Research on guided bone regeneration (GBR) is still ongoing, with evidence mainly from preclinical studies. Various current barrier membranes should fulfill the main design criteria for GBR, such as biocompatibility, occlusivity, spaciousness, clinical manageability and the appropriate integration with the surrounding tissue. These GBR characteristics are required to provide the maximum membrane function and mechanical support to the tissue during bone formation. In this review, various commercially available, resorbable and non-resorbable membranes with different characteristics are discussed and summarized for their usefulness in preclinical studies. Membranes offer promising solutions in animal models; however, an ideal membrane has not been established yet for clinical applications. Every membrane type presents both advantages and disadvantages. Titanium mesh membranes offer superb mechanical properties for GBR treatment and its current efficacy in trials will be a focus in this review. A thorough understanding of the benefits and limitations inherent to various materials in specific clinical applications will be of great value and aid in the selection of an optimal membrane for GBR.

View full abstract

Purpose: TiO₂ and SiO₂ nanoparticles are products of nanotechnology which have been incorporated to acrylic resins (AR) in order to induce antimicrobial properties. However, as additives they can affect the mechanical properties of the final product. The aim of this study was to survey the effects of TiO₂ and SiO₂ nanoparticles on flexural strength (Fs) of poly (methyl methacrylate) acrylic resins.
Methods: Acrylic specimens (Selecta Plus) in size of 5 × 10 (±0.2) × 3.3 (±0.2) mm were prepared and divided into 7 groups: AR containing nanoTiO₂, SiO₂ and TiO₂ with SiO₂ in two concentration of 1% and 0.5%, in addition to a control group. To prepare nano AR, nanoparticles were added to the monomer. All specimens were stored in 37 °C distilled water and underwent Fs test by universal testing machine (Zwick).
Results: The maximum mean flexural strength (43.5 MPa) belongs to the control group and AR containing 0.5% of both TiO₂ and SiO₂ demonstrated the minimum mean Fs (30.1 MPa). Resins contained TiO₂, demonstrated lower values of Fs than those contained SiO₂ with the same concentration, but the differences were not significant (P > 0.05).
Conclusion: Incorporation of TiO₂ and SiO₂ nanoparticles into acrylic resins can adversely affect the flexural strength of the final products, and this effect is directly correlated with the concentration of nanoparticles.

View full abstract

Purpose: To investigate the polymerization efficiency through translucent and opaque glass fiber posts and the bond strength of a self-adhesive resin to root dentin.
Methods: Translucent and opaque silanated conical posts, identical in length, diameter and shape (n = 8), were cemented to incisor bovine roots using RelyX Unicem Clicker. Photoactivation was performed only through the posts. The roots were transversally sectioned (cervical, middle and apical thirds) and the push-out test was carried out. Data were analyzed using two-way ANOVA and Fisher's LSD method (5%). Failure modes were classified under magnification. An elastomer mold of a bovine incisor root was filled with flowable composite and the posts inserted into the mold. After photoactivation through the post and removal of unpolymerized material, the polymerization efficiency was estimated by percentage of mass gain (n = 5). Data were analyzed using t-test (5%).
Results: The bond strength of the translucent post was higher than the opaque post for all root thirds. For both posts the bond strength at the cervical third was higher than at the middle and apical thirds. A predominance of adhesive failures was detected for all conditions. Mixed failures were more frequently observed for the opaque post. Almost all the composite polymerized and bonded to the extension of the translucent post, whereas polymerization of the composite was restricted to the cervical area of the opaque post.
Conclusions: The use of translucent post may positively influence the polymerization efficiency and bond strength of resin cement to intraradicular dentin.

View full abstract

Purpose: The present study aimed to evaluate the retention and stress distribution of conventional (C) RPD and compare to RPD associated to implant for support (IS) and retention (IR).
Methods: Frameworks were cast from cp Ti (n = 18) and Co–Cr alloy (n = 18) by plasma and injected by vacuum–pressure. Conventional RPDs were compared to implant associated RPDs using a distal implant to support (IS) or to support and retain (IR) RPD. The specimens were subjected to insertion/removal cycles simulating 5 years of use and the retention force (N) was measured or evaluated. A mixed linear model was used to analyze the data (α = 0.05). Photoelastic models were qualitatively examined for stress when an occlusal load of 15 kgf was applied over support teeth and RPD.
Results: Retention force of IR RPDs is greater than IS and C RPDs for both cp Ti and Co–Cr alloy specimens. Retention force of cp Ti RPDs increased initially and was maintained throughout 5 years of simulation test while Co–Cr RPDs presented a decrease at the beginning of the test and had their retention force maintained throughout the test. Implant placement at residual alveolar ridge decreased stress around teeth, mainly in the first premolar. Stress concentration in the IS RPD is slightly greater than in the IR RPD.
Conclusion: The results suggest that implant placement at the distal extension improves retention and stress distribution of RPDs.

