Alfonso Sánchez-Ayala

State University of Ponta Grossa, Ponta Grossa, Estado do Parana, Brazil

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Publications (19)12.95 Total impact

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    ABSTRACT: The influence of mandibular movement timing on food breakdown remains unclear. The authors, therefore, sought to relate chewing rate with masticatory performance. Chewing rate, defined as the number of masticatory cycles habitually achieved per minute, was measured in 55 healthy dentulous subjects (age, 22.2 +/- 5.0 years). Subjects were grouped according to obtained values (cycles/minute): slower: < 70; middle: 70-90; and faster: > 90. Masticatory performance was determined through the sieve method, and the estimated comminuted median particle size (X50). Data was analyzed using the one-way ANOVA and chi-square tests (alpha = .05). Subjects with slower chewing rates showed higher (p < .05) masticatory performance (X50 = 3.05 +/- 0.77 mm). X50 was associated with chewing rate when subjects were categorized as better or poorer performers (chi-square = 11.25, p < .005). Thus, chewing rate was related to masticatory performance, with smaller food particles being achieved with a slower chewing rate.
    Cranio: the journal of craniomandibular practice 04/2013; 31(2):118-22. · 1.11 Impact Factor
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    ABSTRACT: 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.
    Journal of Prosthodontics 02/2013; · 0.68 Impact Factor
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    ABSTRACT: 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.
    General dentistry 01/2013; 61(1):65-8.
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    ABSTRACT: This study compared the microleakage of class V restorations bonded with various one-step self-etching adhesives. Seventy class V resin-based composite restorations were prepared on the buccal and lingual surfaces of 35 premolars, by using: Clearfil S 3 Bond, G-Bond, iBond, One Coat 7.0, OptiBond All-In-One, or Xeno IV. The Adper Single Bond etch-and-rinse two-step adhesive was employed as a control. Specimens were thermocycled for 500 cycles in separate water baths at 5°C and 55°C and loaded under 40 to 70 N for 50,000 cycles. Marginal microleakage was measured based on the penetration of a tracer agent. Although the control showed no microleakage at the enamel margins, there were no differences between groups (p = 0.06). None of the adhesives avoided microleakage at the dentin margins, and they displayed similar performances (p = 0.76). When both margins were compared, iBond® presented higher microleakage (p < 0.05) at the enamel margins (median, 1.00; Q3-Q1, 1.25-0.00) compared to the dentin margins (median, 0.00; Q3-Q1, 0.25-0.00). The study adhesives showed similar abilities to seal the margins of class V restorations, except for iBond®, which presented lower performance at the enamel margin.
    Brazilian oral research 01/2013; 27(3).
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    ABSTRACT: Purpose: The aim of this cross-sectional study was to investigate the relationship between body fat and masticatory function. Materials and Methods: One hundred dentate and partially edentulous participants (33 male; mean age, 39.7 ± 16.6 years) were selected. Body fat was established through body mass index (BMI). Masticatory function was evaluated by quantifying occlusal pairs and determining masticatory efficiency and swallowing threshold with the sieving method. During the swallowing threshold test, chewing rate was registered. Masticatory ability was also evaluated with a 5-point Likert scale questionnaire. Data were analyzed with Spearman and chi-square tests, as well as binary logistic regression analysis for the presence of increased BMI (α= 0.05). Results: Age (rho = 0.517), occlusal pairs (chi-square = 26.353), masticatory efficiency (chi-square = 30.935), masticatory ability (chi-square = 25.132; p < 0.001), and swallowing threshold (chi-square = 8.730; p < 0.005) were related to BMI. Age (odds ratio, OR = 1.048, 95% CI = 1.008 to 1.089) and lower masticatory efficiency (OR = 4.792, 95% CI = 1.419 to 16.183) were predictive of increased body fat (p < 0.05). Gender (chi-square = 0.402, p= 0.526) and chewing rate (rho =-0.158, p= 0.117) were not related to BMI. Conclusions: These results suggest that people with lower masticatory efficiency may be at risk for increased body fat.
