Healing Screw Research Articles

Electrochemical Polishing of Ti and Ti6Al4V Alloy in Non-Aqueous Solution of Sulfuric Acid.

This paper reports the results of our study on electrochemical polishing of titanium and a Ti-based alloy using non-aqueous electrolyte. It was shown that electropolishing ensured the removal of surface defects, thereby providing surface smoothing and decreasing surface roughness. The research was conducted using samples made of titanium and Ti6Al4V alloy, as well as implant system elements: implant analog, multiunit, and healing screw. Electropolishing was carried out under a constant voltage (10-15 V) with a specified current density. The electrolyte used contained methanol and sulfuric acid. The modified surface was subjected to a thorough analysis regarding its surface morphology, chemical composition, and physicochemical properties. Scanning electron microscope images and profilometer tests of roughness confirmed significantly smoother surfaces after electropolishing. The surface profile analysis of processed samples also yielded satisfactory results, showing less imperfections than before modification. The EDX spectra showed that electropolishing does not have significant influence on the chemical composition of the samples.

SEM AND IN VIVO STUDY OF ADHESION CHARACTERISTICS OF TITANIUM AND POLYTETRAFLUOROETHYLENE SURFACES HEALING SCREWS

Background: The long-term maintenance of implants and the prostheses they support depends on many factors. Specifically, the patient's biotype is important where the presence of a significant thickness of keratinized gingiva should ensure the presence of a real biological seal, whose formation is also influenced by the healing screw. The healing screws normally used are made of titanium; however, their cost induces the dentist to use them for improper single use. The possibility of using materials other than titanium such as polytetrafluoroethylene (PTFE) for the construction of healing screws can therefore be advantageous. Objectives: The aim of this experimental clinical study is to test new PTFE healing screws by exploiting their chemical-physical characteristics and undoubted economic advantages. Materials and methods: 10 patients were taken into consideration and 2 implants were inserted in each. In each patient in the second phase, a titanium healing screw and a PTFE healing screw were inserted. After 7 days, they were removed to allow analysis under an electron microscope. Results: SEM analysis of the screws showed that the PTFE surface has the ability to accumulate much less organic material than the titanium control screws. Furthermore, PTFE healing screws have been shown to reduce the level of inflammation induced by reuse compared to traditional healing screws. Conclusions: the reduced cost of the PTFE screw, together with the intrinsic characteristics of the material, represent promising characteristics, which can make their use advantageous in clinical practice.

Peri-implantitis increases the risk of medication-related osteonecrosis of the jaws associated with osseointegrated implants in rats treated with zoledronate

This study evaluated the peri-implant tissues under normal conditions and under the influence of experimental peri-implantitis (EPI) in osseointegrated implants installed in the maxillae of rats treated with oncologic dosage of zoledronate. Twenty-eight senescent female rats underwent the extraction of the upper incisor and placement of a titanium dental implant (DI). After eight weeks was installated a transmucosal healing screw on DI. After nine weeks, the following groups were formed: VEH, ZOL, VEH-EPI and ZOL-EPI. From the 9th until the 19th, VEH and VEH-EPI groups received vehicle and ZOL and ZOL-EPI groups received zoledronate. At the 14th week, a cotton ligature was installed around the DI in VEH-EPI and ZOL-EPI groups to induce the EPI. At the 19th week, euthanasia was performed, and the maxillae were processed so that at the implanted sites were analyzed: histological aspects and the percentage of total bone tissue (PTBT) and non-vital bone tissue (PNVBT), along with TNFα, IL-1β, VEGF, OCN and TRAP immunolabeling. ZOL group presented mild persistent peri-implant inflammation, higher PNVBT and TNFα and IL-1β immunolabeling, but lower for VEGF, OCN and TRAP in comparison with VEH group. ZOL-EPI group exhibited exuberant peri-implant inflammation, higher PNVBT and TNFα and IL-1β immunolabeling when compared with ZOL and VEH-EPI groups. Zoledronate disrupted peri-implant environment, causing mild persistent inflammation and increasing the quantity of non-vital bone tissue. Besides, associated with the EPI there were an exacerbated inflammation and even greater increase in the quantity of non-vital bone around the DI, which makes this condition a risk factor for medication-related osteonecrosis of the jaws.

