Long-term follow-up of osseointegrated titanium implants using clinical, radiographic and microbiological parameters

Antimicrobial mouthrinse use as an adjunct method in peri-implant biofilm control

Great possibilities for oral rehabilitation emerged as a result of scientific consolidation, as well as a large number of dental implant applications. Along with implants appeared diseases such as mucositis and peri-implantitis, requiring management through several strategies applied at different stages. Biofilm accumulation is associated with clinical signs manifest by both tooth and implant inflammation. With this in mind, regular and complete biofilm elimination becomes essential for disease prevention and host protection. Chemical control of biofilms, as an adjuvant to mechanical oral hygiene, is fully justified by its simplicity and efficacy proven by studies based on clinical evidence. The purpose of this review was to present a consensus regarding the importance of antimicrobial mouthrinse use as an auxiliary method in chemical peri-implant biofilm control. The active ingredients of the several available mouthrinses include bis-biguanide, essential oils, phenols, quaternary ammonium compounds, oxygenating compounds, chlorine derivatives, plant extracts, fluorides, antibiotics and antimicrobial agent combinations. It was concluded that there is strong clinical evidence that at least two mouthrinses have scientifically proven efficacy against different oral biofilms, i.e., chlorhexidine digluconate and essential oils; however, 0.12% chlorhexidine digluconate presents a number of unwanted side effects and should be prescribed with caution. Chemical agents seem beneficial in controlling peri-implant inflammation, although they require further investigation. We recommend a scientifically proven antiseptic, with significant short and long term efficacy and with no unwanted side effects, for the prevention and/or treatment of peri-implant disease.

Assessment of trabecular bone changes around endosseous implants using image analysis techniques: A preliminary study

Purpose

The objective of this study was to assess the trabecular bone changes that occurred around functional endosseous dental implants by means of radiographic image analysis techniques.

Materials and Methods

Immediate preoperative and postoperative periapical radiographs of de-identified implant patients at the University Dental Hospital of Manchester were retrieved, screened for specific inclusion criteria, digitized, and quantified for structural elements of the trabecular bone around the endosseous implants, by using image analysis techniques. Data were analyzed using SPSS version 11.5. P values of less than 0.05 were considered statistically significant.

Results

A total of 12 implants from 11 patients were selected for the study, and 26 regions of interest were obtained. There was a significant increase in the bone area in terms of the mean distance between nodes (p=0.006) and a significant decrease in the marrow area in terms of the bone area (p=0.006) and the length of marrow spaces (p=0.032).

Conclusion

It appeared that the bone around the implant underwent remodeling that resulted in a net increase in bone after implant placement.

In vitro adherence of periodontopathic bacteria to zirconia and titanium surfaces

Tetragonal zirconia polycrystals (TZP) has drawn attention as a potential alternative to titanium (Ti) in dental implant treatment, as it minimizes both allergic reactions and esthetic problems. It is also important for dental implants to maintain plaque-free surfaces to prevent peri-implantitis. The purpose of this study was to investigate in vitro adherence of periodontopathic bacteria to TZP comparing with Ti.Periodontopathic bacteria were cultured on polished discs of two kinds of TZP, and Ti as a control. After incubation, the numbers of adherent bacteria were estimated. No significant differences among specimens were observed in the initial attachment, although a decrease was observed in initial attachment to saliva-coated specimens. In the bacterial colonization, no significant differences were recognized among specimens. The adherence of the periodontopathic bacteria on TZP was similar to that on Ti. These results suggest that a strategy is required for inhibition of the bacterial adherence to TZP.

Maxillary sinusitis caused by dental implants extending into the maxillary sinus and the nasal cavities

This report describes the case of a patient who underwent osseointegrated dental implant placement. The implants were misplaced inside the nasal fossae and in the right maxillary sinus, causing chronic purulent sinusitis. CT scan without contrast showed signs of right maxillary sinusitis and confirmed the misplacement of four dental implants that surfaced into the nasal cavities. The imaging also revealed the presence of another implant that emerged inside the maxillary sinus. The patient underwent functional endoscopic sinus surgery with complete symptom remission at the long-term follow-up. We propose that sinusitis caused by protrusion of implants and by sinus floor lift procedures could share common physiopathological patterns and predisposing factors.

Ridge expansion alone or in combination with guided bone regeneration to facilitate implant placement in narrow alveolar ridges: a retrospective study

OBJECTIVE

To evaluate the long-term outcomes of ridge expansion technique in dealing with horizontal bony insufficiency of alveolar ridges for implant placement.