    Journal of Prosthodontics 10/2012; · 0.68 Impact Factor
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    ABSTRACT: OBJECTIVE: The aim of this study was to evaluate the effect of unilateral and bilateral loss of posterior occlusal support on the expression of type II collagen, interleukin-1β and VEGF in the condylar cartilage of growing rats. DESIGN: Thirty female Wistar rats (5 weeks old) were randomized into three groups: control, unilateral extraction of mandibular molar teeth, bilateral extraction of mandibular molar teeth. Animals were sacrificed 8 weeks after tooth extraction and the temporomandibular joints were prepared for immunohistochemical analysis. RESULTS: Bilateral molar extraction increased the expression of interleukin-1β (P<0.01) and VEGF (P<0.01), while unilateral extraction increased the expression of interleukin-1β (P<0.05) and type II collagen (P<0.01). The expression of VEGF was higher on the extracted than on the non-extracted side (P<0.01) after unilateral extraction. CONCLUSION: Loss of posterior occlusal support alters the expression of type II collagen, interleukin-1β and VEGF in the condylar cartilage of rats. The expression pattern of these proteins is different when loss of occlusal support was bilateral or unilateral, including differences between extracted and non-extracted sides.
    Archives of oral biology 06/2012; · 1.65 Impact Factor
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    ABSTRACT: To evaluate the effect of thermo-mechanical cycling (TMC) on the microleakage (μL) and axial gap width (AG) of Class V bonded restorations in premolars using self-etching adhesive systems. The bond strength of composite restorations to dentin (μTBS) using the same adhesives was also evaluated in third molars after water storage: 24 h and 6 months. The research hypotheses were tested for the results of two self-etching adhesives in comparison when a conventional two-step adhesive was used: (1) the μL and AG would be lower, regardless of TMC; (2) the μTBS of self-etching adhesives would be higher, irrespective of evaluation times. Sixty Class V composite restorations were made in 30 premolars and bonded with Adper Single Bond 2 (ASB2), AdheSE (ASE), and Adper Prompt L-Pop (APL-P) (n=20). Dentin μL and AG were immediately measured for half of the sample. The other half was evaluated after TMC. Eighteen third molars were also selected and bonded using the same adhesives to test the μTBS to dentin. Specimens were evaluated after 24 h and 6 months of water storage. No differences in μL and AG were found among the groups (P>.05). The μTBS mean values were: ASB2>ASE>APL-P (P<.05); only Adper Single Bond 2 presented a significantly lower μTBS after water storage (P<.05). The bonding approach does not influence the microleakage and interfacial gap extension. Despite the decrease in the mean values, the bond strength to dentin of the conventional, two-step adhesive remains high after 6 months of water storage.
    European journal of dentistry. 04/2012; 6(2):169-77.
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    ABSTRACT: The aim of this study was to determine the influence of occlusal support length (OSL) of free-end removable partial dentures (RPDs) on masticatory function. Twenty-three subjects (mean age: 55.2 ± 8.4 years) who were edentulous in the maxilla and classified as Kennedy Class I in the mandible were selected. Subjects received new maxillary complete dentures and mandibular RPDs. Five OSL conditions were determined by RPD artificial tooth wear: full occlusal support (L1, control), OSL to first molar (L2), OSL to second premolar (L3), OSL to first premolar (L4), and absence of occlusal support (L5). Masticatory performance and efficiency were evaluated using the sieve method. Chewing rate was defined as the number of masticatory cycles per minute. Bolus selection opportunities and bolus breakage function were evaluated using the one-chew method. Qualitative and quantitative measurements of masticatory cycle patterns were recorded kinesiographically. Data were analyzed using repeated-measures analysis of variance and Friedman and Fisher exact tests (α = .05). Masticatory performance and efficiency decreased (P < .05) from L1 (5.46 ± 0.64 mm and 51.21% ± 19.44%, respectively) to L5 (6.24 ± 0.44 mm and 24.50% ± 15.98%, respectively). Chewing rate was higher for L4 than L1 (P < .05). Bolus selection chances and bolus breakage function decreased as OSL was reduced (P < .05); however, there were no differences in masticatory cycle pattern among the OSL conditions (P > .05). Reduction of OSL altered masticatory function, thereby decreasing masticatory performance and efficiency resulting from a lower capacity to select and break down food.
