xml: <clinical_study>
    <!-- This xml conforms to an XML Schema at:
      https://clinicaltrials.gov/ct2/html/images/info/public.xsd -->
    <required_header>
      <download_date>ClinicalTrials.gov processed this data on September 20, 2023</download_date>
      <link_text>Link to the current ClinicalTrials.gov record.</link_text>
      <url>https://clinicaltrials.gov/ct2/show/NCT06022042</url>
    </required_header>
    <id_info>
      <org_study_id>DHZhejiangU-2022(027)</org_study_id>
      <nct_id>NCT06022042</nct_id>
    </id_info>
    <brief_title>Clinical Comparison of On1 Two-stage Abutment With One-stage Abutment on Different Implant Neck Design</brief_title>
    <official_title>Clinical Comparison of On1 Two-stage Abutment With One-stage Abutment on Different Implant Neck Design</official_title>
    <sponsors>
      <lead_sponsor>
        <agency>Yi Zhou</agency>
        <agency_class>Other</agency_class>
      </lead_sponsor>
    </sponsors>
    <source>The Dental Hospital of Zhejiang University School of Medicine</source>
    <oversight_info>
      <has_dmc>No</has_dmc>
      <is_fda_regulated_drug>No</is_fda_regulated_drug>
      <is_fda_regulated_device>No</is_fda_regulated_device>
    </oversight_info>
    <brief_summary>
      <textblock>
        In clinical implant treatment, the healing abutment or temporary abutment needs to be removed&#xD;
        or replaced multiple times after implant insertion and before prosthesis restoration. During&#xD;
        this process, the friction between connective tissue around the implant cannot be avoided.&#xD;
        Different from natural periodontal tissue, soft tissue around the implant lacks the&#xD;
        periodontal ligament barrier and periodontal ligament blood supply, and is more likely to be&#xD;
        damaged during repeated wearing. The integrity, health and stability of the peri-implant&#xD;
        connective tissue is crucial to the implant osseointegratio. Through randomized controlled&#xD;
        trials and meta-analysis, Marco Tallarico et al found that repeated removal of one-stage&#xD;
        abutments can significantly increase bone resorption.&#xD;
  &#xD;
        Based on this situation, the design of implant neck and abutment, especially the design&#xD;
        concept of smooth collar, has attracted widespread attention. The design of smooth collars&#xD;
        with different heights can isolate the mechanical damage of the abutment to the connective&#xD;
        tissue around the implant to different degrees. Among them, the On1 two-stage abutment has a&#xD;
        smooth collar with a height of 1.75-2.5mm, and the Nobel implants have a smooth neck design&#xD;
        ranging from 0-0.75mm to protect the connective tissue around the implant. Through a&#xD;
        systematic review and meta-analysis, Qing-qing Wang et al concludes that direct mechanical&#xD;
        stimulation from the abutment has long-term adverse effects on peri-implant connective tissue&#xD;
        and bone tissue. However, whether the On1 two-stage abutment has a positive effect on the&#xD;
        stabilization of the peri-implant soft tissue and bone tissue remains to be studied.&#xD;
  &#xD;
        At the same time, the relative height of the smooth collar increased by the On1 abutment in&#xD;
        the implants with different neck designs varies to some extent, and further research is still&#xD;
        needed to provide evidence about the effect of the On1 abutment on the tissue surrounding the&#xD;
        implants with different neck designs. In conclusion, this study took On1 two-stage abutment&#xD;
        and traditional one-stage abutment as the research objects to compare and evaluate the&#xD;
        clinical effects of the two in different implant neck design.&#xD;
      </textblock>
    </brief_summary>
    <detailed_description>
      <textblock>
        Research purpose To compare the clinical effects of On1 two-stage abutment and one-stage&#xD;
        abutment in implants with different neck design.&#xD;
  &#xD;
        Research Design and Methods&#xD;
  &#xD;
          1. Type of study design: prospective intervention single-center randomized clinical trial&#xD;
  &#xD;
          2. Study period: 7 years&#xD;
  &#xD;
          3. Start time: from the date of ethics approval, end time: March 2029&#xD;
  &#xD;
          4. This study takes a single-blind method. During research process, the researchers cannot&#xD;
             avoid knowing the type of abutment used by the subjects during the clinical examination&#xD;
             and operation, so the subjects can only be single-blinded.&#xD;
  &#xD;
        Measures to control bias:&#xD;
  &#xD;
          1. Selection bias control: use the random number table method for grouping, and strictly&#xD;
             follow the blinding method. During the recruiting period, the researcher needs to fully&#xD;
             know the subjects and improve the understanding and compliance of the test; during the&#xD;
             recruiting period, at least 2 contact information should be left. In emergencies, the&#xD;
             subjects themselves can be contacted to minimize the rate of loss to follow-up; for&#xD;
             those fail to follow-up, data will be excluded in the follow-up statistical phase;&#xD;
  &#xD;
          2. Control of information bias: 1) rigorously design case report forms, 2) set up two 3)&#xD;
             Collect data on objective indicators as much as possible, conduct regular researcher&#xD;
             training, and unify evaluation standards;&#xD;
  &#xD;
          3. Control confounding bias: improve the study design, control single variable grouping,&#xD;
             and adopt reasonable statistical analysis methods.&#xD;
  &#xD;
        5. Subject inclusion criteria, exclusion criteria, and withdrawal criteria&#xD;
  &#xD;
        Inclusion criteria:&#xD;
  &#xD;
        (1) aged 18 years and above, 70 years old and below; (2) Single crown restoration after&#xD;
        implantation (3) Subjects signed written informed consent; (4) The general health status is&#xD;
        good and adhered to Good oral hygiene conditions; (5) no infection and extraction residues at&#xD;
        the implant site; (6) sufficient keratinized gingiva on the cheek and tongue; (7) good and&#xD;
        stable occlusal relationship; (8) the occlusal gap is higher than 4mm; (9) No other&#xD;
        additional operations are planned to perform.&#xD;
  &#xD;
        Exclusion criteria:&#xD;
  &#xD;
        (1) contraindications to general implant surgery; (2) uncontrolled diabetes mellitus; (3) any&#xD;
        signs of immunosuppression; (4) previous head and neck radiation therapy; (5) past or current&#xD;
        use of bisphosphonates treatment; (6) substance abuse; (7) nocturnal teeth grinding; (8)&#xD;
        signs of periodontitis; (9) smoking more than 10 cigarettes per day; (10) poor oral hygiene;&#xD;
        (11) mental disorders; (12) inability to complete follow-up; (13) History of night grinding.&#xD;
  &#xD;
        Withdrawal criteria:&#xD;
  &#xD;
        (1) abnormal vital organ function (2) poor compliance (3) serious adverse reactions (4) poor&#xD;
        efficacy (5) intolerance of adverse reactions (6) willing to take other treatment methods or&#xD;
        withdraw without any reason.&#xD;
  &#xD;
        6. Design plan and expected duration and specific arrangements for participating in clinical&#xD;
        trials: Subjects are expected to participate in clinical trials for 7 years, and need to&#xD;
