• Users Online: 604
  • Home
  • Print this page
  • Email this page
Home About us Editorial board Ahead of print Current issue Search Archives Submit article Instructions Subscribe Contacts Login 


 
 Table of Contents  
RESEARCH
Year : 2022  |  Volume : 22  |  Issue : 1  |  Page : 29-37

Evaluation of clinical and radiographic outcome of friction fit conical abutment system in implant-supported dental prostheses: An in vivo study


Department of Prosthodontics, Crown, Bridge and Implantology, RUHS College of Dental Sciences, Jaipur, Rajasthan, India

Date of Submission02-Jul-2021
Date of Decision23-Sep-2021
Date of Acceptance19-Nov-2021
Date of Web Publication27-Jan-2022

Correspondence Address:
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/jips.jips_340_21

Rights and Permissions
  Abstract 


Aim: The purpose of this clinical study was to analyze the clinical feasibility of friction fit conical abutment system in implant-supported fixed dental prostheses as an alternative to cement and screw retention.
Settings and Design: This was an in vivo longitudinal study.
Materials and Methods: A total of 10 prostheses were designed as 3- or 4-unit fixed dental prostheses supported by two implants. All the subjects selected were evaluated for pocket probing depth (PPD) and marginal bone loss at the time of implant placement (T1), at the time of placement of friction fit prostheses (T2), and 12 months after placement of friction fit prostheses (T3). Marginal bone loss at T2 and T3 was measured with respect to bone levels at T1 and T2, respectively. The patient satisfaction was assessed at T2 and T3 using FDI clinical criteria and scoring system (modified by Monaco et al.).
Statistical Analysis Used: Shapiro–Wilk test was employed to test the normality of data. Paired sample t-test was performed for quantitative variables.
Results: A total of twenty implants were inserted in ten partially edentulous spaces; the average patient age was 50.2 years. No significant difference was seen between T2 and T3 for PPD. Comparison of marginal bone loss using paired t-test showed a statistically highly significant difference at T2 and T3 with higher value at T2. No prostheses were dislodged during postprosthetic follow-up. The survival rate was 100% for both the abutments and implants. No change in surface luster was observed 12 months following prosthetic rehabilitation in any case. No prostheses or framework fracture was reported and all patients were satisfied with the prosthesis received.
Conclusions: Friction fit conical abutment system can act as a novel approach for the retention of implant-supported fixed dental prostheses.

Keywords: Alternate retention, computer-aided design and computer-aided manufacturing, friction fit


How to cite this article:
Sharma V, Paliwal J, Bhansali S, Meena KK, Gupta N, Dadarwal A. Evaluation of clinical and radiographic outcome of friction fit conical abutment system in implant-supported dental prostheses: An in vivo study. J Indian Prosthodont Soc 2022;22:29-37

How to cite this URL:
Sharma V, Paliwal J, Bhansali S, Meena KK, Gupta N, Dadarwal A. Evaluation of clinical and radiographic outcome of friction fit conical abutment system in implant-supported dental prostheses: An in vivo study. J Indian Prosthodont Soc [serial online] 2022 [cited 2022 Jun 26];22:29-37. Available from: https://www.j-ips.org/text.asp?2022/22/1/29/336683




  Introduction Top


The longevity of restoration is the key objective of a successful treatment plan and so it is with implant-supported prosthetic rehabilitation. A successful treatment plan demands meticulous adherence to established protocols. The implant and prostheses are technique and material sensitive. One of the areas of concern is the abutment-prosthesis junction.[1] Implant-supported prosthetic reconstructions can either be screw retained or cement retained or a combination of both.[2],[3] Although there are many advantages to either approach, inherent risks and drawbacks which negatively affect the long-term success of the implant-supported prosthesis become predominant.[4]