Immediate implant in the esthetic area when immediate loading is not an option: a clinical case report

Aims: Tooth extraction in the frontal area is associated with significant bone resorption, especially at sockets presenting with a thin buccal wall, such as most of the maxillary incisors. In the case of favorable residual hard and soft tissue anatomy, immediate implant placement in the esthetic area might be an opportunity to drive the alveolus healing course in the desired direction. Case presentation: In this clinical case, a fractured upper central incisor was replaced by an immediate two-piece implant covered with a healing screw. After 3 months, the implant was restored. The facial and interdental soft tissue was maintained with appreciable success at the 3-year follow-up visit. Conclusion: When immediate loading of the implant is not an option and the fresh extraction socket presents with fair soft tissue quality, the use of an interim healing screw might help sustain and prevent the shrinkage of peri-implant tissues. This simple technique might be a valuable option when there is no indication for adjunctive hard or soft tissue grafting or immediate loading feasibility conditions.

Investigation of maximum torque values in manual tightening of dental implant healing screws

Aims: This study aimed to investigate the change of the maximum torque values applied by the dentist according to the parameters of gender,dental experience and glove type used in the tightening processes applied manually by pre-graduated and post-graduated dentists to the implant superstructure parts. Methods: 24 dentists (11 Male, 13 Female) participated in our study.Participants were instructed to tighten the implant healing screw (Straumann Dental Implant System, Waldenberg, Switzerland) placed on the digital torque measuring device(Cap torque tester series TT01; Mark10, Copiague, NY)by applying maximum force with a manual wrench.Powdered latex gloves,powderfree latex gloves and sterile surgical gloves were made available to the participants in order to imitate the mouth conditions as much as possible.Manual tightening was repeated three times in each group,with at least three minutes duration. Data were recorded digitally and statistical analysis was performed with IBS SPSS statistics 22 program.Independent sample t-test and one-way Anova analysis were used to evaluate differences between groups, followed by the post-hoc Tukey test. Results: Maximum torque value for tightening with powdered latex gloves (20.01±5.55) N, powder free latex gloves (17.27± 4.34) N and surgical gloves (20.27±6.02) N was found.In addition, we did not find a statistically significant difference in terms of gender and dental experience,which are the other parameters we investigated. Conclusion: Gender, experience and glove type do not statistically affect the maximum torque to be applied in implant superstructure applications.

An Experimental Anodized Titanium Surface for Transgingival Dental Implant Elements-Preliminary Report.

The characteristics such as microtopography, physical and chemical properties influence the behavior of an implant in a soft tissue. Anodization-as a potent method of titanium alloy surface modification-of the transgingival abutment or healing screw, has achieved some improvement. One of the possible surface treatment method is low-pressure radiofrequency oxygen plasma treatment. The aim of the study was to evaluate the chemical properties and cytocompatibility of the experimental surface. Titanium discs made of grade-23 titanium alloy (Ti-6Al-4V) anodized (A sample) with different voltage parameters (28, 67, 78, and 98 V) were included in the study. Half of the samples regarded as the "S" group were additionally treated with low-pressure radiofrequency oxygen plasma treatment. The surfaces were characterized using scanning electron microscopy, X-ray spectroscopy and Raman spectroscopy, and electrochemically investigated via a corrosion test. Furthermore, two cell lines were used, including the CHO-compatible reference line and a primary human fibroblast line for the MTT assay; direct (contact) cytotoxicity of the materials was tested with the cells, and the growth of fibroblasts on the surfaces of the different materials was tested. The morphology of the "S"-treated samples did not differ from the morphology of only-anodized samples. However, the oxygen concentration on the surface in that group slightly increased by about 1% as a result of post-trial treatment. The highest corrosion resistance was observed for both A-78 V and S-78 V samples. The cytotoxicity assay revealed no changes in cell morphology or vitality. The MTT test proved comparable culture viability among all groups; however, the "S" samples showed statistically significantly higher fibroblast proliferation and adhesion scores compared to the "A" samples. Through the in vitro study, the low-pressure radiofrequency oxygen plasma treatment of the anodized Ti-6Al-4V alloy presented itself as an auspicious option in the field of transgingival element surface modification of implants.

Effect of tetracycline on IL-1β and IL-6 levels of the peri-implant sulcular fluid.

