Stereophotogrammetric impression making for polyoxymethylene, milled immediate partial fixed dental prostheses.

Immediate post-extraction and same-day placement of interim prostheses have increased patient acceptance of implant-supported prostheses. However, for immediate prostheses supported by multiple implants, meeting passive fit and esthetic standards is often challenging. In this clinical report, implant photogrammetry was combined with conventionally obtained digitized casts to prepare an interim, milled prosthesis from a polyoxymethylene (POM) disk, using computer-aided design and computer-aided manufacturing techniques. The following 2 conclusions were drawn. First, stereophotogrammetric scanning appears to be a reliable method for making impressions of immediate, implant-supported partial prostheses, and second, POM is suitable for preparing immediate interim screw-retained prosthetic implants.

Does Length, Diameter, or Bone Quality Affect Primary and Secondary Stability in Self-Tapping Dental Implants?

PURPOSE: Implant stability is a clinically valuable measurement of the strength of implant anchorage in the bone during placement and in the post-osseointegration period. This study aimed to determine 1) the effect of implant diameter and length and bone quality on measurements of primary and secondary stability (insertion torque [IT] and implant stability quotient [ISQ]), 2) the correlation between IT and primary and secondary ISQ, and 3) differences in ISQ in the post-osseointegration period (secondary stability) compared with immediate post-placement (primary) stability. PATIENTS AND METHODS: In this longitudinal clinical study, titanium self-tapping implants were inserted in edentulous patients. The implants were grouped according to 3 independent variables: length (10 and 11.5 mm), diameter (3.75 and 4.25 mm), and bone quality (Lekholm and Zarb classification) to analyze primary and secondary implant stability (outcome variables). Statistical analyses were performed using the Student t test for paired data, 1-way analysis of variance, and the Tukey procedure for multiple pairwise comparisons. RESULTS: Data were collected on 88 self-tapping implants inserted in 63 partially edentulous patients. IT and implant stability were affected by diameter (3.75-mm implants, 26.5-N/cm IT and 74.0 ISQ; 4.25-mm implants, 33.8-N/cm IT and 77.0 ISQ) and bone type (type 1 + 2, 34.86-N/cm IT and 77.4 ISQ; type 3, 27.09-N/cm IT and 75.6 ISQ; type 4, 20.63-N/cm IT and 70.5 ISQ; P < .01 for all comparisons). Secondary ISQ was affected by diameter only (77.41 for 3.75- vs 75.51 for 4.25-mm implants). IT correlated with primary ISQ (R = 0.56; P < .01), although no clear correlation with secondary stability was found. CONCLUSIONS: IT and primary ISQ in self-tapping implants differed in patients with different bone quality and implant diameter but did not differ between the 2 implant lengths compared in this study. Secondary stability was not substantially affected by any of these factors. Although IT was closely related to primary ISQ, it was unrelated to secondary ISQ. Very high primary ISQ values tended to decrease, whereas intermediate and low values tended to increase, in the transition to secondary stability.

Oral health-related quality of life in complete denture wearers depending on their socio-demographic background, prosthetic-related factors and clinical condition.

OBJECTIVES: To investigate the differences in impact on oral health-related quality of life (OHRQoL) among complete denture wearers depending on their socio-demographic characteristics, prosthetic-related factors and oral status. STUDY DESIGN: 51 patients aged 50-90 years treated, from 2005 to 2010, with at least one complete denture at the Department of Buccofacial Prostheses of the Complutense University (Madrid) were enrolled in this cross-sectional study. All of the participants answered the Oral Health Impact Profile (OHIP-14sp) questionnaire. The additive scoring method was used. The prevalence of impacts was calculated by using the occasional threshold (OHIP-14sp score ≥ 2). Socio-demographic and prosthetic-related variables were gathered. Patients underwent clinical examination to assess their oral condition. Descriptive probes and Chi-Square tests were run (p ≤ 0.05). RESULTS: The predominant participants' profile was that of a man with a mean age of 69 years wearing complete dentures in both the maxilla and the mandible. The prevalence of impact was 23.5%, showing an average score of 19 ± 9.8. The most affected domains were "functional limitation" and "physical pain", followed by "physical disability". Minor impacts were recorded for the psychological and social subscales ("psychological discomfort", "psychological disability", "social disability" and "handicap"). The prosthesis' location significantly influenced the overall patient satisfaction, the lower dentures being the less comfortable. Having a complete removable denture as antagonist significantly hampered the patient satisfaction. Patients without prosthetic stomatitis and those who need repairing or changing their prostheses, recorded significantly higher OHIP-14sp total scores. CONCLUSIONS: The use of conventional complete dentures brings negative impacts in the OHRQoL of elderly patients, mainly in case of lower prostheses that required reparation or substitution, with a removable total denture as antagonist. The prosthetic stomatitis in this study was always associated to other severe illness, which may have influenced the self-perceived discomfort with the prostheses, as those patients were daily medicated with painkillers.