MATERIALS AND METHODS

During the period 2004-2009, 168 patients with width insufficiency of alveolar ridges were treated using the ridge expansion technique to obtain an improved bony base for implant placement. Depending on the severity of width insufficiency, the surgical procedures were classified into two groups: ridge expansion alone (Group 1) and ridge expansion in combination with guided bone regeneration (Group 2). After 4-6 months of unloaded healing, the implants were restored. The patients were followed up until 2013 with clinical and radiographic examinations.

RESULTS

Among the 168 patients, 11 patients underwent a fracture of labial/buccal bony plate during surgery, which was corrected by changing the procedure into bone grafting, yielding a surgical failure rate of 6.5%. In the remaining 157 patients successfully treated by ridge expansion alone or in combination with GBR, 226 implants were simultaneously placed as planned. No implant failed over 2.8 years (6 months to 8 years) of follow-up, yielding a cumulative implant survival rate of 100% in each group. Six implants in Group 1 and 4 implants in Group 2, although osseointegrated and in function, did not fulfill success criteria: Cumulative implants' success rates were 93.2% in Group 1 and 95.6% in Group 2. The mean marginal bone losses during the first year in Group 1 and Group 2 were 0.69 and 0.43 mm, respectively, followed by an annual loss of ~ 0.06 and 0.07 mm, respectively, in the following years. No clinical parameter was abnormal. Twenty-two (10.4%) implants were exposed to peri-implant mucositis, whereas 19 (11.0%) implant-supported restorations were involved in prosthetic complications.

CONCLUSIONS

The preliminary results of this retrospective study indicate that ridge expansion alone or in combination with GBR can be considered an effective and safe procedure for treatment of width insufficiency of alveolar ridges on the purpose of implant application.

Treatment of the atrophic upper jaw: rehabilitation of two complex cases

In reconstructive surgery, the fresh frozen homologous bone (FFB) represents a valid alternative to the autologous bone, because FFB allows bone regeneration thanks to its osteoinductive and osteoconductive properties. The purpose of this work is to describe the surgical-implant-prosthetic treatment of two complex cases using FFB. In particular, fresh frozen homologous bone grafts were used to correct the severe atrophy of the maxilla, and, then, once the graft integration was obtained, implant therapy was performed and implants placed in native bone were immediately loaded.

Implant surface factors and bacterial adhesion: a review of the literature

The microbiota that forms on implant surfaces placed in the human body can be highly resistant to antimicrobial agents and in some cases cause life-threatening infections. Consequently, to limit bacterial attachment to these surfaces and thereby minimize the risk of implant infection, the process of biofilm formation and bacterial attachment must be well-understood. The oral environment is considered to be an excellent model for research into biofilm formation and implant infection, accounting for many studies carried out in the field of dental medicine. Those studies show that the roughness, free energy, and material characteristics of the implant surface largely determine initial bacterial adhesion. This article reviews the relevant literature on these aspects of biofilm formation.

Immediate versus delayed positioning of dental implants in guided bone regeneration or onlay graft regenerated areas: a systematic review

The aim of this study was to compare success rates in immediate and delayed dental implant placement following guided bone regeneration or onlay bone block ridge augmentation. A systematic review of all studies on this topic was performed. For inclusion, studies had to involve at least five patients, report specific success criteria, and have a minimum follow-up period of 6 months. Studies reporting only the survival rate of implants were excluded. From 287 studies identified, 79 were screened and 13 were included in the analysis. Six studies provided data on simultaneous (immediate) positioning of implants, five studies on delayed positioning, and two studies provided data on both of these approaches. Success rates for implants placed using a simultaneous approach ranged from 61.5% to 100%; success rates for implants placed using a staged approach ranged from 75% to 98%. Even though the current review revealed that there are not many studies reporting data relevant to the analyzed topic, the data obtained suggest that the delayed positioning of implants should be considered more predictable than the immediate positioning. Studies presenting a control group and adopting standardized success criteria are required, and data from this review must be considered indicative.

Bacterial adhesion on the titanium and zirconia abutment surfaces

OBJECTIVE

Microorganisms harboring the oral cavity, mainly those related to periodontal diseases, are the most potential etiologic factor of failure in long-term implant treatment. The material used for abutment components may influence the adhesion and colonization of microbial species. The aim of this in vivo investigation was to evaluate the biofilm formation on machined (MPT) or cast titanium (CPT) and zirconia abutments (Zc).

