Immediate versus early loading of immediately placed bone-level tapered dental implants with hydrophilic surface in full arch maxillary rehabilitation: A pilot randomized clinical trial with 2-year follow-up.

This study aimed to compare implant stabilities between the immediate and early loaded, immediately placed bone-level tapered dental implants in the maxilla and to evaluate marginal bone loss (MBL), oral health-related quality of life (OHRQoL), and patient satisfaction at a 2-year follow-up. A pilot, prospective, randomized, controlled clinical trial was conducted on 24 maxillary failing dentition patients. The bone-level tapered implants of 12 patients were immediately loaded with temporary restorations, while the other 12 patients did not receive any kind of temporization. Implant-supported screw-retained complete porcelain-fused-to-metal prostheses were delivered to all patients in the seventh postoperative week. The insertion torque values of implants assigned to the immediate and early loading groups were 33.0 ± 4.87 and 29.26 ± 8.31 Ncm, respectively. The dynamics of implant stability changes from implant placement up to a 2-year follow-up were similar for both groups (Penguin®, p = 0.268; Ostell®, p = 0.552), while the MBL was at submillimeter level. The cumulative implant survival rate was 91.80% for immediately loaded implants and 97.22% for early loaded implants, without significant difference (p = 0.162). The total score on the Oral Health Impact Profile questionnaire significantly decreased over time in both groups, indicating improvement in OHRQoL (p < 0.001), and the high level of patient satisfaction remained after 2 years of function regardless of a loading protocol. Both loading protocols, immediate and early, of six immediately placed bone-level tapered dental implants are an adequate treatment choice for fixed rehabilitation of the maxillary failing dentition.

Reconstructive Peri-Implantitis Therapy by Using Bovine Bone Substitute with or without Hyaluronic Acid: A Randomized Clinical Controlled Pilot Study.

BACKGROUND: The present pilot study aimed to assess clinical and radiographic efficiencies of bovine bone substitute (BBS) merged with hyaluronic acid (HA) in peri-implantits reconstructive surgery. METHODS: Peri-implantitis (diagnosed 6.03 ± 1.61 years of implant loading) bone defects were randomly treated either with BBS plus HA (test group) or BBS alone (control group). Clinical parameters including peri-implant probing depth (PPD), bleeding on probing (BOP), implant stability (ISQ), and radiographic changes in vertical and horizontal marginal bone (MB) levels were assessed at six months postoperatively. New temporary and permanent screw-retained crowns were made at two weeks and three months postoperatively. Data were analyzed using parametric and non-parametric tests. RESULTS: In both groups, 75% of patients and 83% of implants achieved treatment success after six months (no BOP, PPD <5 mm, and no further MB loss). Clinical outcomes improved over time within groups; however, without significant difference between them. ISQ value obtained significant increases in the test compared to the control group at six months postoperatively (p < 0.05). The vertical MB gain was significantly greater in the test group compared to the control (p < 0.05). CONCLUSIONS: Short-term outcomes suggested that BBS merged with HA could improve clinical and radiographic outcomes in peri-implantitis reconstructive therapy.

Influence of titanium implant macrodesign on peri-implantitis occurrence: a cross-sectional study.

OBJECTIVES: To assess whether implant macrodesign parameters interacting with implant time in function (Tf) could influence the peri-implantitis occurrence. MATERIALS AND METHODS: One hundred and two patients (55.17 ± 11.2 years old) with diagnosed early/moderate peri-implantitis around endosseous implants with implant-supported prosthetics reconstruction (n = 139) were recruited. Implant macrodesign (implant shape, thread number, implant collar), clinical parameters (peri-implant probing depth (PPD), clinical attachment level (CAL), keratinised tissue width (KTW), plaque index, bleeding on probe), implant placement localisation and region, and Tf were assessed and compared. RESULTS: Peri-implantitis occurred approximately 6.1 ± 3.38 years after implant loading. There was a significant positive correlation between the implant macrodesign and Tf. Peri-implantitis rates were statistically significantly higher in implants with a cylindric shape and triple-thread in the posterior part of the mandible (p = 0.037 and 0.012, respectively). The thread number and implant shape interacting with Tf showed statistically significant influences on CAL and PPD increase (p < 0.05). Results indicated a statistically positive interaction between Tf and KTW decrease around the implants with microthreaded collar (p < 0.001). CONCLUSION: Peri-implantitis might be presented as a time-dependent disease. Implant-based factors, such as Tf and implant macrodesign, could influence peri-implantitis occurrence, exacerbate clinical parameters, and promote progressive bone loss. CLINICAL RELEVANCE: Peri-implantitis can be affected by implant macrodesign and Tf. The implant body shape, thread number, and design of the implant collar may be considered peri-implantitis-related risk indicators that should be taken into account in proper implant planning and therapy.

