Bone resorption around fixtures in edentulous patients treated with mandibular fixed tissue-integrated prostheses

The role of the general dental practitioner in the care of the implant patient

Introducing dental implants into a patient's oral health plan requires a collaborative effort between all members of the care team, including the "implant dentist" and referring general dental practitioner (GDP), should the treatment be carried out in a referral practice. This article aims to discuss the pivotal role referring general dental practitioners (GDPs) play in preparing patients for dental implant placement, whatever the setting for the planned treatment. An overview of the patient referral process is outlined, as is the role of GDPs in the ongoing maintenance of the dental implants and the patient's oral health. Furthermore, this article may be viewed as a road map for GDPs who refer patients to an "implant dentist" as part of their treatment plan.

Clinical and radiographic outcomes around 4 mandibular implant-retained overdentures in individuals with type 2 diabetes: A long-term retrospective study

OBJECTIVES

To report the implant survival rates, clinical, and radiographic status after a period of more than 5 years in the function of 4 inter-foraminal implants retaining mandibular overdentures (OVDs) in individuals with T2DM.

METHODS

78 completely edentulous participants with type 2 diabetic mellitus (T2DM) who had worn mandibular OVDs retained by 4 inter-foraminal implants for long-term functional life were selected for this study. The participants were divided into 2 groups according to glycosylated haemoglobin A1c (HbA1c) levels before implant placement: group I with an HbA1c value > 6.5 % (inadequately controlled T2DM), and group II with an HbA1c value ≤6.5 % (well-controlled T2DM). The inadequately controlled T2DM was further subdivided into 2 groups: Group IA with an HbA1c value > 6.5 % and ≤8 % (moderately controlled), and Group IB has an HbA1c value > 8 % (poorly controlled). Implant survival rate, plaque index (PI), bleeding on probing (BOP), probing depth (PD), and radiographic crestal bone level (CBL) around implants were measured.

RESULTS

Among 312 implants, 6 failed, 4 in well-controlled diabetics, and 2 in inadequately controlled diabetics. The overall survival rate was 98.07 %. The mean PI in group Ι was 36.4 (group IA =37.76, group IB = 34.27), and in group ΙΙ it was 19. The mean BOP in group Ι was 45.5 (group IA =47.84, group IB = 41.76), and in group ΙΙ it was 22. The mean PD in group Ι was 4.1 (group IA =4.3, group IB = 3.85) and in group ΙΙ was 2.2. The mean radiographic CBL in group Ι was 3.4 (group IA =3.7, group IB = 2.9), and in group ΙΙ was 1.5. Group IA exhibited a significantly greater level of PI, BOP, PD, and CBL compared to group IB and group IΙ (P1=0.017, P2=0.001).

CONCLUSIONS

Individuals with T2DM can benefit from 4 inter-foraminal implants retained mandibular OVDs, and their inability to maintain proper glucose control may not exclude implant success.

CLINICAL SIGNIFICANCE

This study is a significant step toward improving knowledge of options available for treatment and anticipated outcomes for T2DM completely edentulous populations undergoing implant therapy.

Does the crown-implant ratio affect the survival and complications of implant-supported prostheses? A systematic review

STATEMENT OF PROBLEM

The use of dental implants shorter than 10 mm in length increases the crown-implant ratio. Whether an increased crown-implant ratio affects the survival rate and complications is unclear.

PURPOSE

The purpose of this systematic review was to investigate the effect of the crown-implant ratio on the survival rate and complications of implant-supported prostheses.

MATERIALS AND METHODS

Five databases (PubMed, MEDLINE, Scopus, Google Scholar, and Cochrane) were electronically and manually searched for longitudinal studies with a follow-up period of 3 years or longer. The study question was "Does the crown-implant ratio affect survival rate and complications of implant-supported prostheses?" The outcomes investigated were implant survival rate, peri-implant bone resorption rate, implant fracture rate, and other technical complications in the implant components.

RESULTS

A total of 670 studies were identified from the research in the databases. By applying the inclusion and exclusion criteria to the full texts, 17 articles were included for descriptive analysis. Qualitative data analysis showed that the survival rate of implant-supported prostheses with a crown-implant ratio greater than 2 was 97.2%, and for a ratio lower than 1, it was about 97.6%. Moreover, 9 papers reported that increasing the crown-implant ratio reduced bone resorption, while 8 other studies reported no significant association between the increase in the crown-implant ratio and bone resorption.

CONCLUSIONS

No significant relationship was found between the crown-implant ratio and implant survival rate. However, increasing the crown-implant ratio is likely to decrease bone loss around the implant. Information was insufficient to analyze the relationship between the crown-implant ratio and technical complications in implant-supported prostheses.

Etiology, pathogenesis and treatment of peri-implantitis: A European perspective

Peri-implantitis is a plaque-associated pathological condition occurring in tissues around dental implants. It is characterized by inflammation in the peri-implant mucosa and progressive loss of supporting bone. Over the last 30 years, peri-implantitis has become a major disease burden in dentistry. An understanding of the diagnosis, etiology and pathogenesis, epidemiology, and treatment of peri-implantitis must be a central component in undergraduate and postgraduate training programs in dentistry. In view of the strong role of European research in periodontology and implant dentistry, the focus of this review was to address peri-implantitis from a European perspective. One component of the work was to summarize new and reliable data on patients with dental implants to underpin the relevance of peri-implantitis from a population perspective. The nature of the peri-implantitis lesion was evaluated through results presented in preclinical models and evaluations of human biopsy material together with an appraisal of the microbiological characteristics. An overview of strategies and outcomes presented in clinical studies on nonsurgical and surgical treatment of peri-implantitis is discussed with a particular focus on end points of therapy and recommendations presented in the S3 level Clinical Practice Guideline for the prevention and treatment of peri-implant diseases.

Difference in marginal bone loss around implants between short implant-supported partial fixed prostheses with and without cantilever: a retrospective clinical study

PURPOSE

To investigate the influence of cantilever prosthetic arm on the marginal bone loss (MBL) over time around dental implants supporting short fixed partial dentures (FPDs), in a record-based retrospective study.

METHODS

All cases of 3-unit implant-supported FPDs, supported by 2-3 implants, from the database of cases treated at one specialist clinic were considered for inclusion. Only implants with a minimum of 36 months of radiological follow-up were considered. Univariate linear regression models were used to compare MBL over time between 12 clinical covariates, after which a linear mixed-effects model was built.

