Adding mechanobiological cell features to finite element analysis of an immediately loaded dental implant.

Finite element analysis (FEA) has been used to analyze the behavior of dental materials, mainly in implantology. However, FEA is a mechanical analysis and few studies have tried to simulate the biological characteristics of the healing process of loaded implants. This study used the rule of mixtures to simulate the biological healing process of immediate implants in an alveolus socket and bone-implant junction interface through FEA. Three-dimensional geometric models of the structures were obtained, and material properties were derived from the literature. The rule of mixtures was used to simulate the healing periods-immediate and early loading, in which the concentration of each cell type, based on in vivo studies, influenced the final elastic moduli. A 100 N occlusal load was simulated in axial and oblique directions. The models were evaluated for maximum and minimum principal strains, and the bone overload was assessed through Frost's mechanostat. There was a higher strain concentration in the healing regions and cortical bone tissue near the cervical portion. The bone overload was higher in the immediate load condition. The method used in this study may help to simulate the biological healing process and could be useful to relate FEA results to clinical practice.

Behavior of Implants and Oral Tissues in Maxillary Fixed Prostheses, with a Follow-up of 1 to 12 Years: Analytical Cross-Sectional Study.

PURPOSE: The aim of this study was to evaluate maxillary full-arch implant-supported fixed rehabilitations by identifying biologic complications, implant survival and success rates, and patient satisfaction with treatment. In addition, the study verified the influence of attendance at maintenance appointments on the occurrence of complications. MATERIALS AND METHODS: Data were collected from clinical follow-up appointments. RESULTS: The sample consisted of 52 patients (363 implants) with follow-up of 1 to 12 years (mean: 4.69). The main biologic complication was soft tissue recession (20.8%) at the implant level. Tissue hyperplasia was observed in eight patients (15.4%), and 17 (4.7%) implants had bone loss ≥ 2 mm. The peri-implantitis rate was 3.1% (11 implants). Implant survival and success rates were 97.8% and 93.4%, respectively. Rates of patient satisfaction with treatment were as follows: 21 (40.4%) completely satisfied, 28 (53.8%) satisfied with some complaint, and 3 (5.8%) expected more from treatment. The main complaint was the difficulty of cleaning (64.5%). Patients who attended annual follow-up appointments were associated with less bone remodeling and peri-implant disease, but no significant difference was found in biofilm accumulation. CONCLUSION: This type of rehabilitation is susceptible to biologic complications, but high survival and success rates and patient satisfaction were found. Periodic maintenance was associated with reduced complications, such as bone loss or peri-implantitis.

Influence of a hydrophobic resin coating on the bonding efficacy of three universal adhesives.

OBJECTIVES: To evaluate the effect of an additional hydrophobic resin coating (HE) on the resin-dentine microtensile bond strengths (µTBS), nanoleakage (NL), and in situ degree of conversion (DC) of three universal adhesives used in the etch-and-rinse (ER) and the self-etch (SE) modes. METHODS: Sixty caries-free extracted third molars were divided into 12 groups according to the combination of the factors adhesive (All-Bond Universal [ABU]; G-Bond Plus [GBP] and Scotchbond Universal [SBU]), adhesive strategy (ER and SE), and the use of HE (Heliobond; yes or no). After restorations were constructed, specimens were stored in water (37°C/24h) and sectioned into resin-dentine beams (0.8mm(2)) to be tested under tension (0.5mm/min). Selected beams from each tooth were used for DC quantification and for NL evaluation. Data from each adhesive were analyzed with two-way ANOVA and Tukey's test (α=0.05). RESULTS: ABU and GBP resulted in higher µTBS in the ER mode. The use of HE increased the µTBS of ABU and GBP only in the SE mode. Lower NL was observed for SBU and ABU in the ER mode+HE, and for GBP in the SE mode+HE. SBU and GBP showed higher DC when used in the ER mode, which was increased with HE application. The DC of ABU was similar in all conditions. CONCLUSIONS: The conversion of 1-step SE to 2-step SE may increase the µTBS and DC of current universal adhesives. The reduction in the NL is more dependent on the adhesive composition than on the bonding strategy.

Desordens temporomandibulares em usuários de prótese parcial removível: prevalência de acordo com a classificação de Kennedy / Temporomandibular disorders in patients with removable partial dentures: prevalence according to Kennedy classification

Objetivo: O objetivo deste estudo foi determinar a prevalência das desordens temporomandibulares em pacientes com prótese parcial removível, de acordo com a classificação de Kennedy. Método: A população estudada consistiu de pacientes que procuraram tratamento na Universidade Estadual de Ponta Grossa. Os pacientes selecionados eram usuários de prótese total superior e prótese parcial removível inferior, e esse uso, à época do estudo, fazia entre 1 e 5 anos. Os pacientes foram divididos em cinco grupos (n = 15): G1: usuários de prótese total superior e prótese parcial removível inferior Classe I (Kennedy); G2: usuários de prótese total superior e prótese parcial removível inferior Classe II (Kennedy); G3: usuários de prótese total superior e prótese parcial removível inferior Classe III (Kennedy); G4: usuários de prótese total superior e prótese parcial removível inferior Classe IV (Kennedy), e G5: pacientes totalmente dentados (grupo controle). O questionário de Fonseca foi aplicado para verificar o grau de DTM. O teste qui-quadrado (α = 0,05) foi usado para avaliar a associação entre as variáveis. Resultado: Nenhuma diferença estatística (P > 0,05) foi encontrada entre os grupos. Em todos os grupos, os pacientes apresentaram DTM leve ou moderada. Conclusão: Os resultados deste estudo clínico mostraram que a presença de DTM em pacientes usuários de prótese não pôde ser correlacionada ao uso de prótese, já que a presença de DTM para pacientes desdentados e dentados apresentou-se semelhante.

