Risk factors of peri-implant pathology

Could various angulated implant depths affect the positional accuracy of digital impressions? An in vitro study

PURPOSE

The purpose of this in vitro investigation was to assess how implant depth could affect the three-dimensional positional accuracy of digital impressions made from angulated implants.

MATERIALS AND METHODS

Four modified maxillary models were printed and divided into four study groups. In each model, two angulated implant analogs were placed at the sites of the first premolar and first molar at four different depths of 1 (G1), 2 (G2), 3 (G3), and 4 (G4) mm from the models' edentate area. Scan bodies were connected to the analogs, and one operator made 10 full-arch scans for each master model using an intraoral scanner. Afterward, the marginal gingival part of all models was removed, and digital scans were performed for each model using a laboratory scanner to achieve a reference STL file as the control group. One-way ANOVA and Leven's tests were used to measure and compare the 3D distance deviations across research groups after the superimposing test and control scans.

RESULTS

A significant difference between research groups was revealed by trueness and precision analysis (p < 0.001). The trueness and precision results obtained for G1 and G4 were significantly better than those for G2 and G3 (p < 0.05).

CONCLUSION

This study demonstrated that implant depth could affect the digital implant impressions' 3D positional accuracy.

Genetic polymorphisms of inflammatory and bone metabolism related proteins in a population with dental implants of the Basque Country. A case-control study

BACKGROUND

Peri-implantitis (PI) is a frequent inflammatory disorder characterised by progressive loss of the supporting bone. Not all patients with recognised risk factors develop PI. The aim of this study is to evaluate the presence of single nucleotide polymorphisms (SNP) of inflammatory and bone metabolism related proteins in a population treated with dental implants from the Basque Country (Spain).

METHODS

We included 80 patients with diagnosis of PI and 81 patients without PI, 91 women and 70 men, with a mean age of 60.90 years. SNPs of BMP-4, BRINP3, CD14, FGF-3, FGF-10, GBP-1, IL-1α, IL-1β, IL-10, LTF, OPG and RANKL proteins were selected. We performed a univariate and bivariate analysis using IBM SPSS® v.28 statistical software.

RESULTS

Presence of SNPs GBP1 rs7911 (p = 0.041) and BRINP3 rs1935881 (p = 0.012) was significantly more common in patients with PI. Patients with PI who smoked (> 10 cig/day) showed a higher presence of OPG rs2073617 SNP (p = 0.034). Also, BMP-4 rs17563 (p = 0.018) and FGF-3 rs1893047 (p = 0.014) SNPs were more frequent in patients with PI and Type II diabetes mellitus.

CONCLUSIONS

Our findings suggest that PI could be favoured by an alteration in the osseointegration of dental implants, based on an abnormal immunological response to peri-implant infection in patients from the Basque Country (Spain).

The All-on-4 Concept Using Polyetheretherketone (PEEK)-Acrylic Resin Prostheses: Follow-Up Results of the Development Group at 5 Years and the Routine Group at One Year

BACKGROUND

It is necessary to investigate the application of polymer materials in implant dentistry. The aim of this study was to examine the outcome of full-arch polyetheretherketone (PEEK)-acrylic resin implant-supported prostheses.

METHODS

Seventy-six patients were rehabilitated consecutively with 100 full-arch implant-supported prostheses of PEEK-acrylic resin (a development group (DG): 37 patients with 5 years of follow-up; a routine group (RG): 39 patients with 1 year of follow-up). The primary outcome measure was prosthetic survival. Secondary outcome measures were implant survival, marginal bone loss, biological complications, prosthetic complications, veneer adhesion, plaque levels, bleeding levels, and a patient subjective evaluation (including the Oral Health Impact Profile for the RG).

RESULTS

In both groups, prosthetic (DG: 93.6%; RG: 100%) and implant survival (DG: 98.9%; RG: 99.5%) were high, and marginal bone loss was low (DG: 0.54 mm; RG: 0.28 mm). The veneer adhesion rate was 28.6% of prostheses in DG (RG = 0%). Mechanical complications occurred in 49% and 11.8% of prostheses in DG and RG, respectively. Biological complications, plaque, and bleeding levels were low in both groups. The subjective patient evaluation was excellent in both groups (8.6 < DG < 8.8; 9.3 < RG < 9.5; OHIP = 1.38).

CONCLUSIONS

Within the limitations of this study, PEEK can be considered a viable prosthetic alternative.

Effect of novel prefabricated auxiliary devices attaching to scan bodies on the accuracy of intraoral scanning of complete-arch with multiple implants: An in-vitro study

OBJECTIVES

To examine the effect of novel prefabricated auxiliary devices with different geometric features called Scan Body Clasp (SBC) at different levels on the accuracy of intraoral scanning of complete-arch with multiple implants.

METHODS

An edentulous maxilla 4-implant model and SBCs with different geometric features (flat or curved) were fabricated by a 3D printer (AccuFab-C1s, 3DShining, Hangzhou, China). Test scans were performed using an intraoral scanner (Aoralscan 3, 3DShining, Hangzhou, China) software version 1.0.0.3104 under different scenarios: group A (CO), without any SBCs; group B&C (LC&HC), with curved SBCs adjacent to and away from the mucosa; group D&E (LF&HF), with flat SBCs adjacent to and away from the mucosa. 20 scans were done for each group (CO, LC, HC, LF and HF). Reference Scans were obtained by digitizing the model in group A using a dental laboratory scanner (D2000, 3Shape, Copenhagen, Denmark). The related files were imported into inspection software for trueness and precision assessment. Statistical analysis was performed with One-way ANOVA, Independent-Sample T test for trueness values. Kruskal-Wallis test and Mann-Whitney test were used to assess the precision values. The level of significance was set at α=0.05.