Background Inflammation in the implant-abutment interface is one of the main factors that can reduce implant stability. Therefore, this study investigated the effect of chlorhexidine, tetracycline, saliva, and a dry environment on the interleukin IL-1β and interleukin IL-6 levels of the gingival groove fluid at the implant-abutment interface.Methods Twenty-four (10 men and 14 women) patients referred to the Faculty of Dentistry for implant treatment, who met the inclusion criteria, were examined. Four different materials were used in each implant, including 2% chlorhexidine, 3% tetracycline, saliva, and a dry medium. Each test material was placed inside the implant screw during the anchorage session, and the healing screw was closed. Patients were then sampled in three implantation sessions and one month after prosthesis delivery. Interstitial fluid groove was used for sampling after cleaning the mouth (half an hour after three minutes of thorough brushing). The data were analyzed with SPSS 20 using ANOVA and relevant post hoc tests.Results There was a significant difference in the mean IL-6 and IL-1β levels between the four materials (P<0.05). IL-6β levels were similar in tetracycline and chlorhexidine but significantly higher than in saliva and the dry environment (P<0.05). IL-6 and IL-1β levels in the saliva were significantly higher than in the dry environment (P<0.05).Conclusion The use of tetracycline at the junction of implant and abutment reduces the inflammatory cytokines IL-6 and IL-1β.

CLINICALLY EVALUATED ACCURACY OF SINGLE GUIDED IMPLANTATIONS WITH TWO DIFFERENT SYSTEMS – PRELIMINARY RESULTS

Introduction: Guided single implant placement ensures an optimal implant position, enables in-surgery immediate loading, and creates a predisposition for predictable treatment results.&#x0D; Aim: This article aims to present the surgical and loading protocols and assess the accuracy of two guided implant systems.&#x0D; Materials and methods: Ten patients missing a single molar were included. The semi-guided procedures with the two implant systems – AB Dental and Alpha Bio-Tec, were randomly assigned to each participant. The computer-assisted planning was performed with Implant Studio (3Shape, Denmark). Surgical guides and long-term, temporary, screw-retained restorations were virtually generated within the 3Shape system. Surgical appliances were printed from SG resin (Formlabs, USA), and crowns were milled from Telio CAD (Ivoclar Vivadent, Lichtenstein). Planning accuracy was evaluated based on the crown’s fit and relation to the adjacent teeth and antagonists.&#x0D; Results and discussion: The patients included for preliminary analysis (6 female and 4 male) were with a mean age of 33.42. The youngest was 24, and the oldest 49 years old. There were no surgical and technical complications for the period of evaluation, which ranged from 1 to 3 months. The crown’s fit was excellent in 8 cases. In two cases, minor adjustments were necessary – 1 in relation to the antagonists and 1 to the adjacent teeth. In one case, a healing screw was placed for 48 hours to facilitate adequate soft-tissue space for the Ti-base. &#x0D; Conclusion: The preliminary results presented in this report suggest that the clinical and laboratory protocols used for guided implantation and immediate loading are highly efficient.

Thick soft tissues around implant-supported restoration; stable crestal bone levels?

The peri-implant tissue remodeling just after implant surgery forms a coagulum that occupies the space between mucosa and implant. This is invaded by neutrophils and a barrier forms around implant consisting of dense fibrin network. In another 2 weeks post surgery, it is replaced by connective tissue and vascular structures. In the crestal area, the proliferation of epithelium takes place and forms a junctional epithelium. The barrier epithelium around the implant matures in 6–8 weeks. Formation of biological width begins when the implant gets exposed to the oral environment. This could be through healing screw or prosthetic abutment depending on connection to the implant. It is said that thin or thick tissues have different approaches to healing as the blood supply is varied. Flap is raised during the second stage of implant surgery damaging the blood supply of surrounding tissues. Thin mucosa present around the implant crestal area might lead to more bone loss but not thick tissues as more blood vessels are present here. Bone turnover can lead to crestal bone loss up to 3.2 mm apical to soft-tissue margin. The thickness of the tissues may be a recognized biological factor that might lead to crestal bone stability. In this report, we describe three cases where bone remodeling was camouflaged by thick soft tissues around implant-supported restorations.