METHODS

Six healthy subjects were enrolled in this randomized crossover clinical investigation. The study was conducted in three phases according to abutment surface evaluated. Each subject used an individual oral splint containing four disks of the same tested substrate, two located in the anterior and two in the posterior region, totalizing 12 specimens for subject. Participants were asked to use the removable intraoral splint during 24 h. DNA checkerboard hybridization method was used to identify and quantify 38 bacterial species colonizing formed biofilm on the abutment substrates.

RESULTS

Pathogens and non-pathogens species were found colonizing the three substrates surfaces. Fusobacterium nucleatum, Neisseria mucosa, Porphyromonas aeruginosa, Peptostreptococcus anaerobios, Staphylococcus aureus, Streptococcus gordonii, Streptococcus parasanguinis, and Tanerella forsythia were the only species with no significant differences over the tested materials (P > 0.05). All the other target species presented significant differences sought by Friedman test (P < 0.0001).

CONCLUSIONS

There was a significant difference in the total bacterial count between the three groups. CPT presented the higher mean counts, followed by MPT and Zc. CPT group also showed a higher mean incidence of species than MPT and Zc. The anterior or posterior region of disks placement did not show significant differences in relation to bacterial adhesion.

Microflora around teeth and dental implants

Background:

When an implant is exposed to oral cavity, its surface gets colonized by micro-organisms. The aim of this study is to comparatively assess the microbiological parameters in sulci around the teeth and the crowns supported by dental implants.

Materials and Methods:

In this prospective, cross-sectional study, 34 partially edentulous patients aged between 40 and 50 years with total 50 anterior maxillary single implants with cemented crowns (depth of sulci <4 mm) and 34 similar teeth in the same jaw of the same patients were included. Excluded were the patients with compromised systemic and periodontal health and smoking habits. None of the patients had used any antimicrobial mouthwashes during at least two weeks before the study. All of the implants (ITI) were at least 6 months in place covered by definitive prostheses. Samples of gingival sulci were taken around teeth with paper cone and transported to Stuart transport medium. Samples were cultured and examined by a dark field microscope and eight laboratory tests were performed to determine the micro-organisms The data were evaluated statistically using Chi-square test (α=0.05).

Results:

Six anerobic bacteria found in teeth and implants sulci were Gram-positive cocci, Gram-negative cocci, Prevotella, Porphyromonas gingivalis, Bacteroid Fragilis and Fusobacterium. Gram-positive cocci and Gram-negative cocci had maximum and minimum percentage frequency in the two groups, respectively. There were no significant differences between the two groups (P value >0.05).

Conclusion:

The present study indicated that microflora in implant sulci is similar to the tooth sulci, when the depth of sulci is normal (<4 mm). As a result, implants’ susceptibility to inflammation is the same as teeth.

Accidental displacement and migration of endosseous implants into adjacent craniofacial structures: a review and update

Objectives: Accidental displacement of endosseous implants into the maxillary sinus is an unusual but potential complication in implantology procedures due to the special features of the posterior aspect of the maxillary bone; there is also a possibility of migration throughout the upper paranasal sinuses and adjacent structures. The aim of this paper is to review the published literature about accidental displacement and migration of dental implants into the maxillary sinus and other adjacent structures. Study Design: A review has been done based on a search in the main on-line medical databases looking for papers about migration of dental implants published in major oral surgery, periodontal, dental implant and ear-nose-throat journals, using the keywords “implant,” “migration,” “complication,” “foreign body” and “sinus.” Results: 24 articles showing displacement or migration to maxillary, ethmoid and sphenoid sinuses, orbit and cranial fossae, with different degrees of associated symptoms, were identified. Techniques found to solve these clinical issues include Cadwell-Luc approach, transoral endoscopy approach via canine fossae and transnasal functional endoscopy surgery. Conclusion: Before removing the foreign body, a correct diagnosis should be done in order to evaluate the functional status of the ostiomeatal complex and the degree of affectation of paranasal sinuses and other involved structures, determining the size and the exact location of the foreign body. After a complete diagnosis, an indicated procedure for every case would be decided.

Key words:Implant, oral surgery, foreign body, paranasal sinuses, displacement, migration.

