Comparison of peri-implant clinical and radiographic status around short (6 mm in length) dental implants placed in cigarette-smokers and never-smokers: Six-year follow-up results

The Effect of Nicotine-Containing Products on Peri-Implant Tissues: A Systematic Review and Network Meta-Analysis

INTRODUCTION

Smokers have a higher chance of developing peri-implant diseases and are therefore considered an at-risk population. Our aim was to compare peri-implant characteristics in users of electronic cigarettes (EC), waterpipes (WP), cigarettes (CS), smokeless tobacco (ST), and nonsmokers (nonusers of any nicotine and tobacco product; NS).

AIMS AND METHODS

A systematic search of four electronic databases (PubMed, EMBASE, Web of Science, and CENTRAL) was performed until April 2023, restricted to English language. Thirty-nine observational studies were included in the qualitative synthesis, of which 32 studies were included in a Bayesian network meta-analysis. Using a predesigned form, two researchers independently collected data about marginal bone loss (MBL), probing pocket depth (PPD), plaque index, bleeding on probing, modified plaque index, probing pocket depth > 4 mm (PPD > 4), gingival index, peri-implant sulcular fluid volume, and TNF-α and IL-1β levels. QUIPS and CINeMA were used to evaluate the risk of bias and certainty of evidence.

RESULTS

Nonsmokers had the smallest MBL. Most nicotine-containing product users had significantly higher MBL (CS, mean difference [MD]: 1.34 credible interval [CrI]: 0.85, 1.79; WP, MD: 1.58 CrI: 0.84, 2.35; ST, MD: 2.53, CrI: 1.20, 3.87) than NS. Electronic cigarettes did not show significant difference compared to NS (MD: 0.52 CrI: -0.33, 1.36). In secondary outcomes, NS were ranked in first place. Subset analysis based on smoking habit, implant duration, and maintenance control revealed no differences in ranking probability.

CONCLUSIONS

Most nicotine-containing product users presented worse peri-implant parameters compared to NS, while EC users did not show significant differences to NS in many outcomes.

IMPLICATIONS

Alternative nicotine-containing products are gaining popularity and are often considered less harmful by the general public compared to traditional cigarettes. This is the first network meta-analysis comparing users of four nicotine-containing products and NS. This study shows that CS, WP, and ST have a detrimental effect on the overall health of peri-implant tissues. EC users also presented inferior parameters compared to NS; however, the difference was not significant in many outcomes. It is essential to educate patients who are using nicotine-containing products, and to provide proper maintenance and appropriate cessation support. Well-designed multiarmed studies are needed for direct comparison of different products, including heated tobacco products. Greater transparency of confounding factors is needed regarding smoking habit and oral hygiene.

Clinical Evaluation of Short Tuberosity Implants among Type 2 Diabetic and Non-Diabetic Patients: A 5 Year Follow-Up

Aim: To assess clinical and radiographic parameters including bleeding on probing (BoP); probing depth (PD), plaque index (PI) and crestal bone loss (CBL) around short tuberosity implants (STI) supporting fixed partial dentures in patients with Type 2 diabetes mellitus (T2DM) and non-diabetics. Material and Methods: Participants with T2DM and without T2DM with at least one STI (6 mm) posteriorly restored with a fixed partial denture splinting premolar implant were included. A questionnaire collected demographic details including gender, age, duration of diabetes, habits of brushing, the total number of dental implants and location, implant loading after placement, restoration type, and family history of DM. Clinical and radiographic assessment of peri-implant parameters, i.e., bleeding on probing (BoP), probing depth (PD), plaque index (PI), and crestal bone loss (CBL) was performed. The restorative success of STI was determined by no sensation of the foreign body, lack of pain and dysesthesia, lack of infection, no radiolucency around the implant, and no mobility. The Kruskal-Wallis test was used for statistical analysis. A p-value of less than 0.05 was considered statistically significant. Results: Twenty-five T2DM (19 males and 6 females) and 25 non-diabetic (18 males and 7 females) participants were included. The number of STIs in T2DM was 41, whereas in non-diabetic it was 38. At 1 year follow-up, mean PI% in T2DM participants was 18.9% (19.2-21.4%) and in non-diabetics it was 17.6% (16.3-18.5%). The mean PD was recorded in diabetics (1.3 ± 5.0 mm) and non-diabetics (1.1 ± 3.2 mm). The BoP value in diabetics was 44.9% (39.8-46.4%) and 28.2% in non-diabetics (17.2-24.6%). At 5 years of follow-up, the mean PI% range in T2DM participants was 26.18% (25.4-29.1%) and 24.42% in non-diabetic (20.1-25.5%). The mean PD in millimeters around STI in T2DM was observed to be 2.3 ± 4.8 mm and 1.4 ± 3.4 mm in non-diabetics. In addition, BoP in diabetic participants was 39.54% (27.7-42.1%) and 24.42% in non-diabetics (20.1-25.5%). A total of six STIs failed, i.e., two in the non-diabetic and four in the T2DM group. Conclusions: Patients with T2DM have poor periodontal (BoP, PD, CBL) and restorative peri-implant parameters around STIs when compared to healthy (non-diabetic) participants at five years of follow-up. For long-term stability, glycemic control is pivotal along with following good plaque control.

