Effect of the implant apical exposure and coverage < or ≥ 2 mm bone graft on transcrestal sinus floor elevation: a 1- to 7-year retrospective cohort study

OBJECTIVES

This study aimed to analyze the effect of the apex coverage by the bone graft, including exposure and coverage less than or greater than 2 mm on implant survival rate and peri-implant bone and soft tissue remodeling.

MATERIALS AND METHODS

A total of 264 implants in 180 patients who had undergone transcrestal sinus floor elevation (TSFE) with simultaneous implant placement were included in this retrospective cohort study. Radiographic assessment was used to categorize the implants into three groups based on apical implant bone height (ABH): ≤ 0 mm, < 2 mm, or ≥ 2 mm. The implant survival rate, peri-implant marginal bone loss (MBL) during short-term (1-3 years) and mid- to long-term (4-7 years) follow-up, and clinical parameters were used to evaluate the effect of implant apex coverage after TSFE.

RESULTS

Group 1 had 56 implants (ABH ≤ 0 mm), group 2 had 123 implants (ABH > 0 mm, but < 2 mm), and group 3 had 85 implants (ABH ≥ 2 mm). There was no significant difference in the implant survival rate between groups 2 and 3 compared to group 1 (p = 0.646, p = 0.824, respectively). The MBL during short-term and mid- to long-term follow-up indicated that apex coverage could not be considered a risk factor. Furthermore, apex coverage did not have a significant effect on other clinical parameters.

CONCLUSIONS

Despite limitations, our study found that implant apex coverage by the bone graft, including exposure and coverage levels less than or greater than 2 mm, did not significantly affect implant survival, short-term or mid- to long-term MBL, or peri-implant soft tissue outcomes.

CLINICAL RELEVANCE

Based on 1- to 7-year data, the study suggests that implant apical exposure and coverage levels of less than or greater than 2 mm bone graft are both valid options for TSFE cases.

Limited marginal bone loss in implant-supported fixed full-arch rehabilitations after 5 years of follow-up

PURPOSE

The aim of the present study was to evaluate the 5-year results in terms of marginal bone level (MBL) around implants supporting fixed full-arch metal-ceramic restorations in a series of cases of patients who had lost their teeth in that dental arch because of severe periodontal disease.

MATERIAL AND METHODS

A retrospective cohort study was designed to evaluate the 5-year MBL results of OsseoSpeed™ Astra Tech TX implants with internal tapered conical connection. Age, gender, bone substratum, smoking habits, history of periodontitis, and prosthetic features were recorded. Mixed linear model was used to determine the influence of the different variables on MBL.

RESULTS

In this series, a total of 160 implants placed in 19 patients were evaluated. No implant failure was reported during the 5 years of follow-up. Only 14 (8.75%) implants had more than 2 mm of MBL. Abutment height, F(3,142) = 6.917, p < .001, and implant diameter, F(1,141) = 15.059, p < .001, were determined to be statistically associated with MBL. No other effect was significant. Pairwise comparisons showed that MBL was larger for abutment height = 1 (MBL = -0.987, SE = 0.186) compared with the remaining heights [-0.335 (0.171), -0.169 (0.192) and -0.247 (0.267), 2, 4 and 6 mm, respectively]. MBL was larger for narrow (-0.510, SE = 0.169) than for wide implants (-0.364, SE = 0.190).

CONCLUSION

The current study demonstrates that the vast majority of internal conical connection implants supporting fixed full-arch metal-ceramic restorations do not suffer from relevant MBL after 5 years in function. Particularly, those implants with transmucosal abutments longer than 2 mm show less than 0.5 mm from the implant shoulder to the marginal bone.

The benefit of antimicrobial photodynamic therapy to mechanical debridement in the treatment of smokers with peri-implant diseases: a systematic review and meta-analysis

