Alberto Albaladejo

Influence of sandblasting granulometry and resin cement composition on microtensile bond strength to zirconia ceramic for dental prosthetic frameworks.

OBJECTIVES To evaluate the effect of the particle size of sandblasting and the composition of the resin cement on the microtensile bond strength (MTBS) to zirconia. METHODS Forty zirconia blocks (Cercon, Dentsply) were polished and randomly treated as follows: Group 1 (NT): no treatment; Group 2 (APA-I): airborne particle abrasion (Cobra, Renfert) using 25-μm aluminium-oxide (Al(2)O(3))-particles; Group 3 (APA-II): APA with 50-μm Al(2)O(3)-particles; and Group 4 (APA-III): APA using 110-μm Al(2)O(3)-particles. Ceramic blocks were duplicated in composite resin. Samples of each pretreatment group were randomly divided into two subgroups depending on the resin cement used for bonding the composite disks to the treated zirconia surfaces. Subgroup 1 (PAN), which was a 10-MDP-containing luting system, used Clearfil Ceramic Primer plus Panavia F 2.0 (Kuraray) and Subgroup 2 (BIF) used Bifix SE (VOCO) self-adhesive cement. After 24h, bonded specimens were cut into 1±0.1mm(2) sticks. MTBS values were obtained using a universal testing machine (cross-head speed=0.5mm/min). Failure modes were recorded and the interfacial morphology of the debonded microbars was SEM-assessed. Two-way ANOVA, Student-Newman-Keuls tests, and the step-wise linear regression analysis were performed with the MTBS being the dependent variable (p<0.05). RESULTS Despite the sandblasting granulometry, PAN bonded to air-abraded surfaces attained the highest MTBS and frequently showed mixed fractures. BIF recorded no significant differences in MTBS depending on the conditioning method, and registered the highest rates of premature and adhesive failures. CONCLUSIONS The 10-MDP-containing luting system seems to be the most suitable to bond zirconium-oxide ceramic, mainly after sandblasting.

Validation of two complementary oral-health related quality of life indicators (OIDP and OSS 0-10 ) in two qualitatively distinct samples of the Spanish population

BackgroundOral health-related quality of life can be assessed positively, by measuring satisfaction with mouth, or negatively, by measuring oral impact on the performance of daily activities. The study objective was to validate two complementary indicators, i.e., the OIDP (Oral Impacts on Daily Performances) and Oral Satisfaction 0–10 Scale (OSS), in two qualitatively different socio-demographic samples of the Spanish adult population, and to analyse the factors affecting both perspectives of well-being.MethodsA cross-sectional study was performed, recruiting a Validation Sample from randomly selected Health Centres in Granada (Spain), representing the general population (n = 253), and a Working Sample (n = 561) randomly selected from active Regional Government staff, i.e., representing the more privileged end of the socio-demographic spectrum of this reference population. All participants were examined according to WHO methodology and completed an in-person interview on their oral impacts and oral satisfaction using the OIDP and OSS 0–10 respectively. The reliability and validity of the two indicators were assessed. An alternative method of describing the causes of oral impacts is presented.ResultsThe reliability coefficient (Cronbachs alpha) of the OIDP was above the recommended 0.7 threshold in both Validation and Occupational samples (0.79 and 0.71 respectively). Test-retest analysis confirmed the external reliability of the OSS (Intraclass Correlation Coefficient, 0.89; p < 0.001) Some subjective factors (perceived need for dental treatment, complaints about mouth and intermediate impacts) were strongly associated with both indicators, supporting their construct and criterion validity. The main cause of oral impact was dental pain. Several socio-demographic, behavioural and clinical variables were identified as modulating factors.ConclusionOIDP and OSS are valid and reliable subjective measures of oral impacts and oral satisfaction, respectively, in an adult Spanish population. Exploring simultaneously these issues may provide useful insights into how satisfaction and impact on well-being are constructed.

Dimensional structure of the oral health-related quality of life in healthy Spanish workers

BackgroundOral health-related quality of life (OHQoL) is conceived as a multidimensional construct. Here our aim was to investigate the dimensional structure of OHQoL as measured by the Spanish versions of the Oral Impacts on Daily Performance (OIDP) and the Oral Health Impact Profile (OHIP-14) questionnaires applied simultaneously.MethodsWe recruited a consecutive sample of 270 healthy Spanish workers visiting the Employment Risk Prevention Centre for a routine medical check-up. OHIP-14 was self-completed by participants but the OIDP was completed in face-to-face interviews. An Exploratory Factor Analysis (EFA) was performed to identify the underlying dimensions of the OHQoL construct assessed by both instruments. This factorial structure was later confirmed by Confirmatory Factor Analysis (CFA) using several estimators of goodness of fit indices.ResultsEFA and the CFA identified and respectively confirmed a set of 3 underlying factors in both questionnaires that could be interpreted as functional limitation, pain-discomfort, and psychosocial impacts. The model achieved was seen to fit properly for both instruments, but the factorial structure was clearer for the OIDP.ConclusionsThe results provide evidence for construct equivalence in the latent factors assessed by both OIDP and OHIP-14, suggesting that OHQoL is a three-dimensional construct. The prevalence of impact on these three factors was coherent between both indicators, pain-discomfort having the highest prevalence, followed by psycho-social impact, and functional limitation.

