New bone formation in bone defects after melatonin and porcine bone grafts: experimental study in rabbits.

OBJECTIVE: The aim of this study was to evaluate the effect of the topical application of melatonin compared with collagenized porcine bone grafts to accelerate bone formation 2 months after their insertion in tibiae rabbits. MATERIAL AND METHODS: Twenty New Zealand rabbits weighing 3,900-4,500 g were used. Twenty collagenized porcine bone (MP3) grafts, twenty melatonin-impregnated bone grafts, and twenty control areas were placed in the proximal metaphyseal area of both rear tibias. Four groups were formed according to the moment in which animal killing was carried out: Group I (15 days), Group II (30 days), Group III (45 days) and Group IV (60 days). Cortical width and cortical length of bone formation was measured. Following implantation, an anteroposterior and lateral radiological study was carried out. Samples were sectioned at 5 µm and stained using hematoxylin-Eeosin, Masson's trichromic, and Gordon-Switt reticulin stains. RESULTS: After 60 days of treatment period, melatonin increased the length of cortical bone formation 99.03 ± 0.61% like control 98.90 ± 3.82% compared with porcine bone 92.73 ± 1.08%. Related to perimeter of cortical bone of the tibiae melatonin new bone was 98.35 ± 1.14% like control 98.0 ± 1.43% more than porcine bone 92.05 ± 1.03%. Histomorphometric values related to porcine bone were connective tissue 49.16 ± 2.4%, graft material (MP3) 23.52 ± 2.3%, and new bone formation 27.32 ± 1.4% compared with test group with melatonin 24.5 ± 1.2%, connective tissue 45.1 ± 1.2%, and new bone formation of 30.4 ± 1.0%. CONCLUSION: Melatonin has proven to regenerate the width and length of cortical bone in tibiae rabbits more quickly than collagenized porcine bone. Melatonin acts as a bone stimulator compared with porcine bone and control sites.

Biological response to porcine xenograft implants: an experimental study in rabbits.

PURPOSE: The aim of this study was to evaluate the effect of a new porcine biomaterial and collagen paste in 20 New Zealand rabbits. MATERIALS AND METHODS: Forty implants using a porcine xenograft made up of 80% corticocancellous collagenated bone particles of ≤300 µm in size were placed in the proximal metaphyseal area of both tibiae. Four periods of time were formed: 1h, 5, 8, and 15 months. After implantation, an anteroposterior and lateral radiological study was carried out. Samples were sectioned at 5 µm and stained using hematoxylin-eosin, Masson's trichromic, and Gordon-Switt reticulin stains. RESULTS: These results confirmed the biocompatibility of this porcine biomaterial-collagen paste; only a few, occasional macrophages and scattered lymphocytes were observed. No fibrosis was observed between the implants and the bone. Moreover, the material was osteoconductive acting as a "scaffold" for bone cells, and there was a progressive increase in bone growth in and around the implants. CONCLUSION: This new porcine biomaterial-collagen paste seemed to be biocompatible, bioresorbable, and osteoconductive.

Crestal bone loss evaluation in osseotite expanded platform implants: a 5-year study.

OBJECTIVE: The aim of this prospective clinical study was to evaluate the survival rates at 5 years of expanded platform implants placed in the anterior zone of the maxilla and immediately restored with single crowns. MATERIALS AND METHODS: Implants incorporating the platform-switching concept were placed in fresh extraction sockets in the maxillary arch, with each patient receiving a provisional restoration immediately after implant placement. After 15 days, final screwed restorations were inserted. Mesial and distal bone heights were evaluated using digital radiography on the day following implant placement and at 1, 3, 6, 9, 12, 24, 36 months and 5 years. Primary stability was measured with resonance frequency analysis (RFA) using the Osstell Mentor device. Sixty-four implants were placed in 32 men and 32 women ranging in age between 29 and 60 (mean: 39.64 ± 5.16 years). RESULTS: Mean mesial bone loss was 0.08 mm (SD 0.42). Mean distal bone loss was 0.14 mm (SD 0.56). Over the course of the 5 years, the mean RFA value was 72.5 ± 3.1 SD. CONCLUSION: The platform-switched implants remained stable over the course of 5 years and had an overall survival rate of 97.1%.

Actions of melatonin mixed with collagenized porcine bone versus porcine bone only on osteointegration of dental implants.