Antimicrobial photodynamic therapy (aPDT) has been proposed as an adjunctive treatment strategy for peri-implant diseases. This systematic review aimed to determine whether aPDT as an adjunct to mechanical debridement has an additional benefit for smokers with peri-implant diseases. Randomized controlled trials (RCTs), which evaluated the clinical outcomes of mechanical debridement alone versus mechanical debridement + aPDT among smokers, were considered eligible to be included. The primary outcome was bleeding on probing (BOP) and secondary outcomes included probing depth (PD), plaque index (PI), and crestal bone loss (CBL). Meta-analyses using a random-effects model were conducted to calculate the mean difference (MD) with a 95% confidence interval (CI). The quality of evidence was assessed according to Grading of Recommendations Assessment, Development and Evaluation (GRADE). A total of four RCTs (188 participants) were included. The aPDT group showed significantly improved PD (MD =  - 1.26, 95% CI =  - 2.19 to - 0.32, p = 0.008) and PI (MD =  - 10.6%, 95% CI =  - 14.46 to - 6.74%, p = 0.0001) compared with mechanical debridement group at 3-month follow-up. No significant difference in bleeding on probing (BOP) was observed at 3-month follow-up (MD =  - 0.60%, 95% CI =  - 2.36 to 1.16%, p = 0.50). The subgroup analyses on photosensitizers demonstrated significant differences between the two groups on PD (MD =  - 1.23, 95% CI =  - 2.41 to - 0.05, p = 0.04) and PI (MD =  - 12.33, 95% CI =  - 14.74 to - 9.92, p < 0.00001) by the use of methylene blue (MB). Within the limitation of this study, compared with mechanical debridement alone, combined use of aPDT was more effective in reducing PD and PI in smokers at 3-month follow-up. MB was a predictable photosensitizer for aPDT. However, the findings should be interpreted with caution due to the limited number of included studies, methodological deficiencies, and heterogeneity between studies.

Platelet-Rich Fibrin Reduces IL-1β Release from Macrophages Undergoing Pyroptosis

Background: Pyroptosis is a catabolic process relevant to periodontal disorders for which interleukin-1β (IL-1β) inflammation is central to the pathophysiology of the disease. Despite platelet-rich fibrin (PRF) anti-inflammatory properties and its application to support periodontal regeneration, the capacity of PRF to modulate pyroptosis, specifically the production and release of IL-1β, remains unknown. The question arises whether PRF could regulate IL-1β release from macrophages in vitro. Methods: To answer this question, RAW 264.7 macrophages and primary macrophages obtained from murine bone marrow were primed with PRF before being challenged by lipopolysaccharide (LPS). Cells were then analysed for the pyroptosis signalling components by gene expression analyses and IL-1β secretion at the protein level. The release of mitochondrial reactive oxygen species (ROS) was also detected. Results: PRF lowered the LPS-induced expression of IL-1β and NLRP3 inflammasome, caspase-11 and IL-18 in primary macrophages, and IL-1β and caspase-11 in RAW 264.7 cells. Additionally, PRF diminished the secretion of IL-1β at the protein level in LPS-induced RAW 264.7 cells. This was shown through immunoassays performed with the supernatant and further confirmed by analysing the lysates of permeabilised cells. Furthermore, PRF reduced the ROS release provoked by LPS in RAW 264.7 cells. Finally, to enhance IL-1β release from the LPS-primed macrophages, we introduced a second signal with adenosine triphosphate (ATP). In this setting, PRF significantly reduced IL-1β release in RAW 264.7 cells and a trend to diminish IL-1β release in primary macrophages. Conclusion: These findings suggest that PRF can reduce IL-1β release and, at least in part, inhibit pyroptosis-related factors in LPS-challenged macrophages.

Association between liver cirrhosis and peri-implant diseases: a case-control study on implant- and patient-related risk factors

OBJECTIVE

The objective of this study was to evaluate the potential association between liver cirrhosis and peri-implant diseases, as well as the influence of different risk indicators on this association.

METHODS

This case-control study included 64 cases with liver cirrhosis and 128 controls without liver diseases that presented the same socio-demographic and economic profile. The specific inclusion criteria were the following: aged group of 35-55 years and presenting at least one osseointegrated implant functioning for >5 years. A full-mouth peri-implant and periodontal examination was performed and risk variables were recorded. The association between risk variables and the occurrence of peri-implant diseases was tested through univariate analysis and multivariate logistic regression, stratified by alcohol status. Additionally, a mediation analysis was performed to examine the mediating effect of age with peri-implantitis.

RESULTS

A high prevalence of peri-implantitis (29.7%) was observed among cases when compared to controls (18.0%). Individuals with cirrhosis presented ~2.5 higher chance of having peri-implantitis than controls (p<0.001). Significant variables associated with the occurrence of peri-implantitis in the final logistic model were the following: cirrhosis, alcohol use, age (>55 years), male sex, smoking, periodontitis, and number of ≤14.