        complete follow-up. Imaging examinations, including parallel projection X-rays and CBCT, are&#xD;
        required on the day of surgery, 3 months, 6 months, and 1-7 years after surgery.&#xD;
  &#xD;
        7. Trial suspension criteria: According to the clinical trial protocol, ① Controllable&#xD;
        adverse events occur, or safety problems are found, which can be reasonably controlled by&#xD;
        improving the research design or means. Suspend and adjust clinical trial protocols in a&#xD;
        timely manner. ② Some subjects could not avoid the influence of specific risks, so the trial&#xD;
        was suspended in time and susceptible subjects were excluded. ③ The data obtained are&#xD;
        extremely statistically significant. Apply for an interim analysis.&#xD;
  &#xD;
        Criteria for termination of the trial: ① There are serious adverse events, and the adverse&#xD;
        events are likely to be related to the intervention in the trial; ② External information&#xD;
        (such as other high-quality research or evidence) proves that the intervention is ineffective&#xD;
        or effective, and the current clinical trial is not necessary to continue, ③ According to the&#xD;
        planned interim analysis to achieve the expected difference in efficacy, if it has been&#xD;
        observed that the intervention program of the experimental group is significantly better than&#xD;
        that of the control group.&#xD;
  &#xD;
        Statistical analysis: The homogeneity of variance is planned to be tested within groups, the&#xD;
        outcome indicators of different groups are planned to be analyzed by variance between groups,&#xD;
        and further correlation analysis is planned to perform on indicators with significant&#xD;
        differences.&#xD;
  &#xD;
        8. The clinical observations, clinical examination values, imaging measurements, and clinical&#xD;
        scale scores generated by the investigator's examination in this study, and original records&#xD;
        were made. The source data record shall indicate the record time, record source and recorder.&#xD;
  &#xD;
        9. Main outcome measures: The degree of bone resorption at the shoulder edge of the implant,&#xD;
        the distance between the level of implant shoulder and the alveolar ridge.&#xD;
  &#xD;
        Secondary observation indicators: buccal bone wall thickness at 0/2/4/6 mm below the implant&#xD;
        shoulder; mesial and distal gingival papilla and buccal mucosa recession; abutment buccal&#xD;
        keratinized gingiva width; probing bleeding index; Red aesthetic index, subject&#xD;
        self-satisfaction, and time to subsidence of mucous membrane blushing when wearing teeth.&#xD;
  &#xD;
        10. The specific research plan is as follows: The researchers prospectively and continuously&#xD;
        recruited subjects who underwent implant therapy in the Oral Implantation Center of the&#xD;
        Stomatology Hospital Affiliated to Zhejiang University School of Medicine, and all subjects&#xD;
        who signed written informed consent were divided into 8 groups by random number table method:&#xD;
        ① On1 abutment + Nobel Replace Conical Connection PMC implant group (hereinafter referred to&#xD;
        as Nobel PMC), ②On1 abutment + Nobel Parallel™ Conical Connection implant group (hereinafter&#xD;
        referred to as Nobel PCC), ③On1 abutment + Nobel Replace Conical Connection implant group&#xD;
        (Hereinafter referred to as Nobel CC), ④ One-stage abutment + Nobel PMC implant set, ⑤&#xD;
        One-stage abutment + Nobel PCC implant set, ⑥ One-stage abutment + Nobel CC implant set. The&#xD;
        subjects' basic information, clinical and imaging findings were collected. Complete&#xD;
        preoperative examinations and records were carried out before surgery. Immediately&#xD;
        postoperatively, the width of the buccal keratinized gingiva of the healing abutment was&#xD;
        recorded and examined by imaging. Clinical examinations were performed 1 week, 3 months, 4&#xD;
        months, 6 months, and 1-7 years after surgery, including: mesial and distal gingival papilla&#xD;
        and buccal mucosa recession, and the width of the buccal keratinized gingiva of the abutment.&#xD;
        Among them, regular imaging examinations, including parallel projection X-rays and CBCT, were&#xD;
        performed immediately after surgery, 3 months after surgery, and 1-7 years after surgery.&#xD;
        Only small dental radiographs were taken 6 months after the operation.&#xD;
  &#xD;
        Sample Size Calculation&#xD;
  &#xD;
        The sample size of this study was estimated by G*Power software. To satisfy statistical&#xD;
        significance, set the conditions as t tests, α=0.05, 1-β=0.9. Referring to studies of the&#xD;
        same type [3], the effect size ES f=0.8 was set, and the minimum sample size of each group&#xD;
        was calculated to be 28. Based on the standard of 5% loss to follow-up rate, the number of&#xD;
        subjects recruited in each group of this study is set to be 30. The grouping design and&#xD;
        sample size are as follows:&#xD;
  &#xD;
        group design sample size On1 abutment + Nobel PMC implant set, 30 On1 Abutment + Nobel PCC&#xD;
        Implant Set 30 On1 Abutment + Nobel CC Implant Set 30 One-Stage Abutment + Nobel PMC Implant&#xD;
        Set 30 One-Stage Abutment + Nobel PCC Implant Set 30 One-Stage Abutment + Nobel CC Implant&#xD;
        Set 30 Data management and confidentiality&#xD;
  &#xD;
          1. The clinical examination data were measured and averaged by two independent clinicians,&#xD;
             recorded in the case collection form, and analyzed by a third person using spss19.0&#xD;
             statistical software to evaluate whether there were statistical differences. The imaging&#xD;
             data were called and analyzed by submitting an application to the Affiliated Stomatology&#xD;
             Hospital of Zhejiang University School of Medicine. During the process, the patient's&#xD;
             real name was hidden, and the data quality assurance management was carried out&#xD;
             according to the following requirements: ① Exclude all missing data, unused data and&#xD;
             illogical data. 2) Screening and sorting out the test data that meet the inclusion&#xD;
             criteria, forming a data set of observational safety and various clinical effects and&#xD;
             conducting statistical analysis.&#xD;
  &#xD;
          2. Modification procedure for deviation from the original statistical analysis plan: submit&#xD;
             a deviation report form to the ethics committee. In addition to the deviation statement,&#xD;
             the table shows the frequency of each type of deviation and its impact on the research&#xD;
             results. Behavior is explained and there are actions taken for deviations from the plan.&#xD;
  &#xD;
          3. All records related to the identity of the subjects are kept confidential, and these&#xD;
             materials will not be disclosed to the public outside the scope permitted by relevant&#xD;
             laws and/or regulations.&#xD;
  &#xD;
        Informed consent This study will be conducted by the research doctor in the Oral Implantation&#xD;
        Center of Zhejiang University Affiliated Stomatology Hospital, and the subjects will be&#xD;
        informed and informed consent will be obtained before surgery. The informed consent process&#xD;