This study evaluated the effect of the topical application of melatonin mixed with collagenized porcine bone on the osteointegration on the rough discrete calcium deposit (DCD) surface implants in Beagle dogs 3 months after their insertion. In preparation for subsequent insertion of dental implants, lower molars were extracted from 12 Beagle dogs. Each mandible received two parallel wall expanded platform implants with a DCD surface of 4 mm in diameter and 10 mm in length. The implants were randomly assigned to the distal sites on each mandible in the molar area and the gaps were filled with 5 mg lyophilized powdered melatonin and porcine bone and collagenized porcine bone alone. Ten histological sections per implant were obtained for histomorphometric studies. After a 4-wk treatment period, melatonin plus porcine bone significantly increased the perimeter of bone that was in direct contact with the treated implants (P < 0.0001), bone density (P < 0.0001), and new bone formation (P < 0.0001) in comparison with porcine bone alone around the implants. Melatonin plus collagenized porcine bone on DCD surface may act as a biomimetic agent in the placement of endo-osseous dental implants and enhance the osteointegration. Melatonin combined with porcine bone on DCD implants reveals more bone in implant contact at 12 wk (84.5 +/- 1.5%) compared with porcine bone alone treated area (67.17 +/- 1.2%).

Melatonin stimulates the growth of new bone around implants in the tibia of rabbits.

This study evaluated the effect of the topical application of melatonin in accelerating bone formation associated with implants 2 months after their application to the tibiae of rabbits. Twenty New Zealand rabbits were used. Twenty implants treated with melatonin and 20 control implants without melatonin were placed in the proximal metaphyseal area of each tibia. Studies of new bone formation were subsequently made at 15, 30, 45 and 60 days. Cortical width and cortical length of new bone formation were measured. Following implantation, an anteroposterior and lateral radiologic study was carried out. Collected samples were sectioned at 5 µm and stained using hematoxylin-eosin, Masson's trichromic and Gordon-Switt reticulin stains. After a 60 day treatment period, melatonin increased the length of cortical bone (95.13±0.42%) versus that around control implants (62.91±1.45%). Related to the perimeter of cortical bone of the tibiae, melatonin induced new bone 88.35±1.56% versus 60.20±1.67% in the control implants. Melatonin regenerated the width and length of cortical bone around implants in tibiae of rabbits more quickly than around control implants without the addition of melatonin.

Atraumatic maxillary sinus elevation using threaded bone dilators for immediate implants. A three-year clinical study.

OBJECTIVE: The aim of this study was to evaluate the efficacy of sinus floor elevation using sequential bone dilators. MATERIALS AND METHODS: Thirty patients took part in the study (18 women and 12 men) with ages ranging between thirty-six and sixty-three years, selected according to inclusion and exclusion criteria, who showed a bone deficit in the upper posterior alveolar margin of 5-8 mm in height. Sixty expanded platform internal connection implants were placed with diameters of 4/5/4 mm and lengths varying between 10 (n=10) and 11.5 mm (n= 50). RESULTS: Data obtained were analyzed using SPSS 15.0 software. The average intra-sinus bone gain with MP3 biomaterial of porcine origin was 4.13 +/- 0.97 SD mm at the moment of implant placement, 3.90 +/- 1.15 SD mm after twelve months, 3.74 +/- 1.05 SD mm after 24 months and 3.62 +/- 1.75 SD mm after 36 months. Two implants were lost at the moment of prosthesis placement. CONCLUSIONS: Alveolar lifting technique in the upper maxilla using bone dilators achieved a 96.6 % implant success rate after a three-year follow-up. Intra-sinus bone biomaterial remodeling was 0.51 +/- 0.08 mm from day zero to the thirty-six-month follow-up. This is a procedure that reduces the amount of surgery necessary and is of both aesthetic and functional benefit to the patient.

Melatonin plus porcine bone on discrete calcium deposit implant surface stimulates osteointegration in dental implants.