RESULTS

Groups with SBCs demonstrated trueness enhancement, among which LF revealed the best trueness. Significant differences were also found between LF and HC (p < .01), LF and HF (p < .001), LC and HF (p < .01). LF and HF showed precision enhancement. The best precision was LF, which was found to be more precise than LC (p < .001) and HC (p < .001). HF was more precise than LC (p < .001) and HC (p < .001).

CONCLUSIONS

Attaching the scan bodies with SBCs at different levels significantly influenced the scanning accuracy. The SBCs near the mucosa result in superior trueness, while the flat morphology benefits the precision.

CLINICAL SIGNIFICANCE

The results demonstrated the feasibility of the SBCs in enhancing intraoral complete-arch implant scanning accuracy. Among the configurations tested in the present study, low-level and flat surfaces of the artificial landmarks may be the potential pivotal elements to optimizing long-span scanning accuracy.

Association between smoking and peri-implant diseases: A retrospective study

OBJECTIVES

To determine the association between tobacco and peri-implant diseases in a sample of patients who had received implant-supported restorations in a university dental clinic. Furthermore, the study aimed to investigate patient- and implant-related variables associated with peri-implant diseases.

MATERIALS AND METHODS

The present retrospective study analyzed data from 117 patients treated with implant-supported restorations from 2001 to 2013. A total of 450 implants were evaluated. Patients were selected from an electronic database, and patient- and implant-related variables were evaluated. Detailed information regarding the smoking history (i.e., smoking status, lifetime cumulative dose, duration of exposure, intensity of the habit, and smoking cessation) was recorded. The primary study outcome was peri-implant status [i.e., health (H), peri-implant mucositis (PM) and peri-implantitis (PI)]. Univariate and multinomial regression models comparing PM and PI versus peri-implant health were conducted.

RESULTS

A total of 117 subjects [55 (47%) females and 62 (53%) males] with a mean age at examination of 64.2 years (SD 11.6) and rehabilitated with 450 implants were included. The average number of implants per patient was 4.6 (SD 3.3) with a mean time in function of 8.0 years (SD 1.9). Fifty-six patients (47.9%) were non-smokers, 42 (35.9%) were former-smokers, and 19 (16.2%) were current-smokers. Thirty-nine subjects (33.4%) were H, whereas 41 (35%) and 37 (31.6%) exhibited PM and PI, respectively. At implant level, the corresponding values were 142 (31.6%), 230 (51.1%) and 78 (17.3%). In the multinomial regression model, significant associations for peri-implant diseases were observed for the mean number of implants per patient (p = .016), function time (p = .048), implants placed simultaneously with guided bone regeneration (p = .016), implant surface (p = .020), keratinized mucosa at the buccal aspect (p = .032), and access to interproximal hygiene (p < .001). In addition, ever smokers >23 pack-years exhibited a significantly higher risk for peri-implantitis (p = .002). Finally, the multinomial regression analysis revealed that subjects who had stopped smoking more than 21 years before the last examination presented a significantly lower risk of peri-implant diseases than a smoking cessation of ≤21 years (p = .028).

CONCLUSIONS

Smoke intensity was associated with an increased risk of the development of peri-implantitis. Moreover, the risk of peri-implant diseases might be similar in those subjects who had stopped smoking for more than 21 years with respect to never-smokers.

Presence and implication of Candida spp. in patients with peri-implantitis enrolled in a supportive peri-implant therapy program of the Basque Country (Spain). A case-control study

INTRODUCTION

The peri-implant sulcus is a good niche for infectious colonization such as Candida spp. In this study, the level of Candida spp. fungal colonization is analyzed in patients with peri-implantitis under supportive peri-implant therapy, as well as its correlation with the main clinicopathological data.

METHODS

A case-control study was carried out on 161 patients treated with dental implants, 80 with PI and 81 without PI, which corresponded to 91 women and 70 men, whose mean age was 60.90 years. A specific protocol was completed for the clinical and implant data. Microbiological samples were taken by oral rinse and with paper tips from the peri-implant sulcus. For the quantitative and qualitative analysis Candida Chromogenic Agar/CONDA plates were incubated for 72 h at 36 + 1°C. Fungal growth was considered active when having more than 50 CFU. Specific Candida spp. cultures were later confirmed by API ID 32C and PCR.

RESULTS

Fungal growth was achieved in 28% of oral rinse and 6.75% of peri-implant fluid samples. No significant differences were recognized between study groups. Most of the cultures (>65%) showed more than 50 CFU. The most frequent species were Candida albicans and Candida parapsilosis. There was no association between different PI risk factors and fungal data. The presence of Candida spp. in the oral cavity of patients with dental implants was related to total edentulism and the use of implant-fixed complete prosthesis implant-retained removable prosthesis.

CONCLUSIONS

These results suggest that there is no link between PI and presence of Candida in patients with dental implants undergoing regular supportive periodontal therapy.

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.