        conforms to the principles of complete notification, full understanding, and independent&#xD;
        choice; the expression of informed consent is easy to understand and conforms to the level of&#xD;
        understanding of the subject group.&#xD;
  &#xD;
        This study does not involve vulnerable groups. All subjects will sign the informed consent&#xD;
        form by themselves.&#xD;
  &#xD;
        Adverse event reporting This study did not include measures and interventions other than&#xD;
        routine clinical treatment, and had no other adverse effects on the subjects.&#xD;
  &#xD;
        In the event of an adverse event, we will report it as follows:&#xD;
  &#xD;
        Various adverse events: Take timely measures to deal with them and record them in the case&#xD;
        report form.&#xD;
  &#xD;
        Serious adverse events (SAE): take measures to deal with them timely, and record in a case&#xD;
        report form, stop the trial at the decision of the investigator, immediately report to the&#xD;
        ethics committee, drug clinical trial institutions and sponsors, and report to national and&#xD;
        provincial food within 24 hours Drug Administration.&#xD;
      </textblock>
    </detailed_description>
    <overall_status>Recruiting</overall_status>
    <start_date type="Actual">March 1, 2022</start_date>
    <completion_date type="Anticipated">December 1, 2029</completion_date>
    <primary_completion_date type="Anticipated">December 1, 2029</primary_completion_date>
    <phase>N/A</phase>
    <study_type>Interventional</study_type>
    <has_expanded_access>No</has_expanded_access>
    <study_design_info>
      <allocation>Randomized</allocation>
      <intervention_model>Parallel Assignment</intervention_model>
      <intervention_model_description>The researchers prospectively and continuously recruited subjects who underwent implant therapy in the Oral Implantation Center of the Stomatology Hospital Affiliated to Zhejiang University School of Medicine, and all subjects who signed written informed consent were divided into 8 groups by random number table method: ① On1 abutment + Nobel Replace Conical Connection PMC implant group (hereinafter referred to as Nobel PMC), ②On1 abutment + Nobel Parallel™ Conical Connection implant group (hereinafter referred to as Nobel PCC), ③On1 abutment + Nobel Replace Conical Connection implant group (Hereinafter referred to as Nobel CC), ④ One-stage abutment + Nobel PMC implant set, ⑤ One-stage abutment + Nobel PCC implant set, ⑥ One-stage abutment + Nobel CC implant set.</intervention_model_description>
      <primary_purpose>Treatment</primary_purpose>
      <masking>Triple (Participant, Care Provider, Outcomes Assessor)</masking>
      <masking_description>This study takes a single-blind method. During research process, the researchers cannot avoid knowing the type of abutment used by the subjects during the clinical examination and operation, so the subjects can only be single-blinded.The clinical examination data were measured and averaged by two independent clinicians. The data was analysed by a third person.</masking_description>
    </study_design_info>
    <primary_outcome>
      <measure>The degree of bone resorption at the shoulder edge of the implant</measure>
      <time_frame>1-7 years</time_frame>
      <description>Thickness of the buccal bone plate 0 mm below the implant abutment (W1): Select the mid-axis of the implant in the sagittal plane.The thickness of the lateral buccal plate (W1) is determined by selecting the mid-axis of the implant in the sagittal plane and making a straight line perpendicular to the long axis of the implant to the buccal side of the implant table.&#xD;
  Thickness of the buccal bone plate 2、4、6 mm below the implant abutment (W2、W3、W4): select the sagittal implant centre axis and make a straight line perpendicular to the long axis of the implant, starting from the buccal bone plate.(W2、W3、W4): Choose the mid-axis of the implant in the sagittal plane and start from the buccal bone plate and make a straight line perpendicular to the long axis of the implant to the distance from the buccal side of the implant 2、4、6 mm below the shoulder table.</description>
    </primary_outcome>
    <primary_outcome>
      <measure>The distance between the level of implant shoulder and the alveolar ridge.</measure>
      <time_frame>1-7 years</time_frame>
      <description>The distance between the level of implant shoulder and the alveolar ridge.</description>
    </primary_outcome>
    <secondary_outcome>
      <measure>buccal bone wall thickness at 0/2/4/6 mm below the implant shoulder</measure>
      <time_frame>1-7 years</time_frame>
      <description>Level of the implant at the top of the proximal mesial alveolar ridge (HM): selecting the coronal implant mesial axis, the distance from the proximal mesial alveolar crest to the horizontal line of the implant abutment.&#xD;
  Level of the implant at the top of the distal mesial alveolar ridge (HD): Selection of the coronal implant mesial axis, distance from the top of the distal mesial alveolar ridge to the implant abutment level.The distance from the top of the crest to the horizontal line of the implant abutment.&#xD;
  Level of the implant at the apex of the buccal alveolar ridge (HB): distance from the apex of the buccal alveolar ridge to the level of the implant abutment, with the implant in the sagittal plane selected for the medial axis.</description>
    </secondary_outcome>
    <secondary_outcome>
      <measure>mesial and distal gingival papilla and buccal mucosa recession</measure>
      <time_frame>1-7 years</time_frame>
      <description>mesial and distal gingival papilla and buccal mucosa recession</description>
    </secondary_outcome>
    <secondary_outcome>
      <measure>abutment buccal keratinized gingiva width</measure>
      <time_frame>1-7 years</time_frame>
      <description>abutment buccal keratinized gingiva width</description>
    </secondary_outcome>
    <secondary_outcome>
      <measure>probing bleeding index</measure>
      <time_frame>1-7 years</time_frame>
      <description>probing bleeding index</description>
    </secondary_outcome>
    <secondary_outcome>
      <measure>Patients' self-satisfaction visual analogue scale score</measure>
      <time_frame>within 30 minutes</time_frame>
      <description>Patients were also assessed by visual anlog scale (VAS) for The degree of pain and self-satisfaction of wearing the teeth was assessed using the visual anlog scale (VAS) [11]. A 10 cm long scale with the leftmost end scored as 0 means no pain (unsatisfactory); the rightmost end scored as 0 means no pain (unsatisfactory); the rightmost end scored as 0 means no pain (unsatisfactory); and the rightmost end scored as 0 means no pain (unsatisfactory). (unsatisfactory); the right-most end of the scale was scored as 10, indicating severe pain (extremely satisfactory). The patient marks the scale according to his/her own feelings. The patient marks the scale according to his/her own feelings, with 1cm representing 1 point, and the indicated position is converted into the final score.</description>
    </secondary_outcome>
    <secondary_outcome>
      <measure>time to subsidence of mucous membrane blushing when wearing teeth</measure>
      <time_frame>within 30 minutes</time_frame>
      <description>time to subsidence of mucous membrane blushing when wearing teeth</description>
    </secondary_outcome>
    <number_of_arms>6</number_of_arms>
    <enrollment type="Anticipated">180</enrollment>
