Biomedical subjects

Jaime Lozada

Publications and source records attributed to Jaime Lozada.

At least 19 recordsLinked to original sources

PubMed2006

Use of titanium mesh for staged localized alveolar ridge augmentation: clinical and histologic-histomorphometric evaluation.

The use of titanium mesh for localized alveolar ridge augmentation was evaluated by clinical, radiographic, laboratory, and histologic-histomorphometric evaluation. Seventeen patients participated in this study. All patients required localized alveolar ridge augmentation before placement of dental implants. An equal mixture of autogenous bone graft and inorganic bovine mineral (Bio-Oss) was used as a bone graft material. Autogenous bone graft was harvested intraorally. Titanium mesh was submerged for 8.47 months (SD 2.83). Impressions were taken intraorally before bone grafting, 6 months after bone grafting, and 6 months after implant placement. Impressions were used to measure the volume of alveolar ridge augmentation and provide linear laboratory measurements regarding the results of bone augmentation. Bone quality (type II-IV) was recorded during implant surgery. Standardized linear tomographs were taken before bone grafting and before implant placement. A biopsy was harvested with a trephine bur from the grafted area during implant surgery for histologic-histomorphometric evaluation. In all cases the grafted area had adequate bone volume and consistency for placement of dental implants. Early mesh exposure (2 weeks) was observed in 2 patients, and late exposure (>3 months) was observed in 4 patients. Volumetric laboratory measurements indicated 0.86 cc (SD 0.69) alveolar augmentation 1 month after bone grafting, 0.73 cc (SD 0.60) 6 months after bone grafting, and 0.71 cc (SD 0.57) 6 months after implant placement. This indicated 15.11% resorption 6 months after bone grafting, and no further resorption occurred after implant placement. Linear laboratory measurements indicated vertical augmentation of 2.94 mm (SD 0.86) 1 month after bone grafting, 2.59 mm (SD 0.91) 6 months after bone grafting, and 2.65 mm (SD 1.14) 6 months after implant placement. The corresponding measurements for labial-buccal augmentation were 4.47 mm (SD 1.55), 3.88 mm (SD 1.43), and 3.82 mm (SD 1.47). Radiographic evaluation indicated 2.56 mm (SD 1.32) vertical augmentation and 3.75 mm (SD 1.33) labial-buccal augmentation. Histomorphometric evaluation indicated 36.47% (SD 10.05) new bone formation, 49.18% (SD 6.92) connective tissue, and 14.35% (SD 5.85) residual Bio-Oss particles; 44.65% (SD 22.58) of the Bio-Oss surface was in tight contact with newly formed bone. The use of titanium mesh for localized alveolar ridge augmentation with a mixture of autogenous intraorally harvested bone graft and Bio-Oss offered adequate bone volume for placement of dental implants. Intraorally harvested autogenous bone graft mixed with Bio-Oss under a titanium mesh offered 36.47% new bone formation, and 15.11% resorption occurred 6 months after bone grafting.

Adolescent↗

PubMed2005

The use of intraorally harvested autogenous block grafts for vertical alveolar ridge augmentation: a human study.