RESULTS

One-hundred-thirty-nine patients (64 men, 75 women) with 164 3-unit implant-supported FPDs (333 implants supporting non-cantilevered FPDs, 94 supporting cantilevered FPDs) were included in the study. The patients were followed up clinically and radiographically for a mean of 154.1 ± 78.0 (min-max, 37.3-364.6) and 132.9 ± 77.3 months (min-max, 36.8-329.9), respectively. The total number of marginal bone level double measurements (mesial and distal sides of each implant) was 2909. FPDs with cantilever presented an estimated greater MBL over time compared to FPDs without cantilever. Bruxism, sex (women), implant (modified) surface, and (poor) bone quality were also associated with higher MBL over time.

CONCLUSIONS

The use of a cantilever extension is suggested to negatively affect the bone marginal level over time around implants supporting 3-unit FPDs. Due to the small difference of the estimated MBL over long periods of follow-up between the groups, it is a matter of debate if the observed negative effect may be of clinical significance.

Median mandibular flexure-the unique physiological phenomenon of the mandible and its clinical significance in implant restoration

Mandibular flexure, characterized by unique biomechanical behaviors such as elastic bending and torsion under functional loading, has emerged as a crucial factor in oral clinical diagnosis and treatment. This paper presents a comprehensive review of the current research status on mandibular flexure, drawing insights from relevant studies retrieved from the PubMed database (www.ncbi.nlm.nih.gov/pubmed), including research conclusions, literature reviews, case reports, and authoritative reference books. This paper thoroughly explores the physiological mechanisms underlying mandibular flexure, discussing different concurrent deformation types and the essential factors influencing this process. Moreover, it explores the profound implications of mandibular flexure on clinical aspects such as bone absorption around dental implants, the precision of prosthesis fabrication, and the selection and design of superstructure materials. Based on the empirical findings, this review provides crucial clinical recommendations. Specifically, it is recommended to exert precise control over the patients mouth opening during impression-taking. Those with a high elastic modulus or bone-tissue-like properties should be prioritized when selecting superstructure materials. Moreover, this review underscores the significance of customizing framework design to accommodate individual variations in facial morphology and occlusal habits. Future research endeavors in this field have the potential to advance clinical diagnosis and treatment approaches, providing opportunities for improvement.

Biomechanical Implications of Mandibular Flexion on Implant-Supported Full-Arch Rehabilitations: A Systematic Literature Review

BACKGROUND

Mandibular flexion (MF) is a complex biomechanical phenomenon, which involves a deformation of the mandible, due mainly to the contraction of the masticatory muscles, and it can have numerous clinical effects. The deformation of the lower jaw caused by mandibular flexion is generally very small, and it is often overlooked and considered irrelevant from a clinical point of view by many authors; however, it should be important to remember that median mandibular flexure (MMF) has a multifactorial aetiology. The main aim of the current systematic review is to highlight the different factors that can increase MF in order to help clinicians identify patients to whom they should pay more attention. As a secondary outcome, we wanted to analyse the preventive measures and suitable techniques to be adopted to minimise the negative effects of this phenomenon on oral fixed rehabilitations.

METHODS

The review, which was carried out in accordance with the "Preferred Reporting Items for Systematic reviews and Meta-Analyses" (PRISMA) flowchart, was recorded in the "International Prospective Register of Systematic Reviews" (PROSPERO). As research questions, "Patient/Population, Intervention, Comparison and Outcomes" (PICO) questions were employed. Using the ROBINS-I technique, the risk of bias in non-randomised clinical studies was evaluated.

RESULTS

The initial electronic search identified over 1300 potential articles, of which 54 studies were included in this systematic review. Information regarding the relationship between MF and individual factors, mandibular movements, impression taking, and fixed rehabilitations were obtained.

CONCLUSIONS

The studies included in this systematic review showed that MF is greater during protrusive movements, in the posterior areas of the lower jaw, and in patients with brachial facial type, greater jaw length; small gonial angle; and less density, length, and bone surface of the symphysis. The biomechanical effects of mandibular flexion on fixed restorations are debated. Prospective clinical and radiological observational studies should be conducted to evaluate the potential short-, medium-, and long-term consequences of MF.

Complications Associated with Metal Resin Fixed Complete Dentures Based on Implant Distribution

PURPOSE

To compare prevalence and type of complications associated with metal resin fixed complete dentures based on implant distribution.

MATERIALS AND METHODS

This retrospective study included data collected for a period of 12 years for patients treated with maxillary and mandibular implant-supported fixed complete dentures at Loma Linda University School of Dentistry. In total, 223 patient's charts were reviewed which included 100 maxillary and 123 mandibular fixed complete dentures. Implant distribution and prevalence of complications associated with each implant-supported fixed complete denture were documented. Tooth delamination, the most common complication associated with fixed complete dentures, was compared between 2 implant distribution groups in each arch. Covariates including age, sex, opposing arch, cantilever occluding units, and number of implants were evaluated to determine their association with tooth delamination. Data and hypotheses were statistically analyzed using descriptive statistics along with logistic regression model. All tests of hypotheses were considered statistically significant at an alpha level of 0.05.

RESULTS

In the maxillary arch, some effect of the prevalence of tooth delamination was seen for the group that had implants placed posterior to canine eminence but it was not statistically significant. Denture tooth delamination had the highest prevalence among complications irrespective of implant distribution. Significant denture tooth delamination was seen for patients with opposing fixed complete dentures in comparison to patients with removable opposing arch prostheses.

CONCLUSIONS

Implant distribution is not a significant factor related to metal resin fixed complete dentures. Opposing fixed complete dentures have a significantly higher association with denture tooth delamination.

U-shaped Splitting Technique vs Conventional Bone Grafting in Maxillary Facial Undercut for Dental Implants Placement: A Preliminary Randomized Controlled Clinical Trial

AIM

This prospective randomized clinical trial was designed to compare the apical U-shape splitting technique (AUST) combined with guided bone regeneration (GBR) vs GBR alone for horizontal bone augmentation in maxillary labial undercut areas.

MATERIALS AND METHODS

The study included twelve patients with labial undercuts that made their alveolar ridges not able to compass dental implants. They received a total of 14 dental implants in the anterior maxilla where 7 (group I) were placed after AUST with GBR and the other 7 (group II) after the conventional GBR. The clinical and radiographic evaluations were done preoperatively, after surgery, and 6 months later. Facial flap fracture, peri-implant health, ridge width (RW) gain and loss, marginal bone loss (MBL), and implant esthetics were measured. Data were analyzed and compared and for any of the used tests, results were considered statistically significant if p-value ≤ 0.05.