Immediate Vs Early Loading of Bone Level Tapered Dental Implants With Hydrophilic Surface in Rehabilitation of Fully Edentulous Maxilla: Clinical and Patient Centered Outcomes.

The aim was to: (1) compare changes among primary and secondary implant stability between immediate and early loaded implants in edentulous maxilla, (2) evaluate oral health-related quality of life (OHRQoL), and (3) determine patient satisfaction with 6 implant supported fixed full-arch dentures. A prospective, randomized controlled clinical trial was conducted on 24 edentulous maxilla patients. The BLT SLActive implants in 12 patients were immediately loaded with temporary restorations while 12 patients did not receive temporary restorations. Definitive (final) dentures were delivered to all patients after 6 weeks. Stability of the implants were assessed by insertion torque (IT) and resonance frequency analysis (RFA). Oral Health Impact Profile-19 (OHIP-19) questionnaire was used to evaluate OHRQoL and a visual analogue scale (VAS) was used for patient satisfaction. The IT value of implants assigned for immediate and early loading group was 27.17 ± 9.55 Ncm and 25.01 ± 11.06 Ncm, respectively. Changes in implant stability from baseline to week 6 were similar in both groups when measured by Penguin (P = .881) and Ostell (P = .828). Patients in the immediate loading group reported significantly lower OHIP physical pain scores (P = .016) and OHIP psychological disability score (P = .046), and the patients reported significantly higher VAS function score (P = .009) and VAS esthetics score (P = .009). Implant loading protocols do not have a significant effect on the change in implant stability 6 weeks after implantation; however, immediate loading significantly improves OHRQoL as well as satisfaction of patients with maxillary edentulism treated by fixed full-arch dentures. Future trials will determine the role of immediate loading protocol in clinical scenarios with various amounts of available jaw bone using different numbers of implants to retain a fixed prosthetic restoration in the edentulous maxilla.

Application of Semipermanent Cements and Conventional Cement with Modified Cementing Technique in Dental Implantology.

OBJECTIVES: The aim of this study was to evaluate the influence of artificial ageing on the retention force of original semipermanent cements, as well as the possibility of using conventional cements for semipermanent cementation with adequate modification of the cementing protocol. MATERIALS AND METHODS: Forty CoCrMo alloy crowns were divided in four groups (each group n=10) and fixed with two semipermanent cements (resin-based and glass ionomer-based cements) and one conventional (zinc phosphate), using conventional and modified cementation techniques on titanium abutments. The samples were stored in humid conditions for 24 hours at 37°C and subjected to thermocycling (500 cycles) and mechanical cyclic loading (7 days, 3, 6, 9 and 12 months function simulation). The cast crowns were removed and the retention force was recorded. RESULTS: The highest initial retention force measured was for zinc-phosphate cement - conventional cementing (198,00±61,90 N), followed in descending order by zinc-phosphate cement - modified cementing technique (152,00±45,42 N), long term temporary cement - GC Fuji Temp LT (57,70±20,40 N), and semipermanent cement - Telio CS Cem Implant (56,10±18,68 N). After 12 months, the highest retention force measured was for zinc-phosphate cement - conventional cementing (88, 90±14, 45 N), followed by zinc-phosphate cement - modified cementing (48, 15±14,41N), semipermanent cement GC Fuji Temp LT (16,55±3,88 N) and Telio CS Cem Implant (15,55±5,52 N). CONCLUSIONS: Zinc-phosphate cement - modified cementing technique and original semipermanent cements can be recommended for conditional permanent cementing of implant supported crowns. CLINICAL RELEVANCE: The use of semipermanenet cements and zinc-phosphate cement - modified cementing technique provides a predictable retrievability of implant-supported crowns.