This study presents a clinical, radiographic, laboratory, and histologic/histomorphometric analysis of the use of mandibular block autografts for vertical alveolar ridge augmentation. Twelve patients were included in the study. The autogenous block autografts were fixated at the recipient sites with screws, and a mixture of autogenous bone marrow and inorganic bovine mineral (Bio-Oss) was used at the periphery. At re-entry surgery, all the grafts appeared well incorporated at the recipient sites. Radiographic measurements revealed an average of 5.75 +/- 1.29 mm vertical ridge augmentation at 1 month after surgery and 4.75 +/- 1.29 mm at 4 to 6 months after surgery. This indicated 17.4% resorption. Laboratory volumetric measurements revealed an average of 0.84 +/- 0.34 mL of alveolar ridge augmentation 1 month after surgery and 0.71 +/- 0.28 mL at 6 months postoperatively. The resorption rate according to the laboratory volumetric measurements was 15.5%. Linear laboratory measurements revealed 5.92 +/- 1.38 mm of vertical ridge augmentation 1 month postoperatively and 4.08 +/- 1.01 mm at 4 to 6 months after surgery. Histologic evaluation of the block autografts indicated signs of active remodeling activity in 10 of the 12 specimens. In one case the block graft became exposed and infected, and in another case the block autograft became dislodged during implant placement surgery. Histomorphometric analysis of the peripheral particulate bone indicated bone present at 33.99% +/- 8.82% of the graft surface, while 42.43% +/- 11.06% of the area was occupied by fibrous tissue and 23.89% +/- 9.12% was made up of residual Bio-Oss particles. Residual Bio-Oss particles were in tight contact with newly formed bone along 58.57% +/- 15.22% of their perimeter.

Aged↗

PubMed2004

Immediate loading of hydroxyapatite-coated implants in the maxillary premolar area: three-year results of a pilot study.

STATEMENT OF THE PROBLEM: Although immediate loading of implants in the edentulous mandible has been described in the literature, there is limited information regarding immediate loading of single implants. PURPOSE: This prospective clinical study evaluated the clinical parameters of immediately loaded single-threaded hydroxyapatite-coated (HA) root form implants. MATERIAL AND METHODS: Ten human subjects were included in this report. In all situations, a screw-retained provisional acrylic resin crown was placed in the maxillary premolar area immediately after implant surgery. Definitive screw-retained metal-ceramic prostheses were placed 6 months after surgery. Standardized periapical radiographs were made before implant surgery, immediately after surgery, and 1, 3, 6, 12, and 36 months after implant surgery. Mobility (measured with the Perio-Test), distance from implant platform to the gingival crevice, distance from the implant platform to the depth of the sulcus, peri-implant probing depth, and bleeding on probing index were recorded at 3, 6, 12, and 36 months after implant placement. For clinical measurements, a 5-mm healing abutment was placed. RESULTS: All implants appeared clinically osseointegrated. Standardized radiographs demonstrated mean marginal bone loss of 0.6, 0.7, 0.8, 0.9, and 1.0 mm at 1, 3, 6, 12, and 36 months after implant surgery, respectively. Mean implant mobility was -3.3 at the day of surgery and -3.8, -3.4, -3.6, and -4.2 at 3, 6, 12, and 36 months, respectively. The distance from implant platform to the gingival crevice was 2.8, 2.4, 2.4, and 3.1 mm at 3, 6, 12, and 36 months, respectively. The distance from the implant platform to the depth of the sulcus was 0.8, 0.9, 0.9, and 1.1 mm at 3, 6, 12, and 36 months, respectively. The peri-implant probing depth was 3.6, 3.3, 3.2, and 4.3 mm at 3, 6, 12, and 36 months, respectively. The bleeding on probing index was 0.4, 0.4, 0.4, and 0.1 at 3, 6, 12, and 36 months, respectively. CONCLUSION: The results of this prospective pilot study provide initial evidence that single root form implants may be immediately loaded when placed at the maxillary premolar area.

Adult↗

PubMed2004

Histologic evaluation of a 12-year-old threaded hydroxyapatite-coated implant placed in conjunction with subantral augmentation procedure: a clinical report.

This clinical report presents a histologic evaluation of a threaded hydroxyapatite-coated root-form implant retrieved from the posterior maxillary area of a patient after being in function for 12 years. The implant had been placed in conjunction with subantral augmentation. Histologically, the portion of the implant that was examined under light microscopy appeared to be integrated with the surrounding bone; 74.3% of the surface of the implant had close bone apposition at the interface. The residual graft particles were present and in close proximity to the implant surface. These observations suggest that subantral augmentation procedure performed simultaneously with the placement of a hydroxyapatite-coated implant by using hydroxyapatite as a graft material may result in osseointegration between the implant and the surrounding bone that can be maintained under long-term function.

