Immediate loading of mandibular overdentures supported by unsplinted direct laser metal-forming implants: results from a 1-year prospective study.

BACKGROUND: At present, only some studies have dealt with immediate loading of unsplinted implants supporting mandibular overdentures. The aim of this prospective study is to evaluate treatment outcomes of mandibular overdentures supported by four one-piece, unsplinted, immediately loaded, direct laser metal-forming (DLMF) implants by assessing implant survival rate, implant success, marginal bone loss, and prosthetic complications. METHODS: A total of 96 one-piece DLMF implants were inserted in the edentulous mandible of 24 patients. Four implants were placed in each edentulous mandible. Immediately after implant placement, a mandibular overdenture was connected to the implants. At 1-year follow-up, clinical, radiographic, and prosthetic parameters were assessed. Success criteria included absence of pain, suppuration, and implant mobility; absence of continuous peri-implant radiolucency; and distance between the implant shoulder and the first visible bone contact <1.5 mm. RESULTS: After a 1-year loading time, the overall implant survival rate was 98.9%, with only one implant lost. Among the surviving 95 implants, two did not fulfill the success criteria; therefore, the implant success rate was 97.8%. The mean distance between the implant shoulder and the first visible bone contact was 0.28 ± 0.30 mm (95% confidence interval, 0.24 to 0.32). Some prosthetic complications were reported. CONCLUSION: Based on the present results and within the limits of this study, the immediate loading of four unsplinted DLMF implants by means of ball attachment-supported mandibular overdentures seems to represent a safe and successful procedure.

Prospective evaluation of 2,549 Morse taper connection implants: 1- to 6-year data.

BACKGROUND: The aim of this study is to evaluate the implant survival, the implant-crown success, and the prosthetic complications of 2,549 Morse taper interference-fit connection implants. METHODS: A total of 2,549 Morse taper connection implants were inserted in 893 patients from January 2003 until December 2008. At each annual recall, clinical, radiographic, and prosthetic parameters were assessed. The implant-crown success criteria included the absence of pain, suppuration, and clinical mobility; an average distance between the implant shoulder and the first visible bone contact <2 mm from initial surgery; and the absence of prosthetic complications at the implant-abutment interface. Prosthetic restorations were fixed partial prostheses (462 units); fixed full-arch prostheses (60 units); single crowns (531 units); and overdentures (93 units). RESULTS: The cumulative implant survival rate was 98.23% (97.25% maxilla, 99.05% mandible). The implant-crown success was 92.49%. A few prosthetic complications at implant-abutment interface were reported (0.37%). After 6 years, distance between the implant shoulder and the first visible bone contact was 1.10 mm (± 0.30 mm). CONCLUSION: The use of Morse taper connection implants represents a successful procedure for the rehabilitation of partially and completely edentulous arches.

Engineered bone by autologous osteoblasts on polymeric scaffolds in maxillary sinus augmentation: histologic report.

Several regenerative therapies have been used for maxillary sinus grafting. However, recent advances in modern bone tissue engineering techniques have been evaluated. The aim of this histologic report was to evaluate the bone obtained by a culture of autogenous osteoblasts seeded on polyglycolic-polylactid scaffolds in maxillary sinus augmentation. A 56-year-old partially edentulous male with severe atrophy of the posterior maxilla received 6 polyglycolid-polylactid disks (8 mm diameter × 2 mm depth, Oral Bone), each carrying 1.5 million autogenous osteoblasts into the depth of the sinus cavity. After 6 months healing, a bone core was harvested and histologically evaluated. The augmented maxillary sinus with engineered bone presented a mean of 28.89% and 71.11% of bone and medullary spaces, respectively. Data from this case report demonstrate that the newly formed bone provided by engineered bone tissue allowed proper initial stability for dental implant placement. However, the role of this new bone in the long-term success of dental implant anchorage needs further investigation.

Impact of smoking on human bone apposition at different dental implant surfaces: a histologic study in type IV bone.