Alveolar distraction osteogenesis in the human mandible: a clinical and histomorphometric study

PURPOSE

To identify the quality of newly formed bone in the distraction region and to determine the percentage of mineralized bone formed in the distraction area.

METHODS

Ten patients with vertically deficient mandibular alveolar ridges were treated by means of distraction osteogenesis. Four months after consolidation of distracted segments, a total of 40 dental implants were inserted in native bone and distracted bone. Bone biopsies were taken at the implant sites with trephine burrs for histological and histometric analyses. Four months after implant placement, abutments were connected, and prosthetic loading of the implants was started.

RESULTS

The mean bone gain at the end of distraction was 7.2 ± 0.8 mm. The cumulative success rate of implants 3 years after the onset of prosthetic loading was 100%. The newly formed bone consisted of woven bone reinforced by parallel-fibered bone with bone marrow spaces and the percentage of mineralized bone ranged from 50.56% to 76.88%.

CONCLUSIONS

Alveolar distraction osteogenesis is able to produce adequate mature bone for the correction of mandibular bone deficits before dental implant insertion.

Success rate of dental implants inserted in horizontal and vertical guided bone regenerated areas: a systematic review

This study assessed the success rate of implants placed in horizontal and vertical guided bone regenerated areas. A systematic review was carried out of all prospective and retrospective studies, involving at least five consecutively treated patients, that analysed the success rate of implants placed simultaneously or as second surgery following ridge augmentation by means of a guided bone regeneration (GBR) technique. Studies reporting only the survival rate of implants and studies with a post-loading follow up less than 6 months were excluded. From 323 potentially relevant studies, 32 full text publications were screened and 8 were identified as fulfilling the inclusion criteria. The success rate of implants placed in GBR augmented ridges ranged from 61.5% to 100%; all studies, apart from three, reported a success rate higher than 90% (range 90-100%). The data obtained demonstrated that GBR is a predictable technique that allows the placement of implants in atrophic areas. Despite that, studies with well-defined implant success criteria after a longer follow-up are required.

Implants in reconstructed bone: a comparative study on the outcome of Straumann® tissue level and bone level implants placed in vertically deficient alveolar ridges treated by means of autogenous onlay bone grafts

PURPOSE

To evaluate: (1) the survival rate of Straumann® Tissue Level and Bone Level implants placed in atrophic edentulous jaws previously reconstructed by means of autogenous onlay bone grafts; (2) to compare peri-implant bone resorption values over time.

MATERIALS AND METHODS

From 2005 to 2010, 50 patients presenting with vertical or tridimensional defects of the edentulous ridges were treated with autogenous bone grafts. Three to 7 months afterward, 192 implants were placed (Group A: 97 Tissue Level implants; Group B: 95 Bone Level implants) in the reconstructed areas. After a further waiting period of 2 to 3 months, patients were rehabilitated with implant-supported fixed prostheses. The follow-up ranged from 12 to 68 months after the start of prosthetic loading (mean: 33 months).

RESULTS

No implants were removed (survival rate: 100%), but in Group B 13 implants (8 placed in iliac grafts, 2 placed in ramus grafts, and 3 placed in calvarial grafts) presented peri-implant bone resorption values higher than those proposed by Albrektsson and colleagues. for successful implants: the overall implant success rate was then 100% for Group A and 86.8% for Group B. No prosthetic failures were recorded, thus leading to a 100% prostheses success rate.

CONCLUSION

No significant differences were found between the two types of implants as far as implant survival rate is concerned, but results from this study seem to demonstrate that Tissue Level implants may present better long-term results in terms of peri-implant bone maintenance, as compared with Bone Level implants, when placed in reconstructed areas.

The treatment of sinusitis following maxillary sinus grafting with the association of functional endoscopic sinus surgery (FESS) and an intra-oral approach

AIM OF THE STUDY

To present the results of a prospective study on the management of infectious complications following maxillary sinus floor elevation procedures with a combined endoscopic (FESS) and intra-oral approach.

MATERIALS AND METHODS

From 2005 to 2009, twenty consecutive patients were diagnosed for sinusal chronic infectious complications refractory to medical treatment following maxillary sinus floor elevation and grafting procedures. All patients were treated with a combination of functional endoscopic sinus surgery (FESS) through a transnasal approach and an intra-oral approach, performed by an ear, nose, and throat team and an oral and maxillofacial team, respectively, in the same surgical session under general anesthesia.