Histopathological comparative analysis of periimplant bone inflammatory response after dental implant insertion using flap and flapless surgical technique. An experimental study in pigs.

AIM: To evaluate by histopathological analysis the peri-implant bone inflammation degree, in certain time intervals (7, 14, 21 and 28 days), following mini-incision flapless and flap implant placement. MATERIAL AND METHODS: The experiment was conducted on four domestic pigs. Nine weeks prior to implant insertion, second and third mandibular premolars were extracted. Each animal received six implants in lower jaw. On one randomly chosen side of jaw flapless technique using mini-incision was performed, while on the other side implants were inserted after flap raising. After 7, 14, 21, and 28 days, the experimental animals were sacrificed. Following mandibular resection and decalcification, the samples for histopathological analysis of the peri-implant bone were obtained in the empty implant bed area, from the buccal side of the mandible, adjacent to implant neck region and parallel to crestal edge of implant bed. The degree of inflammatory response of the peri-implant bone was estimated through ordinal scores from 0 to 2. RESULTS: Seven days after the surgery all samples in the flap group had score 2 indicating high inflammation degree, in contrast to lower inflammatory reaction in flapless group. On the 14th and 21st postoperative day decreasing of inflammation degree was noted in all samples of the flapless group (score 1), while in flap group samples presented scores 1 and 2. Twenty-eight days after the implant placement, further reduction of inflammation in the flapless group (33% of samples had score 0) was observed. CONCLUSION: Flapless technique in comparison to conventional flap procedure minimizes postoperative bone inflammatory reactions.

Randomized clinical study of the peri-implant healing to hydrophilic and hydrophobic implant surfaces in patients receiving anticoagulants.

OBJECTIVES: To compare the peri-implant bone healing between TiZr implants with hydrophilic SLActive and hydrophobic SLA implant surface in patients receiving anticoagulants, to assess the implant survival and success rate, as well as to evaluate whether small-diameter TiZr implants could be used in patients on OAT in order to avoid augmentation procedures. MATERIAL AND METHODS: A total of 80 small-diameter tissue-level TiZr implants with SLActive and SLA surfaces were placed in 20 anticoagulated patients, following the "split-mouth" study design. Implant stability was measured up to the third postoperative month by resonance frequency measurements (RFA). One-year implant survival and success rate were evaluated. RESULTS: After one year, 100% implant survival and success rate were observed. A significant decrease in ISQ comparing to baseline values was noted in the SLActive group from the first postoperative week, and in the SLA group, from the 3rd week after the surgery. In both groups, a statistically significant decline in ISQ was observed between second and third postoperative week. No significant differences in ISQ values between SLActive and SLA implants were noted, at any time point. CONCLUSIONS: Titanium-zirconium small-diameter implants with SLActive and SLA surface predictably achieve and maintain adequate bone tissue integration in patients receiving anticoagulants. OAT appears to influence the bone healing events resulting in lower ISQ in the end of 3-month period in comparison with baseline values, although without compromising implant stability.

Submerged flapless technique vs. conventional flap approach for implant placement: experimental domestic pig study with 12-month follow-up.