Objective: The aim of this study was to determine the prevalence of temporomandibular disorders in patients with removable partial dentures according to Kennedy classification. Method: The population consisted of patients who required care at the State University of Ponta Grossa. The patients wore complete upper and lower removable partial dentures between 1 to 5 years. The patients were divided into five groups (n = 15): G1: wearer of complete maxillary denture opposed by a Class I (Kennedy) removable partial denture; G2: wearer of complete maxillary denture opposed by a Class II (Kennedy) removable partial denture; G3: wearer of complete maxillary denture opposed by a Class III (Kennedy) removable partial denture; G4: wearer of complete maxillary denture opposed by a Class IV (Kennedy) removable partial denture and G5: fully dentate patients (control group). Fonseca's questionnaire was applied to verify the level of TMD. The qui-square test (α = .05) was used to analyze association between the variables. Result: No statistical difference (P > 0.05) was found among groups. All groups showed mild or moderate TMD. Conclusion: The findings from this clinical study showed that the presence of TMD in wearers of removable partial denture could not be correlated to the classification of Kennedy, since the presence of TMD for edentulous patients and dentate patients appeared similar.

Immediate bonding properties of universal adhesives to dentine.

OBJECTIVES: To evaluate the dentine microtensile bond strength (µTBS), nanoleakage (NL), degree of conversion (DC) within the hybrid layer for etch-and-rinse and self-etch strategies of universal simplified adhesive systems. METHODS: forty caries free extracted third molars were divided into 8 groups for µTBS (n=5), according to the adhesive and etching strategy: Clearfil SE Bond [CSE] and Adper Single Bond 2 [SB], as controls; Peak Universal Adhesive System, self-etch [PkSe] and etch-and-rinse [PkEr]; Scotchbond Universal Adhesive, self-etch [ScSe] and etch-and-rinse [ScEr]; All Bond Universal, self-etch [AlSe] and etch-and-rinse [AlEr]. After restorations were constructed, specimens were stored in water (37°C/24h) and then resin-dentine sticks were prepared (0.8mm(2)). The sticks were tested under tension at 0.5mm/min. Some sticks from each tooth group were used for DC determination by micro-Raman spectroscopy or nanoleakage evaluation (NL). The pH for each solution was evaluated using a pH metre. Data were analyzed with one-way ANOVA and Tukey's test (α=0.05). RESULTS: For µTBS, only PkSe and PkEr were similar to the respective control groups (p>0.05). AlSe showed the lowest µTBS mean (p<0.05). For NL, ScEr, ScSe, AlSe, and AlEr showed the lowest NL similar to control groups (p<0.05). For DC, only ScSe showed lower DC than the other materials (p<0.05). CONCLUSIONS: Performance of universal adhesives was shown to be material-dependent. The results indicate that this new category of universal adhesives used on dentine as either etch-and-rinse or self-etch strategies were inferior as regards at least one of the properties evaluated (µTBS, NL and DC) in comparison with the control adhesives (CSE for self-etch and SB for etch-and-rinse).

Alternative esthetic management of fluorosis and hypoplasia stains: blending effect obtained with resin infiltration techniques.

STATEMENT OF PROBLEM: New light-polymerized resin composites optimized for rapid infiltration of enamel lesions with resin light curing monomers are commercially available today to prevent enamel lesions from further demineralization and provide a highly conservative therapy. In addition, this technique has proved to be effective treatment for blending white spot lesions because the microporosities of infiltrated lesions are filled with resin. PURPOSE: This clinical report presents and describes cases in which the minimally invasive infiltrant resin technique was used for blending different microporous lesions, mild-to-moderate fluorosis, and hypoplasia stains related to traumatic dental injuries. RESULTS: The fluorosis stain showed visually perceptual improvements. In the cases of hypoplasia, stains were not completely blended. However, the general clinical outcomes of these cases were considered successful and recovered the patients' self-esteem. CONCLUSION: Based on the results obtained, it could be concluded that the resin infiltration technique shows promising results and could be considered a minimally invasive procedure for mild-to-moderate fluorosis and hypoplasia stains. CLINICAL SIGNIFICANCE: This case study allows a better understanding of the concept of the resin infiltration technique applied in other types of porous lesions, increasing its use as a therapeutic alternative for esthetic purposes in the philosophy of minimally invasive dentistry.