Influence of the usual motivation for dental attendance on dental status and oral health-related quality of life

Objectives: To evaluate the influence of dental visiting patterns on the dental status and Oral Health-related Qua-lity of Life (OHQoL) of patients visiting the University Clinic of Salamanca (Spain). Study Design: This cross-sectional study consisted of a clinical oral examination and a questionnaire-based interview in a consecutive sample of patients seeking a dental examination. Patients were classified as problem-based dental attendees (PB) and regular dental attendees (RB). Clinical and OHQoL (OHIP-14 & OIDP) data were compared between groups. Pair-wise comparisons were performed and a Logistic Regression Model was fitted for predicting the Odds Ratio (OR) of being a PB patient. Results: The sample was composed of 255 patients aged 18 to 87 years (mean age: 63.1 ± 12.7; women: 51.8%). The PB patients had a poorer dental status (i.e. caries, periodontal and prosthetic needs), brushed their teeth less,and were significantly more impaired in their OHQoL according to both instruments. The logistic regression coefficients demonstrated that on average the OR of being a PB patient was high in this dental patient sample, but this OR increased significantly if the patient was a male (OR= 1.1-5.0) or referred pain-related impacts according to the OHIP and, additionally, the OR decreased significantly as a function of the number of healthy fillings and the number of sextants coded as CPI=0. Conclusions: Regular dental check-ups are associated with better dental status and a better OHQoL after controlling for potentially related confounding factors. Key words:Dental attendance, oral health-related quality of life.

Effect of adhesive application prior to bracket bonding with flowable composites

OBJECTIVE To evaluate the effect of applying an adhesive, prior to different flowable composite resins, on the shear bond strength (SBS) of orthodontic brackets to acid-etched human enamel. MATERIALS AND METHODS One hundred metal brackets were bonded to 35% phosphoric acid-etched human premolars using four flowable composites (Admira Flow, Tetric Flow, Filtek Supreme, Transbond Supreme) and a conventional orthodontic composite resin (Transbond XT). For each experimental group, half of the specimens were bonded in combination with Transbond XT adhesive. After 24 hours of storage, an SBS test was performed. Adhesive remnant index scores were determined after the failure of brackets. Two-way analysis of variance and Student-Newman-Keuls multiple comparison tests were performed at P < .05. RESULTS When using an adhesive system, the five composites performed equally. The application of adhesive had a significant effect on SBS. Without adhesive, SBS decreased in all groups, except for Transbond Supreme LV. All the test groups exhibited similar bracket failure modes. CONCLUSIONS When using an adhesive system, flowable composite resins exhibited similar SBS. Transbond Supreme was the only resin performing similarly with or without adhesive system application.

Contributions of dental colour to the physical attractiveness stereotype

Dental appearance may play a key role on the way we develop a first impression of another person. To test whether relatively minor changes in the lightness of tooth colour would influence the perceived social appeal (social, intellectual, psychological and relational abilities) of an unknown male and unknown female, this cross-sectional study was performed on 555 Spanish adults. The two major independent variables related to the photograph were tooth lightness (computer-derived), divided into three levels that included lightened teeth, natural teeth and darkened teeth, and the gender of the observed face. Moreover, six independent variables related to the observer were assessed (age, gender, educational level, place of residence, frequency of brushing and self-reported health status). The dependent variables were scored on five-point Likert scales designed to quantify four domains (social, intellectual, psychological and relationship competences) of the Social Appeal Scale (SAS). Tooth lightness influences the perception of social appeal in all dimensions, as darkened smiles received significantly poorer scores than natural-colour smiles, but these were also worse than lightened smiles. A logistic regression analysis revealed that the major predictor of social appeal was tooth lightness, and for each increment in lightness (from darkened to lightened smiles), the odds ratio (OR) of positive values being perceived increased significantly in all items (from 2·3 in Popularity to 6·9 in Happiness). A perceptible change in dental lightness is the strongest factor associated with the dental attractiveness stereotype, affecting significantly the 12 traits assessed, but mainly the Happiness, Social Relations and Academic Performance.