CONCLUSIONS

An important risk association between liver cirrhosis and peri-implantitis was reported. Future studies with a larger sample size controlling for the patient- and implant-related confounders are needed to better understand the link between peri-implantitis and liver cirrhosis.

CLINICAL RELEVANCE

Cirrhosis individuals, age, and periodontitis, as well as alcohol use and smoking interaction, should be considered as potential risk indicators for peri-implantitis.

Long-Term Clinical Study of Implants Placed in Maxillary Sinus Floor Augmentation Using Beta-Tricalcium Phosphate

Introduction. The aim of this study was to show the long-term clinical outcomes of implants placed in maxillary sinus floor augmentation (MFSA) using beta-tricalcium phosphate (β-TCP). Patients and methods. Maxillary patients were diagnosed for MFSA and used beta- β-TCP. After the lateral sinus surgery, implants were loaded at 6 months with restorations. The clinical follow-up was at 10 years. Results. One hundred and one patients (58 females and 43 males) were treated with MFSA. Twenty-nine patients (28.7%) had a history of periodontitis. Thirty-three patients (32.7%) were smokers. One hundred and twenty-one MFSA, 81 unilateral and 20 bilateral sites, with 234 implants were performed. The average vertical bone height available was 4.92 ± 1.83 mm. The average vertical bone gain obtained was 6.95 ± 2.19 mm following MFSA. The implant cumulative survival rate was 97.2%. Three implants (1.3%) were lost during the healing period. Six implants (2.6%) were lost by peri-implantitis. One hundred and fifteen restorations were placed in the patients. Mean marginal bone loss was 1.93 mm ± 1.03 mm. Six patients (27.3%) showed technical complications. Thirty-six implants (15.3%) in 14 patients (13.9%) were associated with peri-implantitis. Conclusions. This study indicates that treatment with implant-supported restoration by MFSA using β-TCP constitutes a successful implant approach.

Risk factors, diagnosis and treatment of peri-implantitis: A cross-cultural comparison of U.S. and European periodontists' considerations

BACKGROUND

Peri-implantitis (PI) is a growing concern in the dental community worldwide. The study aimed to compare U.S. vs. European periodontists' considerations of risk factors, diagnostic criteria, and management of PI.

MATERIALS AND METHODS

393 periodontists from the U.S. and 100 periodontists from Europe (Germany, Greece, Netherlands) responded to anonymous surveys electronically or by mail.

RESULTS

Compared to U.S. periodontists, European respondents were younger, more likely to be female and placed fewer implants per month (9.12 vs. 13.90;p = 0.003). Poor oral hygiene, history of periodontitis, and smoking were considered as very important risk factors by both groups (rated >4 on 5-point scale). European periodontists rated poor oral hygiene (4.64 vs. 4.45;p = 0.005) and history of periodontitis (4.36 vs. 4.10;p = 0.006) as more important and implant surface (2.91 vs. 3.18;p = 0.023), occlusion (2.80 vs. 3.75;p<0.001) and presence of keratinized tissue (3.27 vs. 3.77;p<0.001) as less important than did U.S. periodontists. Both groups rated clinical probing, radiographic bone loss, and presence of bleeding and suppuration as rather important diagnostic criteria. They rated implant exposure/mucosal recession as relatively less important with U.S. periodontists giving higher importance ratings than European periodontists (3.99 vs. 3.54;p = 0.001). Both groups nearly always used patient education, plaque control and mechanical debridement when treating PI. U.S. periodontists were more likely to use antibiotics (3.88 vs. 3.07;p<0.001), lasers (2.11 vs. 1.68;p = 0.005), allograft (3.39 vs. 2.14;p<0.001) and regenerative approaches (3.57 vs. 2.56;p<0.001), but less likely to use resective surgery (3.09 vs. 3.53;p<0.001) than European periodontists.

CONCLUSIONS

U.S. and European periodontists' considerations concerning risk factors, diagnosis and management of PI were evidence-based. Identified differences between the two groups can inform future educational efforts. This article is protected by copyright. All rights reserved.

Periodontal and Implant Radiology

Dental radiography can be used to detect alveolar bone levels around periodontal and peri-implant structures. Periodontal radiographic images can assess alveolar bone height, periodontal ligament, furcation involvement, and evidence of bone destruction. Peri-implant radiographic images can assess the alveolar bone height in relation to the implant structure. As an adjunct to patient care, radiography can aid in the diagnosis of non-health.