Aged↗

PubMed2003

The use of resorbable collagen membrane in conjunction with autogenous bone graft and inorganic bovine mineral for buccal/labial alveolar ridge augmentation: a pilot study.

STATEMENT OF PROBLEM: No study provides human histologic evidence regarding the use of resorbable collagen membrane for a 2-stage localized alveolar augmentation procedure. PURPOSE: The purpose of this pilot study was to evaluate the potential of use of a resorbable collagen membrane in conjunction with an autogenous bone graft and inorganic bovine mineral (IBM) for labial/buccal alveolar ridge augmentation prior to placing dental implants. Material and methods Seven consecutively treated human patients participated in the study. All patients received labial/buccal alveolar ridge augmentation. An autogenous block graft was secured at the recipient site with fixation screws and a mixture of autogenous particulate with IBM was placed at the periphery. Resorbable collagen membrane was used as a barrier. Radiographic and laboratory measurements were made to quantify ridge augmentation and resorption rate. Preoperative and postoperative stone casts were used to quantify alveolar ridge augmentation. Volumetric evaluation was measured in mL whereas linear laboratory evaluation was measured in millimeters. Measurements were made 1 and 6 months after bone grafting. Histologic and histomorphometric analysis from the grafted area evaluated new bone formation, and osteoconductivity of IBM. RESULTS: For all patients Type II to III bone quality was achieved at the augmented sites. The implant survival rate was 100% at second-stage surgery. No complication was observed at the recipient sites. Radiographic evaluation revealed 4.65 mm labial/lingual augmentation, whereas laboratory analysis revealed 4.57 mm. Volumetric laboratory analysis demonstrated 1.00 (+/- 0.29) mL alveolar ridge augmentation 6 months after bone grafting and 13.79% resorption between months 1 and 6. Histomorphometric analysis revealed that on average, the area occupied by bone was 34.28% (range 24 to 50; +/-9.05),] soft tissue 46.00% (+/-9.20%; range 30% to 55%), and IBM particles 19.71% (+/-11.74%, range 3% to 42%). The proportion of the surface of the IBM particles in contact with bone was 47.14% (range 15% to 64%; SD 17.21%). CONCLUSIONS: Resorbable collagen membranes may be used as barriers for labial/buccal alveolar ridge augmentation procedures.

Absorbable Implants↗

PubMed2003

Effect of teeth with periradicular lesions on adjacent dental implants.

OBJECTIVES: It is generally accepted that dental implants should not be placed in infected sites. However, the effect of periradicular infections of natural teeth on adjacent osseointegrated implants is less understood. The purpose of this study was to evaluate effects of periradicular lesions on osseointegration of existing implants. Study design Forty titanium solid root-form implants were placed close to premolars in dogs. After healing following implant placement, the adjacent premolars were treated in 1 of 4 ways: group A, no treatment of the adjacent premolar; group B, induction of a periradicular lesion followed by nonsurgical root canal therapy of the premolar; group C, induction of a periradicular lesion followed by nonsurgical root canal therapy of the premolar and surgical detoxification of the implant surface; and group D, induction of periradicular lesion and no treatment of the tooth. After 7(1/2) months, block sections were prepared and the percentage of osseointegration was analyzed histomorphometrically. RESULTS: The average integration for implants in groups A-B was 54%, 74%, 56%, and 68%, respectively. One-way analysis of variance demonstrated no difference between the 4 groups ( P =.518). CONCLUSIONS: The results of this study indicate that teeth with periradicular lesions do not adversely affect adjacent titanium solid root-form implants.

Acid Etching, Dental↗

PubMed2003

The "Loma Linda stent": a screw-retained resin stent.

