Impact of keratinized mucosa on implant-health related parameters: A 10-year prospective re-analysis study

AIM

To investigate whether the lack of keratinized mucosa (KM) affects peri-implant health after 10 years of loading.

MATERIALS AND METHODS

Data from 74 patients with 148 implants from two randomized controlled studies comparing different implant systems were included and analyzed. Clinical parameters including bleeding on probing (BOP), probing depth (PD), plaque index, marginal bone loss (MBL), and KM width (KMW) at buccal sites were collected at baseline (time of the final prosthesis insertion), 5-year and 10 years postloading. Multivariable logistic and linear regression models by means of a generalized estimated equation (GEE) were used to evaluate the influence of buccal KM on peri-implant clinical parameters; BOP, MBL, PD, and adjusted for implant type (one-piece or two-piece) and compliance.

RESULTS

A total of 35 (24.8%) implants were healthy, 67 (47.5%) had mucositis and 39 (27.6%) were affected by peri-implantitis. In absence of buccal KM (KM = 0 mm), 75% of the implants exhibited mucositis, while in the presence of KM (KMW >0 mm) 41.2% exhibited mucositis. Regarding peri-implantitis, the corresponding percentages were 20% (KM = 0 mm) and 26.7% (KM >0 mm). Unadjusted logistic regression showed that the presence of buccal KM tended to reduce the odds of showing BOP at buccal sites (OR: 0.28 [95% CI, 0.07 to 1.09], p = 0.06). The adjusted logistic regression model revealed that having buccal KM (OR: 0.21 [95% CI, 0.05 to 0.85], p = 0.02) and using two-piece implants (OR: 0.34 [95% CI, 0.15 to 0.75], p = 0.008) significantly reduced the odds of showing BOP. Adjusted linear regression by means of GEE showed that KM and two-piece implants were associated with reduced MBL and MBL changes (p < 0.05).

CONCLUSION

The lack of buccal KM appears to be linked with peri-implant parameters such as BOP and MBL, but the association is weak. The design of one-piece implants may account for their increased odds of exhibiting BOP.

Survival and complication rates of two dental implant systems supporting fixed restorations: 10-year data of a randomized controlled clinical study

OBJECTIVES

To compare clinical, radiographic, biological and technical long-term outcomes of two types of dental implants over a period of 10 years.

MATERIALS AND METHODS

Ninety-eight implants were placed in 64 patients, randomly allocated to one of two manufacturers (AST and STM). All implants were loaded with fixed restorations. Outcome measures were assessed at implant insertion (Ti), at baseline examination (TL), at 1, 3, 5, 8 and 10 (T10) years. Data analysis included survival, bone level changes, complications and clinical measures.

RESULTS

Re-examination was performed in 43 patients (23 AST and 20 STM) at 10 years. The implant level analysis was based on 37 (AST) and 32 (STM) implants. Survival rates of 100% were obtained for both groups. The median changes of the marginal bone levels between baseline and T10 (the primary endpoint) amounted to a loss of 0.07 mm for group AST and a gain of 0.37 mm for group STM (intergroup p = 0.008). Technical complications occurred in 27.0% of the implants in group AST and in 15.6% in group STM. The prevalence of peri-implant mucositis was 29.7% (AST) and 50.1% (STM). The prevalence of peri-implantitis amounted to 0% (AST) and 6.3% (STM).

CONCLUSIONS

Irrespective of the implant system used, the survival rates after 10 years were high. Minimal bone level changes were observed, statistically significant but clinically negligible in favor of STM. Technical complications were more frequently encountered in group AST, while group STM had a higher prevalence of peri-implant mucositis.

Randomized controlled clinical study comparing two types of two‐piece dental implants supporting fixed restorations – results at 8 years of loading

Objectives

To assess clinical, technical, biological, and radiographic outcomes of implants supporting fixed restorations using two types of dental implants with non‐matching implant–abutment junctions at 8 years.

Materials and methods

Sixty‐four patients were randomly assigned to receive one of two implant systems (S1 or S2) and eventually fixed restorations. Patients were examined at loading (T_L), one (T₁), three (T₃), five (T₅), and eight years (T₈). Outcome measures included implant and restoration survival, technical and biological complications, and radiographic bone levels. All data were analyzed on the implant and patient level.