Porphyromonas Gingivalis Load is Balanced by 0.20% Chlorhexidine Gel. A Randomized, Double-Blind, Controlled, Microbiological and Immunohistochemical Human Study

Microbial contamination could compromise the stability of dental implants increasing the risk of inflammatory reactions in the surrounding soft tissues. In this human, randomized, double-blind, clinical study, the presence of Porphyromonas gingivalis on the healing abutment and the inflammatory infiltrate surrounding peri-implant soft tissues were investigated. Experiments were done in order to clarify the effect of 0.20% chlorhexidine (CHX) versus placebo, applied during each rehabilitation stage. Thirty patients (15 per group) were included. The load of adhering P. gingivalis on the healing screw were quantified by quantitative Polymerase Chain Reaction (qPCR) Taq-Man. Immunohistochemical analysis was carried out on the gingival biopsy. Moreover, clinical data were recorded. Analysis of variance and the Holm–Sidak test was used to evaluate differences between groups. The results showed a significant low presence of P. gingivalis load in healing abutments belonging to the 0.20% CHX group. Overall, the differences in terms of P. gingivalis DNA copy number between two groups were statistically significant (p < 0.01). All implants showed very low plaque and bleeding scores, but the placebo group appeared to have the highest expression of inflammation markers for T Lymphocytes, B Lymphocytes and macrophages Cluster definitions (CD3, CD20 and CD68). The use of 0.20% CHX could be recommended in all clinical procedures as it reduces significantly P. gingivalis load and host inflammatory response around implants.

Immediate molar implant placement and the anatomic harmony abutment + a case series

Background The placement of immediate implants in the posterior sector is a widespread procedure where the success and survival rates are similar to those of traditional protocols. However, large extraction sockets are difficult to seal without mucoperiosteal flap reflection, an implant preparation sequence that considerably deviates from typical manufacturer protocols, crestal socket morphology not amenable to standard healing abutment placement. Aim/Hypothesis The purpose of this case series are to assess related technique that will allow chairside manufacturing of custom healing abutments as also called the anatomic healing abutment for immediate molar placement. Material and Methods A 55-year-old nonsmoking male patient, with no systemic condition and a 42-year female healthy with no significant medical history patient had lost her lower first molars due to nonrestorable extensive decay. According to clinical and radiographic examination on the patient detecting decayed remaining roots in molar tooth and performed an extensive restoration presenting deep, subgingival distal decay on tooth. So that, we decided to extract related tooth and then perform immediate implant placement. After minimally traumatic tooth extractions, the alveolus was carefully cleaned and washed surgically with a saline solution, and dental implants (iRES SAGL) was placed in the center of the interradicular bone, in a type A position according to the Tarnow classification. After then a temporary abutment was fabricated utilizing flowable composite, which adapted to the socket architecture, to serve as a customized healing screw. It is called the anatomic or customised healing abutment. Results Uneventful healing was observed during this time period in this cases. It is important to note that the initial contour appeared to have been maintained. The anatomic harmony abutment ultimately allows for more predictable final restorations by providing the dental laboratory a restorative profile. thus idealizing the final restoration. The soft tissue margin was stable and the esthetic appearance of the implant site was well maintained and with no clinical signs of peri-implant inflammation and bleeding on probing. Conclusion and Clinical Implications Implants may be placed in ideal restorative positions at the time of mandibular molar extraction. With the anatomic harmony abutment technique, the soft tissues upon maturation closely resemble the natural root contour, which allows for the generation of esthetic and functional implant-supported restorations.

Impact of 0.5 mm vs 1.5 mm subcrestal implant placement on marginal bone loss and aesthetics ‐ 3‐year results of a multicenter RCT