RESULTS

For group I, no fracture of the bone flap happened and the gain in RW was significantly higher at 6 months postoperatively. Marginal bone loss was similar for both groups. The total pink esthetic score was significantly higher in group I vs group II (p = 0.024).

CONCLUSION

Within the limitations of this study, it was concluded that AUST combined with GBR was more effective in RW gain than GBR alone and it provided a merit approach for restoring function and esthetics if labial fenestration was unavoidable during implant placement.

CLINICAL SIGNIFICANCE

Apical U-shape splitting technique for horizontal ridge augmentation is a valuable option for the benefit of patients in clinics who need dental implants and have anterior undercut areas that may lead to fenestration and usually requires onlay bone grafting which is less successful in maintaining the RW.

Peri-Implant Bone Loss and Overload: A Systematic Review Focusing on Occlusal Analysis through Digital and Analogic Methods

The present review aimed to assess the possible relationship between occlusal overload and peri-implant bone loss. In accordance with the PRISMA guidelines, the MEDLINE, Scopus, and Cochrane databases were searched from January 1985 up to and including December 2021. The search strategy applied was: (dental OR oral) AND implants AND (overload OR excessive load OR occlusal wear) AND (bone loss OR peri-implantitis OR failure). Clinical studies that reported quantitative analysis of occlusal loads through digital contacts and/or occlusal wear were included. The studies were screened for eligibility by two independent reviewers. The quality of the included studies was assessed using the Risk of Bias in Non-randomized Studies of Interventions (ROBINS-I) tool. In total, 492 studies were identified in the search during the initial screening. Of those, 84 were subjected to full-text evaluation, and 7 fulfilled the inclusion criteria (4 cohort studies, 2 cross-sectional, and 1 case-control). Only one study used a digital device to assess excessive occlusal forces. Four out of seven studies reported a positive correlation between the overload and the crestal bone loss. All of the included studies had moderate to serious overall risk of bias, according to the ROBINS-I tool. In conclusion, the reported data relating the occlusal analysis to the peri-implant bone level seem to reveal an association, which must be further investigated using new digital tools that can help to standardize the methodology.

A Three – Dimensional Finite Element Analysis of Polyetheretherketone PEEK in Dental Implant Prosthesis: A Novel Implant System

Purpose:

This current numerical investigation aim to evaluate the benefits of substituting Titanium with CRF- PEEK for better stress distribution in implant- bone interface.

Methods:

3D models of a dental implant for the first mandibular molar were constructed using the computed tomography (CT) scan. Four distinct models using a combination of titanium, carbon reinforced polyetheretherketone (CRF- PEEK), and zirconia for implant /abutment materials were studied. A three- dimensional finite element simulation was used to evaluate the stress distribution at the implant – bone interface under a compressive axial load of magnitude 120 N. A spherical indenter was used to simulate occlusal load.

Results:

Mesh independent study was converged for a very large number of elements. Finite element analysis showed: 1) there was no significant difference in the distribution pattern of stress at the implant – bone interface in the different material models studied, 2) the stress values for all prosthetic implant parts were well below the yield strength, 3) a larger deformation of PEEK implant versus titanium.

Conclusion:

The substitution of titanium with PEEK for the implant does not provide any better stress distribution and may lead to problems from the deformation of the implant.

Analysis of Residual Ridge Morphology in a Group of Edentulous Patients Seeking NHS Dental Implant Provision-A Retrospective Observational Lateral Cephalometric Study

A convenience sample of 154 edentulous patients referred for implant provision at a Regional National Health Service Dental Hospital in the North West of England were identified. The cephalometric radiographs that were taken as part of the patient baseline investigation were assessed. Digital tracing was used to measure the anterior maxillary and mandibular bone height and ridge angle with respect to the maxillary and mandibular planes. The mean height of the bone in the maxilla was found to be 14 mm, and the mean ridge angle for the anterior maxillary residual ridge is 104°. The mean height of bone in the mandible was 18 mm, while the mean ridge angle for the anterior mandibular residual ridge was 77°. Using the Cawood and Howell classification demonstrated that class VI mandibles were the most common. The cross-sectional shape of the mandible varied, with the triangular shape most common. Although there was adequate bone stock for implant placement in these cases, the mandibular residual ridge resorption presents a lingual inclination to the residual bone. The limited residual ridge position and inclination would dictate that conventional implant placement could be challenging.

[Study of the effect of the occlusal surface of a natural tooth and fixed partial dentures supported by dental implants on the stress distribution by finite element analysis]

OBJECTIVE

To study the effect of the occlusal surface of a natural tooth, cement-retained and screw-retained fixed partial dentures supported by dental implants and the coefficient of friction on the stress distribution in the peri-implant bone at maximum and minimum principal stresses.

MATERIAL AND METHODS

Study of maximum and minimum principal stresses in models with natural teeth and artificial crowns supported by dental implants, taking into account the coefficient of friction using the finite element analysis.

RESULTS

In models represented by fixed partial dentures supported by dental implants and a natural tooth, the maximum tensile stresses arise in the cortical bone in the cervical region of the artificial crown, and the maximum compressive stresses occur both in the cortical layer in the cervical region of the artificial crown and in the cervical region of the tooth. In models with two fixed partial dentures supported by dental implants or two natural teeth, the stress distributions in the cortical layers in the upper and lower jaw are almost identical.

CONCLUSION

Modeling the antagonist and adding to the FEA model is important in order to determine the precise and realistic direction of the resulting force vector. Amplification of the number of contact areas should be considered when modeling the occlusal surface of artificial crowns supported by dental implants.

Evaluation of hard and soft tissue changes around implant in partially edentulous patients: a clinico-radiographic study

Introduction

implant supported prosthesis has become a viable treatment option for missing teeth. An important tool to detect early changes around implants is the standardized assessment of peri-implant hard and soft tissue parameters. The purpose of this prospective study was to clinically and radiographically assess the soft and hard tissues around implants.