Smoking has adverse effects on peri-implant bone healing and can cause bone loss around successfully integrated implants placed on type IV bone. This study evaluated the influence of implant surface topography of microimplants retrieved from posterior maxilla of smokers after 2 months of unloaded healing. Seven partially edentulous patients received 2 microimplants (machined and sandblasted acid-etched surface) each during conventional implant surgery. Histometric evaluation showed that the mean bone to implant contact was 10.40 +/- 14.16% and 22.19 +/- 14.68% to machined and sandblasted acid-etched surfaces, respectively (P < .001). These data suggest that the sandblasted acid-etched surface presented better results than the machined surface after a short healing time in smokers.

Early human bone response to laser metal sintering surface topography: a histologic report.

This histologic report evaluated the early human bone response to a direct laser metal sintering implant surface retrieved after a short period of healing. A selective laser sintering procedure using a Ti-6Al-4V alloy powder with a particle size of 25-45 microm prepared this surface topography. One experimental microimplant was inserted into the anterior mandible of a patient during conventional implant surgery of the jaw. The microimplant and surrounding tissues were removed after 2 months of unloaded healing and were prepared for histomorphometric analysis. Histologically, the peri-implant bone appeared in close contact with the implant surface, whereas marrow spaces could be detected in other areas along with prominently stained cement lines. The mean of bone-to-implant contact was 69.51%. The results of this histologic report suggest that the laser metal sintering surface could be a promising alternative to conventional implant surface topographies.

Influence of direct laser fabrication implant topography on type IV bone: a histomorphometric study in humans.

The aim of this histologic study was to evaluate the influence of the direct laser fabrication (DFL) surface topography on bone-to-implant contact (BIC%), on bone density in the threaded area (BA%) as well as bone density outside the threaded area (BD%) in type IV bone after 8 weeks of unloaded healing. Thirty patients (mean age 51.34 +/- 3.06 years) received 1 micro-implant (2.5-mm diameter and 6-mm length) each during conventional implant surgery in the posterior maxilla. Thirty micro-implants with three topographies were evaluated: 10 machined (cpTi); 10 sandblasted and acid etched surface (SAE) and 10 DFL micro-implants. After 8 weeks, the micro-implants and the surrounding tissue were removed and prepared for histomorphometric analysis. Four micro-implants (2 cpTi, 1 SAE and 1DLF) showed no osseointegration after the healing period. Histometric evaluation indicated that the mean BIC% was higher for the DFL and SAE surfaces (p = 0.0002). The BA% was higher for the DFL surface, although there was no difference with the SAE surface. The BD% was similar for all topographies (p > 0.05). Data suggest that the DFL and SAE surfaces presented a higher bone-to-implant contact rate compared with cpTi surfaces under unloaded conditions, after a healing period of 8 weeks.

Histomorphometric evaluation of bioceramic molecular impregnated and dual acid-etched implant surfaces in the human posterior maxilla.

BACKGROUND: Physical and bioceramic incorporation surface treatments at the nanometer scale showed higher means of bone-to-implant contact (BIC) and torque values compared with surface topography at the micrometer scale; however, the literature concerning the effect of nanometer scale parameters is sparse. PURPOSE: The aim of this study was to evaluate the influence of two different implant surfaces on the percentage bone-to-implant contact (BIC%) and bone osteocyte density in the human posterior maxilla after 2 months of unloaded healing. MATERIALS AND METHODS: The implants utilized presented dual acid-etched (DAE) surface and a bioceramic molecular impregnated treatment (Ossean®, Intra-Lock International, Boca Raton, FL, USA) serving as control and test, respectively. Ten subjects (59 ± 9 years of age) received two implants (one of each surface) during conventional implant surgery in the posterior maxilla. After the non-loaded period of 2 months, the implants and the surrounding tissue were removed by means of a trephine and were non-decalcified processed for ground sectioning and analysis of BIC%, bone density in threaded area (BA%), and osteocyte index (Oi). RESULTS: Two DAE implants were found to be clinically unstable at time of retrieval. Histometric evaluation showed significantly higher BIC% and Oi for the test compared to the control surface (p < .05), and that BA% was not significantly different between groups. Wilcoxon matched pairs test was used to compare the differences of histomorphometric variables between implant surfaces. The significance test was conducted at a 5% level of significance. CONCLUSION: The histological data suggest that the bioceramic molecular impregnated surface-treated implants positively modulated bone healing at early implantation times compared to the DAE surface.