A prospective, multicentre study of 6-mm short implants in posterior alveolar bone supporting splinted crowns: A 5-year follow-up study

AIM

To evaluate the clinical and radiographic outcomes of 6-mm short implants, placed in the posterior jaws and supporting splinted crowns, at 5 years after early loading.

MATERIALS AND METHODS

Forty-five patients with 95 implants (diameter: 4 mm; length: 6 mm) were enrolled at three centres. Two to three implants were placed in either the maxillary or the mandibular posterior region in each patient and restored with screw-retained splinted crowns at 6 weeks later. Clinical and radiographic outcomes were evaluated at implant placement, at loading, and at 6, 12, 24, 36, and 60 months after loading. Biological and mechanical complications were recorded. Marginal changes in bone level in relation to clinical parameters were evaluated using a generalized linear mixed model.

RESULTS

During the 5 years of follow-up, the mean change in the marginal bone level (MBL) was 0.04 ± 0.14 mm. Four implants in four patients were lost before loading, one implant in one patient was lost at the 5-year follow-up, and two patients were lost to follow-up. The survival and success rates were 88.4% (38/43) at the patient level. The incidence rates of peri-implant mucositis and peri-implantitis were 29.4% and 7.0%, respectively. The rate of technical complications was 14.0%.

CONCLUSIONS

Over a 5-year period, 6-mm short implants supporting early loaded splinted crowns in maxillary or mandibular posterior regions showed stable MBLs and acceptable technical and biological complication rates.

Long-term effectiveness of 6 mm micro-rough implants in various indications: A 4.6- to 18.2-year retrospective study

Objectives

To evaluate the long‐term effectiveness of 6 mm implants in various indications with a micro‐rough surface after 4.6–18.2 years in function and to assess key factors associated with implant survival, success, and biologic/technical complications.

Materials and methods

Fifty‐five patients with seventy‐four 6 mm implants placed from 2000 to 2013 attended the re‐examination assessing well‐established clinical and radiographic parameters, biologic and prosthetic complications, and patient‐reported outcome measures.

Results

Five implants were lost after a mean follow‐up period of 9.1 years resulting in a survival rate of 93.2%. All losses occurred in free‐end situations in the mandible. Smoking habit significantly reduced implant survival (hazard ratio 36.25). Two implants exhibited a history of peri‐implantitis, and one implant showed progressive marginal bone loss (MBL) resulting in a success rate of 89.2%. The mean MBL amounted to 0.029 mm. Increased MBL was found for implants placed in the maxilla (0.057 mm) and for implants with a diameter of 4.1 mm (0.043 mm). Soft tissue thickness (1.39 mm) and width of keratinized mucosa (1.91 mm) had no effect on MBL. Patient‐reported outcome measures showed high satisfaction (mean VAS scores 88%) and high quality of life (mean OHIP‐G14 score 2.2).

