Microbiological and clinical effects of chlorhexidine enclosed in fixtures of 3I-Titamed®implants

Heterogeneity of outcomes in randomized controlled trials on implant prosthodontic therapy is hindering comparative effectiveness research: meta-research study

BACKGROUND

Consistency in outcomes across clinical trials allows for comparing and combining results from different studies. A core outcome set (COS), representing a minimally agreed standardized group of outcomes that should be monitored and measured through research in a specific field of medicine, is not yet available for trials in implant prosthodontic (dental implant) therapy. This meta-research study aimed to analyze outcomes used in clinical trials on implant prosthodontic therapy.

METHODS

We searched the Cochrane Oral Health Group (COHG) register to identify systematic reviews of interventions in implant prosthodontic therapy published by October 2023. From the randomized controlled trials (RCTs) included in the relevant reviews, we extracted data on the characteristics of the included trials and the outcomes used. We categorized outcomes into domains.

RESULTS

From 182 systematic reviews in the COHG register, we included 11 systematic reviews on dental implant therapy. The reviews included 117 unique RCTs with 4725 participants, published from 1995 to 2020, which analyzed 74 different outcomes. Using different definitions, implant failure was analyzed in 73 RCTs. Seventeen RCTs did not define implant failure. Failure was most often (30 RCTs) followed up for one year. Only one RCT assessed implant failure after five years. Trials used 17 definitions of implant failure, while 17 trials did not report on the criteria of implant failure. Complications were analyzed in 48 RCTs, although they were not clearly defined in 12 RCTs. Failure of prosthodontic supra-structure was analyzed in 74 RCTs, with definitions of failure and criteria not clearly defined in 44 RCTs. Trials considered adverse events, peri-implant tissue health, patient attitudes, and other outcomes, including cost, aesthetics, or procedure duration. These outcomes were often different between trials. Twenty-six outcomes were used only once per study.

CONCLUSIONS

Clinical trials in implant prosthodontics used different outcomes, different definitions of outcomes and used different times to monitor them. Standardization of outcomes is necessary to allow comparability and evidence synthesis about the effectiveness of implant prosthodontic therapy.

Influences of microgap and micromotion of implant-abutment interface on marginal bone loss around implant neck

OBJECTIVE

To review the influences and clinical implications of micro-gap and micro-motion of implant-abutment interface on marginal bone loss around the neck of implant.

DESIGN

Literatures were searched based on the following Keywords: implant-abutment interface/implant-abutment connection/implant-abutment conjunction, microgap, micromotion/micromovement, microleakage, and current control methods available. The papers were then screened through titles, abstracts, and full texts.

RESULTS

A total of 83 studies were included in the literature review. Two-piece implant systems are widely used in clinics. However, the production error and masticatory load result in the presence of microgap and micromotion between the implant and the abutment, which directly or indirectly causes microleakage and mechanical damage. Consequently, the degrees of microgap and micromotion further increase, and marginal bone absorption finally occurs. We summarize the influences of microgap and micromotion at the implant-abutment interface on marginal bone loss around the neck of the implant. We also recommend some feasible methods to reduce their effect.

CONCLUSIONS

Clinicians and patients should pay more attention to the mechanisms as well as the control methods of microgap and micromotion. To reduce the corresponding detriment to the implant marginal bone, suitable Morse taper or hybrid connection implants and platform switching abutments should be selected, as well as other potential methods.

Efficacy of Gutta-Percha and Polytetrafluoroethylene Tape to Microbiologically Seal the Screw Access Channel of Different Prosthetic Implant Abutments

PURPOSE

To evaluate in vitro, the efficacy of gutta-percha (GP) and polytetrafluoroethylene (PTFE) tape to act as a seal against the penetration of Escherichia coli through prosthetic implant abutments (PIA) with external hexagon (EH) and morse taper (MT) connections.

MATERIALS AND METHODS

120 sets of implant analogs with their respective PIA were used. 60 sets from each system were divided into four groups (n = 15): I - GP sealing; II - PTFE tape sealing; III - no sealing (NS) and IV - negative control. Microbiological challenge was performed by placing bacterial colonies inside the titanium PIA before screwing them into their respective analogs. Each set was immersed in 5 mL of BHI and incubated for 14 days with daily checks for contamination, according to the nutrient medium turbidity.

RESULTS

The type of seal used influenced microbial penetration at all evaluation times (p < 0.05). Compared to GP, PTFE led to an increase in turbidity and its effectiveness against microbial penetration was equivalent to group NS. When the sealing efficacy of each group was compared in terms of time, Cochran's Q test revealed that in the two groups sealed with PTFE, there was a progressive increase in the number of turbid nutrient media (p < 0.0001), while in the group sealed with GP, this was only observed in the MT system (p = 0.0310).