This article describes a technique in which an acellular dermal allograft is used in combination with a photopolymerized acrylic resin stent to increase the zone of keratinized tissue around osseointegrated dental implants. During the second-stage surgery, a split thickness labial flap is reflected and apically repositioned by being sutured onto the periosteum and connective tissue. The acellular dermal allograft is then sutured onto the recipient site. The acrylic resin is trimmed and secured with temporary abutments to the implants, fitting passively over the graft and then photopolymerized intraorally. The stent is left for 1 week to secure the graft in place. This technique offers an alternative mucogingival procedure for increasing the zone of keratinized tissue around osseointegrated dental implants.

Acrylic Resins↗

PubMed2003

Effects of sealing the perforated sinus membrane with a resorbable collagen membrane: a pilot study in humans.

The effects of repairing the perforated sinus membrane with collagen membrane are unknown. The purpose of this pilot study was to clinically, histologically, and histomorphometrically evaluate the results of repairing the perforated sinus membrane with resorbable collagen membrane. A split-mouth design was followed in the current study. Five subjects requiring bilateral sinus grafting were included in the study, where one site was accidentally perforated during sinus augmentation procedures and the other site was not perforated. The perforated sites were repaired with a resorbable collagen membrane. Dental implants were placed at a second stage and biopsies were harvested from both sinuses. New bone formation was measured for all sites. Implant survival was recorded at second-stage surgery. Nonperforated sites demonstrated significantly more bone formation (34.40%) than perforated sites (12.80%) (P = .016). Implant survival at second-stage surgery was significantly inferior in perforated sites (54.5%) when compared with nonperforated sites (100%) (P = .0146). The study demonstrated that perforation and repair of the Schneiderian membrane can compromise new bone formation and implant survival rate.

Absorbable Implants↗

PubMed2003

The use of titanium mesh in conjunction with autogenous bone graft and inorganic bovine bone mineral (bio-oss) for localized alveolar ridge augmentation: a human study.

This study evaluated the effects of using a titanium mesh for localized alveolar ridge augmentation. Seven consecutively treated human subjects participated in the study. Clinical, radiographic, laboratory, and histologic/histomorphometric analysis revealed the efficacy of using the titanium mesh in conjunction with intraorally harvested autogenous bone graft and inorganic bovine bone mineral (Bio-Oss). Radiographic measurements detected that a 2.86-mm vertical and 3.71-mm buccolabial ridge augmentation was achieved, while histomorphometry demonstrated that 36.4% of the grafted area consisted of bone. Laboratory measurements revealed 15.08% resorption of the graft for the first 6 months, which appeared to consolidate after placement of the implants. Exposure of the mesh did not appear to compromise the result.

Adult↗

PubMed2003

The "Loma Linda pouch": a technique for repairing the perforated sinus membrane.

A technique, the "Loma Linda pouch," is introduced for repairing the perforated maxillary sinus membrane during sinus grafting procedures. A collagen membrane is placed against the perforated site and subsequently covers the internal surface of the maxillary sinus. The collagen membrane is then folded along the lateral access window to form a pouch that surrounds and isolates the graft material.

Collagen↗

PubMed2002

Evaluation of two vitallium blade-form implants retrieved after 13 to 21 years of function: a clinical report.

This article describes the clinical, radiographic, and histologic evaluation of 2 immediately loaded Vitallium blade-form implants retrieved from the posterior maxilla of 2 patients after 21 and 13 years of function. Neither implant demonstrated mobility or signs of pathosis, and both appeared to have integrated well with surrounding bone. The hydroxyapatite coating of the second implant, which was retrieved after 13 years of function, showed no dissolution. These observations suggest that immediately loaded dental implants have the potential to achieve and maintain osseointegration and that hydroxyapatite coatings can resist degradation over long-term service.

Aged↗

PubMed2002

Histologic evaluation of a hydroxyapatite onlay bone graft retrieved after 9 years: a clinical report.