Role of thin gingival phenotype and inadequate keratinized mucosa width (<2 mm) as risk indicators for peri-implantitis and peri-implant mucositis

BACKGROUND

There is growing evidence on the impact of thin gingival phenotype (TnP) and inadequate keratinized mucosa width (KMW <2 mm) around dental implants on peri-implant health. This study investigated the role of TnP and inadequate KMW (<2 mm) as risk indicators for peri-implantitis and mucositis and on dental patient-reported outcomes.

METHODS

Sixty-three patients with 193 implants (mean follow-up of 6.9 ± 3.7 years) were given a clinical and radiographic examination and a questionnaire to assess patient awareness of food impaction and pain/discomfort. Chi-squared tests and regression analysis for clustered data were used to compare outcomes.

RESULTS

Implants with TnP had a statistically higher prevalence of peri-implantitis (27.1% versus 11.3%; PR, 3.32; 95% confidence interval (CI), 1.64-6.72; P = 0.001) peri-implant mucositis (42.7% versus 33%; PR, 1.8; 95% CI, 1.12-2.9; P = 0.016) and pain/discomfort during oral hygiene (25% versus 5%; PR, 3.7; 95% CI, 1.06-12.96; P = 0.044) than thick phenotype. Implants with inadequate KMW had a statistically higher prevalence of peri-implantitis (24.1% versus 17%; PR, 1.87; 95% CI, 1.07-3.25; P = 0.027) and peri-implant mucositis (46.6% versus 34.1%; PR, 1.53; 95% CI, 1-2.33; P = 0.05) and pain/discomfort during oral hygiene (28% versus 10%; PR, 2.37; 95% CI, 1.1-5.1; P = 0.027) than the adequate KMW. TnP was strongly associated with inadequate KMW (PR = 3.18; 95% CI, 1.69-6.04; P <0.001).

CONCLUSION

TnP and inadequate KMW (<2 mm) may be significant risk indicators for peri-implant disease and pain/discomfort during brushing.

Removable denture is a risk indicator for peri-implantitis and facilitates expansion of specific periodontopathogens: a cross-sectional study

Background

The prevalence of peri-implantitis ranges between 7 and 38.4% depending on risk indicators such as smoking, diabetes mellitus, lack of periodontal maintenance program, and history or presence of periodontitis. Currently, the possible effect of the type of superstructure on peri-implant health is unclear. This cross-sectional study aims to investigate the influence of the superstructure on the prevalence of peri-implant mucositis, peri-implantitis and peri-implant dysbiosis.

Methods

During a 32-month recruitment period dental implants were assessed to diagnose healthy peri-implant tissues, mucositis or peri-implantitis. The study included 1097 implants in 196 patients. Out of all peri-implantitis cases 20 randomly chosen submucosal biofilms from implants with fixed denture (FD) originating from 13 patients and 11 biofilms from implants with removable dentures (RD) originating from 3 patients were studied for microbiome analysis. Composition of transcriptionally active biofilms was revealed by RNAseq. Metatranscriptomic profiles were created for thirty-one peri-implant biofilms suffering from peri-implantitis and microbiome changes associated with superstructure types were identified.

Results

16.41% of the implants were diagnosed with peri-implantitis, 25.00% of implants with RD and 12.68% of implants with FD, respectively. Multivariate analysis showed a significant positive association on patient (p =  < 0.001) and implant level (p = 0.03) between the prevalence of peri-implantitis and RD. Eight bacterial species were associated either with FD or RD by linear discriminant analysis effect size method. However, significant intergroup confounders (e.g. smoking) were present.

Conclusions

Within the limitations of the present work, RDs appear to be a risk indicator for peri-implantitis and seem to facilitate expansion of specific periodontopathogens. Potential ecological and pathological consequences of shift in microbiome from RDs towards higher activity of Fusobacterium nucleatum subspecies animalis and Prevotella intermedia require further investigation.

Influence of marginal bone resorption on two mini implant-retained mandibular overdenture: An in vitro study

PURPOSE

To investigate the biomechanical effect of marginal bone resorption (MBR) on the mandibular mini implant (MI)-retained overdenture (MI-OD) on the edentulous model.