The Influence of Cleaning Solutions on the Retention of Overdenture Attachment Systems

Dental-implant-supported reconstructions provide comfort and improvements in prosthetic function, adaptation, and stability over conventional treatment options. The objective of this study was to evaluate the effect of different denture cleansing solutions and their influence on the deterioration and loss of retention of overdenture attachments in a 12-month clinical-use simulation. In this way, ten specimens each of different brands of retentive caps made of Teflon (OT Equator^® (Rhein83, Bologna, Italy), Locator^® (Zest Anchors, Escondido, CA, USA), Kerator^® (KJ Meditech, Gwangiu, Republic of Korea), and Locator R-Tx^® (Zest Anchors, Escondido, CA, USA)) were immersed in five different cleaning solutions (Kukident^® (P&G Tech, Oxford Parkway, UK), Benfix^® (Laboratorios URGO S.L., Guipúzcoa, Spain), Corega^® (Stafford Miller, Waterford, Ireland), and Protefix^® (Neuhofer Weiche, Parchim, Germany)), and tap water was used as the control group, in a simulation that lasted 12 months. Data were analyzed using two-way ANOVA and a Tukey HSD. Furthermore, a Levene Test and Shapiro-Wilk tests were performed to assess the validation of the ANOVA assumptions. The statistical analysis was performed using R version 4.2.2 software with the significance level set to p < 0.05. There were significant statistical differences between the different manufacturers regarding the retention forces of the attachment's retentive caps (F = 322.066, p < 0.001). For the cleaning solution groups, different statistical results between Kukident^® (P&G Tech, Oxford Parkway, UK) (p < 0.05) and Benfix^® (Laboratorios URGO S.L., Guipúzcoa, Spain) (p < 0.05) were observed. There were no significant statistical differences between Corega^® (Stafford Miller, Ireland), Protefix^® (Neuhofer Weiche, Parchim, Germany), and tap water, even though the retention forces decreased in all of them.

Effect of Er,Cr:YSGG laser with a side-firing tip on decontamination of titanium disc surface: an in vitro and in vivo study

PURPOSE

To evaluate the effectiveness of an erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser with side-firing tip in decontamination of titanium (Ti) disc.

METHODS

In the first test series, 29 Ti-discs were contaminated with Staphylococcus aureus and treated as follows: positive control (no treatment); Perioflow; Laser A (0.75 W, 100 Hz), Laser B (1.5 W, 30 Hz); Laser C (no radiation, 60% water); and Laser D (no radiation, 50% water). For bacterial quantification, colony forming units (CFU, vital cells only) and quantitative PCR (qPCR, vital and devital cells) were performed. In a second test series, 92 Ti-discs were used, contaminated with in vivo-grown biofilm and treated as follows: positive control (no treatment); Perioflow; Laser E (1.5 W, 30 Hz), and Laser F (no radiation, 50% water). Considering the different and unknown culture conditions, quantification of bacteria was performed by broad-spectrum bacterial qPCR only. Based on the assumption that all cells of an organism contain an equivalent complement of genetic information, genome equivalent (GE) determination ensured the detection of the different intact and semi-intact genomes, regardless of type of bacterial species and vitality, circumvent the inherent bias of cultures.

RESULTS

The GE values were significantly reduced by all interventions in both test series, compared to the positive control group (p < 0.001). In the first test series with S. aureus as model organism, Perioflow yielded a lower GE than the Laser groups A-D (all p < 0.025). The number of CFUs was significantly reduced in the intervention groups compared to the positive control (p < 0.001), except for Laser A (p = 0.157) and Laser D (p = 0.393). In the second test series, none of the pairwise comparisons of the intervention conditions showed a significant difference (Perioflow vs. Laser E: p = 0.732; Perioflow vs. Laser F: p = 0.590; Laser E vs. Laser F: p = 0.379).

CONCLUSION

The Er,Cr:YSGG laser with side-firing tip and Perioflow were equally capable of effectively decontaminating a Ti-disc surface. It is assumed that the bacterial reduction was largely due to the mechanical effect of the air and water stream.

Accuracy of Digital Impressions at Varying Implant Depths: An In Vitro Study

PURPOSE

Implants placed at variable depths may vary the amount of visible scannable surface of a scan body. Intraoral scanner technology uses advanced optical principles to record the surface of the scan body to accurately capture the implant position. The purpose of this study is to investigate the effect implant placement depth has on the accuracy of digital implant impressions using an intraoral scanner.

MATERIALS AND METHODS

A partially edentulous gypsum master model was fabricated to allow the positioning of a single implant analog at different depths. Four groups were created based on the planned implant depths of 7, 6, 3, and 0 mm and corresponding visibility of the scan body at 2, 3, 6, and 9 mm. The model was digitized with a laboratory scanner for the reference scan and with an intraoral scanner to generate 15 test scans per group, with a total of 60 scans. The test scans were superimposed onto the reference scan using the best fit algorithm to analyze and measure the positional (dXYZ) and angular deviation (d⍬) of the scan body using three-dimensional metrology software. Statistical analysis was performed using a one-way ANOVA and pairwise comparison was done with a Tukey-Kramer HSD test (α = 0.05).

RESULTS

The one-way ANOVA of the groups for the dXYZ and dθ parameters was statistically significant (F3,56 = 11.45, p < 0.001, F3,56 = 24.04, p < 0.001). Group D (9 mm) showed the least positional deviation at 38.41 μm (95% CI 30.26; 46.56) and the least angular deviation of 0.17° (95% CI 0.12; 0.21). Group A (2 mm) showed the greatest positional deviation of 77.17 μm (95% CI 65.23; 89.11) and greatest angular deviation of 0.84° (95% CI 0.65; 1.03). The positional and angular deviation increased with increased implant depth.

CONCLUSIONS

The accuracy of digital impressions is influenced by the implant depth and the amount of visibility of the scan body. The trueness and precision are highest when the implant is placed at 0 mm depth with complete visibility of the scan body and decreases with subgingival implant placement.

Ten-year follow-up of full-arch rehabilitations supported by implants in immediate function with nasal and full-length palatine bicortical anchorage on the anterior maxilla

PURPOSE

To evaluate the immediate function of anterior maxillary implants.

METHODS

One hundred nine patients (42 males and 67 females; average age 55.2 years; range 38-81 years) were followed for 10 years. One hundred eighty-eight implants using nasal and full-length palatine cortical anchorage were inserted in the anterior section of the maxilla together with 188 tilted implants placed posteriorly. Outcome measures were implant success and survival, prosthesis survival, bone loss, and the incidence of biological and mechanical complications. Cumulative success and survival were computed through Kaplan-Meyer product limit estimator (at patient level) and life tables (implant level).

