International Journal of Oral Implantology, 04/2012

Objectives: To evaluate possible benefits of the adjunctive use of light-activated disinfection (LAD) in the treatment of peri-implantitis. Materials and methods: Eighty patients with at least one implant affected by peri-implantitis defined as at least 3 mm of bone loss from the baseline radiographs in the presence of signs of infection (pus exudation and/or soft tissue swelling and/or soft tissue redness) were nonsurgically or surgically treated. A total of 50% were randomly allocated to receive an additional treatment of LAD (FotoSan) according to a parallel group design at four different centres. Only one implant per patient was considered. Outcome measures recorded up to 4 months after treatment were implant failures, complications, probing pocket depth (PPD) changes and number of re-treatment sessions recorded by blinded assessors. Patients were followed for 4 months after treatment. Results: Five treated patients did not fit the original inclusion criteria, 4 because they were not affected by peri-implantitis (as defined in the present study) and one because the patient was treated with antibiotics, however they were included according to an intention-to-treat analysis concept. Nine patients of the LAD group were treated surgically versus 10 control patients. After 4 months, 1 patient dropped out from the LAD group and no implant failed. Fifteen implants had to be re-treated in the LAD group versus 16 implants in the control group, the difference was not significant. Three minor complications occurred: 2 in the LAD group and 1 in the control group. PPD significantly decreased in both groups, and at 4 months there was no significant differences between groups (difference -0.12 mm, 95% CI of difference -0.94 to 0.69, P = 0.77). There were significant differences between centres for number of re-treatments needed, PPD changes, plaque and marginal bleeding 4 months after treatment. The results did not change when removing the 5 patients who did not match the present inclusion criteria. Conclusions: The use of adjunctive LAD therapy with mechanical cleaning of implants affected by peri-implantitis did not improve any clinical outcomes up to 4 months after treatment, however longer follow-ups are needed to evaluate the possible effect of repeated LAD therapy over time. Keywords: infection, light activation disinfection, peri-implantitis

Purpose: To compare the outcome of immediately loaded single implants inserted with medium (from 25 to 35 Ncm) or high insertion torques (>80 Ncm). Materials and methods: Fifty patients received two single non-adjacent implants, each randomly inserted flapless with a torque between 25 to 35 Ncm or >80 Ncm according to a split-mouth design. Non-occluding temporary crowns were immediately placed on provisional abutments and definitive crowns were delivered after 6 weeks. Patients were followed for 6 months after initial loading. Outcome measures were crown/implant failures, complications, peri-implant marginal bone level changes, postoperative pain and presence of peri-implant apical radiolucency. Results: No drop-out occurred. Seven implants inserted with a torque between 25 to 35 Ncm failed versus none of the implants inserted with a torque >35 Ncm. With the exception of crown/implant failures (exact McNemar significance P = 0.0156, difference in proportions: -0.12; 95% CI -0.21 to -0.02) there were no statistically significant differences between groups for the other outcome measures. Conclusions: It is preferable to insert single implants with a high insertion torque (>80 Ncm), to minimise early implant failures, when loading them immediately. Keywords: dental implants, immediate loading, insertion torque, success

Purpose: To compare the outcome of immediate non-occlusal loading and that of delayed implant loading in the bilateral replacement of single mandibular molars. Materials and methods: This study was designed as a randomised, controlled, split-mouth trial. Twenty patients with bilaterally missing first mandibular molars had one of the sites to be restored randomly assigned to be treated with immediately or conventionally loaded single implants. A total of 40 implants were bilaterally installed. All the implants were inserted in healed healthy bone with an insertion torque between 35 and 45 Ncm. One molar was restored with a non-occluding temporary crown within 24 h after implant placement, while the contralateral molar was restored with a definitive crown 4 to 5 months later, according to a two-stage procedure. Final restorations were provided 4 to 5 months after implant placement for all implants. Outcome measures were implant survival, complications, radiographic marginal bone-level changes, PPD and BOP. Results: No patients dropped out and no implant failed. Only minor prosthetic complications were observed (2 provisional acrylic crown fractures in the immediate loading group and 2 ceramic chipping in the delayed loading group). Mean marginal bone loss was 0.83 ± 0.16 mm (95% CI 0.75 to 0.91) in the immediate loading group and 0.86 ± 0.16 mm (95% CI 0.78 to 0.94) in the conventional loading group and no statistically significant differences between the two groups were observed (P = 0.530). Mean PPD and BOP values were, respectively, 2.76 ± 0.48 (95% CI 2.55 to 2.97) and 1.30 ± 0.73 (95% CI 0.98 to 1.62) in the immediate loading group, and 2.70 ± 0.37 (95% CI 2.54 to 2.86) and 1.40 ± 0.75 (95% CI 1.07 to 1.73) in the conventional loading group. Also, a statistical comparison of BOP and PPD did not show any significant difference (P = 0.163 and P = 0.652, respectively). Conclusions: Within the limitations of this study, the present data seem to confirm the hypothesis that the clinical outcome of immediate versus delayed loading of implants in single mandibular molar sites is comparable. Keywords: delayed loading, immediate loading, single lower tooth