Because of the limited observations of published studies, the condition of hydroxyapatite after a long period of intraoral function remains a concern. This clinical report describes the histologic evaluation of a 9 year-old hydroxyapatite specimen retrieved from a human subject. The residual hydroxyapatite particles showed no sign of resorption, and tight contact with the surrounding bone was observed.

Alveolar Ridge Augmentation↗

PubMed2002

Conversion of a complete denture to a provisional implant-supported, screw-retained fixed prosthesis for immediate loading of a completely edentulous arch.

This article describes the fabrication of a provisional implant-supported, screw-retained restoration for immediate loading of a completely edentulous arch. The technique can be applied to patients with partially edentulous arches as well. Until immediate loading of dental implants becomes a well-documented treatment modality, the described method should not be applied on a routine basis or without careful evaluation.

Aged↗

PubMed2002

Clinical radiographic, and histologic evaluation of maxillary bone reconstruction by using a titanium mesh and autogenous iliac graft: a case report.

The current clinical report describes the use of titanium mesh for maxillary alveolar ridge augmentation. Autogenous bone graft was harvested from the iliac crest and was loaded on a titanium mesh that was left in the patient's maxilla for 7 months before it was removed. Twelve months after the bone grafting procedure the patient received 10 implants on the maxilla, and a biopsy was taken from the augmented ridge. CT scan examination was performed before and after the maxillary ridge augmentation. Clinical evaluation revealed successful integration of the graft. The radiographic analysis demonstrated that a 10-mm vertical ridge augmentation had been achieved. Histologic evaluation revealed remnants of the autogenous bone graft still present, whereas the grafted area had a reduced remodeling activity. The clinical report demonstrated the potential of the titanium mesh to achieve extensive alveolar ridge augmentation, whereas the augmented ridge may possess an inferior capability forbone remodeling.

Aged↗

PubMed2002

A method to assess the clinical outcome of ridge augmentation procedures.

BACKGROUND: Alveolar ridge augmentation procedures are often needed prior to implant placement or prosthetic rehabilitation. The purpose of this study was to develop a quantitative method to assess the clinical outcome of such procedures. METHODS: Two volumetric methods, based on the volume difference between the pre- and postoperative ridge, were developed. Either a transparent vacuum stent material (method A) or a silicone impression material in a custom acrylic tray (method B) was used to make an impression of the postoperative stone cast. This impression was then filled with polyvinylsiloxane bite registration material (PBRM) and placed on the preoperative cast. The volume of PBRM at the site of the augmented ridge (corresponding to the achieved ridge volume increase, in ml) was measured gravimetrically. Two independent examiners used both methods, in random order, to assess the outcome of 6 diverse clinical cases. Triplicate measurements were made (method precision). Method accuracy was assessed by fabrication of metal castings (known volumes) applied on a preoperative cast to simulate an augmentation procedure. RESULTS: Intra- and inter-examiner reproducibility was high (intraclass correlation coefficients > or =0.84) for both methods. The volumetric measurements obtained by method B showed excellent correlation with the predetermined augmentation volumes (r2 = 0.99; y = 0.94x + 0.12), in contrast to the measurements obtained by method A (r2 = 0.46; y = 0.43x + 1.37). CONCLUSIONS: The developed volumetric method (method B) is both precise and accurate in assessing the outcome of ridge augmentation. This simple, cost-effective, and easy to implement method should be helpful in clinical studies of ridge augmentation procedures.

Alveolar Ridge Augmentation↗

PubMed2002

A clinical and histologic evaluation of a block onlay graft in conjunction with autogenous particulate and inorganic bovine mineral (Bio-Oss): a case report.

This article describes a clinical case report in which an autogenous intraorally harvested block graft was used in combination with particulate autogenous and inorganic bovine mineral for localized alveolar ridge augmentation. No barrier was used above the graft material. Clinical evaluation revealed excellent integration of the graft material to the recipient site, while histologic analysis indicated that the block graft was vital and undergoing an active remodeling process. Excellent integration of the inorganic bovine mineral with the newly formed bone was also observed, suggesting that this material can be used as a filler for onlay grafting procedures.