View full abstract

Purpose: Titanium abutments and superstructures are commonly veneered or covered with esthetic materials. The present investigation was carried out to evaluate the effects of an experimental surface treatment using etchant and primer on bond strength between a resin composite and Ti–6Al–4V alloy.
Methods: Disk-shaped Ti–6Al–4V alloy was machine milled, the surface was air abraded with alumina, and the alloy was chemically etched with 5wt% ammonium hydrogen fluoride (F-etch) for 30 s. A phosphate primer (MDP-primer) was applied to the bonding area, and then a resin composite, with or without milled-fiber resin composite (FRC), was veneered on the specimen. Shear bond strengths were determined after thermocycling for 20,000 cycles. Bond strength data were analyzed by means of ANOVA and a multiple comparison test (α = 0.05). The surface of Ti–6Al–4V alloy was observed using a scanning electron microscope before and after the etching procedure.
Results: No-FRC/F-etch/MDP-primer exhibited the highest bond strength (28.2 MPa), followed by No-FRC/No-etching/MDP-primer (24.2 MPa), FRC/F-etch/MDP-primer (19.9 MPa), FRC/No-etching/MDP-primer (17.8 MPa), No-FRC/No-etching/No-primer (13.6 MPa), while FRC/No-etching/No-primer (2.5 MPa) resulted in the lowest value. Microphotographs showed that numerous micro and nano pits were created on the Ti–6Al–4V alloy surface modified with F-etch.
Conclusions: The bond strength between Ti–6Al–4V alloy and the veneering resin composite was the highest when the alloy surface was modified with alumina blasting, fluoride etchant, and phosphate primer successively.

View full abstract

Purpose: The aim of this study was to evaluate the impact of treatment with new complete dentures on oral health-related quality of life and satisfaction of edentulous patients attending the Prosthodontic Department in a Dental School in Brazil. Methods: A total of 70 edentulous subjects (37–86 years) treated by undergradute students at the Araçatuba Dental School, University of State of São Paulo, were accessed. A specific questionnaire for edentulous patients (EDENT) based on the Oral Health Impact Profile (OHIP-EDENT) was applied to collect information on patient oral health-related quality of life. Questions related to the personal satisfaction of the edentulous patients with their complete dentures were also included. The patients were accessed before the treatment, and 3 months after receiving the new dentures. Results: After rehabilitation with new complete dentures, all domains of OHIP-EDENT showed significant improvements. There was also a significant improvement in patient satisfaction after placement of new complete dentures. Furthermore, it was possible to observe association between upper denture satisfaction and age. Conclusion: Conventional complete dentures may have a positive impact on oral health-related quality of life and satisfaction of edentulous patients.

View full abstract

Purpose: The purpose of this study was to investigate whether different types of dentures induced different responses to stimulations in sensory nerve underlying the denture-supporting mucosa using current perception threshold (CPT).
Materials and methods: The study population comprised 45 complete denture wearers with a mean age of 69.7 years (CD), 30 partial denture wearers (PD) with a mean age of 67.1 years, and 40 dentulous participants with a mean age of 69.0 years (Dent). Current perception threshold (CPT) on the greater palatine nerve at 2000 Hz, 250 Hz, and 5 Hz, corresponding to A-beta, A-delta, and C fibers respectively, were measured by the Neurometer^® NS3000 device. The differences CPTs among CD, PD, and Dent groups were analyzed by Kruskal–Wallis test and Mann–Whitney U test with adjusting the multiple comparisons’ inflation of type 1 error rate by a Bonferroni correction.
Results: CPTs of CD, PD, and Dent group at 2000 Hz were 61.5 ± 45.8, 53.5 ± 25.3, 33.0 ± 11.4 (10⁻² mA) respectively. CPTs of CD, PD, and Dent group at 250 Hz were 29.2 ± 28.2, 20.1 ± 13.2, 14.3 ± 5.9 (10⁻² mA) respectively. CPTs of CD, PD, and Dent group at 5 Hz were 28.9 ± 23.4, 17.8 ± 12.2, 12.2 ± 5.6 (10⁻² mA) respectively. The CPTs at all frequencies increased in the following order: Dent < PD < CD wearer. The statistical analyses showed that the different types of dentures significantly affected CPTs at 2000 Hz (p < 0.0001), 250 Hz (p < 0.0001), and 5 Hz (p < 0.0001).
Conclusion: The different types of dentures induce different responses to stimulations in the sensory nerve underlying the denture-supporting mucosa.