RESULTS

Four patients lost one implant each, giving a 10-year cumulative survival rate of 95.8% and 97.7% using the patient and the implant as the unit of analysis, respectively. The prosthesis survival rate was 98.2%, and the average marginal bone loss was 1.79 mm (1.06 mm). The cumulative success rate was 89.1% and 92.5% using the patient and the implant as the unit of analysis, respectively.

CONCLUSION

Full-arch fixed prosthetic rehabilitations supported by immediately functional implants inserted in the anterior maxilla with bicortical anchorage together with posterior-tilted implants are viable in the long term.

Prevalence of peri-implantitis in a sample of HIV-positive patients

OBJECTIVES

This study aimed to assess the prevalence of peri-implantitis in human immunodeficiency virus (HIV)-positive patients and the presence of a possible correlation between the immunological profile and serological values, of peri-implantitis, and of possible differences between all-on-4 and single crown/bridge prostheses.

SUBJECTS AND METHODS

This retrospective study included 58 adult HIV-positive patients (222 implants) with either all-in-4 prostheses or single crowns/bridges on at least one dental implant loaded for more than a year who were followed for 3 year (mean follow-up). Data pertaining to the probing pocket depth (PPD), bleeding on probing, and immunological and systemic profile were collected.

RESULTS

Patients with single crown/bridge implant rehabilitation showed higher prevalence of peri-implantitis (34%) than patients with all-on-4 rehabilitation (0%) (p = 0.012). Patients with all-on-4 rehabilitation were significantly older than those with single crowns/bridges (p = 0.004). Patients with peri-implantitis had implants for a significantly longer duration than those without (p = 0.001), implying that the probability of peri-implantitis increases as the age of implant increases.

CONCLUSIONS

The prevalence of peri-implantitis was 26% in the HIV-positive patients population. No correlation was found between patients' immunological and serological factors and peri-implantitis. The most important risk factor for peri-implantitis and mucositis was implant age.

Efficacy of rehabilitation with different approaches of implant-supported full-arch prosthetic designs: A systematic review

AIM

To evaluate the efficacy of different types of rehabilitation with fixed or removable full-arch implant-supported prosthesis designs in terms of implant loss and success in patients with at least one edentulous jaw, with tooth loss mainly due to periodontitis.

MATERIALS AND METHODS

Clinical studies with at least 12 months reporting on implant loss and implant success were searched. Meta-analysis was conducted to estimate cumulative implant loss considering different prostheses designs.

RESULTS

A total of 11 studies with unclear to low risk of bias were included in the analysis. Estimated cumulative implant loss for fixed prostheses within 1 year and 5 years was 0.64% (95% confidence interval [CI]: 0.31%-1.31%) and 1.85% (95% CI: 0.85%-3.95%), respectively. The corresponding values for removable prostheses amounted to 0.71% (95% CI: 0.22%-2.28%) and 4.45% (95% CI: 2.48%-7.85%). Peri-implantitis affected 10%-50% of the patients restored with implant-supported fixed prostheses.

CONCLUSIONS

Based on the limited low-quality data, the present analysis points to a low and similar cumulative implant loss within 1 year for patients with tooth loss mainly due to stage IV periodontitis restored with either removable or fixed implant-supported full-arch prosthesis. At 5 years of functioning, there was a tendency for better outcomes using fixed designs.

Impact of Mechanical Complications on Success of Dental Implant Treatments: A Case-Control Study

Objective  This study aimed to investigate the impact of mechanical complications on outcome measures for implant dentistry.

Materials and Methods  This case–control study included 282 patients with mechanical complications occurring in fixed prosthetic rehabilitation supported by immediate function implants with external connection (cases) and 282 individuals without mechanical complications (control). Pairing was performed for sex, age (range = 3 years), and follow-up months (range = 11 months). The primary outcome measure was implant survival, while the secondary outcome measures were marginal bone loss and biological complication parameters (peri-implant pathology, soft tissue inflammation, fistula formation, and abscess formation).

Statistical Analysis  Cumulative implant survival was estimated by using life tables. Descriptive statistics with 95% confidence intervals (CI) and inferential statistics (Chi-square test) were performed to evaluate differences between cases and controls. The significance level was set at 5%.

Results  The average follow-up duration was 8.5 years. Mechanical complications included prosthetic fracture ( n = 159), abutment loosening ( n = 89), prosthetic screw loosening ( n = 20), milled abutment ( n = 12), milled prosthetic screw ( n = 1), and decemented crown ( n = 1). Implant failure occurred in one patient from the control group, with survival rates of 100 and 99.6% for cases and controls, respectively ( p = 0.317). The average marginal bone loss was 1.72 (95% confidence interval [CI]: 1.60–1.84) for cases and 1.55 (95% CI: 1.45–1.65) for controls ( p = 0.068). Biological complications were observed in 90 patients, with significant differences between cases ( n = 54) and controls ( n = 36; p = 0.038).

Conclusion  Mechanical complications did not significantly influence survival or marginal bone loss; nevertheless, there is a need for studies with longer follow-up duration. Mechanical complications also significantly influence the incidence of biological complications.

Opportunistic pathogens are associated with deteriorated clinical parameters in peri-implant disease

OBJECTIVES

To assess the association between Gram-negative enteric rods and Pseudomonas with the clinical parameters in peri-implant disease.

MATERIALS AND METHODS

Patients treated with implants and diagnosed with peri-implant mucositis and/or peri-implantitis participate in this cross-sectional research. Unusual microorganisms from the implants were recognized using MALDI-TOF mass spectrometry. Linear regression models were applied.

