensus is based on the results from discussions and consultations among world-leading researchers in the related research areas. Advantages, limitations and relevance of each method are also discussed. The present consensus provides a revised framework of standardised terms to improve the consistent use of masticatory terminology and facilitate further investigations on masticatory function analysis. In addition, this article also outlines various methods used to evaluate the masticatory process and their advantages and disadvantages in order to help researchers to design their experiments.

Influence of lower complete denture use on masseter muscles and masticatory function: A longitudinal study.

BACKGROUND: Edentulism can reduce mastication, leading to changes in food pattern, with possible consequences to masticatory muscle thickness. OBJECTIVES: This study verified masticatory function and oral perception in subjects who did not use lower CDs, and whether the insertion of new upper and lower CDs would improve such variables. METHODS: Fifteen edentulous elderly who wore only the upper CD were selected and received new upper and lower CD. Volunteers were evaluated at baseline and after 1, 3 and 6 months of new prosthesis use. Masticatory performance (MP) was assessed by the sieving method (X50 values). Masseter thickness (MT) was evaluated by ultrasonography. Oral sensorial ability (OSA) was assessed by oral stereognosis test and maximum tongue pressure (MTP) was verified by pressure sensors. Data were submitted to repeated measures ANOVA and Tukey-Kramer posthoc tests (α = 0.05). Correlation between OSA and MTP was verified by Person's correlation. RESULTS: X50 and MTP decreased (P < 0.05) after 1 month and remained stable (P > 0.05) for next assessments. After 3 months, MT in rest position was increased (P < 0.05), while during maximum voluntary contraction 1 month was enough to increase MT (P < 0.05). There were no differences for OSA (P > 0.05) and no correlation between OSA and MTP. CONCLUSION: Masticatory performance and masseter thickness of elderly who did not use the lower dentures were improved after 2 months using new upper and lower CDs. However, new CDs in both dental arch decreased MTP. Brazilian Registry of Clinical Trials (ReBEC #RBR-37gdst).

Long-term survival analysis of standard-length and short implants with multifunctional abutments.

BACKGROUND: Spherical shape and connecting bypass screw of the OT Equator abutment (Rhein83, Italy) provides several retentive possibilities, even in non-parallel implants. OBJECTIVE: This study assessed the long-term survival of standard-length and short implants receiving this multifunctional abutment. METHODS: Partially, edentulous patients (44 males and 64 females) (mean age 58.2 ± 10.5 years) rehabilitated with a fixed implant-supported prosthesis where the OT Equator abutments (Rhein83) were applied. Follow-up evaluations were performed up to 5 years following prosthesis delivery. Kaplan-Meier survival analysis and Cox regression analysis were used to determine whether the distribution of time to failure differed based on implant characteristics (length and region), adjusting for sex (α = 0.05). RESULTS: In total, 216 implants (5 × 8 mm, n = 126; 5 × 6 mm, n = 90) (Betwice, Mech & Human, Italy) were installed. The average follow-up period was 25.3 months (±19.3 months). Eight failures occurred, with most observed before loading (n = 6). Cumulative survival rates (CSR) at implant and abutment levels were 94.3% and 97.1%, respectively. Regarding implant length, CSRs were 97.8% and 90.6% for short and standard-length implants, respectively, with no difference between subgroups (logrank: χ2  = 1.34, df = 1, P = 0.25). No significant difference was also found between implants of maxilla (CSR = 92.2%) and mandible (CSR = 95.5%; logrank: χ2  = 0.08, df = 1, P = 0.78). CONCLUSION: The OT Equator abutment (Rhein83) showed a stable clinical performance, with continuous and predictable survival.

Surface treatments to improve the repair of acrylic and bis-acryl provisional materials.