    The International journal of prosthodontics 01/2012; 25(5):472-9. · 1.63 Impact Factor
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    ABSTRACT: To relate occlusal state, masticatory performance and non-ulcerative functional dyspepsia. 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. 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. 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). Changes in masticatory performance were associated with the presence of non-ulcerative functional dyspepsia.
    Gerodontology 12/2011; 28(4):296-301. · 1.83 Impact Factor
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    Dentistry today 02/2011; 30(2):118, 120-1; quiz 121, 113.
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    ABSTRACT: Purpose: The aim of this case-control study was to investigate the role female hormone fluctuation plays in maximum occlusal force and masticatory performance in female subjects presenting disc displacement with reduction (DDR) and matched controls. Materials and Methods: Sixty-five subjects were initially recruited; however, 4 of them were excluded during the study. The final sample included 14 subjects with DDR taking oral contraceptives, 16 control subjects without DDR taking oral contraceptives, 14 normally cycling subjects with DDR, and 17 normally cycling subjects without DDR. DDR was diagnosed by means of the Research Diagnostic Criteria for Temporomandibular Disorders axis I, and subjects without pain were selected. Maximum occlusal force was measured bilaterally in the molar region using a force transducer, and masticatory performance was analyzed using the artificial material comminution and sieving method. Variables were evaluated in four phases of three menstrual cycles, identified by ovulation testing. Data were submitted to the Mauchly sphericity test and PROC MIXED procedure of the SAS statistical program for repeated measures. Multiple comparisons were made using the Tukey-Kramer test (P ⋜ .05). Results: Comparisons among menstrual cycle phases showed no differences in occlusal force (P = .44) or masticatory performance (P = .09) for all volunteers. Subjects without DDR showed greater occlusal force (P = .01). No difference in occlusal force was found between subjects regardless of whether they took contraceptives (P = .15). Similarly, masticatory performance values did not differ among subjects with or without DDR (P = .09) or among those taking or not taking contraceptives (P = .29). Conclusion: Hormonal fluctuation did not influence mastication. Int J Prosthodont 2011;24:320-327.
    The International journal of prosthodontics 01/2011; 24(4):320-7. · 1.63 Impact Factor
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    ABSTRACT: This study evaluated the relationship among malocclusion, number of occlusal pairs, masticatory performance, masticatory time and masticatory ability in completely dentate subjects. Eighty healthy subjects (mean age = 19.40 ± 4.14 years) were grouped according to malocclusion diagnosis (n = 16): Class I, Class Class II-2, Class III and Normocclusion (control). Number of occlusal pairs was determined clinically. Masticatory performance was evaluated by the sieving method, and the time used for the comminute test food was registered as the masticatory time. Masticatory ability was measured by a dichotomic self-perception questionnaire. Statistical analysis was done by one-way ANOVA, ANOVA on ranks, Chi-Square and Spearman tests. Class II-1 and III malocclusion groups presented a smaller number of occlusal pairs than Normocclusion (p < 0.0001), Class I (p < 0.001) and II-2 (p < 0.0001) malocclusion groups. Class I, and III malocclusion groups showed lower masticatory performance values compared to Normocclusion (p < 0.05) and Class II-2 (p < 0.05) malocclusion groups. There were no differences in masticatory time (p = 0.156) and ability (χ² = 3.58/p= 0.465) among groups. Occlusal pairs were associated with malocclusion (rho = 0.444/p < 0.0001) and masticatory performance (rho = 0.393/p < 0.0001), but malocclusion was not correlated with masticatory performance (rho = 0.116/p= 0.306). In conclusion, masticatory performance and ability were not related to malocclusion, and subjects with Class I, II-1 and III malocclusions presented lower masticatory performance because of their smaller number of occlusal pairs.