RESULTS

A total of 103 implants were evaluated in thirty-one participants. Gram-negative enteric rods/Pseudomonas were observed in 47 implants (46%). Interestingly, there were differences in probing pocket depth (PPD), clinical attachment loss (CA), and bleeding on probing (BOP) between the groups, where implants with the presence of Gram-negative enteric rods/Pseudomonas presented deteriorated clinical parameters (p < .0001). The crude and adjusted linear regression models for PPD in peri-implant mucositis, PPD in peri-implantitis, CA in peri-implantitis, and BOP in peri-implant disease present significant βs, demonstrating deteriorated parameters (p < .0001) in the presence of Gram-negative enteric rods/Pseudomonas. Besides, the model for CA in peri-implantitis showed that cemented restored reconstructions were statistically significant (p = .009). Additionally, the R2 value in most models indicated a high degree of correlation (>85%).

CONCLUSION

The occurrence of Gram-negative enteric rods and Pseudomonas was associated with deteriorated clinical parameters in patients with peri-implant disease.

Clinical, histopathological and immunohistochemical behavior of peri-implant soft tissue

The presence of foreign materials in the tissues, represented in the present study by the insertion of dental implants, creates artificial structures that can sometimes cause adverse consequences, which implies the obligation to perform a complex medical assessment before inserting dental implants. This assessment appreciates the quality of the tissue, depending on which the use of a certain type of biomaterial is indicated and focuses on a certain surgical technique. We assessed the clinical, histopathological (HP) and immunohistochemical (IHC) aspects of peri-implant soft tissue in patients who did not show mobility or imagistic signs of bone resorption, three months after implant insertion, some of them showing no inflammatory clinical signs. Immunohistochemically, on the sections of the peri-implant mucosa, we assessed the presence of mast cells, vascularization and the process of angiogenesis. Mast cells are key cells actively involved in the pathogenesis of peri-implant inflammation, having an immunomodulatory role. Vasodilation and angiogenesis, determined by the release of chemical mediators by degranulation of mast cells under the action of pathogens, induce tissue remodeling, ensuring the healing and formation of a tissue to form a barrier that effectively prevents the development of a bacterial biofilm. Thus, the control of the activity of these cells is important for the management of the local inflammatory process. The correlations between the clinical, HP and IHC behavior of the peri-implant soft tissue bring important information for the clinic, emphasizing the need to identify a therapeutic strategy to modulate mast cell activity, in order to prevent and treat peri-implant disease, to ensure osseointegration and longer survival of the dental implant.

Hybrid Polyetheretherketone (PEEK)-Acrylic Resin Prostheses and the All-on-4 Concept: A Full-Arch Implant-Supported Fixed Solution with 3 Years of Follow-Up

Background: The aim of this three-year prospective study was to examine the outcome of a solution for full-arch rehabilitation through a fixed implant-supported hybrid prosthesis (polyetheretherketone (PEEK)-acrylic resin) used in conjunction with the All-on-4 concept. Methods: Thirty-seven patients (29 females, 8 males), with an age range of 38 to 78 years (average: 59.8 years) were rehabilitated with 49 full-arch implant-supported prostheses (12 maxillary rehabilitations, 13 mandibular rehabilitations and 12 bimaxillary rehabilitations). The primary outcome measure was prosthetic survival. Secondary outcome measures were marginal bone loss, plaque and bleeding scores, veneer adhesion issues, biological complications, mechanical complications, and the patients’ subjective evaluation. Results: There were two patients (maxillary rehabilitations) lost to follow-up, while one patient withdrew (maxillary rehabilitation). One patient with bimaxillary rehabilitation fractured the mandibular PEEK framework, rendering a 98% prosthetic survival rate. Implant survival was 100%. Average (standard deviation) marginal bone loss at 3-years was 0.40 mm (0.73 mm). Veneer adhesion was the only technical complication (n = 8 patients), resolved for all patients. Nine patients (n = 11 prostheses) experienced mechanical complications (all resolved): fracture of acrylic resin crowns (n = 3 patients), prosthetic and abutment screw loosening (n = 4 patients and 3 patients, respectively), abutment wearing (n = 1 patient). One patient experienced a biological complication (peri-implant pathology), resolved through non-surgical therapy. A 90% satisfaction rate was registered for the patients’ subjective evaluation. Conclusions: Based on the results, the three-year outcome suggests the proposed rehabilitation solution as a legitimate treatment option, providing a potential shock-absorbing alternative that could benefit the implant biological outcome.

Volumetric Changes in Morse Taper Connections After Implant Placement in Dense Bone. In-Vitro Study

The stability of the implant-abutment interface is crucial for the maintenance of the implant index integrity. Several factors are capable of inducing deformation in implant-abutment connection, such as the actual insertion of the implant into the bone. This study aimed to evaluate the deformations produced in the connection after the insertion of the implant. Ten implants with two different implant carriers (Type A: carrier attached to platform and Type B: carrier attached inside the index-connection) were placed in artificial Type II bone, and volumetric changes were evaluated for different connection features with a 3D digital microscope. ANOVA (analysis of variance), Wilcoxon, and Tukey HSD post-test were used for statistical comparisons. Type A implants presented deformation at the platform level (inner slot angles and slot width), but no volumetric changes were observed inside the connection. Type B implants presented deformation in three parameters inside the connection (outer channel length, coronal step width, and coronal step length). Within the limitations of this study, we can conclude that more deformation is expected at the internal connection when the implant carrier engages this area. The engagement area should be as far away as possible from the index connection.

Peri-implantitis

OBJECTIVES

This narrative review provides an evidence-based overview on peri-implantitis for the 2017 World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions.