RESULTS

In 16 of 20 patients, the 4-week endoscopic control demonstrated a complete clinical healing and recovery of the normal sinus ventilation and drainage. In two patients, the persisting sinusitis at the 4-week control was successfully treated (8th week) with an antibiotic therapy based on the antibiogram carried out on the bacterial culture obtained by the aspiration of the sinusal content. In one patient, the persisting sinusitis (3 months after surgery) was successfully treated with the aspiration of the infectious material from the maxillary sinus. In one patient, finally, it was necessary to perform a second combined surgical treatment to treat the persisting sinusitis.

DISCUSSION AND CONCLUSIONS

In this study, a relevant number of cases of chronic infectious complications following sinus floor elevation procedures are presented. To the authors' knowledge, it is the first time that well-defined treatment protocols based on a combined endoscopic (FESS) and intra-oral surgical approach are proposed. The positive, albeit preliminary, results obtained in this study seem to validate this treatment modality.

Clinical factors correlated with the success rate of miniscrews in orthodontic treatment

Miniscrews offer a reliable alternative for anchorage during orthodontic treatment, particularly for non-cooperative patients or periodontal patients with alveolar bone loss. The study aims at assessing the correlation of various clinical indicators with the success or failure of miniscrews used for anchorage during orthodontic treatment. Thirty-four consecutive patients with a cumulative total of 82 miniscrews implanted participated in the study. Generalized Estimating Equations were used to assess the correlation of various factors with success rates. The miniscrew was considered the unit of analysis clustered within site and within patient. The overall success rate of miniscrews was 90.2%. For every additional miniscrew used in a patient's oral cavity, the success rate was reduced by 67%. Retromandibular triangle and palatal placement and in movable mucosa resulted in lower success rate. The miniscrew length and diameter were found to correlate with success rates. Orthodontic force applied on miniscrews for uprighting purposes showed a lower success rate than that used for retraction. This study revealed that miniscrews present high success rates. The number of miniscrews used per patient, the miniscrew site placement, the soft tissue type of placement, the miniscrew length and diameter as well as the orthodontic force applied on the miniscrew showed significant correlation with success rates.

Exploitation of a novel polysaccharide nanogel cross-linking membrane for guided bone regeneration (GBR)

Cholesterol-bearing pullulan (CHP) nanogel is a synthetic degradable biomaterial for drug delivery with high biocompatibility. Guided bone regeneration (GBR) is a bone augmentation technique in which a membrane is used to create and keep a secluded regenerative space. The purpose of the present study was to evaluate the effects of the novel CHP nanogel membrane in GBR. Thirty-six adult Wistar rats were used and bilaterally symmetrical full-thickness parietal bone defects of 5 mm diameter were created with a bone trephine burr. Each defect was covered with the collagen membrane or the CHP nanogel membrane or untreated without any membrane. The animals were sacrificed at 2, 4 and 8 weeks and analysed radiologically and histologically. Furthermore, after incubating human serum with CHP nanogel or collagen, the amount of PDGF in the serum was measured using ELISA. New bone formation in terms of bone volume was higher in the nanogel group than in the control or collagen groups at 2 and 4 weeks. At 8 weeks, both membrane groups showed higher bone volumes than the control group. Notably, the newly-formed bone in the bone defect in the nanogel group was uniform and histologically indistinguishable from the original bone, whereas in the collagen group the new bone showed an irregular structure that was completely different from the original bone. After incubating with CHP nanogel, the amount of PDGF in the serum decreased significantly. CHP nanogel GBR membrane favourably stimulated bone regeneration, in which a unique characteristic of CHP nanogel, the storage of endogenous growth factors, was likely implicated.

Titanium-zirconium alloy narrow-diameter implants (Straumann Roxolid(®)) for the rehabilitation of horizontally deficient edentulous ridges: prospective study on 18 consecutive patients

AIM OF THE STUDY

(i) To evaluate the survival and success rates of the new Roxolid narrow diameter implant placed in horizontally deficient ridges; and (ii) to evaluate the incidence of prosthetic complications.

MATERIALS AND METHODS

In a 24-month period (2009-2010) 18 partially or totally edentulous patients received 51 Straumann Roxolid (13 tissue level, 38 bone level) implants. Prosthetic loading of implants was either immediate (four implants; one patient) or delayed (2-12 months after placement; 47 implants; 17 patients). The patients were rehabilitated with either fixed (16 patients; 45 implants) or removable (two patients; six implants) prostheses.