View full abstract

Purpose: The stress relaxation and compressive strength of resin, resin-modified glass ionomer, glass ionomer, polycarboxylate, and zinc oxide eugenol cements were measured to determine the characteristics of these materials after setting.
Methods: A total of 19 luting cements including 12 permanent cements and 7 temporary cements were used. Cylindrical cement specimens (10 mm long and 6 mm in diameter) were obtained by chemical setting or light curing. The specimens were stored for 24–36 h in water at 37 °C and were then used for the stress relaxation and compression tests. The stress relaxation test was carried out using three constant cross-head speeds of 5, 50, and 100 mm/min. Upon reaching the preset dislocation of 0.5 mm, the cross-head movement was stopped, and the load was recorded for 60 s. Fractional stress loss at 1 s was calculated from the relaxation curves. The compressive strength and modulus were measured at a cross-head speed of 1 mm/min. Data were analyzed with the Kruskal–Wallis test and Holm's test.
Results: A zinc oxide eugenol cement [TempBOND NX] exhibited the largest fractional stress loss. A resin cement [ResiCem] showed the largest compressive strength, while a glass ionomer cement [HY-BOND GLASIONOMER CX] showed the largest compressive modulus among all tested cements (p < 0.05).
Conclusion: The fractional stress loss could not be classified by the cement type. Two implant cements [Multilink Implant and IP Temp Cement] showed similar properties with permanent resin cements and temporary glass ionomer cements, respectively. Careful consideration of the choice of cement is necessary.

View full abstract

Purpose: Patients’ preferences of the type of sample collections for clinical testing are currently unknown. The aims of this study were: (1) to assess patients’ preferences of three types of samples for clinical testing (saliva, urine and blood) both before and after collection and (2) to assess whether prior experiences with collection of saliva impacted patients responses.
Methods: Adult outpatients underwent collection of one sample each of saliva, urine and blood. Patients’ perceptions of comfort, convenience and easiness were assessed in pre-collection and post-collection questionnaires.
Results: Post-collection, patients’ endorsement of saliva as being the “most comfortable” and “most convenient” significantly declined (pre vs. post, 61.5% vs. 37.5% and 73.1% vs. 42.3%). However, saliva was still endorsed as the “most convenient” post-collection (compared to urine 33.7% and blood 24.0%).
Although not statistically significant, the proportion of patients who changed their response in terms of what sample was “easiest to collect at home” was considerably higher in the group with vs. without prior experience giving saliva (54.6% vs. 32.6%, p = 0.19 Fisher's exact test).
Conclusions: Overall, saliva remained as the most highly preferred sample to donate despite a decline in patients’ preferences of saliva donation after sample collection.
The results of the study are promising for future widespread patient acceptance of saliva as a diagnostic fluid.

View full abstract

Patient: A 45-year-old female patient with need of fixed replacement of her missing teeth which were lost long time before. Posterior teeth were severally tipped bilaterally in the edentulous space. Hybrid removable partial denture with molar uprighting spring was fabricated for molar uprighting on both side tilted molars. After 3 month and 15 days of treatment with hybrid appliance the molar abutment were uprighted for fabrication of fixed partial dentures.
Discussion: The objective in molar uprighting is ideal positioning of the molar which will eventually become an abutment tooth for a fixed prosthesis. The ideal position will provide an optimal periodontal environment for the molar. The prosthodontic advantages of molar uprighting via distal tipping include an improved line-of-draw if a FPD is being constructed. Concept of designing of appliances was based on our basic knowledge of forces for uprighting the tooth along with maintaining the function during the treatment period. Another advantage of this appliance was that it prevented supra eruption of opposing teeth during the period when the molar was being uprighted.
Conclusion: Uprighting of tilted molar is extremely beneficial for long term success of fixed denture prosthesis by using hybrid appliances in very short period of treatment without hampering the function of the patient during the treatment period which is very economical as well.

View full abstract

Aim: This clinical report aimed to introduce a novel vibratory stimulation-based occlusal splint (VibS) for management of chronic and untreatable masticatory myofascial pain (MMFP).
Methods: This study was conducted on four chronic MMFP patients (mean age: 27.5 ± 5.56 years, females) who were diagnosed according to the research diagnostic criteria for temporomandibular disorders (RDC/TMD), and who were using stabilization splints for more than 6 months and still complained of pain above 40 mm in a 100-mm VAS scale. The included subjects utilized the active VibS and subsequently the inactive VibS during 30 days in each trial, separated by a wash-out period of at least 8 months. VAS pain levels were the only measured dependent variable, and were recorded before and after the use of active VibS and inactive VibS.
Results: At baseline, mean VAS pain levels before using the active or inactive splint were 54.5 ± 19.8 mm and 44.0 ± 13.6 mm, respectively. After using the active VibS, mean pain level decreased by 77% (VASpos-pre = −42.0 ± 30.3 mm). On the other hand, after using the inactive VibS, severe pain aggravation of 67% in magnitude was observed (VASpos-pre = +29.5 ± 21.5 mm).
Conclusion: This case-series study demonstrated a good tendency of this novel VibS in chronic MMFP alleviation after a 4-week management period compared to a control inactive VibS.

View full abstract