Combining scaffolds and osteogenic cells in regenerative bone surgery: a preliminary histological report in human maxillary sinus augmentation.

PURPOSE: The following case series evaluated the maxillary sinus augmentation responses to tissue-engineered bone graft obtained by a culture of autogenous osteoblasts seeded on polyglycolic-polylactic scaffolds and calcium phosphate. MATERIALS AND METHODS: Sinus floor augmentation was performed bilaterally in five patients (mean age 58.4 years) with tissue-engineered bone (test site - Oral Bone, BioTissue, Freiburg, Germany) or calcium phosphate (control site - Biocoral, Novaxa Spa, Milan, Italy). Biopsies were harvested 6 months after sinus augmentation for histometric evaluation. Volumetric measurements were taken at baseline and 6 months after the surgical procedure. RESULTS: The mean of vertical bone gain was 6.47 +/- 1.39 mm and 9.14 +/- 1.19 mm to test and control sites, respectively. The histological sections depicted mature bone with compact and cancellous areas. All biopsies contained varying percentages of newly formed bone and marrow spaces. The mean of bone tissue in the grafted area was 37.32 +/- 19.59% and 54.65 +/- 21.17% for tissue-engineered bone and calcium phosphate, respectively. CONCLUSION: Within the limits of the present report, the histological data in humans confirmed that tissue-engineered bone and calcium phosphate allowed newly formed bone after maxillary sinus augmentation.

Influência de diferentes topografias de implantes sobre o tecido ósseo peri-implantar humano / Influence of different implant tomographies on human peri-implant bone tissue

O principal parâmetro para avaliação do sucesso dos implantes osseointegrados é baseado no percentual do contato do tecido ósseo à superfície do implante. Este processo depende de vários fatores que vão desde a inserção do implante no leito cirúrgico e a formação do coágulo sanguíneo a todos os eventos celulares relacionados à biologia óssea peri-implantar. Logo, o objetivo deste estudo foi avaliar, de maneira sistemática, a sequência de eventos celulares assim como os fatores que influenciam a qualidade e a quantidade de contato do tecido ósseo humano a superfície do implante e suas consequências clínicas.

Histologic analysis of human peri-implant bone in type 1 osteoporosis.

Osteoporosis is a disease that influences the quality of bone tissue. At present, osteoporosis represents a contraindication or a risk factor for osseointegration. The aim of this report was to evaluate the bone-to-implant contact of 2 loaded implants retrieved after prosthetic failure in a woman with type 1 osteoporosis. Histologically, only one implant was osseointegrated, and it appeared surrounded by healthy bone tissue. The bone-to-implant contact presented a mean of 51.25%. No foreign body reaction was found at the bone-to-implant contact, although epithelial downgrowth was observed at the interface. Data from this case report demonstrate that the peri-implant bone histology of the dental implant retrieved from an osteoporotic patient presented no alteration. However, the role of osteoporosis in the long-term success of dental implants needs further investigation.

Human histologic evaluation of a six-year-old threaded implant retrieved from a subject with osteoporosis.

AIM: The aim of this case report was to present the evaluation of the bone-to-implant contact in an implant retrieved from a subject with osteoporosis after six years of load. BACKGROUND: Systemic conditions associated with osteoporosis have been postulated to contribute to the severity of alveolar bone loss. The increase in human life expectancy, the increased number of elderly subjects who are partially or totally edentulous, and the use of dental implants for oral habilitation in subjects with osteoporosis has raised several questions. REPORT: A 68-year-old woman with postmenopausal osteoporosis received a prosthetic evaluation of an implant-supported restoration. Histologically, the peri-implant bone appeared healthy. The peri-implant bone appeared in close contact with the implant surface, whereas marrow spaces could be detected in other areas along with prominently stained cement lines. The mean of bone-to-implant contact was 62.51+1.96. CONCLUSION: The results of the evaluation of the dental implant reported here suggest the presence of osteoporosis may not be a contra-indication for implant placement at least after osseointegration has already been established.

Gingival primary extranodal non-Hodgkin's lymphoma as the first manifestation of acquired immunodeficiency syndrome.