CONCLUSIONS

Sealing the PIA channel with GP was a significantly superior approach to sealing it with PTFE tape. PTFE tape or NS led to a progressive increase in microbiological leakage over time in PIA channels, however, this only occurred with GP in the MT system.

Health, Maintenance, and Recovery of Soft Tissues around Implants

BACKGROUND

The health of peri-implant soft tissues is one of the most important aspects of osseointegration necessary for the long-term survival of dental implants.

PURPOSE

To review the process of soft tissue healing around osseointegrated implants and discuss the maintenance requirements as well as the possible short-comings of peri-implant soft tissue integration.

MATERIALS AND METHODS

Literature search on the process involved in osseointegration, soft tissue healing and currently available treatment modalities was performed and a brief description of each process was provided.

RESULTS

The peri-implant interface has been shown to be less effective than natural teeth in resisting bacterial invasion because gingival fiber alignment and reduced vascular supply make it more vulnerable to subsequent peri-implant disease and future bone loss around implants. And we summarized common procedures which have been shown to be effective in preventing peri-implantitis disease progression as well as clinical techniques utilized to regenerate soft tissues with bone loss in advanced cases of peri-implantitis.

CONCLUSION

Due to the difference between peri-implant interface and natural teeth, clinicians and patients should pay more attention in the maintenance and recovery of soft tissues around implants.

Interventions for replacing missing teeth: maintaining and recovering soft tissue health around dental implants

BACKGROUND

It is important to institute an effective supportive therapy to maintain or recover soft tissue health around dental implants. Different maintenance regimens have been suggested, however it is unclear which are the most effective.

OBJECTIVES

To assess the effects of different interventions for 1) maintaining and 2) recovering soft tissue health around osseointegrated dental implants.

SEARCH STRATEGY

We searched the Cochrane Oral Health Group's Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and EMBASE. Handsearching included several dental journals. We checked the bibliographies of the identified randomised controlled trials (RCTs) and relevant review articles for studies outside the handsearched journals. We wrote to authors of all identified RCTs, to more than 55 oral implant manufacturers and to an Internet discussion group to find unpublished or ongoing RCTs. No language restrictions were applied. The last electronic search was conducted on 2 June 2010.

SELECTION CRITERIA

All randomised controlled trials comparing agents or interventions for maintaining or recovering healthy tissues around dental implants.

DATA COLLECTION AND ANALYSIS

Screening of eligible studies, assessment of the methodological quality of the trials and data extraction were conducted in duplicate and independently by two review authors. Results were expressed as random-effects models using standardised mean differences for continuous data and risk ratios for dichotomous data with 95% confidence intervals.

MAIN RESULTS

Five trials compared interventions for maintaining soft tissue health around implants and a further six trials compared interventions to recover soft tissue health where there was evidence of peri-implant mucositis. No statistically significant differences were found between the effectiveness of powered versus manual toothbrushes for either maintaining or recovering soft tissue health. There was no statistically significant difference found between different types of self administered antimicrobials for maintaining soft tissue health (hyaluronic acid gel compared to chlorhexidine gel, amine fluoride/stannous fluoride mouthwash compared to chlorhexidine mouthwash) and triclosan dentifrice compared to sodium fluoride dentifrice showed no statistically significant difference in recovering soft tissue health. However chlorhexidine irrigation was more effective in reducing plaque and marginal bleeding scores compared to chlorhexidine mouthwash and Listerine mouthwash was found to be statistically significantly better than placebo with regard to reducing mean plaque scores and marginal bleeding scores. When interventions administered by dental professional were compared there was no statistically significant difference found between chlorhexidine and physiologic solutions as irrigants at second stage surgery to maintain health of soft tissues. In patients with peri-implant mucositis two trials evaluated interventions performed by dental professionals. There was no statistically significant difference between mechanical debridement followed by either minocycline or chlorhexidine gel, or between debridement with a titanium curette compared to an ultrasonic debridement tool.

AUTHORS' CONCLUSIONS

There was only low quality evidence for which are the most effective interventions for maintaining or recovering health of peri-implant soft tissues. The included RCTs had short follow-up periods and few subjects and although overall the risk of bias of the studies was either low or unclear, only single trials were available for each outcome. There was no reliable evidence as to which regimens are most effective for long term maintenance. This should not be interpreted as meaning that current maintenance regimens are ineffective. There was weak evidence that antibacterial mouthrinses are effective in reducing plaque and marginal bleeding around implants. More RCTs should be conducted in this area. In particular, there is a definite need for trials powered to find possible differences, using primary outcome measures and with much longer follow up. Such trials should be reported according to the CONSORT guidelines (www.consort-statement.org/).