Results

Ninety‐eight implants were inserted in 64 patients and loaded with fixed restorations. At 8 years, 49 patients with 42 (S1) and 36 (S2) implants (25 in group S1 and 24 in group S2 on the patient level) were re‐examined. The survival rates on the patient level were 97.6% (S1) and 97.2% (S2). The marginal bone levels (the primary endpoint) amounted to a gain of 0.21 mm (Q1: −0.11 mm; Q3: 0.5 mm) (S1) (p = .007) and to a loss of 0.24 mm (Q1: −0.79 mm; Q3: 0.05 mm) (S2) (p = .001) between baseline (T_L) and T₈ (intergroup p < .001). The technical complication rates were 28% (S1) and 12.5% (S2) (intergroup p = .289). Peri‐implant mucositis was observed in 24% (S1) and 50% (S2) of the implants on the patient level (intergroup p = .792). The respective figures for peri‐implantitis were 0% (S1) and 12.5% (S2) (intergroup p = .11).

Conclusions

Dental implants with non‐matching implant–abutment junctions supporting fixed restorations resulted in high survival rates independent of the system used. Differences, mainly observed in terms of technical complications (in favor of S2), biological complications (in favor of S1), and marginal bone‐level changes (in favor of group S1), appear to be clinically negligible.

COMPARATIVE EVALUATION OF CLINICAL APPLICATION OF MONOLITHIC AND FOLDING IMPLANTS IN REHABILITATION OF ELDERLY PATIENTS WITH VARIOUS DEGREES OF ATROPHY OF ALVEOLAR PROCESSES

OBJECTIVE

The aim: Comparative evaluation of long-term results of clinical application of one- and two-stage surgical protocols of dental implantation with the use of monolithic and collapsible implants in the rehabilitation of elderly patients.

PATIENTS AND METHODS

Materials and methods: Under clinical observation were 46 patients with various clinical diagnoses of dentition defects aged 60 to 70 years. The following methods were used in the study: one - stage surgical protocol of dental implantation operation with non - detachable implants of ART IMPLANT system with subsequent temporary splint fixed prosthesis and immediate occlusive functional load, mechanical oscillatory - resonance method, questionnaire and statistical analysis.

RESULTS

Results: The duration of surgical stages of treatment and complete rehabilitation showed statistically significant differences (p <0.05) and was significantly less when using a single-stage protocol of dental implant surgery and non-detachable implants and averaged 3.9 ± 0.8, p <0.05 months against 7.3 ± 1.2, p <0.05 months in implants according to the two-stage protocol. Assessment of patient satisfaction with the treatment was directly correlated with his timing.

CONCLUSION

Conclusions: Thus, it should be noted that the clinical use of one-stage surgical protocol of implantation and non-detachable (monolithic) dental implants of the system «ART IMPLANT» in the rehabilitation of elderly patients with varying degrees of atrophy of the alveolar processes of the jaws is clinically justified.

Radiological Outcomes of Bone-Level and Tissue-Level Dental Implants: Systematic Review

Background: to assess the radiological marginal bone loss between bone-level or tissue-level dental implants through a systematic review of literature until September 2019. Methods: MEDLINE, Embase and other database were searched by two independent authors including only English articles. Results: The search provided 1028 records and, after removing the duplicates through titles and abstracts screening, 45 full-text articles were assessed for eligibility. For qualitative analysis 20 articles were included, 17 articles of them for quantitative analysis counting a total of 1161 patients (mean age 54.4 years) and 2933 implants, 1427 inserted at Tissue-level (TL) and 1506 inserted at Bone-level (BL). The survival rate and the success rate were more than 90%, except for 2 studies with a success rate of 88% and 86.2%. No studies reported any differences between groups in term of success and survival rates. Three studies showed that BL-implants had statistically less marginal bone loss (p < 0.05). Only one study reported statistically less marginal bone loss in TL-implants (p < 0.05). Conclusion: In the most part of the studies, differences between implant types in marginal bone loss were not statistically significant after a variable period of follow-up ranged between 1 and 5 years.

A Non-Interventional Study Documenting Use and Success of Tissue Level Implants

Numerous randomised controlled multicentric studies have investigated various responses to different treatment modalities with dental implants. These studies do not always show the results of daily practice as they are performed under controlled and strict clinical conditions. This multicentric, non-interventionist trial aimed to document the behaviour of implants when used in daily dental practice, without inclusion or exclusion criteria. One hundred and ninety-six screw-shaped, tissue-level implants were placed, and each clinician decided which implant, surgical loading and prosthetic protocol to use. At surgery, data related to the implants were recorded. Additionally, the crestal bone level changes were evaluated for up to two years of follow-up. Two implants were lost before they were loaded. The success rate was 98.31%, and the survival rate was 98.79%. The implant stability quotient (ISQ) at surgery was 68.61 ± 10.35 and at 2 years was 74.39 ± 9.64. The crestal–shoulder distances were 1.25 ± 1.09 mm and 1.68 ± 1.07 mm in the mesial and distal aspects on the day of surgery, respectively, and 2.04 ± 0.91 and 2.16 ± 0.99 mm at 2 years, respectively. At 2 years, 69.3% of the patients were highly satisfied. The use of implants under standard conditions seemed to have success rates similar to their placement in controlled studies.