    Brazilian oral research 12/2010; 24(4):419-24.
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    ABSTRACT: The purpose of this study was to compare digitized models with their current gold-standard plaster models for tooth-size discrepancy and Bolton analysis. Fifteen pairs of plaster models were obtained from orthodontic patients with permanent dentition. These were digitized and evaluated using the Bibliocast Cécile3 v2.5 software. Two examiners measured three times the mesiodistal width of all the teeth and the arch length, and determined the tooth-size discrepancy and Boltońs ratios. The plaster models were measured using a digital vernier caliper. Interclass correlation (ICC), mean differences and paired t-tests were used for comparisons and statistical analysis. The ICC of the digital models were 0.930 (0.852≤ICC<0.973) for the intra-examiner and 0.929 (0.829≤CCI<0.974) for the inter-examiner. The mean differences between plaster and digital models with respect to the anterior and overall Boltońs ratios for examiner 1 was 0.34 mm for both and for examiner 2 were 0.28 mm and 0.21 mm respectively. Although digital model measurements were lower than plaster (p<0.05), these were considered clinically insignificant (differences<0.1mm). The determination of the tooth-size discrepancy and Bolton analysis using digital models and the Bibliocast Cécile3 software are an acceptable alternative to use in clinical practice.
    International orthodontics 09/2010; 8(3):215-26.
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    ABSTRACT: The aim of this study was to present all the relevant studies that have evaluated, with valid scientific methodology, the possible physical and nutrient intake improvement of edentulous subjects rehabilitated with removable and supported or retained implant denture, without restriction of suprastructure modalities, compared with those wearing conventional removable dentures. Several electronic databases (Pubmed, Medline-Medline In-Process, Cochrane Library Database, Embase, and Lilacs) were searched, without language limitation. References from the selected articles were also hand searched. Abstracts which appeared to fulfill the initial selection criteria (comparison of nutritional state between conventional removable and supported or retained implant denture wearers) were selected by consensus and their original articles were then retrieved. Clinical trials that included anthropometric measurements or nutrient intake in removable and supported or retained implant denture wearers without syndrome and systemic influences, nor presenting surgical or other simultaneous treatment, which could affect the integrity during the evaluation period were finally selected. Only 5 articles met the selection criteria. Two studies (randomized clinical trials and prospective) found inadequate nutrient intake after treatment. One randomized clinical trial presented an improvement in nutritional state after treatment. One cross-sectional study showed an adequate nutritional state before and after treatment. These 4 studies found no significant difference between implant and conventional treatments. Finally, 1 cross-sectional study presented a difference between treatments, showing that the risk of malnutrition was higher for removable complete denture wearers. Considering the available evidence, the effect on the nutritional state in edentulous subjects treated with implant therapy is similar to the 1 obtained with conventional removable dentures. This effect does not necessarily mean an optimum nutritional state, which also depends on other factors not related to prosthodontic treatment.
    Implant dentistry 06/2010; 19(3):196-207. · 1.51 Impact Factor
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    ABSTRACT: L’objectif de cette étude était de comparer les modèles numérisés avec les modèles standards existants pour l’évaluation de la dysharmonie dento-dentaire (DDD) et des rapports de Bolton. Quinze paires de modèles en plâtre ont été obtenues sur des patients en denture permanente avant numérisation et évaluation à l’aide du logiciel Cécile3 v2.5 de chez Bibliocast. Deux évaluateurs ont mesuré trois fois la largeur mésio-distale de toutes les dents et la longueur de l’arcade afin de déterminer la dysharmonie dento-dentaire (DDD) et les rapports de Bolton. Les modèles en plâtre ont été mesurés utilisant un pied à coulisse vernier numérique. Les relations interclasses (CCI), les différences moyennes et des tests-t appariés ont été utilisés pour les comparaisons et l’analyse statistique. Les CCI des modèles numérisés étaient 0,930 (0,852 ≤ CCI < 0,973) pour l’intra-évaluateur et 0,929 (0,829 ≤ CCI < 0,974) 0.929 (0.829 ≤ CCI < 0.974) pour l’inter-évaluateurs. Quant aux rapports de Bolton antérieur et global, les différences moyennes entre les modèles en plâtre et les modèles numérisés étaient de 0,34 mm pour les deux chez l’évaluateur no 1 et de 0,28 mm et de 0,21 mm, respectivement, chez l’évaluateur no 2. Malgré le fait que les valeurs des modèles fussent inférieures à celles des modèles en plâtre (p < 0,05), les écarts étaient cliniquement insignifiants (< 0,1 mm). La détermination de la DDD et de l’analyse de Bolton à l’aide de modèles numérisés et du logiciel Cécile3 de Bibliocast constitue un outil alternatif acceptable pour l’utilisation en clinique.