Interventions for replacing missing teeth: maintaining and recovering soft tissue health around dental implants

BACKGROUND

It is important to institute an effective supportive therapy to maintain or recover soft tissue health around dental implants. Different maintenance regimens have been suggested, however it is unclear which are the most effective.

OBJECTIVES

To test the null hypotheses of no difference between different interventions (1) for maintaining healthy peri-implant soft tissues, and (2) for recovering soft tissue health, against the alternative hypothesis of a difference.

SEARCH STRATEGY

We searched the Cochrane Oral Health Group's Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and EMBASE. Handsearching included several dental journals. We checked the bibliographies of the identified randomised controlled trials (RCTs) and relevant review articles for studies outside the handsearched journals. We wrote to authors of all identified RCTs, to more than 55 oral implant manufacturers and to an internet discussion group to find unpublished or ongoing RCTs. No language restrictions were applied. The last electronic search was conducted on 13 June 2007.

SELECTION CRITERIA

All randomised controlled trials comparing agents or interventions for maintaining or recovering healthy tissues around dental implants.

DATA COLLECTION AND ANALYSIS

Screening of eligible studies, assessment of the methodological quality of the trials and data extraction were conducted in duplicate and independently by two review authors. Results were expressed as random-effects models using standardised mean differences for continuous data and risk ratios for dichotomous data with 95% confidence intervals.

MAIN RESULTS

Eighteen RCTs were identified. Nine of these trials, which reported results from a total of 238 patients, were included. Follow ups ranged between 6 weeks and 1 year. No meta-analysis could be made since every RCT tested different interventions. Listerine mouthwash showed a reduction of 54% in plaque and 34% in marginal bleeding compared with a placebo. Two trials evaluated the efficacy of powered and sonic toothbrushes compared to manual toothbrushing and showed no statistically significant differences, though more patients liked the sonic brush. No statistical differences were found between brushing with a hyaluronic or a chlorhexidine gel, between cleaning with an etching gel or manually, between injecting a chlorhexidine or a physiologic solution inside the implant's inner part and between submucosal minocycline and a chlorhexidine gel. When an amine fluoride/stannous fluoride (AmF/SnF(2)) mouthrinse was compared with a chlorhexidine one, no statistically significant differences were found for implant failures and staining index while patients preferred and had less taste change with the AmF/SnF(2) mouthrinse. Self administered subgingival chlorhexidine irrigation resulted in statistically significantly lower plaque and marginal bleeding than a chlorhexidine mouthwash, however the mouthwash was given at a suboptimal dosage.

AUTHORS' CONCLUSIONS

There was only little reliable evidence for which are the most effective interventions for maintaining or recovering health of peri-implant soft tissues. The included RCTs had short follow-up periods and few subjects. There was not any reliable evidence for the most effective regimens for long term maintenance. This should not be interpreted as current maintenance regimens are ineffective. There was weak evidence that Listerine mouthwash, used twice a day for 30 seconds, as an adjunct to routine oral hygiene, is effective in reducing plaque and marginal bleeding around implants. More RCTs should be conducted in this area. In particular, there is a definite need for trials powered to find possible differences, using primary outcome measures and with much longer follow up. Such trials should be reported according to the CONSORT guidelines (http://www.consort-statement.org/).

In vitro sealing ability of two materials at five different implant-abutment surfaces

BACKGROUND

The aim of the present study was to test the sealing ability of two materials at five different implant-abutment surfaces.

METHODS

In the first phase, 2 mul brain-heart infusion (BHI) broth was deposited into the implant wells and glass culture tubes. A varnish or silicon sealant was applied at the cervical implant portion of experimental groups. The control group remained unexposed. The abutments were torque-tightened to 20 Ncm with a manual torque driver. Implants were immersed in 4 ml BHI broth at 37 degrees C for 2 hours to exclude contamination. In the second phase, 100 mul Enterococcus faecalis American Type Culture Collection (ATCC) strain 29212 was deposited into the glass culture tubes. After periods of 7, 14, 21, 35, 49, and 63 days, the sealing capacity was checked. Abutments were removed, and a sterile paper cone collected material inside implant bodies. This material was transferred to new tubes with BHI to verify the presence of cloudy broths within 24 to 48 hours.

RESULTS

There were no statistically significant differences between the two materials for each time period (Fisher exact test; P >0.05). Group E showed the least level of sealing ability (six implants contaminated), whereas group T showed the highest level (only two implants).

CONCLUSIONS

1) Materials tested were not able to prevent contamination over 63 days. 2) Bacterial contamination was verified after 14 and 35 days in the control and experimental groups, respectively. 3) Although materials tested had demonstrated similar sealing capacities, dental implants showed bacterial contamination regardless of their external or internal hexagonal configurations.