Immediate loading of fixed partial prostheses reconstructed using either tapered or straight implants in the posterior area: A randomized clinical trial

BACKGROUND

In immediately loaded implants within 72 h after the implant placement in the unilaterally and partially edentulous ridge, primary stability is considered critical, which can be influenced by the design of the implant fixture.

PURPOSE

To determine the outcomes at 1 year after the immediate loading of multiunit fixed partial prostheses over either tapered implants (TIs) or straight implants (SIs) in the posterior region.

MATERIALS AND METHODS

Forty-eight patients (24 patients, 52 implants in TI group; 24 patients, 50 implants in SI group) were included for the study. Except for the one SI group patient whose two implants showed the insertion torque less than 30 Ncm, provisional prostheses designed and fabricated from intraoral scan data obtained immediately after implant surgery were delivered to rest of the 47 subjects at 3-7 days. After a year, the survival rate was estimated by intention-to-treat (ITT) and per-protocol (PP) analyses, and marginal bone loss (MBL) and implant stability were also analyzed statistically (p < 0.05).

RESULTS

Survival rate at implant level in TI group was 96.2%, and that of SI group in the ITT analysis was 86.0%. Intergroup difference, however, was not statistically significant (p > 0.05). Insertion torque was significantly higher in TI group than SI group (47.12 ± 6.37 Ncm vs. 41.60 ± 9.77 Ncm; p < 0.05). MBLs of both groups were less than 0.1 mm at 1-year follow-up and was similar between two groups (p > 0.05).

CONCLUSIONS

Immediate loading of fixed partial prostheses after TI and SI placement showed reliable outcomes in the partially edentulous posterior ridge. In terms of the initial mechanical stability, the performance was superior for TIs than for SIs.

Outcome of supportive peri-implant therapy on the rates of peri-implant diseases and marginal bone loss: a systematic review and meta-analysis

<p>Objective: The aim of this systematic review and meta-analysis was to evaluate the impact of supportive peri-implant therapy (SPIT) on the rates of peri-implant diseases and peri-implant marginal bone loss. ?Data sources: The guidelines of PRISMA statement were followed in searching for randomized controlled trials, controlled clinical trials, and retrospective studies in several electronic databases and reference lists. The Cochrane Collaboration's Risk of Bias tools for nonrandomized studies were used to assess the risk of bias. Data were analyzed using statistical software. ?A total of 159 studies were identified. Five trials, with 1,570 implants in 617 patients, met the inclusion criteria. Overall meta-analysis showed significantly reduced rates of peri-implantitis with SPIT compared with non-SPIT at implant and patient levels. Peri-implant mucositis was significantly reduced with SPIT at implant level only. Peri-implant marginal bone loss was significantly reduced in patients with SPIT compared to those who did not attend SPIT.<br /> Conclusion: SPIT can significantly reduce the rate of peri-implantitis and marginal bone loss. The evidence on the role of SPIT in reducing the rate of peri-implant mucositis, on the other hand, remains limited. Further well-designed studies on the impact of SPIT on implant treatment outcome are still needed. Clinical significance: There is a need to adopt a SPIT regimen for patients receiving implant therapy to reduce the rate of peri-implant diseases and marginal bone loss. This need should be stipulated in the patient information and consent forms prior to implant therapy. (Quintessence Int 2021;52:122-131; doi:&nbsp;10.3290/j.qi.a45428)</p>.

[Effect of vertical soft tissue thickness on clinical manifestation of peri-implant tissue in patients with periodontitis]

OBJECTIVE

To observe and investigate the effect of vertical soft tissue thickness on the peri-implant tissue condition and the prevalence of peri-implant disease in patients with history of periodontitis.

METHODS

Among 210 patients who showed initial interest of implant therapy, 92 patients were included in this study and received implant surgery during 2010 and 2015. Sixty-six patients with 66 implants finally came back for T2 evaluation. Prior to the implant therapy, all the patients had received periodontal treatment. During the implant placement surgery, the distance from palatal soft tissue edge to the alveolar crest, which was defined as vertical soft tissue thickness (VT), was measured after the buccal full thickness flap was elevated. According to the cut off point which was adopted from the operating characteristic curve, 66 implants within 66 patients were divided into two groups, which were called normal group (VT≤4.5 mm) and thick group (VT>4.5 mm), respectively. Information of the patient's general status, periodontal situation and implant information were recorded. After a follow-up period of 42.9 months, the parameters of peri-implant tissue and condition of peri-implant disease were recorded. Mann-Whitney U test as well as Chi-square test were used to compare the parameters between two groups. Moreover, Kaplan-Meier method was chosen to draw the event(peri-implantitis)-free survival curve.

RESULTS

The survival rate of the implants was 100%. At the end of the follow-up examination(T2), the parameters including max PDi, mean PDi, max BIi, mean BIi, mean MBL, MBL at distal side, MBL at mesial side, mean PLIi presented significantly higher values in thick group than in normal group (P < 0.05). Moreover, the prevalence of peri-implantitis and peri-implant disease (peri-implant mucositis & peri-implantitis) in thick group was respectively 34.8% and 73.9%, which was significantly higher than 2.3% and 48.8% respectively in normal group (P<0.05). The prevalence of peri-implant mucositis did not show significant difference in the two groups. In addition, Kaplan-Meier analysis showed that there was significant difference between the event-free survivals of the two groups.

CONCLUSION

The vertical soft tissue thickness around implants in patients with periodontitis has a significant effect on the health of the peri-implant tissue. Excessive vertical soft tissue thickness may result in deeper peri-implant probing depth as well as more peri-implant marginal bone loss, and eventually increase the risk of peri-implant disease. The vertical remodeling of soft tissue may be a new direction to indicate the role of periodontitis in peri-implant tissue condition. Moreover, the biological mechanism of the association between soft tissue thickness and peri-implantitis risk as well as effective approaches to prevent the adverse effect of excessive soft tissue thickness on peri-implant tissue is necessary to be investigated.

A 5-year longitudinal cohort study on crown to implant ratio effect on marginal bone level in single implants

BACKGROUND

A 5-year longitudinal cohort study was carried out to evaluate the influence of anatomical crown to implant ratio (CIR) on peri-implant marginal bone level (MBL) in single implants.

MATERIALS AND METHODS

The longest possible implants, according to the availability of pristine bone, were inserted, one per patient, among periodontally healthy teeth in consecutively recruited subjects. CIR and MBL changes were measured on standardized radiographs. The relationship between MBL and multiple predictors was investigated. A statistical analysis suitable for mixed type distributions was conducted: for the discrete component a logistic regression model was used and for the continuous component the impact of the variables on MBL was examined by using robust nonparametric comparison tests.

RESULTS

Seventy-eight dental implants were inserted in 34 mandibles and 44 maxillae, with one stage procedure in 40 cases and two stage in 38 cases. Thirty-five implants were <10 mm, while 43 were ≥ 10 mm long; 28 implants had a CIR ≤1 and 50 had a CIR >1. No drop-outs or implant loss were observed. Bone loss occurred only in a few cases, measuring less than 0.5 mm and being significantly more pronounced for implant length ≥10 mm, for lower CIR values and for the two stage procedure.

CONCLUSION

Higher CIR values were not related to increased peri-implant bone loss; a <10 mm long implant insertion may be safely considered for reduced bone heights.