MATERIALS AND METHODS

The experimental mandibular edentulous model was modified from a commercial model with 2 mm thick artificial soft tissue under denture base. Two MIs (Φ2.6 mm × 10 mm) were bilaterally placed between the lateral incisor and the canine area and attached with magnetic attachments. Three groups were set up as follows: 1) alveolar bone around the MI without MBR (normal group), 2) with MBR to 1/2 the length of the implant (resorption group), and 3) complete denture (CD) without MI (CD group). Strain around the MI, pressure near the first molar area, and displacement of denture were simultaneously measured, loading up to 50 N under bilateral/unilateral loading. Statistical analysis was performed using independent-samples t test and one-way ANOVA (α=.05).

RESULTS

The strain around the MI with MBR was approximately 1.5 times higher than that without MBR. The pressure in CD was higher than in MI-ODs (P <.05), while there was no statistical difference between the normal and resorption group (P >.05). Similarly, the CD demonstrated a greater displacement of the denture base than did the MI-ODs during bilateral and unilateral loadings (P <.05).

CONCLUSION

The strain around the MI with MBR was approximately 1.5 times higher than that without MBR. The pressure on posterior alveolar ridge and denture displacement of MI-ODs significantly decreased compared to CDs, even when MBR occurs. Bilateral balanced occlusion was recommended for MI-ODs, especially when MBR occurred.

In vitro Interactions between Streptococcus intermedius and Streptococcus salivarius K12 on a Titanium Cylindrical Surface

Peri-implantitis is a steadily rising disease and is caused by oral bacterial pathogens able to form biofilm on implant surfaces and peri-implant tissues, making antibiotics treatment less effective. The use of commercial probiotics against oral pathogens could serve as an alternative to prevent biofilm formation. Streptococcus intermedius is one of the early colonizers of biofilm formation in dental implants. The aim of this study was to model the interaction between S. intermedius and Streptococcus salivarius strain K12, a probiotic bacterium producing bacteriocins. S. intermedius was co-cultured with S. salivarius K12 in an in vitro model simulating the biofilm formation in a dental implant composed by a titanium cylinder system. Biofilm formation rate was assessed by Real-Time PCR quantification of bacterial count and expression levels of luxS gene, used in response to cell density in the biofilm. Biofilm formation, bacteriocin production, luxS expression patterns were found to be already expressed within the first 12 h. More importantly, S. salivarius K12 was able to counter the biofilm formation in a titanium cylinder under the tested condition. In conclusion, our dental implant model may be useful for exploring probiotic-pathogen interaction to find an alternative to antibiotics for peri-implantitis treatment.

Risk indicators for mucositis and peri-implantitis: results from a practice-based cross-sectional study

Purpose

This practice-based cross-sectional study aimed to investigate whether common risk indicators for peri-implant diseases were associated with peri-implant mucositis and peri-implantitis in patients undergoing supportive implant therapy (SIT) at least 5 years after implant restoration.

Methods

Patients exclusively restored with a single implant type were included. Probing pocket depth (PPD), bleeding on probing (BOP), suppuration, and radiographic bone loss (RBL) were assessed around implants. The case definitions were as follows: peri-implant mucositis: PPD ≥4 mm, BOP, no RBL; and peri-implantitis: PPD ≥5 mm, BOP, RBL ≥3.5 mm. Possible risk indicators were compared between patients with and without mucositis and peri-implantitis using the Fisher exact test and the Wilcoxon rank-sum test, as well as a multiple logistic regression model for variables showing significance (P<0.05).

Results

Eighty-four patients with 169 implants (observational period: 5.8±0.86 years) were included. A patient-based prevalence of 52% for peri-implant mucositis and 18% for peri-implantitis was detected. The presence of 3 or more implants (odds ratio [OR], 4.43; 95 confidence interval [CI], 1.36-15.05; P=0.0136) was significantly associated with an increased risk for mucositis. Smoking was significantly associated with an increased risk for peri-implantitis (OR, 5.89; 95% CI, 1.27-24.58; P=0.0231), while the presence of keratinized mucosa around implants was associated with a lower risk for peri-implantitis (OR, 0.05; 95% CI, 0.01-0.25; P<0.001).

Conclusions

The number of implants should be considered in strategies to prevent mucositis. Furthermore, smoking and the absence of keratinized mucosa were the strongest risk indicators for peri-implantitis in patients undergoing SIT in the present study.