Methods

ten (10) patients with 13 implant supported prosthesis were included in the study. Clinical parameters plaque index (PI), gingival index (GI), modified sulcus bleeding index (mSBI), peri-implant Probing Depth (PD), gingival margin Level, width of keratinized mucosa (WKM) and implant mobility were measured at loading and at 3 and 6 months. The radiographic crestal bone loss and peri-apical implant radiolucencies were also evaluated at loading and at 3 and 6 months. Student paired t test and correlation and regression analysis was done to evaluate the effect of clinical variables over bone loss.

Results

there was decrease in the site specific PI, GI, mSBI and peri-implant PD and an increase in the gingival recession from baseline to 6 months. The WKM remained stable throughout the study. Significant crestal bone loss was observed around implants more on the distal as compared to the mesial aspect. No mobility or peri-apical implant radiolucency was observed. Regression analysis of the confounding variables with bone loss showed no significant effect.

Conclusion

the occlusal loading of implants after 6 months showed significant bone loss (<1mm), which was within acceptable limits and the soft tissues around implants were in good health.

Stress distribution around different abutments on titanium and CFR-PEEK implant with different prosthetic crowns under parafunctional loading: A 3D FEA study

Aim & objectives

Clinical trials had concluded a significant relationship between implant failure and bruxism. A three-dimensional (3D) finite element analysis (FEA) was done to evaluate the stress distribution in straight and angled abutments around titanium and carbon fiber-reinforced polyetheretherketone (CFR-PEEK) implant with 2 different prosthetic crowns under parafunctional loading.

Materials and method

Twelve 3D models of bone block were created representing the maxillary right premolar area with osseointegrated implants. The models were divided in two group; CFR-PEEK implant (n ​= ​6) and group titanium implant (n ​= ​6).Each group was subdivided based on implants with three different abutments (straight, 15°, 25° angled abutments) and having two different prosthetic crowns: porcelain fused to metal (PFM) and polyetheretherketone (PEEK). A vertical load of 1000 ​N was applied to the central fossa and an oblique load of 500 ​N (30°) was applied to the buccal incline of the palatal cusp. The von Mises stresses and principal stresses were analyzed using ANSYS software.

Results

CFR-PEEK and titanium implants produced similar stress in bone under vertical and oblique loading. Straight abutment showed better results than 15° and 25° angled abutments in all the groups. PEEK crown produced lesser stress than PFM crown under vertical and oblique loading.

Conclusion

The study concluded that straight abutment along with PEEK crown could be given in patients with bruxism to reduce the stress concentration in bone, thus preventing possible implant failure. Titanium and CFR-PEEK implants with straight abutments if given, then it should be provided with an occlusal splint.

A meta analysis for evaluation of marginal bone level changes at dental implants

Aim

The aim of this study was to assess the marginal bone level changes at dental implants after 1 year in function.

Methods

Detailed searches from PubMed databases were made. A MEDLINE search (PubMed) published in the English language from 1980 to December 2018 was included in this study.

Results

The electronic database research (MEDLINE) produced 166 corresponding articles. One hundred and twenty studies were excluded on the basis of abstract while the 46 researches were used chosen for full-text examination after the title and abstract testing, and 41 studies were excluded that did not meet the requirements of our inclusion and exclusion criteria. A total of 5 studies for a quantitative analysis were taken into account.

Conclusion

Within the limits of the study, the mean marginal bone loss (MBL) was found to be 0.56 mm. A statistically significant difference in the MBL was found between the various studies.

The comparative evaluation of transcrestal and lateral sinus floor elevation in sites with residual bone height ≤6 mm: A two-year prospective randomized study

OBJECTIVES

To compare clinical and radiographic outcomes between transcrestal sinus floor elevation (TSFE) and lateral sinus floor elevation (LSFE) approaches of simultaneous implant placement in atrophic maxilla.

MATERIALS AND METHODS

Patients with a residual bone height (RBH) ≤6 mm were enrolled and randomly assigned to TSFE and LSFE groups. Patients in both groups simultaneously underwent sinus floor elevation with bovine-derived xenograft and implant placement. Clinical and radiographic results were evaluated immediately after surgery and after 6, 12, 18, and 24 months. The endo-sinus bone gain (ESBG), apical implant bone height (ABH), endo-sinus bone-implant contact rate (EBICR), and crestal bone level (CBL) were assessed using panoramic radiographs.

RESULTS

Forty-one implants (TSFE: 21, LSFE: 20) were placed in cases with a mean RBH of 3.77 ± 1.16 mm. All implants obtained clinical success and satisfactory ESBG at 24 months. No significant differences were found in ESBG and ABH between two groups immediately after surgery, but LSFE group showed significantly higher values than TSFE group thereafter. Grafts in TSFE group reached stability 6 months earlier than that in LSFE group. In both groups, EBICR was almost 100%, and CBL showed no detectable changes.

CONCLUSIONS

LSFE can achieve higher ESBG 2 years after surgery. Otherwise, TSFE could be an alternative to LSFE, when the access for lateral window preparation is limited. Both approaches were highly predictable for RBH ≤6 mm during 24-month observation period for the implants placed simultaneously.

Utility of measuring anterior-posterior spread to determine distal cantilever length off a fixed implant-supported full-arch prosthesis: A review of the literature

BACKGROUND

Historically, anterior-posterior (AP) spread assessments were often used to determine the length that a distal cantilever could be extended off an implant-supported fixed full-arch prosthesis.

TYPES OF STUDIES REVIEWED

The authors searched the literature for articles that used AP spread to calculate cantilever size to be constructed off implants bearing a fixed implant-supported full-arch rehabilitation.

RESULTS

The data indicate that the relationship between AP spread and cantilever length is not linear and many influences (such as beam theory, cantilever size differences in the mandible versus maxilla, number and distribution of placed implants, prosthetic materials, and framework design) need to be considered when computing cantilever length with respect to fixed implant-supported prostheses.

PRACTICAL IMPLICATIONS

Recommendations using AP spread assessments to compute cantilever lengths have not been validated by means of prospective scientific evaluations. Therefore, AP spread evaluation is just one of many issues that need to be considered when determining distal cantilever length associated with a fixed full-arch implant-bearing prosthesis.