Impact of the retention system of implant fixed dental restorations on the peri-implant health, state of the prosthesis, and patients' oral health-related quality of life.

OBJECTIVES: To investigate the impact of the retention system (screwed or cemented) of implant fixed dental prostheses (i-FDPs) on the peri-implant health, prosthesis' state, patient self-evaluation of functionality and aesthetics, and oral health-related quality of life (OHRQoL). METHODS: 35 participants were classified into two groups according to the retention system of their metal-ceramic i-FDPs. For the analysis of peri-implant health and prosthetic complications, the implant units were individually assessed. Group 1 (SPD; n = 22): implant units for screwed i-FDPs; and Group 2 (CPD; n = 36): implant units for cemented i-FDPs. Data related to socio-demographics, design and installation of the superstructures, peri-implant condition, prosthetic complications, functionality, and aesthetics, were gathered. Patients answered the Oral Health Impact Profile (OHIP-14sp) questionnaire. Descriptive and parametric probes were run to evaluate the impact scores considering the study variables (α = 0.05). RESULTS: The plaque index, gingival index, functionality, aesthetics, and global evaluation made by the patient recorded significantly better results for the SPD group. The most affected OHIP-14sp domain was 'Physical pain', followed by 'Psychological discomfort', and 'Functional limitation'. The subscales: 'Functional limitation', 'Physical disability', and 'Social disability', attributed significantly worst OHRQoL to CPD users. CONCLUSION: A major presence of peri-implant disease, together with a worse functionality, aesthetics, and patient satisfaction were recorded in cemented i-FDPs with respect to the screwed ones. CLINICAL SIGNIFICANCE: The retention system of i-FDPs can impact the peri-implant health, the subjective functional and aesthetic evaluation of the restoration, and the patients' OHRQoL; the screw retention providing superior results than the cementation.

Validation of the 'Quality of Life with Implant Prostheses (QoLIP-10)' questionnaire for wearers of cement-retained implant-supported restorations.

OBJECTIVES: To validate the 'Quality of Life with Implant-Prostheses (QoLIP-10)' questionnaire for assessing the impact of cemented implant prostheses on Oral Health-Related Quality of Life (OHRQoL). METHODS: 84 subjects wearing implant restorations were distributed as follows: Group 1 (SD-I; n=35): screwed FDPs (fixed dental prostheses) supported by 2 implants; Group 2 (SD-II; n=7): screwed FDPs supported by 3-5 implants; Group 3 (CD-I; n=36): cemented FDPs supported by 2 implants; and Group 4 (CD-II; n=6): cemented FDPs supported by 3-5 implants. The QoLIP-10 and the Oral Health Impact Profile (OHIP-14sp) scales were used. Data related to global oral satisfaction, socio-demographics, health-behaviors, and prostheses, were gathered. Reliability and validity of the QoLIP-10 were investigated. Correlations between both indices were explored with the Spearman's rank test. Descriptive and non-parametric probes were run to evaluate the effect of the study variables on the OHRQoL (α=0.05). RESULTS: The QoLIP-10 confirmed its psychometric capacity for cemented implant prosthesis wearers. Both tests were inversely correlated. The QoLIP-10 attributed the significantly worst QoL to long-span cemented prostheses. Groups were significantly discriminated by the QoLIP-10 performance dimension. The variable complaints about the mouth and the three global oral satisfaction measures significantly modulated the OHRQoL. CONCLUSIONS: Patient satisfaction depends upon the extension and the type of retention of implant FDPs. CLINICAL SIGNIFICANCE: The QoLIP-10 may help estimating the effect of cemented FDPs on patients' well-being. When compared to screwed FDPs, short cemented implant restorations lead to greater improvements in patients' self-perceived QoL.

A new, short, specific questionnaire (QoLIP-10) for evaluating the oral health-related quality of life of implant-retained overdenture and hybrid prosthesis wearers.

