Short dental implants: a systematic review

Growing evidence has suggested the utility of short dental implants for oral reconstructive procedures in clinical situations of limited vertical bone height. The aim of this review was to systematically evaluate clinical studies of implants < 10 mm in length, to determine short implant-supported prosthesis success in the atrophic jaw. Implant survival, incidence of biological and biomechanical complications, and radiographic peri-implant marginal bone loss were evaluated. Screening of eligible studies, quality assessment, and data extraction were conducted by two reviewers independently. Meta-analyses were performed by the pooling of survival data by implant surface, surgical technique, implant location, type of edentulism, and prosthetic restoration. Two randomized controlled trials and 14 observational studies were selected and analyzed for data extraction. In total, 6193 short-implants were investigated from 3848 participants. The observational period was 3.2 ± 1.7 yrs (mean ± SD). The cumulative survival rate (CSR) was 99.1% (95%CI: 98.8-99.4). The biological success rate was 98.8% (95%CI: 97.8-99.8), and the biomechanical success rate was 99.9% (95%CI: 99.4-100.0). A higher CSR was reported for rough-surfaced implants. The provision of short implant-supported prostheses in patients with atrophic alveolar ridges appears to be a successful treatment option in the short term; however, more scientific evidence is needed for the long term.     

Psychological impact of osseointegrated dental implants

This longitudinal study of 39 patients who underwent treatment involving osseointegrated implants examined problems in oral and psychosocial functioning, expectations and experiences of difficulties with surgery, satisfaction with surgery, body image, neuroticism, self-concept, and extroversion. Patients completed six questionnaires from before phase 1 surgery to the final recall appointment for the new prosthesis (12 to 18 months after phase 1 surgery). The most common problems reported before treatment were those associated with eating; esthetics was less of a concern. Significant improvements in all problem areas were observed immediately after phase 2 surgery. Expectations of surgery-related problems were generally consistent with experiences immediately after phase 1 surgery, but more negative than experiences following phase 2 surgery. Body image before treatment was most negative vis-à-vis teeth. Significant improvements were found not only regarding teeth, but also on facial, mouth, and even overall body image. Satisfaction scores were generally high, but showed continued improvements through the final assessment. The only group experiencing negative outcomes consisted of patients scoring high on neuroticism.     

Microbiota of successful osseointegrated dental implants

BACKGROUND: The long-term survival of dental implants depends, in part, on control of bacterial infection in the peri-implant region. Periodontal pathogens colonized implants symptomatic through infection, whereas the microbiota of successful implants was similar to that of periodontal health. This study examined the impact on the peri-implant microbiota of crown restorations; implant type; length of time of loading; history of implant or periodontal infections; and whether implants replaced single or multiple teeth. It was of particular interest to evaluate implant colonization by species in a newly described red complex of periodontal pathogens, Porphyromonas gingivalis and Bacteroides forsythus. METHODS: This study sampled 43 partially edentulous subjects with successfully osseointegrated titanium root-form dental implants. Eighty-one (81) non-submerged and 20 submerged asymptomatic implants, 83 crowned, and 36 uncrowned teeth were sampled from peri-implant or subgingival sites. The microbiota of samples was evaluated using whole genomic DNA probes in a checkerboard assay to 23 subgingival species. RESULTS: Implants were colonized principally by oral streptococci, capnocytophagae, Veillonella parvula, Peptostreptococcus micros, and Fusobacterium nucleatum. The periodontal species, P. gingivalis, B. forsythus, Prevotella intermedia, Prevotella nigrescens, and Campylobacter rectus were detected in a few subjects. The microbiota around crowned implants and crowned teeth was similar. Streptococcus oralis, P. intermedia, and Selenomonas noxia were elevated in samples from uncrowned teeth compared to crowned teeth and implants. Microbial complexity increased as loading time increased, but colonization by periodontal pathogens, including red complex species, was higher in subjects with previous periodontal disease. No differences were observed in the microbiota of 1- and 2-stage implants, or between implants supporting single or multiple restorations. CONCLUSIONS: While presence of crowns had only a minor impact on the peri-implant microbiota, microbial changes were observed the longer the implants had been in function and in those patients with a history of periodontal or peri-implant infections. A history of periodontitis had a greater impact on the peri-implant microbiota than implant loading time. The major influence on the peri-implant microbiota was, however, the microbiota on remaining teeth. P. gingivalis and B. forsythus, red complex periodontal pathogens, colonized several implants, although all implants were successfully osseointegrated.     