OBJECTIVES: The aim of our study was to compare osseointegration and peri-implant crestal bone resorption in submerged flapless and conventional flap surgery over a 12-month follow-up. MATERIALS AND METHODS: The study used five domestic pigs. Implants were inserted 9 weeks after tooth extraction. Each animal received six implants in the mandible, following a split-mouth design: one side was treated using a flapless technique using mini-incisions, while a flap was raised on the other. The animals were sacrificed at 2 weeks, 1, 3, 6 and 12 months after implant placement. Radiographic images were taken to analyze crestal bone loss, and samples were extracted for histopathological and bone-to-implant contact (BIC) analyses. RESULTS: Significantly, greater crestal bone loss (P = 0.005) was obtained in the flap group compared with the flapless group. The flapless group presented significantly higher percentages of BIC (P < 0.05) at 3, 6 and 12 months compared with the conventional flap group. CONCLUSIONS: Within the limitations of this experimental animal study, it may be concluded that the type of surgery (flap or flapless) affects peri-implant bone preservation and osseointegration of regular platform implants. Flapless surgery is associated with peri-implant crestal bone preservation. Flapless surgery in combination with submerged implants allows higher osseointegration values.

Effect of surgical drill guide and irrigans temperature on thermal bone changes during drilling implant sites - thermographic analysis on bovine ribs.

Background/Aim: During drilling implant sites, mechanical energy is converted into thermal one resulting in transient rise in temperature of surrounding bone. The temperature of 47°C exeeding one minute impairs osseointegration, compromises mechanical properties of the local bone and could cause early implant failure. This in vitro study aimed to assess the effect of surgical drill guide and temperature of irrigans on thermal changes of the local bone during drilling implant sites, and to test the influence of irrigans temperature on the temperature of surgical drill guide. Methods: A total of 48 specimens obtained from bovine ribs were randomly allocated to four experimental conditions according to the 2 x 2 factorial design: drill guide (with or without) and saline (at 25°C or 5°C). Real-time infrared thermography was used as a method for temperature measurement. The primary outcome was bone temperature change during drilling implant sites measured at 3 osteotomy depths, whereas the second one was change in the temperature of the drill guide. Data were analyzed by Brunner and Langer nonparametric analysis and Wilcoxon test. Results: The effect of drill guide on the changes of bone temperature was significant at the entrance of osteotomy, whereas the effect of saline temperature was significant at all osteotomy levels (p < 0.001). No significant interaction was found (p > 0.05). Guided surgery and irrigation with saline at 25°C were associated with the highest bone temperature increase. Increase in drill guide temperature was significantly higher when saline at 25°C was used (p < 0.001). Conclusion: Guided implant site preparation generates higher temperature of the local bone than conventional drilling, not exceeding the threshold for thermal bone necrosis. Although saline at room temperature provides sufficient heat control during drilling, cooled saline is more effective regardless the use of surgical drill guide.

Histopathological comparative analysis of peri-implant soft tissue response after dental implant placement with flap and flapless surgical technique. Experimental study in pigs.

AIM: The aim of this study was comparing the effect of flapless vs. flap technique of implant placement on inflammation degree of peri-implant soft tissue, through histopathological analysis. METHOD: The experiment was conducted on five domestic pigs. Nine weeks after tooth extraction, implants were installed. Each animal received six implants in mandible. According to split-mouth design, randomly one side was used for flapless technique using mini-incision, while on the other side, flap was raised. After 7, 14, 21, 28, and 90 days, the experimental animals were sacrificed. Samples for histopathological analyzes were taken from the buccal side of peri-implant mucosa next to the neck of implants, from three levels. The degree of inflammatory response in the peri-implant soft tissue was estimated through ordinal scores from 0 to 3. RESULTS: In the flap group Score 3 indicating high degree of inflammation was present from day 7 to day 21, in contrast to flapless group where Score 3 was not recorded during the entire follow-up. Three months after implantation, there were no signs of inflammation neither around flap nor around flapless implants. CONCLUSION: Flapless surgical implantation technique using mini-incision decreases peri-implant soft tissue inflammatory reaction compared with flap surgery.

Immediately loaded mini dental implants as overdenture retainers: 1-Year cohort study of implant stability and peri-implant marginal bone level.