METHODS

A literature review was conducted addressing the following topics: 1) definition of peri-implantitis; 2) conversion from peri-implant mucositis to peri-implantitis, 3) onset and pattern of disease progression, 4) characteristics of peri-implantitis, 5) risk factors/indicators for peri-implantitis, and 6) progressive crestal bone loss in the absence of soft tissue inflammation.

CONCLUSIONS

1)Peri-implantitis is a pathological condition occurring in tissues around dental implants, characterized by inflammation in the peri-implant connective tissue and progressive loss of supporting bone. 2)The histopathologic and clinical conditions leading to the conversion from peri-implant mucositis to peri-implantitis are not completely understood. 3)The onset of peri-implantitis may occur early during follow-up and the disease progresses in a non-linear and accelerating pattern. 4a)Peri-implantitis sites exhibit clinical signs of inflammation and increased probing depths compared to baseline measurements. 4b)At the histologic level, compared to periodontitis sites, peri-implantitis sites often have larger inflammatory lesions. 4c)Surgical entry at peri-implantitis sites often reveals a circumferential pattern of bone loss. 5a)There is strong evidence that there is an increased risk of developing peri-implantitis in patients who have a history of chronic periodontitis, poor plaque control skills, and no regular maintenance care after implant therapy. Data identifying "smoking" and "diabetes" as potential risk factors/indicators for peri-implantitis are inconclusive. 5b)There is some limited evidence linking peri-implantitis to other factors such as: post-restorative presence of submucosal cement, lack of peri-implant keratinized mucosa and positioning of implants that make it difficult to perform oral hygiene and maintenance. 6)Evidence suggests that progressive crestal bone loss around implants in the absence of clinical signs of soft tissue inflammation is a rare event.

Peri-implantitis

OBJECTIVES

This narrative review provides an evidence-based overview on peri-implantitis for the 2017 World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions.

METHODS

A literature review was conducted addressing the following topics: 1) definition of peri-implantitis; 2) conversion from peri-implant mucositis to peri-implantitis, 3) onset and pattern of disease progression, 4) characteristics of peri-implantitis, 5) risk factors/indicators for peri-implantitis, and 6) progressive crestal bone loss in the absence of soft tissue inflammation.

CONCLUSIONS

1)Peri-implantitis is a pathological condition occurring in tissues around dental implants, characterized by inflammation in the peri-implant connective tissue and progressive loss of supporting bone. 2)The histopathologic and clinical conditions leading to the conversion from peri-implant mucositis to peri-implantitis are not completely understood. 3)The onset of peri-implantitis may occur early during follow-up and the disease progresses in a non-linear and accelerating pattern. 4a)Peri-implantitis sites exhibit clinical signs of inflammation and increased probing depths compared to baseline measurements. 4b)At the histologic level, compared to periodontitis sites, peri-implantitis sites often have larger inflammatory lesions. 4c)Surgical entry at peri-implantitis sites often reveals a circumferential pattern of bone loss. 5a)There is strong evidence that there is an increased risk of developing peri-implantitis in patients who have a history of chronic periodontitis, poor plaque control skills, and no regular maintenance care after implant therapy. Data identifying "smoking" and "diabetes" as potential risk factors/indicators for peri-implantitis are inconclusive. 5b)There is some limited evidence linking peri-implantitis to other factors such as: post-restorative presence of submucosal cement, lack of peri-implant keratinized mucosa and positioning of implants that make it difficult to perform oral hygiene and maintenance. 6)Evidence suggests that progressive crestal bone loss around implants in the absence of clinical signs of soft tissue inflammation is a rare event.

A Prognostic Model for the Outcome of Nobel Biocare Dental Implants with Peri-Implant Disease after One Year

Background: This investigation, based on a 1-year retrospective cohort study, aimed to estimate and validate a prognostic model for ailing and failing implants due to peri-implant disease. Methods: A total of 240 patients (male: 97; female: 143; average age of 57.3 years) with at least one ailing or failing implant were included: 120 patients for model derivation and 120 patients for model validation. The primary outcome measure was the implant status: success, defined as the arrest of the disease, or failure defined as implant extraction, prevalence or re-incidence of peri-implant disease). Potential prognostic risk indicators were collected at the baseline evaluation. The relative risk (RR) was estimated for the predictors through logistic regression and the c-statistic (95% confidence interval) was calculated for both derivation and validation sets. The significance level was set at 5%. Results: The risk model retrieved the prognostic factors age (RR = 1.04), history of Periodontitis (RR = 3.13), severe peri-implant disease status (RR = 3.26), implant length (RR = 3.52), early disease development (RR = 3.99), with good discrimination in both the derivation set (0.763 [0.679; 0.847]) and validation set (0.709 [0.616; 0.803]). Conclusions: A prognostic risk model for estimating the outcome of implants with peri-implant disease is available, with a good performance considering the c-statistic evaluation.

Evaluation of FGF-23 and 25(OH)D3 levels in peri-implant sulcus fluid in peri-implant health and diseases

BACKGROUND

There are limited studies to date investigating vitamin D and fibroblast growth factor (FGF)-23 in different peri-implant conditions.

PURPOSE

To evaluate the peri-implant sulcus fluid (PISF) FGF-23 and 25-hydroxy-vitamin D₃ (25(OH)D₃ ) levels in peri-implant health and diseases.

MATERIALS AND METHODS

A total of 90 dental implant sites (peri-implant healthy group [n = 30], peri-implant mucositis group [n = 30], and peri-implantitis group [n = 30]) in 53 participants were included in the study. Probing depth (PD), clinical attachment level (CAL), suppuration (S), modified plaque index (mPI), gingival index (GI), modified sulcus bleeding index (mSBI), and keratinized mucosa width (KMW) were recorded as clinical parameters, and PISF samples were obtained. FGF-23 and 25(OH)D₃ levels were analyzed by enzyme-linked immunosorbent assay.