RESULTS

All implants successfully achieved osseointegration and all patients completed the planned prosthetic rehabilitation. Peri-implant bone resorption values ranged from 0 to 1 mm at the end of the observation period (range: 3-19 months). Implant survival and success rates were therefore 100%. No prosthetic complications occurred and all implants are still in function; therefore the prosthesis success rate was 100%.

CONCLUSION

Narrow diameter implants fabricated with the new titanium-zirconium alloy were demonstrated to be reliable in supporting both fixed and removable prosthetic rehabilitations in horizontally deficient ridges. Implant survival, peri-implant bone resorption, and prosthetic complication rates were consistent with those reported in the literature for standard diameter implants placed in non-deficient edentulous ridges.

Evaluation of peri-implant bone resorption around Straumann Bone Level implants placed in areas reconstructed with autogenous vertical onlay bone grafts

AIM OF THE STUDY

To evaluate the survival and success rate of Straumann Bone Level implants placed in vertically atrophied edentulous jaws previously reconstructed with autogenous onlay bone grafts taken from the calvarium or the mandibular ramus.

MATERIALS AND METHODS

From 2007 to 2009, 18 patients presenting with vertical deficits of the edentulous ridges were treated with autogenous cortical bone grafts harvested from the mandibular ramus or the calvarium. Four to seven months afterward, 60 Straumann Bone Level implants were placed in the reconstructed areas. After a further waiting period of 2-3 months, patients were rehabilitated with implant-supported fixed prostheses. Follow-up ranged from 12 to 36 months (mean: 19 months) after the start of prosthetic loading. Graft resorption before implant placement, as well as survival and success rates of implants, were recorded.

RESULTS

The mean bone resorption prior to implant placement was 0.18 mm for calvarial grafts and 0.42 mm for ramus grafts. Survival rate was 100% either for implants placed in calvarial grafts or implants placed in ramus grafts, while success rate was 90.3% for implants placed in calvarial grafts, and 93.1% for implants placed in ramus grafts.

CONCLUSION

Results from this study seem to demonstrate that implants with a platform-switching design may predictably integrate in edentulous areas reconstructed with autogenous bone grafts, with survival rates consistent with those reported in recent literature reviews on the same topic, and also with implants placed in native bone. Conversely, this study was not able to demonstrate that implants with platform-switching design may reduce bone resorption around implants placed in reconstructed areas.

Comparison of the success rate of endodontic treatment and implant treatment

Dentists and patients are facing a perplexity between saving a compromised tooth through endodontic treatment and restoration or by extraction and replacement with an implant. The purpose of this paper was to compare the success rates of these two treatments. Success was measured as the longevity of the tooth or implant. Studies which met strict inclusion criteria to ensure best evidence were included. Searches were performed in Ovid Medline, Pubmed, Scopus database, and the Cochrane Library. Evidence-based groups were formed following the assessment of inclusion/exclusion criteria. The overall success rates for primary endodontic, nonsurgical retreatment, and surgical treatment were (86.02%), (78.2%), and (63.4%), respectively, implants was 90.9%. In conclusion, choice between implant and endodontic therapy cannot be exclusively based on outcome as both treatments differ in the biological process, diagnostic modalities, failure patterns, and patients preferences. More research is required with improved study designs before long-term success rates can be compared.

Long-term outcome of dental implants placed in revascularized fibula free flaps used for the reconstruction of maxillo-mandibular defects due to extreme atrophy

PURPOSE

the objectives of this study were to evaluate (a) the clinical outcome of revascularized fibula flaps used for the reconstruction of extremely atrophic jaws and (b) the survival rates of dental implants placed in the reconstructed areas.

MATERIALS AND METHODS

between 1999 and 2004, 12 patients presenting with extreme atrophy of the edentulous jaws were reconstructed with fibula free flaps. Five to 12 months after the reconstructive procedure, 75 titanium dental implants were placed in the reconstructed areas, while prosthetic rehabilitation was started 4-6 months afterward. The mean follow-up of patients after the start of prosthetic loading was 77 months (range: 48-116).

RESULTS

an uneventful healing of the bone transplants occurred in all patients. One out of the 75 dental implants placed was not loaded due to prosthetic reasons. No dental implants failed to integrate before prosthetic loading, while three were removed during the follow-up period. Despite the high survival rate of dental implants (95.8%), a relevant number of them presented relevant peri-implant bone-level loss, ranging from 1 to 7 mm for maxillary dental implants and from 1 to 4.5 mm for mandibular dental implants.