Longevity and marginal bone loss of narrow-diameter implants supporting single crowns: A systematic review

PURPOSE

To compare the longevity and marginal bone loss of narrow-diameter (≤3.3-mm) versus standard-diameter implants supporting single crowns.

MATERIAL AND METHODS

The MEDLINE (via PubMed), Scopus, and SciELO databases were searched for relevant publications. In addition, the scientific references provided by each of the implant companies that appeared in the search were reviewed. Intervention studies comparing longevity and bone loss between narrow-diameter and standard-diameter implants were included.

RESULTS

The search was limited to in vivo studies in humans. The query returned 1931 results, of which 4 met the inclusion criteria. The implant success rate ranged from 93.8% to 100% over a maximum follow-up of 3 years, with no difference between narrow- and standard-diameter implants. Meta-analysis of all included studies showed greater bone loss in narrow-diameter implants as compared with standard ones; however, when analysis was restricted to randomized trials, no such difference was present.

CONCLUSION

The meta-analysis showed no difference in longevity between narrow implants and standard implants when supporting single crowns. However, narrow-diameter implants may be associated with greater marginal bone loss. These findings should be regarded cautiously due to the short follow-up duration and methodological heterogeneity of the primary studies.

The amount of keratinized mucosa may not influence peri-implant health in compliant patients: A retrospective 5-year analysis

AIM

(a) To investigate the influence of the keratinized mucosa (KM) on peri-implant health or disease and (b) to identify a threshold value for the width of KM for peri-implant health.

MATERIALS AND METHODS

The total dataset was subsampled, that is one implant was randomly chosen per patient. In 87 patients, data were extracted at baseline (prosthesis insertion) and 5 years including the width of mid-buccal KM, bleeding on probing, probing depth, plaque index and marginal bone level (MB). Spearman correlations with Holm adjustment for multiple testing were used for potential associations.

RESULTS

Depending on the definition of peri-implant diseases, the prevalence of peri-implantitis ranged from 9.2% (bleeding on probing threshold: <50% or ≥50%) to 24.1% (threshold: absence or the presence). The prevalence of peri-implant mucositis was similar, irrespective of the definition (54%-55.2%). The width of KM and parameters for peri-implant diseases demonstrated negligible (Spearman correlation coefficients: -0.2 < ρ < 0.2). No threshold value was detected for the width of mid-buccal KM in relation to peri-implant health.

CONCLUSION

The width of KM around dental implants correlated to a negligible extent with parameters for peri-implant diseases. No threshold value for the width of KM to maintain peri-implant health could be identified.

Comparative evaluation of the stability of two different dental implant designs and surgical protocols-a pilot study

Background

The purpose of this study was to compare a parallel wall design implant to a tapered apex design implant when placed in the posterior maxilla using two different surgical protocols.

Methods

Twenty-seven patients (30 implants) were divided into three groups. All implants were 4 mm wide in diameter and 8 mm long.

Group A received 10 tapered implants (OSPTX) (Astra Tech OsseoSpeed TX™) using the soft bone surgical protocol (TXSoft).

Group B received 10 tapered implants (OSPTX) (AstraTech OsseoSpeedTX™) using the standard surgical protocol (TXStd).

Group C received 10 parallel wall implants (OSP) (AstraTech OsseoSpeed™) using the standard surgical protocol (OStd).

All implants were placed in the posterior maxilla in areas with a minimum of 8-mm crestal bone height.

Resonance frequency measurements (implant stability quotient (ISQ)) and torque values were recorded to determine initial implant stability. All implants were uncovered 6 weeks after placement and restored with a functionally loaded resin provisional screw-retained crown. Resonance frequency measurements were recorded at the time of implant placement, at 6 weeks and 6 and 12 months. Twelve months after implant placement, the stability of the implants was recorded and the final restorations were placed using custom CAD/CAM fabricated abutments and cement-retained PFM DSIGN porcelain crowns. After implant restoration, bone levels were measured at 6 and 12 months with standardized radiographs.

Results

Radiographic mean bone loss was less than 0.5 mm in all groups, with no statistically significant differences between the groups. Implant survival rate at 1 year was 93.3%, with 2/30 implants failing to integrate prior to functional loading at 6 weeks. No statistically significant difference was found between ISQ measurements between the three groups at all time intervals measured. Strong positive correlations were found between overall bone loss at 6 months and insertion torque at time of placement. A very weak correlation was found between insertion torque and ISQ values at time of implant placement.

Conclusions

Survival and stability of OSPTX and OSP implants is comparable. Osteotomy preparation by either standard or soft bone surgical protocol presented no significant effect on implant survival and stability for the specific implant designs.