RESULTS

There were no statistically significant differences in FGF-23 concentrations among the groups (P > .05). The 25(OH)D₃ concentration was significantly lower in peri-implantitis group compared with the other two groups (P < .05). The mean total amount of FGF-23 in the peri-implantitis group was significantly higher than the peri-implant healthy group whereas 25(OH)D₃ total amount was significantly lower in the peri-implantitis group than the peri-implant healthy group. The 25(OH)D₃ concentration was significantly negatively correlated with CAL, PD, mPI, S, GI, and mSBI and statistically significant relationship was found between FGF-23 total amount and these clinical parameters (P < .05). There was a negligible positive correlation between 25(OH)D₃ and FGF-23 concentrations (τ = 0.169; P = .018).

CONCLUSION

Within the limitations of this study, it can be concluded that FGF-23 and vitamin D seems to affect peri-implant bone health, and further studies are needed to explain the association between FGF-23 and 25(OH)D₃ in peri-implant conditions.

A Peri-Implant Disease Risk Score for Patients with Dental Implants: Validation and the Influence of the Interval between Maintenance Appointments

Background: There is a need for tools that provide prediction of peri-implant disease. The purpose of this study was to validate a risk score for peri-implant disease and to assess the influence of the recall regimen in disease incidence based on a five-year retrospective cohort. Methods: Three hundred and fifty-three patients with 1238 implants were observed. A risk score was calculated from eight predictors and risk groups were established. Relative risk (RR) was estimated using logistic regression, and the c-statistic was calculated. The effect/impact of the recall regimen (≤ six months; > six months) on the incidence of peri-implant disease was evaluated for a subset of cases and matched controls. The RR and the proportional attributable risk (PAR) were estimated. Results: At baseline, patients fell into the following risk profiles: low-risk (n = 102, 28.9%), moderate-risk (n = 68, 19.3%), high-risk (n = 77, 21.8%), and very high-risk (n = 106, 30%). The incidence of peri-implant disease over five years was 24.1% (n = 85 patients). The RR for the risk groups was 5.52 (c-statistic = 0.858). The RR for a longer recall regimen was 1.06, corresponding to a PAR of 5.87%. Conclusions: The risk score for estimating peri-implant disease was validated and showed very good performance. Maintenance appointments of < six months or > six months did not influence the incidence of peri-implant disease when considering the matching of cases and controls by risk profile.

Five-year outcome of a retrospective cohort study comparing smokers vs. nonsmokers with full-arch mandibular implant-supported rehabilitation using the All-on-4 concept

The aim of this study was to compare the 5-year outcome of full-arch mandibular fixed prosthetic rehabilitation using the All-on-4 concept in smoking and nonsmoking patients. This retrospective cohort study included 200 patients (n = 100 smokers, n = 100 nonsmokers), 119 women and 81 men, with an average age of 53.7 years, rehabilitated in immediate function with 800 implants. Implant cumulative survival rate estimation (Kaplan-Meier with log-rank test) and marginal bone resorption (MBR) at 5 years (Mann-Whitney test) were compared between both groups. Multivariable analysis was used to investigate potential risk indicators for MBR ≥ 2.8 mm at 5 years. Nine patients (4.5%) were lost to follow-up. Four patients lost eight implants, specifically one nonsmoking patient (n = 1 implant) and three smoking patients (n = 7 implants), resulting in a cumulative survival rate estimation of 99.0% and 96.9% for nonsmokers and smokers, respectively (P = 0.296). The average (standard deviation) MBR at 5 years was 1.68 mm (0.76 mm) and 1.98 mm (1.02 mm) for nonsmokers and smokers, respectively (P = 0.045). Smoking (odds ratio = 2.92) was the only risk indicator significantly associated with MBR ≥ 2.8 mm in multivariable analysis. Smoking should not be an absolute contraindication for rehabilitation of the edentulous mandible through the All-on-4 concept; however, smoking habits were significantly associated with MBR ≥ 2.8 mm.

Prevalence of periodontitis, dental caries, and peri-implant pathology and their relation with systemic status and smoking habits: Results of an open-cohort study with 22009 patients in a private rehabilitation center

OBJECTIVES

This investigation, based on a 3-year epidemiological surveillance open cohort study, aimed to provide an insight of the prevalence of periodontitis, dental caries and peri-implant pathology and to compare inferentially between healthy and systemic compromised patients.

METHODS

A total of 22009 patients were observed consisting in 9035 men (41.1%) and 12974 women (58.9%) with an average age of 48.5 years (standard deviation of 15.6years). The prevalence of the 3 chronical oral diseases was calculated. The comparison between healthy and systemic compromised patients for each oral disease was performed through multivariate logistic regression: Odds ratios (OR) with 95% confidence intervals (95%CI) were estimated in one general model and one systemic condition specific model adjusted for age and gender. Attributable fractions were estimated for systemic conditions (both models). The level of significance was set at 5%.

RESULTS

The prevalence rate of periodontitis, dental caries and peri-implant pathology was 17.6%, 36.6% and 13.9%, respectively. The systemic compromised status was associated with the prevalence of the three chronical oral diseases on the general models. The systemic condition specific models yielded Diabetes [OR=1.49, 95%CI (1.24;1.79)] and HIV+ [OR=4.37, 95%CI (1.05;18.24)] as risk indicators for Periodontitis; cardiovascular conditions [OR=1.10, 95%CI (1.01;1.20)], Diabetes [OR=1.24, 95%CI (1.05;1.46)] and neurologic conditions [OR=1.84, 95%CI (1.32;2.57)] as risk indicators for dental caries; and smoking habits as a risk indicator for all three oral diseases [OR=1.90, 95%CI (1.74;2.07) for Periodontitis; OR=1.18, 95%CI (1.09;1.27) for dental caries; OR=1.84, 95%CI (1.64;2.07) for peri-implant pathology]. Attributable fractions estimated a potential reduction of 12.2% of Periodontitis, and 4.3% of dental caries cases if the exposure to systemic conditions was prevented; while the prevention of exposure to smoking alone would result in a potential reduction of 37%, 7%, and 39% of Periodontitis, dental caries, and peri-implant pathology cases, respectively.