CONCLUSION

although no failures of the bone transplants occurred and a high long-term survival rate of dental implants were observed, this study showed that fibula free flaps do not guarantee dimensional stability of peri-implant bone, despite the immediate blood supply delivered by the vascular pedicle. The peri-implant bone resorption was higher when compared with the one related to dental implants placed in native bone.

Removal of a migrated dental implant from the maxillary sinus after 7 years: a case report

BACKGROUND

The accidental displacement of dental implants into the maxillary sinus is an infrequent but possible complication in dental clinical practice. The main cause of implant displacement is the inadequate bone height in the posterior maxilla. This event usually occurs during surgery, and it is more rarely reported in the post-operative period, especially with long-term follow-ups.

CASE REPORT

Here, a case of an implant migrated inside the maxillary sinus at the time of abutment connection and removed 7 years later is described.

DISCUSSION

Postoperative recovery was uneventful. To the author's best knowledge, this case represents the first report concerning migration of an oral implant into the maxillary sinus removed after 7 years.

Analysis of microbiota associated with peri-implantitis using 16S rRNA gene clone library

BACKGROUND

Peri-implantitis (PI) is an inflammatory disease which leads to the destruction of soft and hard tissues around osseointegrated implants. The subgingival microbiota appears to be responsible for peri-implant lesions and although the complexity of the microbiota has been reported in PI, the microbiota responsible for PI has not been identified.

OBJECTIVE

The purpose of this study was to identify the microbiota in subjects who have PI, clinically healthy implants, and periodontitis-affected teeth using 16S rRNA gene clone library analysis to clarify the microbial differences.

DESIGN

Three subjects participated in this study. The conditions around the teeth and implants were evaluated based on clinical and radiographic examinations and diseased implants, clinically healthy implants, and periodontally diseased teeth were selected. Subgingival plaque samples were taken from the deepest pockets using sterile paper points. Prevalence and identity of bacteria was analyzed using a 16S rRNA gene clone library technique.

RESULTS

A total of 112 different species were identified from 335 clones sequenced. Among the 112 species, 51 (46%) were uncultivated phylotypes, of which 22 were novel phylotypes. The numbers of bacterial species identified at the sites of PI, periodontitis, and periodontally healthy implants were 77, 57, and 12, respectively. Microbiota in PI mainly included Gram-negative species and the composition was more diverse when compared to that of the healthy implant and periodontitis. The phyla Chloroflexi, Tenericutes, and Synergistetes were only detected at PI sites, as were Parvimonas micra, Peptostreptococcus stomatis, Pseudoramibacter alactolyticus, and Solobacterium moorei. Low levels of periodontopathic bacteria, such as Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans, were seen in peri-implant lesions.

CONCLUSIONS

The biofilm in PI showed a more complex microbiota when compared to periodontitis and periodontally healthy teeth, and it was mainly composed of Gram-negative anaerobic bacteria. Common periodontopathic bacteria showed low prevalence, and several bacteria were identified as candidate pathogens in PI.

A 10-year retrospective analysis of radiographic bone-level changes of implants supporting single-unit crowns in periodontally compromised vs. periodontally healthy patients

AIM

To compare the 10-year peri-implant bone loss (BL) rate in periodontally compromised (PCP) and periodontally healthy patients (PHP) around two different implant systems supporting single-unit crowns.

MATERIALS AND METHODS

In this retrospective, controlled study, the mean BL (mBL) rate around dental implants placed in four groups of 20 non-smokers was evaluated after a follow-up of 10 years. Two groups of patients treated for periodontitis (PCP) and two groups of PHP were created. For each category (PCP and PHP), two different types of implant had been selected. The mBL was calculated by subtracting the radiographic bone levels at the time of crown cementation from the bone levels at the 10-year follow-up.

RESULTS

The mean age, mean full-mouth plaque and full-mouth bleeding scores and implant location were similar between the four groups. Implant survival rates ranged between 85% and 95%, without statistically significant differences (P>0.05) between groups. For both implant systems, PCP showed statistically significantly higher mBL rates and number of sites with BL> or =3 mm compared with PHP (P<0.0001).

CONCLUSIONS

After 10 years, implants in PCP yielded lower survival rates and higher mean marginal BL rates compared with those of implants placed in PHP. These results were independent of the implant system used or the healing modality applied.