Aged↗

PubMedDate not supplied

The use of ramus autogenous block grafts for vertical alveolar ridge augmentation and implant placement: a pilot study.

PURPOSE: This study presents a clinical, radiographic, laboratory, and histologic/histomorphometric analysis of the use of mandibular ramus block autografts for vertical alveolar ridge augmentation and implant placement. MATERIALS AND METHODS: Autogenous block autografts were fixed at the recipient site with fixation screws while a mixture of autogenous bone marrow and inorganic bovine material (Bio-Oss) was used at the periphery. All grafts appeared well incorporated at the recipient site during reentry surgery. RESULTS: Radiographic measurements revealed an average of 6.12 mm vertical ridge augmentation 1 month after surgery and 5.12 mm 4 to 6 months after surgery. Laboratory volumetric measurements revealed an average of 0.91 mL alveolar ridge augmentation 1 month after surgery and 0.75 mL 6 months postoperatively. Linear laboratory measurements revealed 6.12 mm of vertical ridge augmentation 1 month postoperatively and 4.37 mm 4 to 6 months after surgery. Histologic evaluation indicated signs of active remodeling in all the specimens. Histomorphometric analysis of the peripheral particulate bone indicated bone present at 34.33% of the grafted area, while 42.17% of the area was occupied by fibrous tissue and 23.50% by residual Bio-Oss particles. DISCUSSION: The results demonstrated the potential of mandibular block autografts harvested from the ascending ramus to maintain their vitality. Volumetric resorption rate of 17.58% and radiographic resorption rate of 16.34% were in accordance with previously published literature. Early exposure appeared to compromise the results, while late exposures did not affect the vitality of the block autografts. CONCLUSION: Mandibular block autografts can maintain their vitality when used for vertical alveolar ridge augmentation. Inorganic bovine mineral (Bio-Oss) can be used at the periphery of the block graft when mixed with autogenous bone marrow.

Aged↗

PubMedDate not supplied

Effects of immediate loading with threaded hydroxyapatite-coated root-form implants on single premolar replacements: a preliminary report.

PURPOSE: This prospective study evaluated the immediate loading of single, threaded, root-form implants placed in the maxillary premolar area. MATERIALS AND METHODS: Ten human subjects were included in this preliminary report. In all cases, a screw-retained temporary acrylic resin crown was placed immediately after implant surgery. The definitive screw-retained metal-ceramic crown was placed 6 months later. RESULTS: Standardized radiographs demonstrated 0.58, 0.73, 0.84, and 0.90 mm mean marginal bone loss at 1, 3, 6, and 12 months after implant surgery, respectively. Implant mobility was evaluated with the Periotest device. At the day of surgery, mean mobility was -3.3, while minor changes were observed thereafter: mean values of -3.77, -3.47, and -3.63 were recorded at 3, 6, and 12 months after implant surgery, respectively. Sulcus depth appeared relatively stable after the 3rd month when the implant platform was used as a reference. Recession of 0.43 mm was recorded between the 3rd and 12th month; when the depth of the peri-implant sulcus was measured from the implant platform, 0.1 mm of change was seen between the 3rd and 12th month. Probing depth measurements revealed that 3 months after implant placement, average probing depth was 3.60 mm, while at 12 months it was 3.20 mm. DISCUSSION: The peri-implant soft tissue parameters (bleeding on probing, probing depth, peri-implant soft tissue level), mobility, and marginal bone level appeared to be similar to findings of previous studies regarding the conventional 2-stage loading protocol. CONCLUSION: Results of the current study provided evidence that, under the condition of this investigation, single root-form implants can be immediately loaded when placed in the maxillary premolar area.

Alveolar Bone Loss↗