Radiotherapy and the survival of dental implants: a systematic review

For patients with head and neck cancer, the effects of treatment with adjuvant radiotherapy can be devastating. Frequently there is loss of function due to tooth loss, pain and discomfort from xerostomia and mucositis, and a significant psychosocial impact. Dental implants provide an effective means of rehabilitation for many, but irradiation poses a unique set of challenges that can affect the outcome of treatment. The aims of this review were to find out whether radiotherapy in these patients affects the survival of dental implants, and to discuss details of pertinent influencing factors. An electronic search of the Medline, Web of Science, and CENTRAL databases was done to identify studies on the survival of implants in irradiated patients within specified inclusion and exclusion criteria. No restriction was placed on the year of publication. The primary outcome measure was implant survival. Seven studies involving 441 participants and 1502 implants placed into irradiated bone were included. Meta-analysis indicated that survival was significantly higher in the mandible compared with the maxilla (p = 0.04), and in non-irradiated cases compared with irradiated cases (p < 0.001). Other factors that showed a strong association with survival were radiation dose and timing of surgery. Implant-based rehabilitation is a viable option for head and neck cancer patients who have undergone radiotherapy. Whilst the short to medium-term implant survival in these cases is high, multiple factors require careful consideration for a favourable outcome. Further high-quality research and randomised controlled trials are required in this field.     

Impact of excessive occlusal load on successfully‐osseointegrated dental implants: a literature review

The aim of the present study was to review the available evidence on the response of the peri‐implant bone when subjected to excessive occlusal forces. The search strategy included papers published in English in the Medline database and the Wiley Online Library from January 1991 to December 2011. Experimental or review papers reporting the conditions of the peri‐implant bone of dental implants submitted to excessive occlusal loading in the presence of a controlled oral hygiene regime were eligible for inclusion. The knowledge regarding the response of the peri‐implant bone when the dental implant is excessively loaded is limited, and the level of evidence is poor. With animal experimental studies showing conflicting results, it is unclear whether occlusal overload might cause marginal bone loss or total loss of osseointegration to already osseointegrated dental implants when the applied load exceeds the biologically‐acceptable limit. This biological limit is also unknown. Furthermore, higher remodeling activity of the peri‐implant bone is found around implants subjected to high loading forces.     

Systematic review of primary osseointegrated dental implants in head and neck oncology

The aim of this paper is to provide a systematic review of articles concerning primary osseointegrated dental implants in the head and neck oncology setting. We searched MEDLINE (1950 to March 2009) and Embase (1980 to March 2009) using the terms head and neck, oral, maxillofacial, craniofacial, jaws, mandible, maxilla, zygoma, dental implants, osseointegrated implants, implants, tumour, cancer, oncology, immediate, simultaneous, and primary. Two authors independently reviewed the abstracts, and all those written in the English language that referred to the placement of primary dental implants in patients with cancer of the head neck were included. Articles that referred to craniofacial or extraoral implants were excluded. Of 892 abstracts 83 were eligible for further consideration; the full articles were evaluated, and 41 that complied fully with the inclusion criteria are presented as a tabulated summary. There are three case reports, 13 reviews, and 25 clinical studies. Eight of the clinical studies refer solely to the insertion of dental implants at the time of primary oncological resection, and only two were of a prospective design. We have concisely summarised publications concerning primary dental implants, and our findings will help to inform head and neck cancer teams, particularly oncological surgeons, restorative dentists, and maxillofacial prosthodontists of the evidence base surrounding this approach to oral rehabilitation.     

Osseointegration and clinical success of zirconia dental implants: a systematic review

PURPOSE: Various ceramic implant systems made of yttria-stabilized tetragonal zirconia polycrystals (Y-TZP) have become commercially available in recent years. A systematic search of the literature was performed to assess the clinical success of dental Y-TZP implants and whether the osseointegration of Y-TZP is comparable to that of titanium, the standard implant material. MATERIALS AND METHODS: The internet database MEDPILOT was searched cumulatively for the keywords zircon* and dent* and implant as well as for zircon* and osseointegration. The last search was conducted on January 31st, 2007. Subsequently, the reference lists of the relevant publications were searched. Furthermore, a letter was sent to the 5 identified manufacturers of zirconia dental implants to ask for peer-reviewed publications. RESULTS: Ninety-six articles were found by the search strategy. No controlled clinical studies in humans regarding clinical outcomes or osseointegration could be identified. Clinical data were restricted to case studies and case series. Only 7 animal studies fulfilled the inclusion criteria. Osseointegration was evaluated at 4 weeks to 24 months after placement in different animal models and sites and under different loading conditions. The mean bone-implant contact percentage was above 60% in almost all experimental groups. In studies that used titanium implants as a control, Y-TZP implants were comparable to or even better than titanium implants. Surface modifications may further improve initial bone healing and resistance to removal torque. CONCLUSIONS: Y-TZP implants may have the potential to become an alternative to titanium implants but cannot currently be recommended for routine clinical use, as no long-term clinical data are available.     