AIM: This 1-year cohort study investigated stability and peri-implant marginal bone level of immediately loaded mini dental implants used to retain overdentures. MATERIALS AND METHODS: Each of 30 edentulous patients received 4 mini dental implants (1.8 mm × 13 mm) in the interforaminal mandibular region. The implants were immediately loaded with pre-made overdentures. Outcome measures included implant stability and bone resorption. Implant stability was measured using the Periotest Classic(®) device immediately after placement and on the 3rd and 6th weeks and the 4th, 6th and 12th months postoperatively. The peri-implant marginal bone level (PIBL) was evaluated at the implant's mesial and distal sides from the polished platform to the marginal crest. Radiographs were taken using a tailored film holder to reproducibly position the X-ray tube at the 6th week, 4th and 12th months postoperatively. RESULTS: The primary stability (Periotest value, PTV) measured -0.27 ± 3.41 on a scale of -8 to + 50 (lower PTV reflects higher stability). The secondary stability decreased significantly until week 6 (mean PTV = 7.61 ± 7.05) then increased significantly reaching (PTV = 6.17 ± 6.15) at 12 months. The mean PIBL measured -0.40 mm after 1 year of functional loading, with no statistically significant differences at the various follow-ups (p = 0.218). CONCLUSIONS: Mini dental implants placed into the interforaminal region could achieve a favorable primary stability for immediate loading. The follow-up Periotest values fluctuated, apparently reflecting the dynamics of bone remodeling, with the implants remaining clinically stable (98.3%) after 1 year of function. The 1-year bone resorption around immediately loaded MDIs is within the clinically acceptable range for standard implants.

Immunohistochemical analysis of blood vessels in peri-implant mucosa: a comparison between mini-incision flapless and flap surgeries in domestic pigs.

AIM: The aim of this experimental study is to compare the effect of mini-incision flapless versus flap technique of implant placement on the amount of vascular structures and blood vessel elements in peri-implant soft tissue, using immunohistochemical analysis. METHOD: The experiment was conducted on five domestic pigs. Each animal received six implants in mandible according to the split-mouth design. On one randomly chosen jaw side, mini-incision flapless surgery was performed, whereas on the opposite jaw side, flap was raised. After 3 months of implant healing through submerged approach, the experimental animals were sacrificed and samples for immunohistochemical analyses were taken from the buccal side of peri-implant mucosa next to the neck of implants, from three levels. The study outcome was the presence of vascular structures and elements of the blood vessels in the peri-implant mucosa per microscopic field, estimated through ordinal scores from 0 to 2. Effects of surgical approach, site of implantation, and their interaction on vascular scores of peri-implant mucosa were assessed by Brunner and Langer nonparametric analysis of longitudinal data. RESULTS: Statistically significant effect of surgical approach on vascularity of peri-implant mucosa has been revealed in the second mucosal layer, where flapless approach provided higher vascularity compared with flap approach (P = 0.002). In the remaining two layers, surgical approach did not affect mucosal vascularity significantly (layer 1: P = 0.071; layer 3: P = 0.433). CONCLUSION: The flapless surgical implant placement approach using mini-incision provides better vascularization of peri-implant mucosa after 3 months of healing compared with flap surgery.

A 1-Year Prospective Clinical and Radiographic Study of Early-Loaded Bone Level Implants in the Posterior Maxilla.

PURPOSES: The primary aim of the study was to investigate a 1-year success rate of early-loaded bone level implants with a chemically modified sand-blasted, large grit, acid-etched surface (SLActive®, Institut Straumann AG, Basel, Switzerland) in the posterior maxilla. Secondary objectives included stability of these implants and peri-implant bone level. MATERIALS AND METHODS: Bone level® implants (Institut Straumann AG) inserted into premolar and/or molar maxillary sites were loaded after 6 weeks of healing. The implants were monitored for 1 year using the following outcome measures: implant success, primary and secondary stability, and peri-implant bone level. RESULTS: Out of 37 implants placed in 13 patients, 36 reached sufficient stability and were early loaded, whereas one underwent a delayed loading protocol. One-year success rate of early-loaded implants was 100%. Implant stability at baseline was 71.7 ± 5. 6 to be steadily increased thereafter up to 1 year (80.3 ± 3.3), except at 2 weeks when a nonsignificant decrease was noticed (71.9 ± 3.9). Continuous and significant bone loss was observed, reaching 0.4 ± 0.1 mm in the first postoperative year. CONCLUSION: Bone level implants with the SLActive surface placed into low-density bone and loaded after 6 weeks of healing can predictably achieve and maintain a successful tissue integration.