BACKGROUND: Non-Hodgkin's lymphomas (NHLs) are a heterogeneous group of lymphoproliferative malignancies that may be associated with acquired immunodeficiency syndrome (AIDS). NHL can disseminate to extranodal sites; however, its dissemination to the jaws and mouth is not common. This report presents and discusses two unusual cases of gingival primary extranodal non-Hodgkin's lymphoma (PE-NHL) as the first manifestation of AIDS. METHODS: Two males presented with asymptomatic gingival swelling. They were examined clinically. Biopsies of the gingival tissue were evaluated using routine histologic techniques and immunohistochemistry. The patients were tested for human immunodeficiency virus (HIV) infection. RESULTS: The clinicopathological evaluation and the serological HIV examination of the patients led us to the final diagnosis of gingival PE-NHL as the first manifestation of AIDS. Both patients were referred to an oncologist and to an infectious disease specialist and were given antineoplastic chemotherapy and highly active antiretroviral therapy. Only one patient presented a favorable clinical evolution. CONCLUSION: The present case reports have important clinical implications; the two unusual presentations of gingival PE-NHL contribute to information about the differential diagnosis of rapidly progressing gingival swelling.

Evaluation of human bone around a dental implant retrieved from a subject with osteoporosis.

Osteoporosis is a metabolic bone disease that leads to bone fragility and an increase in the risk of bone fracture. Nowadays, osteoporosis may represent a contraindication or a risk factor for osseointegration; however, this field still is controversial in the literature. This article sought to evaluate the bone-to-implant contact of a loaded implant that had been retrieved (due to prosthetic failure) from a woman with Type 1 osteoporosis. Histologically, the implant was osseointegrated and appeared to be surrounded by healthy bone tissue. The bone-to-implant contact demonstrated a mean of 40.07% (+/- 1.07%). No foreign body reaction was found at the bone-to-implant contact, although epithelial downgrowth was observed at the interface. Data from this case report demonstrate that the peri-implant bone histology is not altered even when a patient has been diagnosed with osteoporosis.

Prevalence of maxillary sinus septa in 1024 subjects with edentulous upper jaws: a retrospective study.

Maxillary sinus floor augmentation has been routinely performed to optimize dental implant placement in the posterior maxilla. However, complications during a sinus grafting procedure, such as perforation of the Schneiderian membrane, have been reported. This complication is generally associated with the presence of maxillary septa. Therefore, the aim of this retrospective study was to evaluate the prevalence of maxillary sinus septae in completely edentulous subjects by means of panoramic radiography. A total of 1024 panoramic radiographs were evaluated by 3 calibrated examiners. From these radiographs, 307 maxillary septa were detected in 221 subjects (21.58%); 86 (8.40%) of the subjects showed maxillary septa in both maxillary sinuses. Logistic regression failed to detect any correlation between the presence of maxillary septa, age, and gender (P > .05). Within the limits of the study, the prevalence of maxillary septa in this Brazilian population was shown to be moderate, indicating that dentists must be aware of the presence of this anatomic structure during maxillary sinus elevation grafting.

Implant surface analysis and microbiologic evaluation of failed implants retrieved from smokers.

The aim of this study was to evaluate the microbiota and surface of failed titanium dental implants from 4 manufacturers. Twelve mobile dental implants were retrieved from 10 smokers after 3 to 10 years of functional loading. Before implant removal, microbial samples were taken and evaluated using polymerase chain reaction. After implant removal, analyses of the failed implant surfaces were performed using scanning electron microscopy and energy-dispersive spectrometer x-ray. Periodontal pathogens such as Aggregactibacter actinomycetemcomitans, Campylobacter rectus, Eikenella corrodens, Fusobacterium nucleatum, Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythia, and Treponema denticola were detected in all implants in different proportions. Surface analysis showed varying degrees of surface roughness between the samples and the presence of proteinaceous material, appearing mainly as dark stains. Foreign carbon, oxygen, sodium, calcium, aluminum, and silicon elements were also found. Although no material-related causes of implant failure were detected, several periodontal pathogens were identified independently of the surface topography or manufacturer.

Restoration of the soft-tissue margin in single-tooth implant in the anterior maxilla.