Background Among the legends circulating in implant dentistry there is the belief that aesthetics can be improved by placing implants in a subcrestal position.In literature, there are only a few RCT evaluating the differences between crestal and subcrestal placement and their main outcome is limited to short term bone loss.The influence of implant depth in subcrestal placement on the mid-long term esthetic and biological outcomes remains poorly investigated, especially in conical connection implant. Aim/Hypothesis To evaluate if the placement of single dental implants either 0.5 or 1.5 mm subcrestally in healed bone crests has an impact on long term esthetic and biological outcomes. Material and Methods Sixty partially edentulous patients requiring two single implant-supported crowns were recruited from six centres. According to a split-mouth design , the two sites were randomly allocated either to 0.5 mm or 1.5 mm subcrestal implant placement. During the healing period of 3 months, surgical sites in aesthetic areas were closed while a one-stage approach with transgingival healing screw was followed in non-aesthetic areas . Provisional acrylic crowns were delivered and were replaced after 2 months by definitive metal-ceramic crowns. Patients were followed to 3 years after loading. Outcome measures were- crown and implant failures, complications, aesthetics assessed using the pink esthetic score (PES), peri-implant marginal bone level changes, and patient preference, recorded by blinded assessors. Results At delivery of definitive crowns, 2 months after loading, the mean pink aesthetic score was 11.2 ± 1.9 and 11.1 ± 1.5 for the 0.5 and 1.5 mm group, respectively. At 3 years after loading, the mean pink aesthetic score was 12 ± 1.9 and 12.2 ± 1.8 for the 0.5 and 1.5 mm group, respectively. There were no statistically significant differences between the two groups at 2 months (P = 0.626), at 1 year (P = 0.920) or at 3 years (P = 0.296). Three years after loading, patients of the 0.5 mm group lost on average 0.34 ± 0.87 mm and those of the 1.5 mm group 0.19 ± 0.54 mm, the difference being statistically significant (difference = 0.15 mm; 95% CI 0.00 to 0.30; P = 0.046). The implant placement was not reflected in patient preference. There were no differences in outcomes among centres. Conclusion and clinical implications Both surgical protocols resulted in very high esthetic outcome (PES > 12) and minimal bone resorption (<0.5 mm) after 3 years. A slightly lower bone resorption was measured with 1.5 mm subcrestal placement compared to 0.5 mm, with no impact on the esthetic score. This tends to show that deeper implant placement might be beneficial only regarding bone stability, which will be confirmed after 5 years of follow-up.

Retention force and allowable range of the angle of an implant-supported overdenture attachment system using healing screws and a silicone resilient denture liner

Statement of problemChanges in the intraoral condition immediately after implant placement and in patients using fixed prosthetic appliances with implant abutments cause problems that require the use of an easily adjustable implant-supported overdenture system. PurposeThe purpose of this in vitro study was to develop a simulated implant-supported overdenture attachment system by using healing screws for the patrix and a silicone resilient denture liner for the matrix and to investigate the initial retention force, time-course changes, and allowable range of the angle between attachments. Material and methodsTests on the retention force and allowable range of the angle were performed. Attachments using tissue-level healing screws (height: 2.0 and 3.0 mm) for the patrix and a silicone resilient denture liner for the matrix were prepared. In the retention force measurement test, the frequency of insertion and removal was set at 3 per day to simulate a 4-month relief period. The joined attachment model was pulled apart, and the maximum traction (N) required to remove it was defined as the retention force. The retention force was measured every 90 times (representing the number of insertions and removals per month). To test the allowable angle range, 2 patrices were used. The angle between the 2 patrices was set at 0, 10, 20, and 30 degrees, and the angular limit for joining with the matrix was measured. The initial retention force of the healing screw attachments was compared with that of a polymeric O-ring by using 1-way layout ANOVA followed by the Bonferroni test (α=.05). To analyze time-course changes in the 2 types of healing screw attachments, the retention force before insertion and removal was compared with that after repeated insertions and removals for each simulated period using 1-way layout ANOVA followed by the Dunnett test (α=.05). ResultsThe initial retention force of the 2.0- and 3.0-mm healing screws was 2.4 ±0.1 and 2.6 ±0.2 N. After repeating insertions and removals to simulate use for 4 months, the retention force of the 2.0- and 3.0-mm healing screws was 1.8 ±0.2 and 2.2 ±0.1 N, respectively, both showing significant differences from the initial retention force (P<.05). The allowable angle range test revealed that insertion and removal of the healing screws was possible up to 30 degrees. ConclusionsUnder the conditions of this in vitro study, repeated insertion and removal attenuated the retention force but was still equivalent to the retention force of the O-ring. The allowable range of the angle between patrices for insertion and removal was up to 30 degrees.