The aim of this study was to evaluate the effect of the topical application of melatonin mixed with collagenized porcine bone to accelerate the osteointegration on the rough discrete calcium deposit (DCD) surface implants in Beagle dogs 3 months after their insertion. In preparation for subsequent insertion of dental implants, lower premolars and molars were extracted from 12 Beagle dogs. Each mandible received three parallel wall implants with discrete calcium deposit (DCD) surface of 4 mm in diameter and 10 mm in length. The implants were randomly assigned to the distal sites on each side of the mandible in three groups: group I implants alone, group II implants with melatonin and group III implants with melatonin and porcine bone. Prior to implanting, 5 mg lyophylized powdered melatonin was applied to one bone hole at each side of the mandible. None was applied at the control sites. Ten histological sections per implant were obtained for histomorphometric studies. After a 4-wk treatment period, melatonin significantly increased the perimeter of bone that was in direct contact with the treated implants (P < 0.0001), bone density (P < 0.0001), new bone formation (P < 0.0001) in comparison with control implants. Topical application of melatonin on DCD surface may act as a biomimetic agent in the placement of endo-osseous dental implants and enhance the osteointegration. Melatonin combined with porcine bone on DCD implants reveals more bone to implant contact at 12 wk (84.5 +/- 1.5%) compared with melatonin treated (75.1 +/- 1.4%) and nonmelatonin treated surface implants (64 +/- 1.4%).

Immediate maxillary restoration of single-tooth implants using platform switching for crestal bone preservation: a 12-month study.

PURPOSE: The aim of this prospective clinical study was to evaluate the survival rates at 12 months of a new implant design placed in the anterior and premolar areas of the maxilla and immediately restored with single crowns. Crestal bone loss was also assessed. MATERIALS AND METHODS: Patients seeking replacement of at least one failing maxillary tooth were recruited to participate in the study. Exclusion criteria included compromised general health conditions, severe maxillomandibular skeletal discrepancies, severe parafunctional habits, drug or alcohol abuse, poor oral hygiene, and a need for bone augmentation. Implants incorporating the platform-switching concept were placed into fresh extraction sockets in the maxilla, with each patient receiving a provisional restoration immediately after implant placement. After 15 days, definitive restorations were inserted. Mesial and distal bone levels were evaluated with digital radiography on the day after implant placement, 15 days later, and 1, 2, 3, 6, 8, and 12 months later. Primary stability was measured with resonance frequency analysis (RFA). Analysis of variance for repeated measures and a binary logistic regression model were used to assess the data. RESULTS: Sixty-one implants were placed into fresh extraction sites in 25 men and 25 women ranging in age from 29 to 51 years (mean, 39.64 +/- 6.06 years). One of the implants failed, and one was lost to follow-up. The mean bone loss measured on the mesial was 0.08 mm (SD 0.53 mm). Mean distal bone loss was 0.09 mm (SD 0.65 mm). Over the course of 12 months, the mean RFA value between baseline and 12 months was 71.1 +/- 6.2. CONCLUSIONS: The implants remained stable over the course of 12 months and had an overall survival rate of 96.7%. Minimal crestal bone loss was recorded around the surviving implants.

Implant platform switching concept: an updated review.

PURPOSE: To review published articles dealing with platform switched implants in order to assess survival rates and clarify their influence both on marginal bone loss around the cervical region of the implant and on soft tissue aesthetics. MATERIAL AND METHODS: PubMed and GallileUM databases were used to identify any studies or clinical cases involving implant platform switching published between January 2000 and August 2008. Studies both of human beings and animals were reviewed whenever they included the relevant implant diameter, length, surface and connection data. RESULTS: Twelve studies of platform switching in humans (75%) and in animal models (25%) were evaluated. Mean implant length was found to be 11.66 +/- 0.2 SD mm and mean diameter was 4.9+/- 0.52 SD mm. CONCLUSION: It was shown that platform switching helps to prevent crestal bone loss after implant placement and helps obtain satisfactory aesthetic results.

Immediate loading and immediate restoration in 105 expanded-platform implants via the Diem System after a 16-month follow-up period.

OBJECTIVE: The aim of this study was to report on our experience and outcomes with Certain Prevail Implants and immediate loading via the Diem System after a 16-month follow-up period. MATERIALS AND METHODS: Over a 16-month period, 105 (14 maxilla, 91 mandible) expanded-platform implants were placed in 18 patients (15 females, 3 males; 55.97 +/-7.25 SD years). Resonance frecuency analysis (RFA) was measured on the day of placement and at 3, 12 and 16 months. All prostheses were screw mounted on IOL DIEM standard abutments. The follow-up time varied between 3 up to 16 months. RESULTS: One implant (0.9%) failed during final prothetic placement (3 months).The RFA (ISQ) measurements at 16 months evalution for 4 mm- and 5 mm diameter implants were: 76.13 +/- 5.0 SD and 76 +/-7.7 SD respectively. The RFA data related to mandible and maxilla, the day 0 mean was 76.47 +/- 4.75 SD and 70.13 +/- 1.35 SD, at 3 months 70.53 +/- 4.0 SD and 66.07 +/-2.9 SD, at 12 months 68.23+/- 3.6 SD and 66.40 +/-2.7 SD and 16 months 68.23+/- 3.6 SD and 66.60 +/- 2.5 SD respectively. The crestal bone resorption was 0.6 mm at 16 months in platform switching implants. CONCLUSIONS: The cumulative implant survival rate during the follow-up period was 99.1% Immediate loading on IOL Diem abutments is a reliable and effective technique for edentulous patients in the maxilla and mandible.