Electrochemical Behavior of Ti6Al4V Alloy Used in Dental Implants Immersed in Streptococcus gordonii and Fusobacterium nucleatum Solutions

The titanium alloy, Ti6Al4V, is used in dentistry for dental implants because of its excellent resistance to corrosion and its high biocompatibility. However, periimplantitis is considered the main reason for treatment failure. The Ti6Al4V alloy was used to study the corrosion behavior for dental implant applications, using an experimental arrangement of three electrodes with the bacteria Streptococcus gordonii and Fusobacterium nucleatum, in addition to Ringer's lactate as electrolytes, at 37 °C and a pH of 5.6. Their electrochemical behavior was studied by open circuit potential (OCP) and cyclic potentiodynamic polarization (CPP) according to ASTM G3-14 and ASTM G61-11, respectively. Scanning electron microscopy (SEM) was employed to determine the morphology of the alloy studied. An experimental model, in situ, was established with the bacteria present in an oral environment to understand the electrochemical behavior of the alloy used in dental implants. The greatest corrosion in Ti6Al4V alloy was produced by the medium that contained the bacterium Streptococcus gordonii, which is considered a primary colonizer. In addition, the Ti6Al4V alloy presented uniform corrosion in the three solutions at the different exposure times showing a negative hysteresis in CPP.

Effect of supporting implants inclination on stability of fixed partial denture: A finite element study

The aim of this finite element study was to analyze effect of supporting implants inclination on stress distribution in the bone for a four-unit fixed partial denture. A three-dimensional finite element model of mandibular molar section of the bone to receive implants was constructed. Three implant-supported fixed partial dentures, with null, moderate and wide tilting, of 0°, 15° and 30° implant inclinations, respectively, were modeled. A mechanical load of 10 MPa was applied in coronal–apical direction on bridge framework at the regions of crowns positions. The finite element analysis was performed, and von Mises stress levels were calculated. Peak stress concentration in the cortical bone was observed mostly around the implant necks, in inter-implants line. There was favorable stress distribution during loading, with peak stress being 90.04 MPa for 0°, which decreased to 54.33 MPa for 15° and 46.36 MPa for 30° inclination. The supporting implants inclination in fixed partial denture plays an important role in stress distribution and may be helpful in preventing bone loss and implant failure. This phenomenon is likely to be more pronounced in bones of poor quality. Within the limitation of this study, it seems that the inclination of implants in fixed partial denture has a favorable effect on stress distribution pattern values around the supporting implants.

Effect of Different Implant Designs on Strain and Stress Distribution under Non-Axial Loading: A Three-Dimensional Finite Element Analysis

Implant design evolved alongside the development of implant therapy. The purpose of this finite element analysis (FEA) study was to analyze the influence of different implant designs on the stress and strain distribution to the implants and surrounding bone. Three implant designs with the same length and diameter were used. The three-dimensional geometry of the bone was simulated with a cortical bone of three different thicknesses and two medullar bone densities: low density (150 Hounsfield units) and high density (850 Hounsfield units). A 30° oblique load of 150 N was applied to the implant restoration. Displacement and stress (von Mises) results were obtained for bone and dental implants. The strain and stress distributions to the bone were higher for the tissue-level implant for all types of bone. The maximum principal strain and stress decreased with an increase in cortical bone thickness for both cancellous bone densities. The distribution of the load was concentrated at the coronal portion of the bone and implants. All implants showed a good distribution of forces for non-axial loads, with higher forces concentrated at the crestal region of the bone–implant interface. Decrease in medullar bone density negatively affects the strain and stress produced by the implants.

Relevant Design Aspects to Improve the Stability of Titanium Dental Implants

Post-extractional implants and immediate loading protocols are becoming much more frequent in everyday clinical practice. Given the existing literature about tapered implants, the objective of this paper was to understand whether implant shape had a direct influence on the results of the insertion torque (IT) and implant stability quotient (ISQ). Seven tapered implant prototypes were developed and distributed into three groups and compared with a control cylindrical implant-VEGA by Klockner Implant System. The implants were inserted into bovine bone type III according to Lekholm and Zarb Classification. The sample size was n = 30 for the three groups. Final IT was measured with a torquemeter, and the ISQ was measured with Penguin Resonance Frequency Analysis (RFA). Modifications done to the Prototype I did not reveal higher values of the ISQ and IT when compared to VEGA. In the second group, when comparing the five prototypes (II-VI) with VEGA, it was seen that the values of the ISQ and IT were not always higher, but there were two values of the ISQ that were statistically significantly higher with the 4.0 mm diameter Prototypes II (76.3 ± 6.1) and IV (78 ± 3.7). Prototype VII was the one with higher and significant values of the ISQ and IT. In both diameters and in both variables, all differences were statistically significant enough to achieve the higher values of primary stability values (IT and ISQ). Given the limitations of this study, it can be concluded that when there is an increase of the diameter of the implant and body taper, there is an increase of the ISQ and IT, showing that the diameter of the implant is an important criteria to obtain higher values of primary stability.

Implant-based factor as possible risk for peri-implantitis

Peri-implantitis is currently a topic of major interest in implantology. Considered one of the main reasons of late implant failure, there is an emerged concern whether implant characteristics could trigger inflammatory lesion and loss of supporting bone. The purpose of this narrative review is to provide an evidence based overview on the influence of implant-based factors in the occurrence of peri-implantitis. A literature review was conducted addressing the following topics: implant surface topography; implant location; occlusal overload; time in function; prosthesis-associated factors (rehabilitation extension, excess of cement and implant-abutment connection); and metal particle release. Although existing data suggests that some implant-based factors may increase the risk of peri-implantitis, the evidence is still limited to consider them a true risk factor for peri-implantitis. In conclusion, further evidences are required to a better understanding of the influence of implant-based factors in the occurrence of peri-implantitis. Large population-based studies including concomitant analyses of implant- and patient-based factors are required to provide strong evidence of a possible association with peri-implantitis in a higher probability. The identification of these factors is essential for the establishment of strategies to prevent peri-implantitis.

Randomized controlled clinical trial on calcium phosphate coated and conventional SLA surface implants: 1-year study on survival rate and marginal bone level

BACKGROUND

Calcium phosphate (CaP)-coated surface showed enhanced contact osteogenesis around dental implant and finally accelerate osseointegration in early healing phase.

PURPOSE

The aim of this randomized controlled trial was to compare the peri-implant marginal bone level around uncoated and CaP-coated sandblasted, large-grit, acid-etched (SLA) surface implants during the first year after placement.

MATERIALS AND METHODS

This study was performed upon 34 patients with randomized and double-blinded design. Clinical and radiographic examinations were performed immediately after implant placement, at re-entry after 3 months, and after 12 months to evaluate the initial stability and change in the marginal bone level. The distance from the implant shoulder to the top of the bone-to-implant contact was defined as the marginal bone level, and its alteration was measured at 1 year after implant installation.