Maintaining Tissue Architecture in Immediate Implant Placement Following Extraction of Natural Teeth Using Custom Healing Screw

Maintaining Tissue Architecture in Immediate Implant Placement Following Extraction of Natural Teeth Using Custom Healing Screw

Evaluation of the Sealing Capability of the Implant Healing Screw by Using Real Time Volatile Organic Compounds Analysis: Internal Hexagon Versus Cone Morse.

Implant sealing capability is a crucial issue in assessment of implant success and peri-implant marginal bone loss. Clinical studies demonstrated presence of viable bacteria in the internal part of functioning implants during tissue healing. For this study, a volatile organic compounds (VOCs) emission test was developed to evaluate the existing "seal" between implant and healing screw. Two kinds of implant-screw connection were compared: 1) internal hexagon; and 2) cone Morse. Fifteen patients were enrolled in the study, three males and 12 females, who required fixed prosthetic rehabilitation. A total of 37 implants was placed, 23 with a cone Morse taper internal connection and 14 with a screw-retained internal hexagon abutment. VOCs real-time measures were performed in the implant site immediately after removing the healing screw. Statistical analysis was carried out. Results showed VOCs maximum peak amplitude in cone Morse versus internal hexagon showed significant difference (P <0.001), whereas VOCs time to peak showed no significant difference (P = 0.7). Use of the new methodology for the VOCs emission test may lead to important new data for understanding how the "failed" attachment of implant components, in two-part assemblies, may contribute to implant losses. In particular, study results support the hypothesis that the microgap of the implant-screw healing junction could cause differences in bacterial penetration. VOCs emission test evaluation represents a new diagnostic tool with an effective approach to quickly analyze, in real time, sealing capability of dental implants with healing screw interfaces.

Peri-Implant Bone Level Stability With and Without Platform Switching: A Six-Years Follow-Up Case

Purpose : The aim of this case is the long-term, clinical and radiographical, evaluation of bone resorption around implants rehabilitated with and without the platform switching. Materials and Methods : Two implants with external connection were placed in a 41 years old healthy woman in order to replace the upper right first molar and the upper right first premolar. The implant replacing the upper right first molar was managed, for both the healing screw and the final prosthesis, according to the platform switching paradigm (i.e. the healing screw and the final abutment were 1 mm narrower than the implant platform diameter), whereas for the other implant no platform switching was performed. The measurements of bone levels were carried out on intraoral radiographs, taken at 12 and 72 months after implant loading, using AutoCAD software on both the mesial and the distal aspect of each implant. Results : The bone loss around the implant with platform switching was, on average, 0.1 and 0.18 at 1 year and 6 years after loading, respectively; whereas, bone resorption around the implant without platform switching was, on average, 1.15 and 1.98 at 1 year and 6 years, respectively. Conclusions : Within the limits of the present study, the results obtained demonstrate that the platform switching can reduce peri-implant bone resorption by increasing long-term predictability of dental implants.

Implant Dentistry: Monitoring of Bacteria Along the Transmucosal Passage of the Healing Screw in Absence of Functional Load.

To assess the changes in bacterial profile along the transmucosal path of healing screws placed immediately after insertion of two-piece endosseus implants during the 4-month osseointegration phase, in absence of functional load. Two site-specific samples were collected at the peri-implant mucosa of the healing screws of 80 two-piece implants, for a total of 640 samples. Implants placement was performed following a single protocol with flapless technique, in order to limit bacterial contamination of the surgical site. Identical healing screws (5 mm diameter/4 mm height) were used for each of the 80 implants. During the 4 months of the study, the patients followed a standard oral care regimen with no special hygiene maneuvers at the collection sites. The present research documents that during the 4-month period prior to application of function load the bacterial profile of all sites exhibited a clear prevalence of cocci at the interface between implant neck and osteoalveolar crest margin. A potentially pathogenic bacterial flora developed only along the peri-implant transmucosal path.