PURPOSE: To evaluate the in vitro effects of the Composite Primer and different surface treatments on the shear bond strength (SBS) of acrylic and bis-acryl repairs with resin composite (RC). METHODS: Acrylic (Alike) and bis-acryl (Protemp 4) blocks were prepared. Surface roughness was standardized (0.16 µm) and grit blasting was applied to half of the samples. Blocks were divided randomly into groups according to surface treatment [methyl methacrylate monomer (MMA) for 180 seconds or bonding agents (Composite Primer and Scotchbond Multi Purpose), applied alone or following MMA]. Two consistencies of RC [ regular (Filtek Z350XT and Solare composite) or flowable (Filtek Z350XT flowable and G-aenial flowable composite) ] were used to test bond repair. Cylinders (2 mm diameter) of each RC (n= 10/group) were attached to the block surface, and SBS was measured using a universal testing machine at 0.5 mm/minute. Failure (adhesive, cohesive or mixed) was assessed under ×3.5 magnification. SBS data were analyzed using factorial ANOVA, followed by Tukey post-hoc, and Weibull moduli estimation (α = 0.05). RESULTS: The highest SBS, Weibull modulus (m) and scale parameter (σ0) were found in combined use of MMA and bonding agents (P< 0.001), regardless of the substrate, RC consistency or brand. The use of the Composite Primer and flowable RC also increased SBS (P< 0.001). Significant interaction between surface treatment and RC consistency was observed for the PMMA substrate (P< 0.001). Sandblasting did not influence SBS (P> 0.05). Adhesive failure was most prevalent (93.5%) and SBS values were significantly higher in mixed fractures (19.2± 3.8 MPa) compared to the adhesive ones (9.7± 6.0 MPa) (P< 0.001). No cohesive fracture was observed. CLINICAL SIGNIFICANCE: Composite Primer improved the adhesion of acrylic and bis-acryl repairs, especially when a flowable composite was used. When such product is not available, the combined use of MMA and a bonding agent is necessary, increasing the number of clinical steps, cost, and time required.

Intra- and extraoral prostheses retained by zygoma implants following resection of the upper lip and nose.

Upper lip cancers are infrequent lesions, being aggressive unless diagnosed and treated early. After the surgical resection, maxillofacial defects require special care in rehabilitation. This article describes the maxillofacial rehabilitation of an edentulous patient diagnosed with upper lip squamous cell carcinoma. The treatment consisted of a large amount of upper lip and nose tissue resection, followed by chemoradiotherapy. After the first surgical healing, zygoma implants were inserted in a two-step procedure. The maxillary and nasal prostheses were installed and fixed by a titanium framework. After 6 years follow-up, no recurrences were observed, and the patient did not develop metastases. Tissues around implants were in good health, and the prostheses remained well-fitted. The use of implant-retained prostheses improved the quality of life, and the patient was extremely satisfied with the final result. The implant-retained prostheses are well accepted by the patient, improving comfort and safety during function while recovering her esthetic apperance.

Implant retainers for free-end removable partial dentures affect mastication and nutrient intake.

OBJECTIVES: This study measured swallowing threshold parameters and nutrient intake in partially dentate subjects rehabilitated by conventional free-end removable partial dentures (RPD) and by RPD over posterior implant retainers and ball attachments (BA). MATERIALS AND METHODS: Eight subjects (two men and six women; mean age 60.1 ± 6.6 years old) received conventional total maxillary dentures and free-end RPD in the mandible. Two months after denture insertion, swallowing threshold and nutrient intake assessments occurred, which included an evaluation of the number of masticatory cycles and medium particle size (X50) of a silicone test material (Optocal). A 3-day food diary verified nutrient intake based on a standard Brazilian Food Composition Table. Then, osseointegrated implants were placed bilaterally in the mandibular first molar region, followed by BA, which was fitted in the RPD bases after healing. After 2 months of the RPD over implants and BA use, variables were again assessed. Wilcoxon signed rank tests evaluated the data (P < 0.05). RESULTS: Masticatory cycles did not differ (P > 0.05); however, subjects showed decreased X50 values at the swallowing moment (P = 0.008) and increased daily energy (P = 0.008), carbohydrate (P = 0.016), protein (P = 0.023), calcium (P = 0.008), fiber (P = 0.016), and iron (P = 0.016) intake with RPD implants and BA inserts. No differences were found in fat consumption (P > 0.05). CONCLUSION: Implants and BA retainers over a free-end RPD resulted in smaller swallowed median particle size and improved nutrient intake.

Implant retention and support for distal extension partial removable dental prostheses: satisfaction outcomes.

STATEMENT OF PROBLEM: The rotational movements of the distal extension denture base of partial removable dental prostheses frequently harm the prosthesis stability, leading to discomfort during function. PURPOSE: This study evaluated the use of distal implants to retain and support partial removable dental prostheses and assessed the outcomes with respect to specific aspects of patient satisfaction. MATERIAL AND METHODS: Twelve participants (mean age, 62.6 ± 7.8 years) received new conventional mandibular partial removable dental prostheses and complete maxillary dentures. After 2 months of conventional prosthesis use, the participants completed a questionnaire assessing their satisfaction. Implants were then inserted bilaterally in the mandibular posterior region and, after 4 months, ball attachments were placed on the implants and on the partial removable dental prosthesis acrylic resin base. The implants and remaining teeth were followed up with clinical and image examinations. After 2 months, satisfaction was reevaluated, and the data were analyzed by the paired Student t test and the Bonferroni correction (α=.05). RESULTS: Clinical evaluation found stable periodontal conditions around the implants, no intrusions or mobility of teeth, and no radiographic changes in bone level. Participants reported significant improvements (P<.05) in retention, comfort, masticatory capacity, and speaking ability after implant placement. CONCLUSIONS: Implant-retained and -supported removable prostheses improve retention and stability, minimize rotational movements, and significantly increase participant satisfaction.