Conclusion

The present study demonstrated survival and success rates of 93.2% and 89.2% for 6 mm implants used in various indications. A factor leading to higher implant failure was smoking, whereas modulating factors increasing annual MBL included implants placed in the maxilla and implants with a diameter of 4.1 mm compared to 4.8 mm.

Clinical, radiographic and restorative parameters for short tuberosity implants placed in smokers: a retrospective study with 5 year follow-up

This study aimed to estimate and compare the clinical, radiographic, and restorative parameters around short tuberosity implants (STIs) placed in cigarette smokers (CS) and never smokers (NS). In this 60-month follow-up retrospective study, a total of 50 (37 males + 13 females) individuals who had received 82 dental implants were included. These participants were categorized into two groups as follows: (i) Group-1: 25 self-reported systemically healthy CS with 43 STIs; and (ii) Group-2: 25 self-reported systemically healthy NS with 39 STIs. In both groups, peri-implant plaque index (PI), probing depth (PD), bleeding on probing (BOP), and crestal bone loss (CBL) and restorative parameters were measured at 12 and 60 months of follow-up. Group comparisons were performed utilizing the Kruskal-Wallis test. The significance level was set at p < 0.05. In CS and NS, the mean age of participants was 58.5 and 60.7 years, respectively. No statistically significant differences were observed in the overall mean levels of PD and CBL around STIs among CS and NS. However, a statistically significant increase was observed in the mean scores of BOP and PI around STIs in the NS and CS at 12 and 60 months follow-up, respectively. In both groups, the loosening of the implant was the most frequently encountered type of STI failure. The outcomes of the present study suggest that STIs placed in maxillary tuberosity can show reliable clinical, radiographic, and restorative stability among cigarettes smokers and non-smokers. However, the role of smoking status and oral hygiene cannot be disregarded in this scenario.

Prevalence and risk indicators for peri-implant diseases: A literature review

Peri-implant diseases are known as undesirable conditions that can occur after implant therapy. Although several risk indicators are becoming clear, the causes of peri-implant diseases have not been completely investigated. The purpose of this review was to summarize the prevalence and risk indicators for peri-implant diseases by referring to current papers from various angles. Many studies have reported the varied prevalence of peri-implant mucositis (23.9%-88.0% at the patient level and 9.7%-81.0% at the implant level) and peri-implantitis (8.9%-45% at the patient level and 4.8%-23.0% at the implant level). Additionally, several studies concluded that poor oral hygiene and lack of regular maintenance were strongly correlated with the development of both peri-implant mucositis and peri-implantitis. Diabetes and a history of periodontitis were revealed as risk indicators for peri-implantitis. However, there was no definitive conclusion about the correlations between peri-implant diseases and other factors such as smoking, the shape of the implant superstructure, and the condition of the keratinized mucosa. Further studies useful for evidence-based decision-making are needed for predictable implant therapy in the long term.

Survival Rates of Splinted and Nonsplinted Prostheses Supported by Short Dental Implants (≤8.5 mm): A Systematic Review and Meta-Analysis

PURPOSE

To evaluate and compare the implant survival rates, marginal bone loss, and mechanical complications of prostheses supported by splinted and nonsplinted short implants (≤8.5 mm).

MATERIAL AND METHODS

Electronic database (MEDLINE, CENTRAL, Web of Science, and EMBASE) and manual searches up to May 2021 were conducted to identify studies comparing splinted and nonsplinted short implants (≤8.5 mm). The primary outcome was implant survival rate. Secondary outcomes were marginal bone loss and mechanical complications. The quality of included studies and risk-of-bias were assessed according to the Newcastle-Ottawa Scale. A random-effects model was used to analyze the data.

RESULTS

Twelve studies fulfilled the inclusion criteria and featured 1506 short implants (596 nonsplinted and 910 splinted) with a follow-up time ranging from 1 to 16 years. Quantitative analysis found no statistically significant differences between splinted and nonsplinted short implants (≤8.5 mm) for survival rate (RR = 0.98; 95% CI 0.96, 1.01; p = 0.26)) and marginal bone loss (SMD = -0.08; 95% CI - 0.23, 0.07; p = 0.28). Veneer chipping, abutment screw breakage, screw loosening, and loss of retention were reported in the selected studies as common complications. However, no statistically significant difference was found between splinted and nonsplinted short implants (RR = 0.56; 95% CI 0.20, 1.54; p = 0.26).