RESULTS

None of the implants failed, and most of them showed a marginal bone loss of less than 1 mm. Small changes in the bone level were noted at all sites in the control and test groups, and there were no clinically significant differences in the changes in the marginal bone.

CONCLUSION

Both CaP-coated and uncoated SLA surface implants showed comparably successful marginal bone stability without any complications during the first year after placement.

Efficacy of a Polyglycol Dimethacrylate-Based Adhesive in Sealing the Implant-Abutment Interface

PURPOSE

The purpose of this study was to assess the effectiveness of a polyglycol dimethacrylate-based adhesive in preventing bacterial leakage through implant-abutment interfaces (IAIs).

MATERIALS AND METHODS

After implant installation, the adhesive was applied in the experimental group (n = 10). None was applied in the control group (n = 10). Samples were collected from the inner walls of implants on days 0 and 90. The real-time polymerase chain reaction was used to detect bacterial DNA.

RESULTS

All samples from the control group, versus 30% from the experimental group, harbored bacterial DNA on day 90.

CONCLUSIONS

This polyglycol dimethacrylate-based adhesive may be used to seal the IAI. Further studies are warranted to verify its effectiveness over longer time periods.

The effect of different occlusal contact situations on peri-implant bone stress - A contact finite element analysis of indirect axial loading

Implant restoration is one of the basic treatments in dentistry today, yet implant loss from occlusal overload is still a problem. Complex biomechanical problems such as occlusal overload are often analyzed by means of the finite element method. This numerical method makes it possible to analyze in detail the influence that different loading situations have upon implants and tissues, which is a key element in optimizing these dental procedures. This study was designed to investigate the stress distribution in peri-implant bone of a single-tooth implant crown using the finite element method. The load was applied indirectly via an occluding tooth through a three and five contact setup into the implant crown. The friction coefficient values between the crown and antagonist were varied between 0.1 and 1.0. Additionally, three crowns with cusp inclinations of 20°, 30° and 40° were modeled. Non-linear contact computations indicated that an increase in friction changed the direction and magnitude of contact forces, which also led to reduced stresses in the bone. Furthermore, the stress magnitudes were higher when cusps of a greater inclination were used. The intensity of stress alterations was strongly dependent on the distribution and number of contacts, and the contact force vector. In maximum intercuspation, a resulting axial load due to well-distributed contacts prevented high stresses in bone even with high cusp inclinations and low friction. Therefore for long-term clinical success, particular attention should be paid to occlusal adjustment so as to prevent oblique loading onto dental implant restorations.

Effectiveness and compliance of an oscillating-rotating toothbrush in patients with dental implants: a randomized clinical trial

Background

The aim of this randomized clinical trial was to assess the efficacy of an oscillating-rotating toothbrush in reducing plaque and inflammation around dental implants.

Methods

Eighty patients presenting dental implants were enrolled in this study and assigned randomly to two different groups: 40 patients in the test group and 40 in the control one. Each patient in the test group received an oscillating-rotating toothbrush while in the control group patients kept using the manual toothbrush. Furthermore, the test group received a special toothbrush head designed for dental implants and another one for natural teeth. Domiciliary oral hygiene instructions were given to both groups. Periodontal parameters like plaque index (PI), bleeding on probing (BoP), and probing pocket depth (PPD) were recorded at the baseline and after 1 and 3 months.

Results

At the end of the study, the difference of plaque and bleeding indices with the baseline was statistically significant for both test and control groups (P < 0.0001). Implant sites showed higher values of both BoP and PI when compared to the natural teeth. In the second part of the study, comparing the 1–3-month period, the oscillating-rotating toothbrush was effective in reducing new plaque formation (P < 0.0001) and bleeding (P < 0.0001) both at the implant sites and the dental sites comparing to manual ones (P > 0.05). No significant differences were appreciated concerning the PPD.

Conclusions

The oscillating-rotating toothbrush can be successfully used for the plaque and bleeding control of the peri-implant tissues.

The effect of the heights and thicknesses of the remaining root segments on buccal bone resorption in the socket-shield technique: An experimental study in dogs

BACKGROUND

To date only a few studies have been done on the use of the socket-shield technique for preserving the resorption of the buccal bone in aesthetically sensitive sites. Besides, there have been no further studies on the effect of the heights and thicknesses of the remaining root segments on buccal bone resorption when using this method.

PURPOSE

The aim of this study was to evaluate the effect of different heights and thicknesses of the remaining root segments on bone resorption in the socket-shield technique.

MATERIALS AND METHODS

Four healthy female beagle dogs were used in this study. The third premolar (P3) and the fourth premolar (P4) on both sides of the mandible were hemisected in the buccal-lingual direction, and the clinical crown of the distal root was beheaded. In the experimental groups, the roots were worn down in the apical direction until they were located at the buccal crestal level (Group A) or 1 mm higher than that level (Group B). In the control group, the distal root segments were extracted. Then, implant placement was performed into the distal root. After 3 months of healing, the specimens were prepared for histological diagnosis.

RESULTS

There was no difference between Group A and Group B when using the socket-shield technique, but the results of both groups were better than those of the control group.

CONCLUSIONS

The height of the root segments has little effect on the bone absorption of alveolar bone, while the bone absorption was strongly influenced by the thickness of the root segments. More precisely, the absorption may decrease if the thickness of the root fragment increases, when the thickness of the root plate is in the 0.5-1.5 mm range.

The Dynamics in Implantation for Patients with Clefts

Objective

To investigate the stresses and strains of an endosseous dental implant in patients with different types of cleft palate in a finite element model.

Materials and Methods

Seven three-dimensional (3D) maxillary models were designed on a personal computer according to computed tomography slice data obtained from seven dry skulls. Next, computer-aided modification was performed on each model to produce three other 3D models with different cleft patterns. Thus, four model types with different cleft patterns were designed and termed NORM (without cleft), ALVEOLAR (only alveolar cleft), PALATAL (only palatal cleft), and COMPLETE (complete cleft). An implant was embedded into the molar region of each model, and a 300-N vertical load and 50-N horizontal load were applied to simulate mastication. Under these conditions, the stresses occurring at the implant-bone interface were calculated by finite element analysis.