Purpose: The purpose of this randomised controlled trial was to compare the long-term clinical outcome of cemented and screw-retained implant-supported single-tooth crowns. Materials and methods: Eighteen consecutive patients presenting with single-tooth bilateral edentulous sites in the canine/molar region with adequate bone width, similar bone height at the implant sites, and an occlusal scheme that allowed for the establishment of identical occlusal cusp/fossa contacts were treated. Each patient received two identical implants according to a split-mouth design. One side was randomly selected to be restored with a cemented implant-supported single crown, and the other was restored with a screw-retained implant-supported single crown. Outcome measures were implant success, complications, marginal bone levels and peri-implant soft tissue health. Results: Ten years after initial loading, 2 patients moved away and were lost to follow-up. Two implants placed in the same patient failed 5 years after their insertion; the remaining 30 implants survived, resulting in a cumulative implant success rate of 93.7%. No complication occurred. The mean marginal bone resorption at 10 years after implant placement, measured on intraoral radiographs, was 1.1 ± 0.2 mm for both types of restorations. There were no statistically significant differences between the two groups with respect to peri-implant marginal bone level at the 10-year follow-up appointment (T2) (P = 0.58); at the 4-year follow-up appointment (T1) a statistically significant difference was observed (P = 0.01), but this was not considered clinically relevant (mean difference: -0.06 mm). The status of the soft tissue around the implants remained stable over the evaluation period. No statistically significant difference was identified for the facial keratinised gingiva between the two groups at T1 (P = 0.10) or at T2 (P = 0.07). Conclusions: Within the limitations of this study, the results indicate that there was no evidence of a significant difference in the clinical behaviour of the peri-implant marginal bone or of the peri-implant soft tissues when cemented or screw-retained single-tooth implant restorations were provided. Keywords: cement-retained crowns, dental implants, screw-retained crowns, single implant-supported crowns

Aim: The aim of this 1-year prospective cohort study was to evaluate the outcomes and complications of immediately loaded mini dental implants used for stabilizing mandibular overdentures in edentulous patients wearing conventional complete dentures. Materials and methods: Thirty patients received mandibular conventional complete dentures that were subsequently retained by 4 immediately loaded mini dental implants placed in the interforaminal region. Overdenture success, implant success and biological and prosthetic complications were evaluated after the first year of service. Quality of life using the Oral Heath Impact Profile (OHIP)- EDENT test, satisfaction with dental prosthesis and chewing efficiency using questionnaires and a Visual Analogue Scale (VAS) were evaluated twice: after they had received mandibular complete dentures, and again after they had received mandibular overdentures. Results: After 1 year, no overdenture failed and 2 implants did not osseointegrate, resulting in a 98.3% success rate for loaded implants and 95.9% for total implants used (3 out of 123 were not loaded due to fracture). A flap surgical approach was performed in 7 patients, 3 implants fractured during insertion, 3 overdentures fractured, occlusion balancing was necessary for 11 dentures and relining for 8. Implant rehabilitation provided significant improvement in quality of life, stability, comfort, chewing and speaking ability while no significant differences were found in quality of maintenance of hygiene and for aesthetics. Conclusions: Mini dental implant retained overdentures can be a successful therapeutic procedure for treating mandibular edentulism that improves quality of life, patient satisfaction and chewing ability in patients wearing maxillary dentures. Longer follow-ups are needed to validate this therapy in the medium and long-term. Keywords: lower complete denture, lower overdenture, mini dental implants, patient satisfaction, quality of life

Purpose: Receptor activator for nuclear factor kappa B ligand (RANKL)/RANK/OPG pathway plays a redundant role in osteoclastogenesis, osteoclast activation and regulation of bone resorption. Recently, single nucleotide polymorphisms (SNP) have been reported as a co-factor in pathogenesis of inflammatory diseases. The aim of this study was to investigate the relationship between osteoprotegerin (OPG) gene polymorphisms and chronic periodontitis and peri-implantitis in an Iranian population. Materials and methods: 77 patients with chronic periodontitis (CP), 40 patients with peri-implantitis (PI) and 89 periodontally healthy subjects were enrolled in this study. A total of 5 ml of blood was obtained from the arm vein of participants. DNA was extracted based on the salting out method. Two functional SNPs (T950C and G1181C) were analysed by using polymerase chain reaction and restriction fragment length polymorphism (PCR_RFLP). The prevalence differences in three batches were evaluated by chi-square test. Results: An evaluation of the T950C genotype found that there was no statistical difference between groups. A comparison of the G1181C genotype distribution between peri-implantitis and chronic periodontitis groups, and between peri-implantitis and normal groups found that the frequency of the CC genotype was significantly higher in patients with peri-implantitis (P = 0.005). Conclusions: Our results indicate that a SNP at G1181C is associated with the presence of PI. Keywords: gene polymorphism, osteoprotegerin, peri-implantitis, periodontitis

Purpose: The aim of this article is to present a clinical case of severe descending mediastinitis following the insertion of three dental implants in the mandible. Materials and methods: A 64-year-old female was treated with an implant-supported rehabilitation for her mandibular missing teeth in positions 36, 45 and 46. Results: Three days after the dental implant surgery, the patient complained of malaise, shiver and fever (38°C) with dysphagia and swelling of the mouth floor. The following day the patient was admitted to the hospital with a diagnosis of larynx oedema. Due to the worsening clinical conditions on day 5, she was transferred to the Thoracic Surgery Division with a diagnosis of left neck phlegmon and underwent cervicotomy. A CT scan at day 9 showed mediastinal extension of the phlegmon with initial pleural reaction. The patient then underwent cervicotomy again for drainage. On day 16, she underwent videothoracoscopy to drain a left pleural effusion. The patient was discharged on day 31. Conclusions: Despite the fact that descending mediastinitis has a very high mortality rate, in the present case proper treatment was able to resolve this serious complication. It is likely that the early diagnosis and prompt treatment prevented neck and mediastinal infection diffusion. Clinicians should always keep in mind that a potential fatal infection complication may arise after routine dental implant surgery in the mandible. Keywords: complication, dental implants, infection, mediastinitis