Tobacco-product usage as a risk factor for dental implants

The oral cavities of tobacco smokers and users of smokeless tobacco products are exposed to high concentrations of nicotine. A limited number of animal studies have assessed the effect of nicotine on osseointegration. Results from experimental studies have reported a statistically significant decrease, at 4 weeks of follow-up, in bone-to-implant contact among rats exposed to nicotine compared with unexposed rats. Nicotine increases the production of inflammatory cytokines (such as interleukin-6 and tumor necrosis factor-alpha) by osteoblasts. Waterpipe, pipe, and cigarette smokers are at increased risk of developing oral cancer, periodontal disease, and alveolar bone loss. One explanation for this is that smokers (regardless of the type of tobacco product) are exposed to similar chemicals, such as nicotine, tar, oxidants, polyaromatic hydrocarbons, and carbon monoxide. Moreover, raised levels of proinflammatory cytokines have been identified in the gingival crevicular fluid of cigarette smokers with peri-implant diseases. Therefore, it is hypothesized that nicotine and chemicals in tobacco smoke induce a state of oxidative stress in peri-implant tissues (gingiva and alveolar bone), thereby increasing the likelihood of peri-implant disease development via an inflammatory response, which if left uncontrolled, will result in implant failure/loss. In this regard, tobacco smoking (including cigarettes, waterpipe, and pipe) is a significant risk factor for peri-implant diseases. The impact of vaping electronic cigarettes using nicotine-containing e-juices remains unknown. Habitual use of smokeless tobacco products is associated with oral inflammatory conditions, such as oral precancer, cancer, and periodontal disease. However, the effect of habitual use of smokeless tobacco products on the success and survival of dental implants remains undocumented.

Host response and peri-implantitis

Considering the absence of predictable and effective therapeutic interventions for the treatment of peri-implantitis, scientific evidence concerning the host response profile around dental implants could be important for providing in the future a wider preventive and/or therapeutic window for this peri-implant lesion, indicating biomarkers that provide quantifiable measure of response to peri-implant therapy. Moreover, a better knowledge of pattern of host osteo-immunoinflammatory modulation in the presence of peri-implantitis could either benefit the early diagnostic of the disease or to cooperate to prognostic information related to the status of the peri-implant breakdown. Finally, new evidences concerning the host profile of modulators of inflammation and of osseous tissue metabolism around dental implants could explain the individual susceptibility for developing peri-implant lesions, identifying individuals or sites with increased risk for peri-implantitis. The focus of this chapter was, based on a systematically searched and critically reviewed literature, summarizing the existing knowledge in the scientific research concerning the host osteo-immunoinflammatory response to the microbiological challenge related to periimplantitis.

Dense cancellous bone as evidenced by a high HU value is predictive of late implant failure: a preliminary study

OBJECTIVES

The mechanism of late implant failure is unclear. This study examined the association between sclerosing cancellous bone images and the risk of late implant failures using multi-detector row computed tomography (CT) imaging data.

METHODS

We performed a case-control study. The study group consisted of consecutive patients with implant failures treated at Kyushu Dental University between 2001 and 2016. CT data for late failure of 36 implants in 16 patients were available. The study cohort consisted of 16 patients with 36 late failed implants and 28 patients with 113 successful implants.

RESULTS

The mean survival rate was 6.9 months for early implant failure, 76.6 months for late failure with marginal bone resorption, inflammation symptoms, and so-called peri-implantitis, and 95.0 months for late failure caused by implant fracture. The mean HU value for cases in the control group was 507 compared with 1231 for cases with late failure implants. Logistic regression was used for analysis. There were signs of high radiodensity of peri-implant cancellous bone when comparing adjusted radiodensity per 100 HU using CT data (OR 2.35; 95% CI 1.73-3.20; p < 0.001).

CONCLUSIONS

Within the limits of our study, the presence of high radiodensity and cancellous bone consolidation on imaging may be related to risk factors for late implant failure. Therefore, CT images of the host cancellous bone status for observation of visible sclerosis could be a useful diagnostic indicator for late implant failure.