CLINICAL SIGNIFICANCE

The present study describes an epidemiological approach to the distribution and determinants of the three principal chronical oral diseases. The association of systemic conditions and smoking habits with oral disease prevalence highlight the importance of a narrow monitoring system.

CONCLUSIONS

The present study reported a high prevalence for oral disease and a potential association of a systemic compromised status and smoking habits with the three chronical oral diseases.

Vitamin D deficiency in early implant failure: two case reports

An association between vitamin D deficiency and early dental implant failure is not properly verified, but its role in osteoimmunology is discussed. This article illustrates two case reports with vitamin D deficiency and early implant failure. Prior to implant placement, the first patient received crestal bone grafting with autologous material. Both patients received dental implants from different manufacturers in the molar region of the mandible. In the case of bone grafting in the first patient, all implants were placed in a two-stage procedure. All implants had to be removed within 15 days after implant placement. Vitamin D serum levels were measured: Both patients showed a vitamin D deficiency (serum vitamin D level <20 μg/l). After vitamin D supplementation, implant placement was successful in both patients. Prospective, randomized clinical trials must follow to affirm the relationship between vitamin D deficiency, osteoimmunology, and early implant failure.

Risk Factors for Implant Failure and Peri-Implant Pathology in Systemic Compromised Patients

PURPOSE

To identify the possible risk factors for implant failure and peri-implant pathology in a population of systemically compromised patients.

MATERIALS AND METHODS

This retrospective clinical study included a total of 721 systemically compromised patients (422 women, 299 men), with an average age of 51 years (range: 20 to 87) rehabilitated with dental implants. The average follow-up time was 7.3 years. The patients' demographic variables (age and gender) and clinical variables (implant location, type of implant surface, and systemic conditions) were recorded. Outcome measures were implant failure and peri-implant pathology. Binary logistic regression models were performed to investigate the effect of the patients' demographic and clinical characteristics on the dependent variables implant failure and peri-implant pathology. A linear regression model was performed to correlate the patient's characteristics with the number of failed implants. Odds ratios (OR) with 95% confidence intervals and corresponding levels of significance were estimated for each variable.

RESULTS

Multivariate logistic regression disclosed increased age (patients over 40 years of age) as a risk factor for implant failure (OR = 2.63) and hepatitis as a risk factor for peri-implant pathology (OR = 3.74). Multivariate linear regression disclosed rheumatologic and cardiac diseases to be correlated with a higher number of failed implants.

CONCLUSIONS

Within the limitations of this study, the results suggest no absolute contraindications for implant rehabilitation in a population of systemically compromised patients. Nevertheless, this study suggests that increasing age, rheumatological condition, cardiovascular condition, and hepatitis should be considered when performing implant-supported rehabilitations due to their negative influence on the outcome.

Attributable fractions, modifiable risk factors and risk stratification using a risk score for peri-implant pathology

PURPOSE

This study aimed to estimate the impact of risk factors for peri-implant pathology, to identify potentially modifiable factors, and to evaluate the accuracy of the risk algorithm, risk scores and risk stratification.

METHODS

This retrospective case-control study with 1275 patients (255 cases; 1020 controls) retrieved a model according to the predictors: history of Periodontitis, bacterial plaque, bleeding, bone level, lack of passive fit or non-optimal screw joint, metal-ceramic restoration, proximity to other implants/teeth, and smoking habits. Outcome measures were the attributable fraction; the positive and negative likelihood ratios at different disease cut-off points illustrated by the area under the curve statistic.

RESULTS

Six predictors may be modified or controlled directly by either the patient or the clinician, accounting for a reduction in up to 95% of the peri-implant pathology cases. The positive and negative likelihood ratios were 9.69 and 0.13, respectively; the area under the curve was 0.96; a risk score was developed, making the complex statistical model useful to clinicians.

CONCLUSIONS

Based on the results, six predictors for the incidence of peri-implant pathology can be modified to significantly improve the outcome. It was possible to stratify patients per risk category according to the risk score, providing a tool for clinicians to support their decision-making process.

Interruption of Electrical Conductivity of Titanium Dental Implants Suggests a Path Towards Elimination Of Corrosion

Peri-implantitis is an inflammatory disease that results in the destruction of soft tissue and bone around the implant. Titanium implant corrosion has been attributed to the implant failure and cytotoxic effects to the alveolar bone. We have documented the extent of titanium release into surrounding plaque in patients with and without peri-implantitis. An in vitro model was designed to represent the actual environment of an implant in a patient’s mouth. The model uses actual oral microbiota from a volunteer, allows monitoring electrochemical processes generated by biofilms growing on implants and permits control of biocorrosion electrical current. As determined by next generation DNA sequencing, microbial compositions in experiments with the in vitro model were comparable with the compositions found in patients with implants. It was determined that the electrical conductivity of titanium implants was the key factor responsible for the biocorrosion process. The interruption of the biocorrosion current resulted in a 4–5 fold reduction of corrosion. We propose a new design of dental implant that combines titanium in zero oxidation state for osseointegration and strength, interlaid with a nonconductive ceramic. In addition, we propose electrotherapy for manipulation of microbial biofilms and to induce bone healing in peri-implantitis patients.