Results

Different stress patterns were observed between the models with a palatal cleft (PALATAL and COMPLETE) and those without palatal cleft (NORM and ALVEOLAR). Regarding vertical load application, greater stresses occurred in PALATAL and COMPLETE types than in NORM and ALVEOLAR types. On application of a horizontal load, though the stresses did not show quantitative difference, their vector patterns differed.

Conclusion

In patients with palatal clefts, characteristic stress patterns occur on the bone-implant interface during mastication. This should be taken into consideration when performing an implant treatment in patients with clefts.

Fracture load of complete-arch implant-supported prostheses reinforced with nylon-silica mesh: An in vitro study

STATEMENT OF PROBLEM

Complete-arch implant-supported prostheses without a framework have a high risk of failure: a straightforward and inexpensive reinforcement material, such as nylon mesh, could improve their longevity.

PURPOSE

The purpose of this in vitro study was to evaluate a nylon-silica mesh compound on the fracture strength of acrylic resin and the fracture load of complete-arch implant-supported prostheses.

MATERIAL AND METHODS

Twenty-four complete mandibular arch implant-supported prostheses were divided into 2 groups according to cantilever length (molar and premolar) and subdivided into another 2 subgroups according to the presence or absence of reinforcing mesh. The specimens were submitted to a maximum load-to-fracture test in a universal testing machine, with a 100-N load cell, a 2 mm/min crosshead speed, and a spherical metal tip diameter of 4 mm at different points (molar and premolar). These were submitted to 1-way analysis of variance for repeated measurement and the post hoc Tukey multiple comparison test (α=.05).

RESULTS

The mean maximum load ±standard deviation for the molar group was 393.4 ±95.0 N with reinforcement and 305.4 ±76.3 N without reinforcement (P=.02); and for the premolar group was 1083.3 ±283.7 N with reinforcement and 605.3 ±90.5 N without reinforcement (P=.001).

CONCLUSIONS

Reinforcement with nylon mesh increased the mean maximum load of implant-supported complete-arch prostheses at both cantilever lengths. The cantilever to the premolar (5 mm) presented the highest maximum load values to fracture.

The Role of Occlusion in Implant Therapy: A Comprehensive Updated Review

PURPOSE

Occlusal overload may cause implant biomechanical failures, marginal bone loss, or even complete loss of osseointegration. Thus, it is important for clinicians to understand the role of occlusion in implant long-term stability. This systematic review updates the understanding of occlusion on dental implants, the impact on the surrounding peri-implant tissues, and the effects of occlusal overload on implants. Additionally, recommendations of occlusal scheme for implant prostheses and designs were formulated.

MATERIALS AND METHODS

Two reviewers completed a literature search using the PubMed database and a manual search of relevant journals. Relevant articles from January 1950 to September 20, 2015 published in the English language were considered.

RESULTS

Recommendations for implant occlusion are lacking in the literature. Despite this, implant occlusion should be carefully addressed.

CONCLUSION

Recommendations for occlusal schemes for single implants or fixed partial denture supported by implants include a mutually protected occlusion with anterior guidance and evenly distributed contacts with wide freedom in centric relation. Suggestions to reduce occlusal overload include reducing cantilevers, increasing the number of implants, increasing contact points, monitoring for parafunctional habits, narrowing the occlusal table, decreasing cuspal inclines, and using progressive loading in patients with poor bone quality. Protecting the implant and surrounding peri-implant bone requires an understanding of how occlusion plays a role in influencing long-term implant stability.

A Clinical Retrospective Study of Distal Extension Removable Partial Denture with Implant Surveyed Bridge or Stud Type Attachment

This study was performed to make comparative analysis of the clinical findings between the two different types of the implant-assisted removable partial dentures: removable partial dentures using implant surveyed bridge as an abutment (ISBRPD) and overdenture type of removable partial denture using implant attachment (IARPD). Implant cumulative survival rate, marginal bone resorption, probing depth, peri-implant inflammation, bleeding, plaque, calculus, and complications were evaluated on 24 patients who were treated with implants in conjunction with removable partial denture and have used them for at least 1 year (ISCRPD: n = 12; IARPD: n = 12). There was no failed implant and all implants were functioning without clinical mobility. Marginal bone loss of ISCRPD (1.44 ± 0.57 mm) was significantly lower than that of IARPD (p < 0.05). There was no significant difference in probing depth, peri-implant inflammation, bleeding, and plaque between the two groups (p > 0.05), while the calculus was significantly more observed in ISCRPD group than in IARPD group (p < 0.05). The retention loss of IARPD was the most common complication. Within the limits of the present study, it was found that well-planned ISBRPD was clinically appropriate. Longitudinal and systematic clinical studies are necessary to confirm these results.

Use of narrow-diameter implants in the posterior jaw: a systematic review

STATEMENT OF PROBLEM

Evidence is limited on the efficacy of narrow-diameter implants (NDIs) in the posterior jaw.

PURPOSE

The purpose of this systematic review was to assess the survival of NDIs and provide guidelines for their safe use.

MATERIALS AND METHODS

Electronic search of the English-language literature enriched by hand search to identify suitable publications was made. Only peer-reviewed clinical studies published from January 1990 through March 2014 were included.

RESULTS

Seventeen studies with a total of 1644 implants met the inclusion criteria, with an observation period from 1 up to 12 years. The mean survival rate of 98.6% was reported. Technical and other complications were observed.

CONCLUSION

Short-term clinical data suggest that NDIs may serve in the posterior jaw as an alternative to standard-diameter implants. However, certain clinical conditions must be observed to assure long-term success.

Stress and Inflammation as a Detrimental Combination for Peri-implant Bone Loss

The causes of peri-implant bone loss continue to be controversial. To determine the impact of biomechanical stress and inflammation, we investigated a total of 80 interforaminal implants in situ for more than 10 years. Two stress groups, with 14 patients each, were established: a low-stress situation with single-standing implants, and an increased-stress situation with splinted implants. To categorize inflammation, we introduced a Composite Inflammation Score using 4 inflammatory parameters. Peri-implant bone loss was calculated from digital panoramic radiographs. To differentiate between the effects of stress and inflammation, we compared bone loss in both stress groups at equivalent levels of inflammation. With greater Composite Inflammation Score values, a clear discrepancy between single-standing and splinted implants was evident (p = 0.117/0.000, regression analysis; p = 0.135/0.000, analysis of variance; p = 0.002, t tests). While stress and inflammation alone may not necessarily be detrimental factors, the presence of stress heightens peri-implant bone loss significantly as inflammation increases.