Kinesiographic study of masticatory movements in denture wearers with normal and resorbed denture-bearing areas.

STATEMENT OF PROBLEM: An unfavorable denture-bearing area could compromise denture retention and stability, limit mastication, and possibly alter masticatory motion. PURPOSE: The purpose of this study was to evaluate the masticatory movements of denture wearers with normal and resorbed denture-bearing areas. MATERIAL AND METHODS: Completely edentulous participants who received new complete dentures were selected and divided into 2 groups (n=15) according to the condition of their denture-bearing areas as classified by the Kapur method: a normal group (control) (mean age, 65.9 ± 7.8 years) and a resorbed group (mean age, 70.2 ± 7.6 years). Masticatory motion was recorded and analyzed with a kinesiographic device. The patients masticated peanuts and Optocal. The masticatory movements evaluated were the durations of opening, closing, and occlusion; duration of the masticatory cycle; maximum velocities and angles of opening and closing; total masticatory area; and amplitudes of the masticatory cycle. The data were analyzed by 2-way ANOVA and the Tukey honestly significant difference post hoc test (α=.05). RESULTS: The group with a resorbed denture-bearing area had a smaller total masticatory area in the frontal plane and shorter horizontal masticatory amplitude than the group with normal denture-bearing area (P<.05). CONCLUSIONS: Denture wearers with resorbed denture-bearing areas showed reduced jaw motion during mastication.

Mastication movements and sleep quality of patients with myofascial pain: occlusal device therapy improvements.

STATEMENT OF PROBLEM: Patients with myofascial pain experience impaired mastication, which might also interfere with their sleep quality. PURPOSE: The purpose of this study was to evaluate the jaw motion and sleep quality of patients with myofascial pain and the impact of a stabilization device therapy on both parameters. MATERIAL AND METHODS: Fifty women diagnosed with myofascial pain by the Research Diagnostic Criteria were enrolled. Pain levels (visual analog scale), jaw movements (kinesiography), and sleep quality (Epworth Sleepiness Scale; Pittsburgh Sleep Quality Index) were evaluated before (control) and after stabilization device use. Range of motion (maximum opening, right and left excursions, and protrusion) and masticatory movements during Optosil mastication (opening, closing, and total cycle time; opening and closing angles; and maximum velocity) also were evaluated. Repeated-measures analysis of variance in a generalized linear mixed models procedure was used for statistical analysis (α=.05). RESULTS: At baseline, participants with myofascial pain showed a reduced range of jaw motion and poorer sleep quality. Treatment with a stabilization device reduced pain (P<.001) and increased both mouth opening (P<.001) and anteroposterior movement (P=.01). Also, after treatment, the maximum opening (P<.001) and closing (P=.04) velocities during mastication increased, and improvements in sleep scores for the Pittsburgh Sleep Quality Index (P<.001) and Epworth Sleepiness Scale (P=.04) were found. CONCLUSION: Myofascial pain impairs jaw motion and quality of sleep; the reduction of pain after the use of a stabilization device improves the range of motion and sleep parameters.

New adhesive protocol improves shear bond strength of Polyetherketoneketone (PEKK).

OBJECTIVE: Inert surface of Polyetherketoneketone (PEKK) jeopardizes resin bonding. This study aimed to present a new adhesive protocol to improve PEKK bonding. METHODS: A total of 360 PEKK blocks were milled, polished (maximum roughness of 0.20 µm), and randomly assigned to groups. The new protocol was applied (n = 36) and compared to conventional treatments (no treatment; sandblasting (110-µm Al2O3 and silica); no adhesive; Visiolink (Bredent); and PEKKbond (AnaxDent)) (n = 36). For the new protocol, the surface was blasted (110 µm Al2O3 and 96% isopropyl alcohol at 60 psi), followed by 96% isopropyl alcohol washing, and air drying. PEKKbond was applied (dried for 3 min at 77 °C), followed by Visiolink (dried for 3 min at 60 °C); both light-cured for 3 min (800 mW/cm2). Preopaque (GC Europe) and Opaque (AnaxDent) were applied and light-cured (5 min). Morphological topography was analyzed, and flowable gingiva-colored composite (AnaxGum, AnaxDent) was bonded. All specimens were aged for 24 h and thermocycled (5000 cycles, 5-55 °C). Shear bond strength (SBS) was measured (MPa) and data were analyzed by two-way ANOVA, Tukey, and Weibull moduli estimation (α = 0.05). RESULTS: The highest SBS values were found in the new protocol (p < 0.05), regardless of aging. Thermocycling reduced SBS (p < 0.05), while Al2O3 and PEKKbond produced higher SBS values than silica and Visiolink, respectively (p < 0.05). SIGNIFICANCE: The new protocol strongly improves PEKK adhesiveness, and this can reflect in the longevity of prostheses.