CONCLUSIONS

Within the limitations of the present meta-analysis, it might be concluded that splinted short implants (≤8.5 mm) do not present superior performance in survival rate, marginal bone maintenance and prevention of mechanical complications compared with single-unit prostheses.

Prevalence of early and late oral implant loss among smokers: a nationwide survey in Japan

A cross-sectional, nationwide survey was conducted in Japan to examine the relationship between tobacco smoking and oral diseases including implant failure. A questionnaire survey was sent to designated facilities by post, and 158 answered questions regarding implant loss. Smoking status, number of implant failures, and other related variables were collected from the participating dentists as secondary data. A total of 1966 patients who were treated with dental implants by participating dentists during the survey period were analysed. Among the total sample, 90 (5%) had early implant loss (≤12 months) and 153 (8%) had late implant loss (>12 months and ≤120 months). The number of pack-years was significantly higher in the total (early and late) implant loss group (31.2±15.9) than in the group with no implant loss (26.1±18.1) (P=0.026). In the multivariate analysis, the number of implants installed, smoking, and pack-years were significant factors for total implant loss. The adjusted odds ratio for implant failure for current smokers compared with never smokers was 2.07 (95% CI 1.19-3.62) for early implant loss and 1.48 (95% CI 0.92-2.37) for late implant loss. This study reaffirms that current smoking is associated with an increased risk of early implant loss, irrespective of the duration of smoking exposure.

Assessment of Peri-Implant Soft Tissues Conditions around Short and Ultra-Short Implant-Supported Single Crowns: A 3-Year Retrospective Study on Periodontally Healthy Patients and Patients with a History of Periodontal Disease

The aim of this retrospective study was to evaluate implant survival, marginal bone loss and peri-implant complications in 326 short and ultra-short implants. Implants were placed in the maxillary and mandibular posterior regions of 140 patients with (PP) and without (NPP) a history of periodontal disease. Clinical and radiographic examinations were performed at 3-year recall appointments. The 8.0, 6.0 and 5.0 mm-length implants placed in PP and NPP were respectively 43.75% and 38.46%, 35.10% and 34.19%, 21.15% and 27.35%; 325 implants (one early failure) were rehabilitated with single crowns in 139 patients. Overall implant survival after 3 years of follow-up was 97.55%, 98.08% and 96.61% for PP and NPP (p = 0.46). Crestal bone level variations were not statistically different among PP and NPP; 15.41% of implants presented signs of mucositis, 14.71% and 16.67% in PP and NPP (p = 0.64). Setting the threshold for bone loss at 2 mm after 36 months, peri-implantitis prevalence was 2.2%, 1.96% and 2.63% in PP and NPP (p = 0.7). Overall implant success was 82.39%, 83.33% and 80.7% for PP and NPP (p = 0.55). Short-term outcomes suggest that short and ultra-short locking-taper implants can successfully be restored with single crowns in the posterior jaws both in PP and NPP.

Clinical peri-implant health and biological bone marker levels in tobacco users treated with photodynamic therapy

BACKGROUND

What impact does tobacco smoking have on photodynamic therapy (PDT) outcome is still unknown. The aim of the present clinical trial was to evaluate the clinical, radiographic, and biological bone markers after provision of PDT in cigarette, e-cigarette, and never-smokers with peri-implantitis (PI) at 6 months post treatment.

MATERIALS AND METHODS

Twenty-five healthy patients with PI were divided into three groups: Group I: cigarette smokers; Group II: e-cigarettes users; Group III: never-smokers. Full-mouth mechanical debridement with adjunctive methylene blue-mediated PDT was performed. Clinical recordings included peri-implant plaque index (Pi), bleeding on probing (BOP) and probing depth (PD). Peri-implant sulcular fluid was collected for the assessment of biological bone biomarkers including receptor activator of nuclear factor-ligand (RANK-L) and osteoprotegrin (OPG). All assessments were performed at baseline, 3 months and 6 months. P-value of <0.05 was considered significant.