    International Orthodontics. 01/2010; 8(3):215-226.
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    ABSTRACT: The aim of this study was to determine the reproducibility, reliability and validity of measurements in digital models compared to plaster models. Fifteen pairs of plaster models were obtained from orthodontic patients with permanent dentition before treatment. These were digitized to be evaluated with the program Cécile3 v2.554.2 beta. Two examiners measured three times the mesiodistal width of all the teeth present, intercanine, interpremolar and intermolar distances, overjet and overbite. The plaster models were measured using a digital vernier. The t-Student test for paired samples and interclass correlation coefficient (ICC) were used for statistical analysis. The ICC of the digital models were 0.84 +/- 0.15 (intra-examiner) and 0.80 +/- 0.19 (inter-examiner). The average mean difference of the digital models was 0.23 +/- 0.14 and 0.24 +/- 0.11 for each examiner, respectively. When the two types of measurements were compared, the values obtained from the digital models were lower than those obtained from the plaster models (p < 0.05), although the differences were considered clinically insignificant (differences < 0.1 mm). The Cécile digital models are a clinically acceptable alternative for use in Orthodontics.
    Brazilian oral research 01/2009; 23(3):288-95.
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    ABSTRACT: Previous studies have demonstrated the efficacy of mineral trioxide aggregate (MTA) in repair of furcal perforation. In this article, the use of MTA in treating 2 cases of furcal perforation (accidental and caries-related) and subsequent long-term follow-up are described.
    Journal (Canadian Dental Association) 11/2008; 74(8):729-33. · 0.62 Impact Factor
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    ABSTRACT: Mastication was evaluated in subjects presenting extremely shortened dental arches (ESDAs) rehabilitated with mandibular free-end removable partial dentures (RPDs). Subjects were divided into four groups (n = 10): those with a complete dentition, those with ESDAs, and those with ESDAs who were rehabilitated with an RPD, who were evaluated both with and without their prostheses. Mastication was measured through masticatory performance, time, and ability. RPD wearers showed higher masticatory performance (P < .01) and ability (P < .001) and lower masticatory time (P < .001) than when not wearing their prostheses as well as ESDA subjects who had not received RPD therapy. Those with a complete dentition showed the best results (P < .001). It can be suggested that RPDs improve mastication in ESDA subjects but without achieving normal mastication levels.
    The International journal of prosthodontics 24(6):517-9. · 1.63 Impact Factor

Publication Stats

21 Citations
12.95 Total Impact Points

Institutions

  • 2012–2013
    • State University of Ponta Grossa
      • Department of Dentistry
      Ponta Grossa, Estado do Parana, Brazil
  • 2010–2013
    • University of Campinas
      • Faculty of Dentistry from Piracicaba
      Conceição de Campinas, São Paulo, Brazil
    • Universidad Peruana Cayetano Heredia
      Λίμα, Provincia de Lima, Peru
    • University of Alberta
      Edmonton, Alberta, Canada
  • 2011
    • National University of San Marcos
      Λίμα, Provincia de Lima, Peru
  • 2009–2010
    • University of São Paulo
      San Paulo, São Paulo, Brazil