Vertical misfit of laser-sintered and vacuum-cast implant-supported crown copings luted with definitive and temporary luting agents.

Objectives. This study aimed to evaluate the vertical discrepancy of implant-supported crown structures constructed with vacuum-casting and Direct Metal Laser Sintering (DMLS) technologies, and luted with different cement types. Study Design. Crown copings were fabricated using: (1) direct metal laser sintered Co-Cr (LS); (2) vacuum-cast Co-Cr (CC); and (3) vacuum-cast Ti (CT). Frameworks were luted onto machined implant abutments under constant seating pressure. Each alloy group was randomly divided into 5 subgroups (n = 10 each) according to the cement system utilized: Subgroup 1 (KC) used resin-modified glass-ionomer Ketac Cem Plus; Subgroup 2 (PF) used Panavia F 2.0 dual-cure resin cement; Subgroup 3 (RXU) used RelyX Unicem 2 Automix self-adhesive dual-cure resin cement; Subgroup 4 (PIC) used acrylic/urethane-based temporary Premier Implant Cement; and Subgroup 5 (DT) used acrylic/urethane-based temporary DentoTemp cement. Vertical misfit was measured by scanning electron microscopy (SEM). Two-way ANOVA and Student-Newman-Keuls tests were run to investigate the effect of alloy/fabrication technique, and cement type on vertical misfit. The statistical significance was set at α = 0.05. Results. The alloy/manufacturing technique and the luting cement affected the vertical discrepancy (p < 0.001). For each cement type, LS samples exhibited the best fit (p < 0.01) whereas CC and CT frames were statistically similar. Within each alloy group, PF and RXU provided comparably greater discrepancies than KC, PIC, and DT, which showed no differences. Conclusions. Laser sintering may be an alternative to vacuum-casting of base metals to obtain passive-fitting implant-supported crown copings. The best marginal adaptation corresponded to laser sintered structures luted with glass-ionomer KC, or temporary PIC or DT cements. The highest discrepancies were recorded for Co-Cr and Ti cast frameworks bonded with PF or RXU resinous agents. All groups were within the clinically acceptable misfit range. Key words:Dental alloy, laser sintering, implant-supported prostheses, vertical discrepancy, vertical misfit.

Accuracy in the legal age estimation according to the third molars mineralization among Mexicans and Columbians.

OBJECTIVES This study aims to assess the accuracy of age estimation according to two cut-off points of Demirjians developmental stages (G and H) in the wisdom teeth, using panoramic radiographs from Colombian and Mexican teenagers. STUDY DESIGN The degree of maturation of the third molars was classified according to Demirjian in 8 stages (from A to H) by a blinded trained assessor. The sensitivity, specificity and efficacy of two cut-off points (G and H) were calculated for both samples. RESULTS The orthopantomographies of 316 subjects, 171 Colombians (54.1%) and 145 Mexicans (45.9%), were analyzed. The stage H was found to be the best threshold for detecting juveniles (because the high specificity) in all the third molars assessed. The specificity was higher for lower third molars than for upper third molars, but no asymmetrical discrepancy was noted. CONCLUSIONS The stage H is the best cut-off point for detecting the adulthood when a high-specificity test is required.

Influence of cyclic loading on the adhesive effectiveness of resin‐zirconia interface after femtosecond laser irradiation and conventional surface treatments

The aim of this study was to evaluate the influence of cyclic loading on the shear bond strength (SBS) of a self‐adhesive resin cement to zirconia surfaces after femtosecond laser irradiation at different steps and several conventional surface treatments.

The role of topical simvastatin on bone regeneration: A systematic review

Objectives: The aim of this systematic review was to summarize the results concerning the use of simvastatin for promoting bone regeneration and to discuss the level of scientific evidence supporting such findings. Material and Methods: A Pubmed search using “Simvastatin”[Mesh] AND “Bone Regeneration”[Mesh] as Boolean operators was constrained to the last 10 years and only included papers written in English. Results: Of the 41 relevant papers reviewed, most of them (76.2%) have been published in the last 5 years, and most of them address animal studies (66.6%) performed on rats or rabbits in extraoral regions. Only 4 randomized controlled trials (RCTs) assessed the role of topical simvastatin in periodontal patients. Conclusions: A large part of the evidence concerning the role of topical simvastatin on bone regeneration comes from animal studies (mainly rats) focusing on extraoral bone defects. Only the use of subgingival simvastatin after root scaling has been properly supported by RCT. Key words:Simvastatin, bone regeneration, topical administration, osteogenesis, osteoinduction.