OBJECTIVES: This study aimed to validate a new questionnaire for assessing the oral health-related quality of life (OHRQoL) of implant-prosthesis wearers. METHODS: A group of specialists designed the 10-item scale: 'Quality of Life with Implant-Prostheses' (QoLIP-10). After completing a pilot trial, 150 subjects wearing implant-prostheses or complete dentures who were not requesting dental treatment participated in the main investigation. They were divided into three groups (n=50 each) depending on the type of dental restoration. Group 1 (CD): complete denture wearers (control); Group 2 (IO): implant-retained overdenture wearers and Group 3 (HP): subjects with fixed implant hybrid prostheses. Participants answered the QoLIP-10 and the Oral Health Impact Profile (OHIP-20sp) questionnaires. Information on global oral satisfaction, socio-demographic, health-behavioural, clinical and prosthetic-related data were gathered. The psychometric characteristics of the QoLIP-10 were investigated. The Spearman's rank correlation test was used to determine the association between the total scores of the QoLIP-10 and OHIP-20sp. Descriptive and non-parametric probes were run to evaluate the impact scores obtained depending on the study variables. RESULTS: The QoLIP-10 scale is reliable and valid. The factor analysis confirmed the existence of three dimensions and meaningful inter-correlations among the 10 items. HP wearers demonstrated better biopsychosocial QoL, as indicated by their answers to Item 1 (oral pain) and Item 3 (chewing difficulty). CONCLUSIONS: The QoLIP-10 index confirmed its psychometric capacity for assessing the OHRQoL of implant overdenture and hybrid prosthesis wearers. Overall, the participants were satisfied with their mouth and implant-restorations. CLINICAL SIGNIFICANCE: The QoLIP-10 may be recommended for determining the influence of implant-retained overdentures and hybrid prostheses on the well-being of future patients. Hybrid prostheses are the most predictable treatment option for improving patient satisfaction in terms of oral pain and chewing functionality when compared to implant overdentures and complete dentures.

Impact of various screwed implant prostheses on oral health-related quality of life as measured with the QoLIP-10 and OHIP-14 scales: a cross-sectional study.

OBJECTIVES: This study aimed to validate the Quality of Life with Implant-Prostheses (QoLIP-10) questionnaire for assessing the impact of screwed implant-supported rehabilitations on oral health-related quality of life (OHRQoL). METHODS: 131 patients wearing screw-retained implant restorations were assigned to the following groups: Group 1 (HP; n=50): fixed-detachable hybrid prostheses (control), Group 2 (S-PD; n=43): metal-ceramic screwed partial dentures, and Group 3 (S-CD; n=38): metal-ceramic screwed complete dentures. Impacts on OHRQoL were evaluated using the QoLIP-10 and Oral Health Impact Profile (OHIP-14sp) scales. Data on global oral satisfaction, socio-demographics, health-behaviours, and prosthetics were gathered. Reliability and validity of the QoLIP-10 were investigated for screwed prosthesis wearers. The Spearman's rank test was applied to determine the correlation between both indices. Descriptive and non-parametric probes were run to evaluate the influence of the study variables on OHRQoL. RESULTS: The QoLIP-10 confirmed its psychometric capacity for screwed prosthesis wearers. Both tests were inversely correlated. HP wearers reported the worst dental-facial aesthetics, performance, and functional limitation outcomes. Gender, education level, complaints about the mouth, perception of treatment needs, and prosthetic status modulated the OHRQoL. CONCLUSIONS: Screwed implants restorations provide better OHRQoL than do fixed-detachable hybrid prostheses.

Influence of technique and pouring time on dimensional stability of polyvinyl siloxane and polyether impressions.

This study aimed to determine how impression technique and pouring time affect casts obtained using polyvinyl siloxane (PVS) and polyether (PE) impressions. A total of 480 impressions were taken using three techniques: single-step (SS), two-step (TS), and two-step with a spacer (TSS). Impressions were poured after 1 and 24 hours and 7 and 14 days. Significant differences (P < .01) were found between the TS technique and the SS and TSS methods as well as between PE and PVS (P < .01) in terms of the effects of pouring time. SS and TSS yielded similar dimensional results, while greater dimensional change was induced with TS. PE impressions had to be poured no later than 7 days after preparation to ensure dimensional stability.

Differences in impact of patient and prosthetic characteristics on oral health-related quality of life among implant-retained overdenture wearers.