Real-time thermographic analysis of low-density bone during implant placement: a randomized parallel-group clinical study comparing lateral condensation with bone drilling surgical technique.

OBJECTIVES: To compare the effect of two surgical techniques, lateral condensation and bone drilling, on changes in temperature of the adjacent low-density bone during implant placement into posterior maxilla and to investigate the influence of the host factors - age, gender, region of implantation, bone density, and thickness of the cortical bone at the recipient sites. MATERIAL AND METHODS: Local bone temperature was measured thermographically during implant placement into posterior maxilla following lateral bone condensing (test group) or bone drilling (controls). The main study outcomes were baseline bone temperature prior to implantation and maximum bone temperature recorded during implantation. Early implant success was evaluated after 6 months of healing. RESULTS: A total of 40 implants were randomly allocated to test and control groups and placed into maxillary premolar and/or molar region of 18 participants of both genders and average age of 51.74 years. All recorded bone temperatures were below the threshold for thermal necrosis. Although both groups showed significant increase in bone temperature during implant placement procedure (P ≤ 0.0005), it was significantly higher for bone condensing compared with drilling (P ≤ 0.0005; 3.79 ± 1.54°C; 1.91 ± 0.70°C respectively). No host factor was singled out as a significant predictor of bone temperature changes, although trend of higher increase was observed in young patients, regardless of gender, during implant placement procedure into maxillary first premolar region with bone density type 3 and cortical layer thicker than 1 mm. Early implant success rate after 6 months follow-up was 100%. CONCLUSION: Although both surgical techniques, bone condensing and bone drilling, can be considered safe regarding their thermal effect on the bone of posterior maxilla, bone drilling is associated with fewer local bone heating during implantation. Host factors do not affect the bone thermal changes significantly.

Finite element analysis in defining the optimal shape and safety factor of retentive clasp arms of a removable partial denture.

BACKGROUND/AIM: Retentive force of removable partial denture (RPD) directly depends on elastic force of stretched retentive clasp arms (RCAs). During deflection RCA must have even stress distribution. Safety factor is the concept which can be applied in estimating durability and functionality of RCAs. This study was based on analyzing properties of clasps designed by conventional clasp wax profiles and defining the optimal shapes of RCAs for stress distribution and safety factor aspects. METHODS: Computer-aided-design (CAD) models of RCAs with simulated properties of materials used for fabrication of RPD cobalt-chromium-molybdenum (CoCrMo) alloy, commercially pure titanium (CPTi) and polyacetale were analzed. RESULTS: The research showed that geometrics of Rapidflex profiles from the BIOS concept are defined for designing and modeling RCAs from CoCrMo alloys. I-Bar and Bonihard clasps made from CPTi might have the same design as Co-CoCrMo clasp only by safety factor aspect, but it is obvious that CPTi are much more flexible, so their shape must be more massive. Polyacetale clasps should not be fabricated by BIOS concept for CoCrMo alloy. A proof for that is the low value of safety factor. CONCLUSION: The BIOS concept should be used only for RCAs made of CoCrMo alloy and different wax profiles should be used for fabricating clasps of other investigated materials. The contribution of this study may be the improve ment of present systems for defining the clasps shapes made from (CoCrMo alloys. The more significant application is the possibility of creating new concepts in defining shapes of RCA made from CPTi and polyacetale.

Free-end saddle length influence on stress level in unilateral complex partial denture abutment teeth and retention elements.