    <condition>Implant Site Reaction</condition>
    <arm_group>
      <arm_group_label>On1 Abutment + Nobel PMC implant Set</arm_group_label>
      <arm_group_type>Experimental</arm_group_type>
      <description>Subjects who takes implant therapy using On1 Abutment + Nobel PMC implant</description>
    </arm_group>
    <arm_group>
      <arm_group_label>On1 Abutment + Nobel PCC Implant Set</arm_group_label>
      <arm_group_type>Experimental</arm_group_type>
      <description>Subjects who takes implant therapy using On1 Abutment + Nobel PCC Implant</description>
    </arm_group>
    <arm_group>
      <arm_group_label>On1 Abutment + Nobel CC Implant Set</arm_group_label>
      <arm_group_type>Experimental</arm_group_type>
      <description>Subjects who takes implant therapy using On1 Abutment + Nobel CC Implant</description>
    </arm_group>
    <arm_group>
      <arm_group_label>One-Stage Abutment + Nobel PMC Implant Set</arm_group_label>
      <arm_group_type>Active Comparator</arm_group_type>
      <description>Subjects who takes implant therapy using One-Stage Abutment + Nobel PMC Implant</description>
    </arm_group>
    <arm_group>
      <arm_group_label>One-Stage Abutment + Nobel PCC Implant Set</arm_group_label>
      <arm_group_type>Active Comparator</arm_group_type>
      <description>Subjects who takes implant therapy using One-Stage Abutment + Nobel PCC Implant</description>
    </arm_group>
    <arm_group>
      <arm_group_label>One-Stage Abutment + Nobel CC Implant Set</arm_group_label>
      <arm_group_type>Active Comparator</arm_group_type>
      <description>Subjects who takes implant therapy using One-Stage Abutment + Nobel CC Implant</description>
    </arm_group>
    <intervention>
      <intervention_type>Device</intervention_type>
      <intervention_name>On1 two-stage abutment and one-stage abutment</intervention_name>
      <description>the On1 two-stage abutment has a smooth collar with a height of 1.75-2.5mm, and the Nobel implants have a smooth neck design ranging from 0-0.75mm to protect the connective tissue around the implant.</description>
      <arm_group_label>On1 Abutment + Nobel CC Implant Set</arm_group_label>
      <arm_group_label>On1 Abutment + Nobel PCC Implant Set</arm_group_label>
      <arm_group_label>On1 Abutment + Nobel PMC implant Set</arm_group_label>
      <arm_group_label>One-Stage Abutment + Nobel CC Implant Set</arm_group_label>
      <arm_group_label>One-Stage Abutment + Nobel PCC Implant Set</arm_group_label>
      <arm_group_label>One-Stage Abutment + Nobel PMC Implant Set</arm_group_label>
      <other_name>Nobel PMC implant, Nobel CC implant, Nobel PCC implant</other_name>
    </intervention>
    <eligibility>
      <criteria>
        <textblock>
          Inclusion Criteria:&#xD;
  &#xD;
            -  (1) aged 18 years and above, 70 years old and below; (2) Single crown restoration&#xD;
               after implantation (3) Subjects signed written informed consent; (4) The general&#xD;
               health status is good and adhered to Good oral hygiene conditions; (5) no infection&#xD;
               and extraction residues at the implant site; (6) sufficient keratinized gingiva on the&#xD;
               cheek and tongue; (7) good and stable occlusal relationship; (8) the occlusal gap is&#xD;
               higher than 4mm; (9) No other additional operations are planned to perform.&#xD;
  &#xD;
          Exclusion Criteria:&#xD;
  &#xD;
            -  (1) contraindications to general implant surgery; (2) uncontrolled diabetes mellitus;&#xD;
               (3) any signs of immunosuppression; (4) previous head and neck radiation therapy; (5)&#xD;
               past or current use of bisphosphonates treatment; (6) substance abuse; (7) nocturnal&#xD;
               teeth grinding; (8) signs of periodontitis; (9) smoking more than 10 cigarettes per&#xD;
               day; (10) poor oral hygiene; (11) mental disorders; (12) inability to complete&#xD;
               follow-up; (13) History of night grinding.&#xD;
        </textblock>
      </criteria>
      <gender>All</gender>
      <minimum_age>18 Years</minimum_age>
      <maximum_age>70 Years</maximum_age>
      <healthy_volunteers>No</healthy_volunteers>
    </eligibility>
    <overall_official>
      <last_name>Weida Li</last_name>
      <role>Principal Investigator</role>
      <affiliation>Stomatological Hospital Affiliated to Zhejiang University School of Medicine</affiliation>
    </overall_official>
    <overall_contact>
      <last_name>Yi Zhou</last_name>
      <phone>87217419</phone>
      <phone_ext>0571</phone_ext>
      <email>zhouyizyzyzy@163.com</email>
    </overall_contact>
    <overall_contact_backup>
      <last_name>Junru Wen</last_name>
      <phone>18080131510</phone>
      <phone_ext>+86</phone_ext>
      <email>wenjunru@zjkq.com.cn</email>
    </overall_contact_backup>
    <location>
      <facility>
        <name>The Stomatologic Hospital, School of Medicine, Zhejiang University</name>
        <address>
          <city>Hangzhou</city>
          <state>Zhejiang</state>
          <zip>310003</zip>
          <country>China</country>
        </address>
      </facility>
      <status>Recruiting</status>
      <contact>
        <last_name>Yi Zhou</last_name>
        <phone>87217419</phone>
        <phone_ext>0571</phone_ext>
        <email>zhouyizyzyzy@163.com</email>
      </contact>
      <contact_backup>
        <last_name>Junru Wen</last_name>
        <phone>18380131510</phone>
        <phone_ext>+86</phone_ext>
        <email>1103178170@qq.com</email>
      </contact_backup>
    </location>
    <location_countries>
      <country>China</country>
    </location_countries>
    <reference>
      <citation>Tallarico M, Caneva M, Meloni SM, Xhanari E, Covani U, Canullo L. Definitive Abutments Placed at Implant Insertion and Never Removed: Is It an Effective Approach? A Systematic Review and Meta-Analysis of Randomized Controlled Trials. J Oral Maxillofac Surg. 2018 Feb;76(2):316-324. doi: 10.1016/j.joms.2017.08.025. Epub 2017 Aug 24.</citation>
      <PMID>28923270</PMID>
    </reference>
    <reference>
      <citation>Wang QQ, Dai R, Cao CY, Fang H, Han M, Li QL. One-time versus repeated abutment connection for platform-switched implant: A systematic review and meta-analysis. PLoS One. 2017 Oct 19;12(10):e0186385. doi: 10.1371/journal.pone.0186385. eCollection 2017.</citation>
      <PMID>29049323</PMID>
    </reference>
    <verification_date>August 2023</verification_date>
    <study_first_submitted>March 9, 2022</study_first_submitted>
    <study_first_submitted_qc>August 30, 2023</study_first_submitted_qc>
    <study_first_posted type="Actual">September 1, 2023</study_first_posted>
    <last_update_submitted>August 30, 2023</last_update_submitted>
    <last_update_submitted_qc>August 30, 2023</last_update_submitted_qc>
    <last_update_posted type="Actual">September 1, 2023</last_update_posted>
    <responsible_party>
      <responsible_party_type>Sponsor-Investigator</responsible_party_type>
      <investigator_affiliation>The Dental Hospital of Zhejiang University School of Medicine</investigator_affiliation>
      <investigator_full_name>Yi Zhou</investigator_full_name>
      <investigator_title>Deputy Chief Physician, Deputy Director of Dental Implant Department</investigator_title>
    </responsible_party>
    <patient_data>
      <sharing_ipd>No</sharing_ipd>
    </patient_data>
    <!-- Results have not yet been posted for this study                                          -->
  </clinical_study>
  