Immune Response in Patients with Mandibular Fracture Complicated with Suppuration of a Bone Wound

Modern clinical observations focused on the increasing complications at the open mandible fracture, which indicated about severe immune suppression in patients with this pathology. For estimation cellular immunity in a peripheral blood there were examined 25 patients in basic group (15 men, 10 women) with mandible fracture, complicated with abscess of a bone wound; control group included 20 practically healthy persons (10 men and 10 women). To assess cellular immunity in the peripheral blood were determined: absolute number of leukocytes, relative amount of lymphocytes; phagocytic activity. Determination relative number of T–lymphocytes (phenotype CD2+, СD3+) and B – lymphocytes (phenotype СD22+) was performed by method of immunofluorescence with monoclonal antibodies. In a case of mandible fracture, complicated with abscess of bone wound and leukocytosis, in the patients were reduced parameters of cellular immunity: on 40.3% – phagocytic index, on 47.7% – phagocytic number, on 43.9% – content of CD2+– and CD3+– lymphocytes. Content of null cells was increased on 76.8 %

A combined digital and stereophotogrammetric technique for rehabilitation with immediate loading of complete-arch, implant-supported prostheses: A randomized controlled pilot clinical trial

STATEMENT OF PROBLEM

Traditional impressions for complete-arch restorations are complex and time-consuming, and they can be uncomfortable for the patient. New digital techniques such as stereophotogrammetry may mitigate this.

PURPOSE

The purpose of this randomized controlled pilot clinical trial was to compare the patient and dentist satisfaction and work times of traditional impressions (control group) and digital impressions with stereophotogrammetry in complete-arch, implant-supported prostheses. Success rates, implant survival, marginal bone loss around the dental implants, and prosthesis survival were also analyzed.

MATERIAL AND METHODS

This randomized controlled pilot clinical trial included 18 participants who received 131 dental implants. Implant impressions in the experimental group were made with stereophotogrammetry (8 participants with 66 implants), while traditional impressions were made in the control group (10 participants with 65 implants). Working times were measured in minutes starting from removal of the healing abutments to their replacement after the impression. Patient and dentist satisfaction was analyzed using a questionnaire with a visual analog scale, and implant success was assessed using the Buser success criteria. Prosthesis survival was defined as the presence of the prosthesis in the mouth, without screw loosening or fracture.

RESULTS

The work times were 15.6 (experimental group) and 20.5 minutes (control group) (P<.001). The patient satisfaction scores were 8.8 in the experimental and 7.9 in the control group (P=.02). The dentist satisfaction scores were 9.1 in the experimental group and 8.5 in the control group (P=.03). The implant success rate was 100% in both groups. Marginal bone loss was 0.6 ±0.5 mm (experimental group) and 0.6 ±0.2 mm (control group) (P=.72).

CONCLUSIONS

Digital impressions using stereophotogrammetry may be an alternative to traditional impressions. Patient and dentist satisfaction improved, and the work time was reduced in the experimental group. No statistically significant differences were found in terms of the implant success rate, implant survival, marginal bone loss, or prosthesis survival between the 2 groups.

The Prosthetic Influence and Biomechanics on Peri-Implant Strain: a Systematic Literature Review of Finite Element Studies

Objectives

To systematically review risks of mechanical impact on peri-implant strain and prosthetic influence on stability across finite element studies.

Material and Methods

An online literature search was performed on MEDLINE and EMBASE databases published between 2011 and 2016. Following keywords tiered screening and selection of the title, abstract and full-text were performed. Studies of finite element analysis (FEA) were considered for inclusion that were written in English and revealed stress concentrations or strain at peri-implant bone level.

Results

There were included 20 FEA studies in total. Data were organized according to the following topics: bone layers, type of bone, osseointegration level, bone level, design of implant, diameter and length of implant, implant-abutment connection, type of supra-construction, loading axis, measurement units. The stress or strain at implant-bone contact was measured over all studies and numerical values estimated. Risks of overloading were accented as non-axial loading, misfits, cantilevers and the stability of peri-implant bone was related with the usage of platform switch connection of abutment.

Conclusions

Peri-implant area could be affected by non-axial loading, cantilever prosthetic elements, crown/implant ratio, type of implant-abutment connection, misfits, properties of restoration materials and antagonistic tooth. The heterogeneity of finite element analysis studies limits systematization of data. Results of these studies are comparable with other findings of in vitro, in vivo, prospective and retrospective studies.

Risk indicators related to peri-implant disease: an observational retrospective cohort study

Purpose

The aim of the present study was to retrospectively investigate the influence of potential risk indicators on the development of peri-implant disease.