Immediate Implant Placement in the Infected Site with Presence of a Pre-Existing Cyst: Report of Two Cases

Aim: The purpose of this report is to illustrate the possibility of inserting immediate implants into the fresh extraction sockets in the infected site with presence of a pre-existing cyst. Presentation of case: The 1 of two cases: A 31-year-old man, presented to severe periodontitis with presence of a pre-existing infected cysts developed, which was 5mm × 7mm on the labial side of mandible. The radiography showed that a large translucent image around the periapical portion of 31 with mobility of II° in mandible. The extraction and implantation including bone grafting to substitute 31 tooth had been performed in one appointment. One implant (14mm length × 3.7mm in diameter SIN implants Dentis, made in Korea) was inserted apically through a cyst cavity. Three months later, the second surgery phase (healing screw insertion) had been followed, and no sign of alternation of radiography and clinical indication after 18 months. The other, a 53-year-old man came to our attention, with presence of a pre-existing infected cyst on labial side of 42 tooth. We placed one implant in the infected position of the mandible with a small amount of heterologous bone after the elimination of the infected 42 tooth, the meticulous cleaning, and alveolar debridement. A second surgery phase had been done after three months. Discussion and conclusion: This report showed that the placement of immediate implants in presence of a pre-existing infected cyst may not be necessarily contraindicated if appropriate clinical procedures like antibiotic administration, meticulous cleaning, and alveolar debridement are performed before implant surgical procedure. Immediate placement of implants for replacement of teeth with the pre-existing infected cysts is a predictable treatment and can be indicated for replacing teeth lost. This report regards the immediate placement of an implant into a residual cyst; some anatomical, surgery techniques, clinical and pathological considerations arise from this case. Both implants were successfully osseointegrated, and the cysts were healed.

Marginal masticatory mucosa dimensional changes in immediate post-extractive implants: a 2year prospective cohort study.

The present two-year prospective cohort study was undertaken to evaluate marginal masticatory mucosa dimensional changes around immediate post-extractive implants positioned transgingivally with a non-submerged healing screw. Twenty-one immediate post-extractive implants from 21 patients were enrolled, peri-implant gap was filled with bovine bone mineral, and soft tissue was allowed to heal around a non-submerged healing screw. Post-extractive socket dimension was recorded. Intraoperative (T0) vertical distances: bone margin level (BML) from the bone margin to the implant platform and mucosal margin height (MMH) from marginal mucosa to implant platform were taken; MMH measurement was repeated 4months later (T4). Horizontal mucosal level (HML): from customized stent to marginal mucosa at 0, 4, 12, and 24months postoperatively (T0, T4, T12, T24) and vertical mucosal level (VML): from the stent to marginal mucosa at T4, T12, T24 were registered. One implant failed at 3weeks; in the remaining 20 cases the MMH, coronally positioned with respect to the BML ≅2mm at T0, showed a statistically significant vertical contraction of the mucosa at T4. Other vertical mucosal measurements (VML) did not show further changes over time. HML measures showed a, statistically significant, shrinkage of the mucosa on the transverse plane between T0/T12 and T0/T24 and between T4/T12 and T4/T24. Immediate post-extractive implant inserted transgingivally with a non-submerged healing screw and internal peri-implant gap filled with bovine bone mineral may favor an early and stable peri-implant soft tissue healing over 2years.

Influence of bacterial colonization of the healing screws on peri-implant tissue

Background/purposeA bacterial adhesion to implant surfaces is a first stage of peri-implant mucositis and peri-implantitis. The aim of this longitudinal study was to examine the quantitative and qualitative biofilm formation on healing screws and the presence of periodontal pathogens in peri-implant crevicular fluid (PCF). In each of the 30 participants, one healing screw was adapted to every single implant. Materials and methodsThirty patients, 18 females and 12 males, were selected. Thirty healing abutments were left in situ for 20, 30 and 90 days. At regular times, the presence/absence of bleeding on probing (BOP) was determined. The specific periodontal pathogens were determined in PCF, by polymerase chain reaction (PCR). After 20, 30 and 90 days, the healing screws were removed and analyzed to establish the total bacterial count by a culture method. ResultsBOP+ increased significantly after 90 days. Biofilm was detected on all healing abutments and the number of cultivable oral flora showed a significant increase from 20 days to 30 days and to 90 days. At 90 days, the anaerobic counts constituted the bulk of plaque examined and Veillonella spp. were present in higher percentages levels (19.82%) among the Gram-negative bacteria. No significant differences among the experimental groups were detected in the frequencies of detection of each monitored bacteria in PCF. ConclusionThe healing screws left in situ for a period of 90 days caused a peri-implant inflammation and the presence of periodontal pathogenic bacteria in the peri-implant sulcus, due to the plaque accumulation on screw surfaces.