  
text: download date: ClinicalTrials.gov processed this data on September 20, 2023
  link text: Link to the current ClinicalTrials.gov record.
  url: https://clinicaltrials.gov/ct2/show/NCT06022042
  org study id: DHZhejiangU-2022(027)
  nct id: NCT06022042
  lead sponsor: 
  has dmc: No
  is fda regulated drug: No
  is fda regulated device: No
  In clinical implant treatment, the healing abutment or temporary abutment needs to be removed
        or replaced multiple times after implant insertion and before prosthesis restoration. During
        this process, the friction between connective tissue around the implant cannot be avoided.
        Different from natural periodontal tissue, soft tissue around the implant lacks the
        periodontal ligament barrier and periodontal ligament blood supply, and is more likely to be
        damaged during repeated wearing. The integrity, health and stability of the peri-implant
        connective tissue is crucial to the implant osseointegratio. Through randomized controlled
        trials and meta-analysis, Marco Tallarico et al found that repeated removal of one-stage
        abutments can significantly increase bone resorption.
  
        Based on this situation, the design of implant neck and abutment, especially the design
        concept of smooth collar, has attracted widespread attention. The design of smooth collars
        with different heights can isolate the mechanical damage of the abutment to the connective
        tissue around the implant to different degrees. Among them, the On1 two-stage abutment has a
        smooth collar with a height of 1.75-2.5mm, and the Nobel implants have a smooth neck design
        ranging from 0-0.75mm to protect the connective tissue around the implant. Through a
        systematic review and meta-analysis, Qing-qing Wang et al concludes that direct mechanical
        stimulation from the abutment has long-term adverse effects on peri-implant connective tissue
        and bone tissue. However, whether the On1 two-stage abutment has a positive effect on the
        stabilization of the peri-implant soft tissue and bone tissue remains to be studied.
  