BACKGROUND/AIM: Different types of dental restorations are used for the therapy of unilateral free-end saddle edentulism. Unilateral complex partial denture is one of the indications for the Kennedy class II partial edentulism. The abscence of major connector and denture plate is an advantage compared to the conventional restorations, because of better comfort and shorter period of adaptation. The aim of the study was to analyse the influence of free-end saddle length change on the behaviour of unilateral complex partial denture supporting structures. METHODS: Stress levels of the canine and the first premolar as retentional teeth and the attachments were tested under the influence of physiological forces with the loading point shifting distally in relation to the saddle length change. A virtual real size 3D model of the fixed part of the restoration (the canine and the first premolar with milled crowns) was created using the CATIA computer program. It was connected to the mobile part of partial denture with the SD snap in latch attachment. Mobile part of the restoration was designed in the region of 2, 3 and 4 lateral teeth (second premolar, first, second and third molar). By using the finite element method (FEM) stress levels analysis was performed under the load of physiological forces of 150 N in the free-end saddle teeth zone. RESULTS: The results of analysis show that physiological forces cause a different stress distribution on the abutment teeth and the attachment, depending on the saddle length. CONCLUSION: The stress level values obtained for the abutment teeth as well as the attachment are far lower than the marginal ones. The behaviour of the system changes under this defined stress, but no plastic deformation occurs.

A 1-year prospective cohort study on mandibular overdentures retained by mini dental implants.

AIM: The aim of this 1-year prospective cohort study was to evaluate the outcomes and complications of immediately loaded mini dental implants used for stabilizing mandibular overdentures in edentulous patients wearing conventional complete dentures. MATERIALS AND METHODS: Thirty patients received mandibular conventional complete dentures that were subsequently retained by 4 immediately loaded mini dental implants placed in the interforaminal region. Overdenture success, implant success and biological and prosthetic complications were evaluated after the first year of service. Quality of life using the Oral Heath Impact Profile (OHIP)- EDENT test, satisfaction with dental prosthesis and chewing efficiency using questionnaires and a Visual Analogue Scale (VAS) were evaluated twice: after they had received mandibular complete dentures, and again after they had received mandibular overdentures. RESULTS: After 1 year, no overdenture failed and 2 implants did not osseointegrate, resulting in a 98.3% success rate for loaded implants and 95.9% for total implants used (3 out of 123 were not loaded due to fracture). A flap surgical approach was performed in 7 patients, 3 implants fractured during insertion, 3 overdentures fractured, occlusion balancing was necessary for 11 dentures and relining for 8. Implant rehabilitation provided significant improvement in quality of life, stability, comfort, chewing and speaking ability while no significant differences were found in quality of maintenance of hygiene and for aesthetics. CONCLUSIONS: Mini dental implant retained overdentures can be a successful therapeutic procedure for treating mandibular edentulism that improves quality of life, patient satisfaction and chewing ability in patients wearing maxillary dentures. Longer follow-ups are needed to validate this therapy in the medium and long-term.

Design and processing of high-density single-mode fiber arrays for imaging and parallel interferometer applications.

The design and fabrication procedures for implementing a high-density (16-microm center spacing) single-mode fiber (SMF) array are described. The specific application for this array is a parallel optical coherence tomography system for endoscopic imaging. We obtained fiber elements by etching standard single-mode SMF-28 fibers to a diameter of 14-15 microm. We equalized 1-m lengths of fiber to within 1 mm by using a fiber interferometer setup, and we describe a method for packaging arrays with as many as 100 fibers.

Holographic edge-illuminated polymer Bragg gratings for dense wavelength division optical filters at 1550 nm.

We discuss the use of holographic photopolymer materials for use as dense wavelength division multiplexing filters in the C-band of the optical communication spectrum. An edge-illuminated hologram configuration is described that effectively extends the grating length to achieve narrow band filters operating near 1550 nm in photopolymers that are 100-200-microm thick. This configuration enables the formation of apodized and cascaded filter systems. Rouard's method is used to examine the properties of both apodization and cascaded gratings and indicates the potential for narrow spectral bandwidths (< 0.2 nm) and high side-lobe suppression (<-- 30 dB). Initial experimental results with a commercially available photopolymer are provided that verify narrowband spectral-transmittance properties (< 0.6 nm) and the ability to apodize the index profile. The primary limitation of the design is the absorption of existing photopolymer materials. Optimizing the polymer chemistry for filter design at 1550 nm may solve this problem.