Influence of length of occlusal support on masticatory function of free-end removable partial dentures: short-term adaptation.

PURPOSE: To analyze masticatory function after a short adaptation period relative to occlusal support length reduction in free-end removable partial denture (RPD) wearers. MATERIALS AND METHODS: Twenty-three patients (55.2 ± 8.4 years) were rehabilitated with maxillary complete and mandibular free-end RPDs extending to the second molars. Five occlusal support length conditions were determined by removing artificial teeth from the RPDs: full occlusal support (control); occlusal support to the first molars, second premolars, and first premolars; and no occlusal support. To explore a probable short-term adaptation to occlusal support length reduction, participants wore their dentures at each condition for a period of 1 week before starting masticatory function assessment. For this purpose, masticatory performance, masticatory efficiency, chewing rate, selection chance, and breakage function were evaluated at each condition using the sieving method. Data were analyzed using repeated-measures ANOVA and post hoc Dunnett tests (α = 0.05). RESULTS: Masticatory performance and masticatory efficiency for 2 to 4 mm particles under the condition of occlusal support to the first molars and second premolars were similar to control values (p > 0.05). Masticatory efficiency relative to particles smaller than 2 mm was also seen at the condition of support length to the first premolars (p > 0.05). Chewing rates showed adaptation only at the condition of support length to the first molars (p > 0.05). A similar trend was noted for the selection chance of 8-mm particles, and breakage function for 8- and 2.4-mm particles (p > 0.05). CONCLUSION: After a 1-week adaptation period to free-end RPDs with occlusal support lengths reduced to the premolars, participants were able to achieve adequate masticatory function.

Surgical resection and prosthetic treatment of an extensive mandibular torus.

The aim of this case report was to describe the surgical removal of an extensive mandibular torus and the conventional prosthetic treatment that was performed. During surgery, the torus was exposed by a intrasulcular lingual incision from molar to contralateral molar side and displacement of the mucoperiosteal flap. The bone volume was carefully removed in three separate blocks by sculpting a groove in the superior lesion area and chiseling. After a 30-day postoperative period, a prosthetic treatment was performed using a conventional distal extension removable partial denture. The patient's esthetic and functional expectations were achieved. The surgical procedure and prosthetic treatment performed in the treatment of the mandibular torus in this clinical case is a viable treatment that produces few complications and re-establishes normal masticatory function.

Relationship between non-ulcerative functional dyspepsia, occlusal pairs and masticatory performance in partially edentulous elderly persons.

OBJECTIVE: To relate occlusal state, masticatory performance and non-ulcerative functional dyspepsia. BACKGROUND: In spite of the relationship between gastric disturbances and number of present teeth being recognised, the influence of the number of occlusal pairs and masticatory performance, expressed as median particle size, has not been considered. MATERIALS AND METHODS: Thirty-eight subjects (mean age = 71.8 ± 7.7 years) diagnosed with non-ulcerative functional dyspepsia were selected. A further 38 healthy subjects (mean age = 71.9 ± 7.0 years) acted as controls. Subjects were subdivided according to their number of occlusal pairs: (1) 0-4, (2) 5-9 and (3) 10-14. Masticatory performance was evaluated by using the sieving method. Data were analysed using 2-way anova and Bonferroni post-hoc, Chi-square and Odd ratio tests. RESULTS: Subjects presenting with non-ulcerative functional dyspepsia and 0-4 occlusal pairs showed the lowest masticatory performance (p < 0.01). No association between the dyspepsia and the number of occlusal pairs (χ(2) = 0.48, p = 0.785) was observed, however results showed association between functional dyspepsia and masticatory performance (χ(2) = 4.07, p = 0.0437) presenting an odds ratio = 3.46 (Confidence Interval = 0.99-12.10). CONCLUSION: Changes in masticatory performance were associated with the presence of non-ulcerative functional dyspepsia.