        At the same time, the relative height of the smooth collar increased by the On1 abutment in
        the implants with different neck designs varies to some extent, and further research is still
        needed to provide evidence about the effect of the On1 abutment on the tissue surrounding the
        implants with different neck designs. In conclusion, this study took On1 two-stage abutment
        and traditional one-stage abutment as the research objects to compare and evaluate the
        clinical effects of the two in different implant neck design.
  Research purpose To compare the clinical effects of On1 two-stage abutment and one-stage
        abutment in implants with different neck design.
  
        Research Design and Methods
  
          1. Type of study design: prospective intervention single-center randomized clinical trial
  
          2. Study period: 7 years
  
          3. Start time: from the date of ethics approval, end time: March 2029
  
          4. This study takes a single-blind method. During research process, the researchers cannot
             avoid knowing the type of abutment used by the subjects during the clinical examination
             and operation, so the subjects can only be single-blinded.
  
        Measures to control bias:
  
          1. Selection bias control: use the random number table method for grouping, and strictly
             follow the blinding method. During the recruiting period, the researcher needs to fully
             know the subjects and improve the understanding and compliance of the test; during the
             recruiting period, at least 2 contact information should be left. In emergencies, the
             subjects themselves can be contacted to minimize the rate of loss to follow-up; for
             those fail to follow-up, data will be excluded in the follow-up statistical phase;
  
          2. Control of information bias: 1) rigorously design case report forms, 2) set up two 3)
             Collect data on objective indicators as much as possible, conduct regular researcher
             training, and unify evaluation standards;
  
          3. Control confounding bias: improve the study design, control single variable grouping,
             and adopt reasonable statistical analysis methods.
  
        5. Subject inclusion criteria, exclusion criteria, and withdrawal criteria
  
        Inclusion criteria:
  
        (1) aged 18 years and above, 70 years old and below; (2) Single crown restoration after
        implantation (3) Subjects signed written informed consent; (4) The general health status is
        good and adhered to Good oral hygiene conditions; (5) no infection and extraction residues at
        the implant site; (6) sufficient keratinized gingiva on the cheek and tongue; (7) good and
        stable occlusal relationship; (8) the occlusal gap is higher than 4mm; (9) No other
        additional operations are planned to perform.
  
        Exclusion criteria:
  
        (1) contraindications to general implant surgery; (2) uncontrolled diabetes mellitus; (3) any
        signs of immunosuppression; (4) previous head and neck radiation therapy; (5) past or current
        use of bisphosphonates treatment; (6) substance abuse; (7) nocturnal teeth grinding; (8)
        signs of periodontitis; (9) smoking more than 10 cigarettes per day; (10) poor oral hygiene;
        (11) mental disorders; (12) inability to complete follow-up; (13) History of night grinding.
  
        Withdrawal criteria:
  
        (1) abnormal vital organ function (2) poor compliance (3) serious adverse reactions (4) poor
        efficacy (5) intolerance of adverse reactions (6) willing to take other treatment methods or
        withdraw without any reason.
  
        6. Design plan and expected duration and specific arrangements for participating in clinical
        trials: Subjects are expected to participate in clinical trials for 7 years, and need to
        complete follow-up. Imaging examinations, including parallel projection X-rays and CBCT, are
        required on the day of surgery, 3 months, 6 months, and 1-7 years after surgery.
  
        7. Trial suspension criteria: According to the clinical trial protocol, ① Controllable
        adverse events occur, or safety problems are found, which can be reasonably controlled by
        improving the research design or means. Suspend and adjust clinical trial protocols in a
        timely manner. ② Some subjects could not avoid the influence of specific risks, so the trial
        was suspended in time and susceptible subjects were excluded. ③ The data obtained are
        extremely statistically significant. Apply for an interim analysis.
  
        Criteria for termination of the trial: ① There are serious adverse events, and the adverse
        events are likely to be related to the intervention in the trial; ② External information
        (such as other high-quality research or evidence) proves that the intervention is ineffective
        or effective, and the current clinical trial is not necessary to continue, ③ According to the
        planned interim analysis to achieve the expected difference in efficacy, if it has been
        observed that the intervention program of the experimental group is significantly better than
        that of the control group.
  
        Statistical analysis: The homogeneity of variance is planned to be tested within groups, the
        outcome indicators of different groups are planned to be analyzed by variance between groups,
        and further correlation analysis is planned to perform on indicators with significant
        differences.
  
        8. The clinical observations, clinical examination values, imaging measurements, and clinical
        scale scores generated by the investigator's examination in this study, and original records
        were made. The source data record shall indicate the record time, record source and recorder.
  
        9. Main outcome measures: The degree of bone resorption at the shoulder edge of the implant,
        the distance between the level of implant shoulder and the alveolar ridge.
  
        Secondary observation indicators: buccal bone wall thickness at 0/2/4/6 mm below the implant
        shoulder; mesial and distal gingival papilla and buccal mucosa recession; abutment buccal
        keratinized gingiva width; probing bleeding index; Red aesthetic index, subject
        self-satisfaction, and time to subsidence of mucous membrane blushing when wearing teeth.
  