Methods

Overall, 103 patients referred for implant treatment from 2000 to 2012 were randomly enrolled. The study sample consisted of 421 conventional-length (>6 mm) non-turned titanium implants that were evaluated clinically and radiographically according to pre-established clinical and patient-related parameters by a single investigator. A non-parametric Mann-Whitney U test or Kruskal-Wallis rank test and a logistic regression model were used for the statistical analysis of the recorded data at the implant level.

Results

The diagnosis of peri-implant mucositis and peri-implantitis was made for 173 (41.1%) and 19 (4.5%) implants, respectively. Age (≥65 years), patient adherence (professional hygiene recalls <2/year) and the presence of plaque were associated with higher peri-implant probing-depth values and bleeding-on-probing scores. The logistic regression analysis indicated that age (P=0.001), patient adherence (P=0.03), the absence of keratinized tissue (P=0.03), implants placed in pristine bone (P=0.04), and the presence of peri-implant soft-tissue recession (P=0.000) were strongly associated with the event of peri-implantitis.

Conclusions

Within the limitations of this study, patients aged ≥65 years and non-adherent subjects were more prone to develop peri-implant disease. Therefore, early diagnosis and a systematic maintenance-care program are essential for maintaining peri-implant tissue health, especially in older patients.

A Prospective Longitudinal Study on Implant Prosthetic Rehabilitation in Controlled HIV-Positive Patients with 1-Year Follow-Up: The Role of CD4+ Level, Smoking Habits, and Oral Hygiene

BACKGROUND

A recent study showed that implant-prosthetic rehabilitation in well-controlled HIV patients gave slightly worse results than in an healthy population, and failures were all linked to infection.

PURPOSE

The aim of this study was to examine the associations between the success of implant-prosthetic treatment and systemic CD4+ level, smoking habits, and oral hygiene.

MATERIALS AND METHODS

This mono-centric study included HIV patients with a stable disease and good oral hygiene requiring implant rehabilitation. Each patient received at least one dental implant. Prosthesis were delivered after 90 days in the upper jaw and 60 days in the lower jaw. Primary outcome measures were prosthetic failures, implant failures, peri-implant marginal bone level changes, and biological complications (peri-implantitis, pus, pain, paresthesia). The possible association with CD4 count, smoking habits, and oral hygiene was analyzed.

RESULTS

Sixty-eight patients received 194 implants, and 66 patients (190 implants) were followed for 1 year. No significant associations were found between CD4+ count, oral hygiene-associated variables, and any of the outcome measures. If compared with nonsmoking/light smoking patients, patients who smoked >10 cigarettes/day suffered a statistically significant greater number of implant failures (p ≤ .005), presented a comparatively higher number of peri-implantitis (p < .001), as well as a higher frequency of pus (p ≤ .007), and reported pain (p ≤ .009).

CONCLUSION

Within the limitation of the present study, placement of dental implants in HIV-positive patients with stable disease seems a reasonable treatment option, regardless of CD4+ cell count, provided that they are in a normal range. Oral hygiene variables were not influent in this group of patient following recall appointments, while HIV-positive heavy smokers (>10 cigarettes/day) demonstrated an increased risk of early implant failure, peri-implantitis, episodes of pus, and self-reported pain.

Effect of UV-photofunctionalization on oral bacterial attachment and biofilm formation to titanium implant material

Bacterial biofilm infections remain prevalent reasons for implant failure. Dental implant placement occurs in the oral environment, which harbors a plethora of biofilm-forming bacteria. Due to its trans-mucosal placement, part of the implant structure is exposed to oral cavity and there is no effective measure to prevent bacterial attachment to implant materials. Here, we demonstrated that UV treatment of titanium immediately prior to use (photofunctionalization) affects the ability of human polymicrobial oral biofilm communities to colonize in the presence of salivary and blood components. UV-treatment of machined titanium transformed the surface from hydrophobic to superhydrophilic. UV-treated surfaces exhibited a significant reduction in bacterial attachment as well as subsequent biofilm formation compared to untreated ones, even though overall bacterial viability was not affected. The function of reducing bacterial colonization was maintained on UV-treated titanium that had been stored in a liquid environment before use. Denaturing gradient gel-electrophoresis (DGGE) and DNA sequencing analyses revealed that while bacterial community profiles appeared different between UV-treated and untreated titanium in the initial attachment phase, this difference vanished as biofilm formation progressed. Our findings confirm that UV-photofunctionalization of titanium has a strong potential to improve outcome of implant placement by creating and maintaining antimicrobial surfaces.