Survival of dental implants placed in HIV-positive patients: a systematic review

No consensus has been reached on the use of dental implants in human immunodeficiency virus (HIV)-positive patients. This systematic review evaluated dental implants in HIV-positive patients in terms of implant survival and success rates, marginal bone loss, and complications. The review was conducted according to the PRISMA checklist. Two independent reviewers performed a comprehensive search of the PubMed/MEDLINE, Scopus, and Cochrane Library databases for studies published until October 2017. Six studies were selected for review. In total, 821 implants were placed: 493 in 169 HIV-positive patients, and 328 in 135 HIV-negative patients. The mean duration of follow-up was 47.9 months. Weighted mean survival rate, success rate, and marginal bone loss values were calculated for the HIV-positive patients. Mean survival and success rates at the patient level (according to the number of patients) were 94.76% and 93.81%, respectively; when calculated at the implant level (according to the number of implants), these rates were 94.53% and 90.37%, respectively. Mean marginal bone loss was 0.83 mm at the patient level and 0.99 mm at the implant level. Thus, dental implants are suitable for the rehabilitation of HIV-positive patients with controlled risk factors and normal CD4+ cell counts.     

Longevity of dental implants in type IV bone: a systematic review

Bone quality and quantity are important factors with regard to the survival rate of dental implants. The aim of this study was to conduct a systematic review of dental implants inserted in low-density bone and to determine the survival rate of dental implants with surface treatments over time. A systematic review of the literature was undertaken by two independent individuals; the Medline/PubMed database was searched for the period July 1975 to March 2013. Relevant reports on bone quality and osseointegration of dental implants were selected. The search retrieved 1018 references, and after inclusion and exclusion criteria were applied, 19 studies were selected for review. A total of 3937 patients, who had received a total of 12,465 dental implants, were analyzed. The survival rates of dental implants according to the bone density were: type I, 97.6%; type II, 96.2%; type III, 96.5%; and type IV, 88.8%. The survival rate of treated surface implants inserted in low-density bone was higher (97.1%) than that of machined surface implants (91.6%). Surface-treated dental implants inserted in low-density bone have a high survival rate and may be indicated for oral rehabilitation. However, more randomized studies are required to better evaluate this issue.     

Maxillary fixed prostheses on osseointegrated dental implants

The clinical and technical procedures used in the production of a fixed prosthesis on osseointegrated implants in the edentulous maxillae were described. The subjective evaluation and some clinical recordings in 21 treated patients were reported. Initial results were very favorable.     

Splinting osseointegrated implants and natural teeth in partially edentulous patients: a systematic review of the literature

Dental implants in partially edentulous patients are a predictable therapeutic option. In patients with reduced bone volume, tooth-to-implant connected prostheses have been described as a treatment option. In this systematic review, the incidence of biologic and technical complications and the long-term survival rates of tooth-implant supported fixed partial dentures (FPDs) are analyzed. In cases where a natural tooth is connected with an implant to support a FPD, a rigid connection should be preferred.     

An evaluation of impression techniques for osseointegrated implants

A passive fit between osseointegrated implants and the prosthesis they will support has been advocated. An experimental model was developed to test the accuracy of three impression techniques and the components used to make the transfer records. Statistically, no significant difference was found between the three methods tested. From this initial study, it appears that further work is needed to isolate techniques that will predictably provide accurate registration of the position of endosseous implants.     

Tissue-engineered injectable bone regeneration for osseointegrated dental implants

The present study investigated a correlation between osseointegration in dental implants and an injectable tissue-engineered bone, using mesenchymal stem cells (MSCs) and platelet-rich plasma (PRP). Initially, the teeth in the mandible region were extracted and the healing period was 1 month. Bone defects on both sides of the mandible were prepared with a trephine bar. The defects were implanted with graft materials as follows: PRP, dog MSCs (dMSCs), and PRP, autogenous particulate cancellous bone and marrow (PCBM), and control (defect only). Two months later, the animals were evaluated by histology, and at the same time dental implants were installed. Two months later, the animals were sacrificed and nondecalcified sections were evaluated histologically and histometrically. According to the histological observations, the dMSCs/PRP group had well-formed mature bone and neovascularization, compared with the control (defect only) and PRP groups, as was the same for the PCBM group. A higher marginal bone level was observed around implants with PRP, PCBM, and dMSCs/PRP compared with the control. Furthermore, the values describing the amount of bone-implant contact (BIC) at the bone/implant interface were significantly different between the PRP, PCBM, dMSCs/PRP, and control groups. Significant differences were also found between the dMSCs/PRP and control groups in bone density. The findings of this experimental study indicate that the use of a mixture of dMSCs/PRP results in good results such as the amount of BIC and bone density comparable with that achieved by PCBM.