        10. The specific research plan is as follows: The researchers prospectively and continuously
        recruited subjects who underwent implant therapy in the Oral Implantation Center of the
        Stomatology Hospital Affiliated to Zhejiang University School of Medicine, and all subjects
        who signed written informed consent were divided into 8 groups by random number table method:
        ① On1 abutment + Nobel Replace Conical Connection PMC implant group (hereinafter referred to
        as Nobel PMC), ②On1 abutment + Nobel Parallel™ Conical Connection implant group (hereinafter
        referred to as Nobel PCC), ③On1 abutment + Nobel Replace Conical Connection implant group
        (Hereinafter referred to as Nobel CC), ④ One-stage abutment + Nobel PMC implant set, ⑤
        One-stage abutment + Nobel PCC implant set, ⑥ One-stage abutment + Nobel CC implant set. The
        subjects' basic information, clinical and imaging findings were collected. Complete
        preoperative examinations and records were carried out before surgery. Immediately
        postoperatively, the width of the buccal keratinized gingiva of the healing abutment was
        recorded and examined by imaging. Clinical examinations were performed 1 week, 3 months, 4
        months, 6 months, and 1-7 years after surgery, including: mesial and distal gingival papilla
        and buccal mucosa recession, and the width of the buccal keratinized gingiva of the abutment.
        Among them, regular imaging examinations, including parallel projection X-rays and CBCT, were
        performed immediately after surgery, 3 months after surgery, and 1-7 years after surgery.
        Only small dental radiographs were taken 6 months after the operation.
  
        Sample Size Calculation
  
        The sample size of this study was estimated by G*Power software. To satisfy statistical
        significance, set the conditions as t tests, α=0.05, 1-β=0.9. Referring to studies of the
        same type [3], the effect size ES f=0.8 was set, and the minimum sample size of each group
        was calculated to be 28. Based on the standard of 5% loss to follow-up rate, the number of
        subjects recruited in each group of this study is set to be 30. The grouping design and
        sample size are as follows:
  
        group design sample size On1 abutment + Nobel PMC implant set, 30 On1 Abutment + Nobel PCC
        Implant Set 30 On1 Abutment + Nobel CC Implant Set 30 One-Stage Abutment + Nobel PMC Implant
        Set 30 One-Stage Abutment + Nobel PCC Implant Set 30 One-Stage Abutment + Nobel CC Implant
        Set 30 Data management and confidentiality
  
          1. The clinical examination data were measured and averaged by two independent clinicians,
             recorded in the case collection form, and analyzed by a third person using spss19.0
             statistical software to evaluate whether there were statistical differences. The imaging
             data were called and analyzed by submitting an application to the Affiliated Stomatology
             Hospital of Zhejiang University School of Medicine. During the process, the patient's
             real name was hidden, and the data quality assurance management was carried out
             according to the following requirements: ① Exclude all missing data, unused data and
             illogical data. 2) Screening and sorting out the test data that meet the inclusion
             criteria, forming a data set of observational safety and various clinical effects and
             conducting statistical analysis.
  
          2. Modification procedure for deviation from the original statistical analysis plan: submit
             a deviation report form to the ethics committee. In addition to the deviation statement,
             the table shows the frequency of each type of deviation and its impact on the research
             results. Behavior is explained and there are actions taken for deviations from the plan.
  
          3. All records related to the identity of the subjects are kept confidential, and these
             materials will not be disclosed to the public outside the scope permitted by relevant
             laws and/or regulations.
  
        Informed consent This study will be conducted by the research doctor in the Oral Implantation
        Center of Zhejiang University Affiliated Stomatology Hospital, and the subjects will be
        informed and informed consent will be obtained before surgery. The informed consent process
        conforms to the principles of complete notification, full understanding, and independent
        choice; the expression of informed consent is easy to understand and conforms to the level of
        understanding of the subject group.
  
        This study does not involve vulnerable groups. All subjects will sign the informed consent
        form by themselves.
  
        Adverse event reporting This study did not include measures and interventions other than
        routine clinical treatment, and had no other adverse effects on the subjects.
  
        In the event of an adverse event, we will report it as follows:
  
        Various adverse events: Take timely measures to deal with them and record them in the case
        report form.
  