Esthetic requirements for dental implant restoration have arisen in recent years. Despite several surgical techniques that have been developed, the treatment of the peri-implant soft-tissue defect is still difficult. The purpose of this clinical article is to describe a grafting technique using subepithelial connective tissue grafts to recontour soft-tissue margin discrepancy for single-tooth implant restorations in the anterior maxilla. After 2-year follow-up, this procedure shows that the use of connective tissue grafts can be a predictable approach to establish new and stable peri-implant soft-tissue margin.

Avaliação clínica e laboratorial da estomatite por prótese / Clinical and laboratorial study of denture stomatitis

Este estudo avaliou a estomatite por prótese total e as variáveis relacionadas à sua etiologia, considerando as características clínicas do indivíduo, as características micológicas e de adesão das espécies de Candida e o grupo sanguíneo dos indivíduos. Sessenta indivíduos portadores de prótese total superior (grupo teste) e 15 indivíduos não usuários de próteses removíveis (grupo controle) foram avaliados. As amostras micológicas foram coletadas da mucosa do palato, face interna da prótese e dorso da língua, por imprint. A identificação das espécies de Candida foi realizada por métodos clássicos (cultura) e moleculares (RAPD). A avaliação da qualidade das próteses totais foi realizada com base em cinco indicadores (defeitos, material, estabilidade, retenção e oclusão) e a qualidade da higiene da prótese total, por meio da visualização do biofilme com o uso de evidenciador de placa. Não houve diferença significativa no diagnóstico de EP e na detecção de Candida spp. entre os gêneros, hábito de fumar, presença de doença sistêmica, uso de medicamentos e hábitos de higiene (cavidade bucal e PT). A EP foi correlacionada com detecção de Candida spp. no palato e com indivíduos O Rh+. Entretanto não foi correlacionada com um perfil genotípico de Candida spp. ou uma espécie de Candida, com a quantidade de células aderidas nos corpos de prova de resina, com o estado secretor do indivíduo, com o uso contínuo ou qualidade e higiene da prótese total. A detecção de Candida spp. foi correlacionada com a presença de EP, com doença sistêmica, uso de medicamentos, com a qualidade e higiene das próteses e com indivíduos A Rh+. Com base nos resultados obtidos verificamos que a presença de estomatite por prótese total foi correlacionada com o grupo sanguíneo do indivíduo e com Candida spp...

Analysis of failed commercially pure titanium dental implants: a scanning electron microscopy and energy-dispersive spectrometer x-ray study.

BACKGROUND: The failure of osseointegration in oral rehabilitation has gained importance in current literature and in clinical practice. The integration of titanium dental implants in alveolar bone has been partly ascribed to the biocompatibility of the implant surface oxide layer. The aim of this investigation was to analyze the surface topography and composition of failed titanium dental implants in order to determine possible causes of failure. METHODS: Twenty-one commercially pure titanium (cpTi) implants were retrieved from 16 patients (mean age of 50.33 +/- 11.81 years). Fourteen implants were retrieved before loading (early failures), six after loading (late failures), and one because of mandibular canal damage. The failure criterion was lack of osseointegration characterized as dental implant mobility. Two unused implants were used as a control group. All implant surfaces were examined by scanning electron microscopy (SEM) and energy-dispersive spectrometer x-ray (EDS) to element analysis. Evaluations were performed on several locations of the same implant. RESULTS: SEM showed that the surface of all retrieved implants consisted of different degrees of organic residues, appearing mainly as dark stains. The surface topography presented as grooves and ridges along the machined surface similar to control group. Overall, foreign elements such as carbon, oxygen, sodium, calcium, silicon, and aluminum were detected in failed implants. The implants from control group presented no macroscopic contamination and clear signs of titanium. CONCLUSION: These preliminary results do not suggest any material-related cause for implant failures, although different element composition was assessed between failed implants and control implants.

Connective tissue graft to correct peri-implant soft tissue margin: A clinical report.

This clinical report describes the use of a subepithelial connective tissue graft to recontour a soft tissue margin discrepancy for a single-implant crown in the anterior maxilla. This procedure demonstrates that the use of soft tissue grafts to correct an esthetic deficiency may be a feasible approach to establish new and stable peri-implant soft tissue contours. The patient presented was followed for 18 months.