Occlusal trauma and mucositis or peri-implantitis?

BACKGROUND AND OVERVIEW

The aim of this study was to describe the effects of bruxism in peri-implant bone loss 6 years after the placement of a successful implant-supported prosthesis, to describe its treatment, and to propose a differential diagnosis of the lesion.

CASE DESCRIPTION

A 62-year-old, nonsmoking, systemically healthy partially edentulous woman received 2 osseointegrated implants in the mandibular left region, which supported a 3-element fixed prosthesis. Six years later, the patient reported the development of bruxism. Clinical examination results indicated bleeding on probing, deepening of the peri-implant sulcus, and marginal soft-tissue overgrowth. Radiographic images suggested peri-implant bone loss. The authors diagnosed the lesion as trauma from occlusion and mucositis. Treatment involved anti-infective therapy and the use of a bite platform, resulting in bone recovery after 10 months. These results were maintained for 4 years.

CONCLUSIONS AND PRACTICAL IMPLICATIONS

Considering the existing contradictions in the literature, this case highlights the role of trauma from occlusion in the onset, progression, and treatment of lesions produced by occlusal overload around osseointegrated implants. In addition, it provides clinical background on the outcomes of anti-infective therapy associated with the use of a bite platform in the treatment of combined lesions of mucositis and trauma from occlusion in osseointegrated implants.

Clinical evaluation of mandibular implant overdentures via Locator implant attachment and Locator bar attachment

PURPOSE

The aim of this study was to evaluate the clinical findings and patient satisfaction on implant overdenture designed with Locator implant attachment or Locator bar attachment in mandibular edentulous patients.

MATERIALS AND METHODS

Implant survival rate, marginal bone loss, probing depth, peri-implant inflammation, bleeding, plaque, calculus, complications, and satisfaction were evaluated on sixteen patients who were treated with mandibular overdenture and have used it for at least 1 year (Locator implant attachment: n=8, Locator bar attachment: n=8).

RESULTS

Marginal bone loss, probing depth, plaque index of the Locator bar attachment group were significantly lower than the Locator implant attachment group (P<.05). There was no significant difference on bleeding, peri-implant inflammation, and patient satisfaction between the two denture types (P>.05). The replacement of the attachment components was the most common complication in both groups. Although there was no correlation between marginal bone loss and plaque index, a significant correlation was found between marginal bone loss and probing depth.

CONCLUSION

The Locator bar attachment group indicates lesser marginal bone loss and need for maintenance, as compared with the Locator implant attachment group. This may be due to the splinting effect among implants rather than the types of Locator attachment.

Effect of cantilever length on stress distribution around implants in mandibular overdentures supported by two and three implants

Objective:

There is no definitive study comparing stress distribution around two versus three implants in implant-retained overdentures with different cantilever length. The purpose of this finite element study was to evaluate stress pattern around the implants of the 2 or 3 implant- supported mandibular overdenture with different cantilevered length.

Materials and Methods:

The models used in this study were 2 and 3 implant-supported overdenture with bar and clip attachment system on an edentulous mandibular arch. Each model was modified according to cantilever length (0 mm, 7 mm, and 13 mm); thus, 6 models were obtained. The vertical load of 15 and 30 pounds were applied unilaterally to the first molar and 15 pounds to the first premolar, and the stress in bone was analyzed.

Results:

With increasing cantilever length, no similar stress pattern changes were observed in different areas, but in most instances, an increase in cantilever length did not increase the stress around the implant adjacent to cantilever.

Conclusions:

Within the limitations of this study, it can be concluded that increasing of cantilever length in mandibular overdentures retained by 2–3 implants did not cause distinct increasing in stress, especially around the implant adjacent to cantilever, it may be helpful to use cantilever in cases of mandibular overdenture supported by splinted implants with insufficient retention and stability. Based on the findings of this study, optimal cantilever length in mandibular overdenture cannot be determined.

A prospective cross-over study to evaluate the effect of two different occlusal concepts on the masseter muscle activity in implant-retained mandibular overdentures

BACKGROUND

The purpose of this prospective cross-over study is to evaluate the effect of bilateral balanced occlusion and canine guidance occlusion on the masseter muscle activity using implant-retained mandibular overdentures.

METHODS

After evaluation of 12 completely edentulous patients using cone beam computed tomography (CBCT), mucoperiosteal flaps were reflected exposing the mandibular interforaminal region. Two implants were placed in the interforaminal region for each of the 12 patients. After a healing period of 3 months, acrylic maxillary complete dentures and mandibular overdentures were fabricated with bilateral balanced occlusion for 6 patients and canine guidance occlusion for the other 6 patients. Electromyographic evaluation of the masseter muscles, during clenching on a silicon index and chewing peanuts and cake, was conducted on the patients after using their dentures for 4 weeks. Each occlusion concept was then converted into the other concept using the same dentures, and the procedure of evaluation was repeated after 4 weeks. The recordings were analyzed statistically using Wilcoxon signed ranks test. p < 0.05 was considered statistically significant.

RESULTS

The highest electromyographic activity of the masseter muscles was recorded during clenching on a preformed silicon index followed by chewing peanut then cake for both occlusal concepts. The recordings of the masseter muscle associated with canine guidance occlusion were higher than bilateral balanced occlusion but with no statistically significant difference except between the right masseter muscles during clenching (p = 0.042*).

CONCLUSIONS

Both bilateral balanced occlusion and canine guidance occlusion can be used successfully in implant-retained mandibular overdentures without affecting masseter muscle activity.

Clinical importance of median mandibular flexure in oral rehabilitation: a review

The mandible has a property to flex inwards around the mandibular symphysis with change in shape and decrease in mandibular arch width during opening and protrusion of the mandible. The mandibular deformation may range from a few micrometres to more than 1 mm. The movement occurs because of the contraction of lateral pterygoid muscles that pulls mandibular condyles medially and causes a sagittal movement of the posterior segments. This movement of mandible can have a profound influence on prognosis and treatment outcome for various restorative, endodontics, fixed, removable and implant-related prosthesis. The review unfolds the causes, importance and clinical implications of median mandibular flexure in oral rehabilitation. This review also highlights the appropriate preventive measures and techniques that should be adopted by clinicians to minimise the effect of flexural movement of the jaw during oral rehabilitation. This would not only help clinicians to achieve a good prosthesis with accurate fit and longevity but also maintain the health of the surrounding periodontal or periimplant gingival tissues and bone.