        Serious adverse events (SAE): take measures to deal with them timely, and record in a case
        report form, stop the trial at the decision of the investigator, immediately report to the
        ethics committee, drug clinical trial institutions and sponsors, and report to national and
        provincial food within 24 hours Drug Administration.
  allocation: Randomized
  intervention model: Parallel Assignment
  intervention model description: The researchers prospectively and continuously recruited subjects who underwent implant therapy in the Oral Implantation Center of the Stomatology Hospital Affiliated to Zhejiang University School of Medicine, and all subjects who signed written informed consent were divided into 8 groups by random number table method: ① On1 abutment + Nobel Replace Conical Connection PMC implant group (hereinafter referred to as Nobel PMC), ②On1 abutment + Nobel Parallel™ Conical Connection implant group (hereinafter referred to as Nobel PCC), ③On1 abutment + Nobel Replace Conical Connection implant group (Hereinafter referred to as Nobel CC), ④ One-stage abutment + Nobel PMC implant set, ⑤ One-stage abutment + Nobel PCC implant set, ⑥ One-stage abutment + Nobel CC implant set.
  primary purpose: Treatment
  masking: Triple (Participant, Care Provider, Outcomes Assessor)
  masking description: This study takes a single-blind method. During research process, the researchers cannot avoid knowing the type of abutment used by the subjects during the clinical examination and operation, so the subjects can only be single-blinded.The clinical examination data were measured and averaged by two independent clinicians. The data was analysed by a third person.
  measure: The degree of bone resorption at the shoulder edge of the implant
  time frame: 1-7 years
  description: Thickness of the buccal bone plate 0 mm below the implant abutment (W1): Select the mid-axis of the implant in the sagittal plane.The thickness of the lateral buccal plate (W1) is determined by selecting the mid-axis of the implant in the sagittal plane and making a straight line perpendicular to the long axis of the implant to the buccal side of the implant table.
  Thickness of the buccal bone plate 2、4、6 mm below the implant abutment (W2、W3、W4): select the sagittal implant centre axis and make a straight line perpendicular to the long axis of the implant, starting from the buccal bone plate.(W2、W3、W4): Choose the mid-axis of the implant in the sagittal plane and start from the buccal bone plate and make a straight line perpendicular to the long axis of the implant to the distance from the buccal side of the implant 2、4、6 mm below the shoulder table.
  measure: The distance between the level of implant shoulder and the alveolar ridge.
  time frame: 1-7 years
  description: The distance between the level of implant shoulder and the alveolar ridge.
  measure: buccal bone wall thickness at 0/2/4/6 mm below the implant shoulder
  time frame: 1-7 years
  description: Level of the implant at the top of the proximal mesial alveolar ridge (HM): selecting the coronal implant mesial axis, the distance from the proximal mesial alveolar crest to the horizontal line of the implant abutment.
  Level of the implant at the top of the distal mesial alveolar ridge (HD): Selection of the coronal implant mesial axis, distance from the top of the distal mesial alveolar ridge to the implant abutment level.The distance from the top of the crest to the horizontal line of the implant abutment.
  Level of the implant at the apex of the buccal alveolar ridge (HB): distance from the apex of the buccal alveolar ridge to the level of the implant abutment, with the implant in the sagittal plane selected for the medial axis.
  measure: mesial and distal gingival papilla and buccal mucosa recession
  time frame: 1-7 years
  description: mesial and distal gingival papilla and buccal mucosa recession
  measure: abutment buccal keratinized gingiva width
  time frame: 1-7 years
  description: abutment buccal keratinized gingiva width
  measure: probing bleeding index
  time frame: 1-7 years
  description: probing bleeding index
  measure: Patients' self-satisfaction visual analogue scale score
  time frame: within 30 minutes
  description: Patients were also assessed by visual anlog scale (VAS) for The degree of pain and self-satisfaction of wearing the teeth was assessed using the visual anlog scale (VAS) [11]. A 10 cm long scale with the leftmost end scored as 0 means no pain (unsatisfactory); the rightmost end scored as 0 means no pain (unsatisfactory); the rightmost end scored as 0 means no pain (unsatisfactory); and the rightmost end scored as 0 means no pain (unsatisfactory). (unsatisfactory); the right-most end of the scale was scored as 10, indicating severe pain (extremely satisfactory). The patient marks the scale according to his/her own feelings. The patient marks the scale according to his/her own feelings, with 1cm representing 1 point, and the indicated position is converted into the final score.
  measure: time to subsidence of mucous membrane blushing when wearing teeth
  time frame: within 30 minutes
  description: time to subsidence of mucous membrane blushing when wearing teeth
  arm group label: On1 Abutment + Nobel PMC implant Set
  arm group type: Experimental
  description: Subjects who takes implant therapy using On1 Abutment + Nobel PMC implant
  arm group label: On1 Abutment + Nobel PCC Implant Set
  arm group type: Experimental
  description: Subjects who takes implant therapy using On1 Abutment + Nobel PCC Implant
  arm group label: On1 Abutment + Nobel CC Implant Set
  arm group type: Experimental
  description: Subjects who takes implant therapy using On1 Abutment + Nobel CC Implant
  arm group label: One-Stage Abutment + Nobel PMC Implant Set
  arm group type: Active Comparator
  description: Subjects who takes implant therapy using One-Stage Abutment + Nobel PMC Implant
  arm group label: One-Stage Abutment + Nobel PCC Implant Set
  arm group type: Active Comparator
  description: Subjects who takes implant therapy using One-Stage Abutment + Nobel PCC Implant
  arm group label: One-Stage Abutment + Nobel CC Implant Set
  arm group type: Active Comparator
  description: Subjects who takes implant therapy using One-Stage Abutment + Nobel CC Implant
  intervention type: Device
  intervention name: On1 two-stage abutment and one-stage abutment
  description: the On1 two-stage abutment has a smooth collar with a height of 1.75-2.5mm, and the Nobel implants have a smooth neck design ranging from 0-0.75mm to protect the connective tissue around the implant.
  arm group label: On1 Abutment + Nobel CC Implant Set
  arm group label: On1 Abutment + Nobel PCC Implant Set
  arm group label: On1 Abutment + Nobel PMC implant Set
  arm group label: One-Stage Abutment + Nobel CC Implant Set
  arm group label: One-Stage Abutment + Nobel PCC Implant Set
  arm group label: One-Stage Abutment + Nobel PMC Implant Set
  other name: Nobel PMC implant, Nobel CC implant, Nobel PCC implant
  criteria: 
  gender: All
  minimum age: 18 Years
  maximum age: 70 Years
  healthy volunteers: No
  last name: Weida Li
  role: Principal Investigator
  affiliation: Stomatological Hospital Affiliated to Zhejiang University School of Medicine
  last name: Yi Zhou
  phone: 87217419
  phone ext: 0571
  email: zhouyizyzyzy@163.com
  last name: Junru Wen
  phone: 18080131510
  phone ext: +86
  email: wenjunru@zjkq.com.cn
  facility: 
  status: Recruiting
  contact: 
  contact backup: 
  country: China
  citation: Tallarico M, Caneva M, Meloni SM, Xhanari E, Covani U, Canullo L. Definitive Abutments Placed at Implant Insertion and Never Removed: Is It an Effective Approach? A Systematic Review and Meta-Analysis of Randomized Controlled Trials. J Oral Maxillofac Surg. 2018 Feb;76(2):316-324. doi: 10.1016/j.joms.2017.08.025. Epub 2017 Aug 24.
  PMID: 28923270
  citation: Wang QQ, Dai R, Cao CY, Fang H, Han M, Li QL. One-time versus repeated abutment connection for platform-switched implant: A systematic review and meta-analysis. PLoS One. 2017 Oct 19;12(10):e0186385. doi: 10.1371/journal.pone.0186385. eCollection 2017.
  PMID: 29049323
  responsible party type: Sponsor-Investigator
  investigator affiliation: The Dental Hospital of Zhejiang University School of Medicine
  investigator full name: Yi Zhou
  investigator title: Deputy Chief Physician, Deputy Director of Dental Implant Department
  sharing ipd: No