RESULTS

BOP in Group II and III significantly reduced at 3 months (p < 0.05). Group I showed significant reduction only at 6 months (p < 0.05). Mean PD showed no statistically significant difference between the groups at any time-point. Inter-group comparison showed Group III demonstrating statistically significantly reduced mean RANK-L levels at both 3 and 6 months (p < 0.05). A slight increase in the OPG levels were observed at 3 months and followed by a slight decrease at 6 months for all the study groups when compared with baseline values, however, these values did not show statistical significance (p > 0.05).

CONCLUSION

Adjunctive PDT helped in reducing the clinical peri-implant inflammation. However, no significant change was observed for biological bone biomarkers among tobacco smokers.

Influence of crown-to-implant ratio and different prosthetic designs on the clinical conditions of short implants in posterior regions: A 4-year retrospective clinical and radiographic study

BACKGROUND

Short implants (intra-bony length ≤ 8 mm) are generally considered as an alternative to bone augmentation in challenging situations; however, clinical evidence from large-scale studies with long follow-up regarding the application of short implants remains deficient.

PURPOSE

The present study aimed to assess the mid-term clinical outcomes of short implants supporting fixed prostheses in the posterior region, and to investigate the effects of the crown-to-implant ratio (C/I), and other patient-, implant-, prosthesis-relevant factors on the clinical conditions around short implants.

MATERIALS AND METHODS

180 Thommen short implants in 130 partially edentulous patients were enrolled in the study after 3 to 7 (mean 4.2) years of follow-up. Potential risk factors (patient sex and age, implant diameter and location, splinted vs single-tooth restorations, retention mode, anatomical and clinical C/I ratios) were evaluated according to the following outcomes: Implant survival, marginal bone loss (MBL), and mechanical and biological complications.

RESULTS

In total, four implants in four patients failed as a result of peri-implantitis. The cumulative survival rate was 97.8% for implant-based analysis. The peri-implant MBL around 180 short implants was 0.90 ± 0.78 mm. The mean clinical C/I ratio was 1.16 ± 0.36. Correlation analysis revealed that the influence of the clinical C/I ratio and patient age were significant for MBL (P < .05), whereas other potential risk factors showed no significant association with the outcome. Among 180 short implants, 24 cases (13.3%) had biological complications and 32 cases (17.8%) had mechanical complications, respectively. Peri-implant MBL and complication rates around splinted and non-splinted implants were not statistically different.

CONCLUSION

Within the limitations of this study, short implants supporting fixed prostheses in the posterior region achieved predictable clinical outcomes over a 3 to 7 year period. Within the range of 0.47 to 3.01, the higher the C/I ratio, the less the peri-implant MBL.

Risk indicators for marginal bone resorption around implants in function for at least 4 years: A retrospective longitudinal study

BACKGROUND

Marginal bone stability is considered one of the most important issues in implant dentistry. It is essential to understand how various factors influence bone resorption around implants. The purpose of this retrospective longitudinal study was to identify potential risk indicators associated with marginal bone resorption around implants in function for at least 4 years.

METHODS

Several systemic-related, intraoral-related, implant-related factors were collected. Marginal bone level change (MBLC) was determined by comparing intraoral radiographs taken at baseline (1 year after prosthesis delivery), and at follow-up (over 3 years from baseline). A hierarchical regression analysis using liner mixed-effects models was performed to examine correlations between MBLC and various factors.

RESULTS

Overall, 514 patients with 1535 implants were analyzed. The mean age of the participants was 62.9 years. Mean annual MBLC was 0.048 mm, and mean functional time was 5.96 years. The result showed that the following explanatory variables had significant effects on MBLC: functional time, plaque control record > 20%, Eichner index C1-3, maxilla, cement-retained superstructure, and keratinized mucosa width < 2 mm. We did not find statistically significant associations between bone resorption and some variables known as risk factors, such as diabetes, smoking, and history of periodontitis.

CONCLUSIONS

Within the limits of this study, longer functional time, poor oral hygiene, loss of occlusal support, location in the maxilla, cement-retained superstructure, and less keratinized mucosa should be considered as risk indicators for bone resorption around implants.