OBJECTIVES: To evaluate the oral health-related quality of life (OHRQoL) of implant-retained overdenture users. METHODS: 63 patients aged 50-90 years treated with at least one implant overdenture at the Complutense University (Madrid) in 2000-2010 were included. Of those, 42 answered the Oral Health Impact Profile (OHIP-14 sp) questionnaire. The additive method was used in the OHIP analysis. Data regarding sociodemographic background, overdenture features, and clinical factors were recorded. Sociodemographic and overdenture-related variables for the lost patients (n=21) were also gathered from their history files. Descriptive probes, Mann-Whitney and Kruskal-Wallis tests, and the Spearman correlation coefficient were applied (p ≤ 0.05). RESULTS: The predominant participants' profile was that of a 71-80-year-old woman wearing a mandibular overdenture with a bar retention system and a complete denture in the opposite jaw. 71.4% of the respondents suffered from some kind of impact on OHRQoL, showing an average score of 2.7 ± 3.0 (range: 0-13). 100% of respondents reported no impact for the "social disability" and "handicap" dimensions. The most prevalently affected domain was "physical pain", followed by "functional limitation" and "psychological discomfort". Variables such as the overdenture location or the retention system affected specific OHIP subscales (p ≤ 0.05). The greatest total score was achieved when the antagonist was a complete denture (p<0.01). CONCLUSIONS: Implant-retained overdentures provide a seemingly acceptable quality of life in the elderly population studied, irrespective of the influence of the location, retention system, and antagonist. CLINICAL SIGNIFICANCE: Although further research is necessary, mandibular implant overdentures are more comfortable than maxillary ones. Ball-retained prostheses facilitate eating the most, whereas the presence of oral ulcers and/or candidiasis was only detected in the case of bars, thus impairing OHRQoL. A complete denture as antagonist decreases the patient overall satisfaction.

A 10-year retrospective study of the survival rate of teeth restored with metal prefabricated posts versus cast metal posts and cores.

OBJECTIVE: The aim of this retrospective study was to compare the cumulative survival rate of teeth restored with prefabricated posts and with cobalt-chrome cast post-cores. METHODS: 112 endodontically treated teeth restored with prefabricated post and cobalt-chrome cast post-and-cores were evaluated. Teeth were considered as failures when were objective or radiologic sign of endodontic failure, post or root fracture, or when they had been extracted at the moment of the evaluation. Kaplan-Meier's method was used to reconstruct the survival curves of the restorations and to test the variable type of post-and-core restoration. RESULTS: 93 of the posts were still in function without clinical or radiographic signs of failure at the time of the examination resulting in a survival rate of 83.03% after a mean follow-up period of 10.08 years. When comparing the two techniques, prefabricated posts showed a slightly higher survival rate: 84.6% versus 82.6%.Focusing on tooth-type, maxillary premolars (n=30) had the highest failure rate (30%) and also the lowest mean lifetime, with 6-and-a-half years. Maxillary incisors (n=20) showed the highest success rate (5%) with only one case of failure. CONCLUSIONS: The results showed no significant difference between both groups after a 10-year average follow-up.

The correlation between crown-implant ratios and marginal bone resorption: a preliminary clinical study.

PURPOSE: The crown-implant ratio is defined as the physical relationship between each individual restoration's parts located both inside and outside the bone. This relationship represents the physical concept of a type I lever, which may be of biomechanical importance in implant treatment outcomes. MATERIALS AND METHODS: Specific patient data related to fixed implant prostheses were retrieved and studied in an effort to clinically and radiographically correlate crown-implant ratios. RESULTS: Recorded marginal bone resorption around implants (2.11 +/- 1.30 mm) at the end of a defined observation period did not correlate with the measured crown-implant ratio, which yielded values between 0.43 and 1.5 mm (P > .05). CONCLUSION: The mechanical determinants of implant success or failure are still not defined. It has been postulated that an increase in both crown-tooth, and comparably crown-implant, ratios would lead to a resultant increase in the magnitude of nonaxial forces transmitted to the tooth or implant. This could then lead to an increased vulnerability of either tooth or implant abutments to supporting bone loss. However, additional factors appear to impact long-term bone maintenance behavior around either type of abutment. Within the limited scope of this study, crown-implant ratios were not associated with recorded peri-implant bone loss. Int J Prosthodont 2010;23:33-37.

In vivo study of the wear of a reinforced composite used to cover implant-supported frameworks.

The goal of this study was to research the wear shown by a material (Cristobal+) offered as an alternative to ceramics in the covering of an implant-supported fixed prosthesis. Twenty-six active cusps were used in this study; the control group consisted of 12 cusps adjacent to restorations composed of Cristobal+. Five images were obtained from each sample and analyzed using computer software that creates an arch along each cusp, so each image gives the value of the radius described by that arch. If a sample showed any sign of wear, the values for the successive radii would be increasingly larger since a flattened arch would produce a larger radius. An analysis of the paired Student t test was applied. After assessing the results, a statistically significant difference in wear was noted (P < .05). Within the limitations of this study, it can be concluded that the wear of the cusps under function made with Cristobal+ reinforced composite was greater than that of the natural adjacent cusps.