Atraumatic maxillary sinus elevation using threaded bone dilatorsfor immediate implants. A three-year clinical study

Objective: The aim of this study was to evaluate the efficacy of sinus floor elevation using sequential bone dilators.Materials and Methods: Thirty patients took part in the study (18 women and 12 men) with ages ranging betweenthirty-six and sixty-three years, selected according to inclusion and exclusion criteria, who showed a bone deficitin the upper posterior alveolar margin of 5-8 mm in height. Sixty expanded platform internal connection implantswere placed with diameters of 4/5/4 mm and lengths varying between 10 (n=10) and 11.5 mm (n= 50). Results:Data obtained were analyzed using SPSS 15.0 software. The average intra-sinus bone gain with MP3 biomaterialof porcine origin was 4.13 +/- 0.97 SD mm at the moment of implant placement, 3.90 +/- 1.15 SD mm after twelvemonths, 3.74 +/- 1.05 SD mm after 24 months and 3.62 +/- 1.75 SD mm after 36 months. Two implants were lost atthe moment of prosthesis placement. Conclusions: Alveolar lifting technique in the upper maxilla using bone dilatorsachieved a 96.6 % implant success rate after a three-year follow-up. Intra-sinus bone biomaterial remodelingwas 0.51 +/- 0.08 mm from day zero to the thirty-six-month follow-up. This is a procedure that reduces the amountof surgery necessary and is of both aesthetic and functional benefit to the patient (AU)

Implant platform switching concept: An updated review

Purpose: To review published articles dealing with platform switched implants in order to assess survival ratesand clarify their influence both on marginal bone loss around the cervical region of the implant and on soft tissueaesthetics.Material and Methods: PubMed and GallileUM databases were used to identify any studies or clinical cases involvingimplant platform switching published between January 2000 and August 2008. Studies both of humanbeings and animals were reviewed whenever they included the relevant implant diameter, length, surface andconnection data.Results: Twelve studies of platform switching in humans (75%) and in animal models (25%) were evaluated.Mean implant length was found to be 11.66 ± 0.2 SD mm and mean diameter was 4.9± 0.52 SD mm.Conclusion: It was shown that platform switching helps to prevent crestal bone loss after implant placement andhelps obtain satisfactory aesthetic results (AU)

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Immediate loading and immediate restoration in 105 expanded-platform implants via the Diem System after a 16-month follow-up period

No disponible

Objective: The aim of this study was to report on our experience and outcomes with Certain Prevail Implants andimmediate loading via the Diem System after a 16-month follow-up period. Materials and Methods: Over a 16- month period, 105 (14 maxilla, 91 mandible) expanded-platform implants were placed in 18 patients (15 females, 3 males; 55.97 ±7.25 SD years). Resonance frecuency analysis (RFA) was measured on the day of placement and at 3, 12 and 16 months. All prostheses were screw mounted on IOL DIEM standard abutments. The follow-up time varied between 3 up to 16 months. Results: One implant (0.9%) failed during final prothetic placement (3 months). The RFA (ISQ) measurements at 16 months evalution for 4 mm- and 5 mm diameter implants were: 76.13 ± 5.0 SD and 76 ±7.7 SD respectively. The RFA data related to mandible and maxilla, the day 0 mean was 76.47 ± 4.75 SD and 70.13 ± 1.35 SD, at 3 months 70.53 ± 4.0 SD and 66.07 ±2.9 SD, at 12 months 68.23± 3.6 SD and 66.40 ±2.7 SD and 16 months 68.23± 3.6 SD and 66.60 ± 2.5 SD respectively. The crestal bone resorption was 0.6 mm at 16 months in platform switching implants.Conclusions: The cumulative implant survival rate during the follow-up period was 99.1% Immediate loading on IOL Diem abutments is a reliable and effective technique for edentulous patients in the maxilla and mandible