Screw-retained implant prostheses have an inherent lack of esthetics with a channel cast in metal or a compromised strength of the superstructure around the access hole. In addition, the problems of screw loosening and plastic deformation arise due to biomechanical overload. Subsequently, the restoration becomes mobile as the screw loosens, leading to an inflammatory reaction or a screw fracture.[5],[6] Cement-retained implant prostheses are associated with peri-implantitis attributed to residual excess cement.[7],[8] Residual excess cement can be eliminated by using a screw-retained cemented prosthesis or a combination implant crown in which screw access hole is on the occlusal surface of prosthetic crown which is extraorally cemented to abutment allowing removal of excess cement. Thereafter, the assembly is retained through screw. Although this technique allows the elimination of residual cement, it leaves the occlusal, usually functional cusp/fossa area to be restored with a composite that is more susceptible to wear and abrasion, thereby compromising occlusal contacts. Moreover, with multiple units, this technique becomes more difficult.[9]

To overcome the aforementioned shortcomings of the screw- or cement-retained implant prosthesis, friction fit implant-supported dental prosthesis that uses a tapered cone design to retain the coping on the abutment by surface friction can be designed. The conical coping is retained on conical abutment by surface contact. Tapered cone design creates friction when the prosthesis is completely seated over the abutment. The tapered attachment design ensures complete seating of the prosthesis as the diameter of the coping is greater than the diameter of the abutment.[10],[11],[12]

The aim of this clinical study was to analyze the clinical feasibility of friction fit conical abutment system in implant-supported fixed dental prostheses as an alternative to cement and screw retention. The objective is to analyze the clinical outcome by evaluating the health of peri-implant tissues over time by assessing the pocket probing depth (PPD), clinical parameters, and complications in terms of esthetic and functional properties[13] and radiographic outcome by evaluating the peri-implant bone changes (marginal bone loss) to demonstrate the feasibility of the friction fit conical abutment system as a novel approach for the retention of the prostheses.


  Materials and Methods Top


The study was approved by the Institutional Ethical Committee (RUHS-CDS/EC/2017/Proposal/001). All partially edentulous patients registered in the Department of Prosthodontics were assessed for implant-supported prostheses. Ten partially edentulous cases were selected following the inclusion criteria. All sites had opposing natural dentition. A total of ten prostheses supported by two implants were designed. All the subjects selected were evaluated at the time of implant placement (T1), at the time of placement of friction fit prostheses (T2), and 12 months after placement of friction fit prostheses (T3). The implant system used in the study was NobelReplace Conical Connection Implant System (Nobel Biocare).

The study included healthy subjects of 18 years and above with no temporomandibular joint pathosis, normal maxillomandibular relationship, sufficient interarch space, sufficient bone volume, and physically or psychologically fit for implant-supported fixed dental prostheses. Subjects with recent myocardial infarction, bleeding disorder, psychiatric disorder, undergoing intravenous bisphosphonate treatment, uncontrolled diabetes, pregnant women, and chronic smokers were excluded from the study. Prior to the study, the approval of the Institutional Ethical Committee (RUHS-CDS/EC/2017/Proposal/001) and informed consent of each participant were obtained. The participant data were formulated and used for research purposes.

Surgical phase

Surgery was performed by one experienced operator. All patients were operated under local anesthesia (2% lignocaine with 1:100,000 adrenaline). The osteotomy site was prepared as recommended by Branemark to minimize trauma to the bone and thereby prevent necrosis of the bone.[14] Cover screws were placed and flaps were approximated to achieve complete closure using simple interrupted and/or simple mattress lock sutures using a 3-0 braided nonresorbable silk suture. The patients were called for the postoperative checkup after 24 h and then after 10 days of surgery for suture removal. Delayed loading protocol was followed for the study. After completion of the requisite period of 6 months for the bone to implant integration, second-stage surgery was performed and per-mucosal attachments were placed for the formation of the gingival collar.

Prosthetic phase

Irreversible hydrocolloid impression material (Zelgan 2002 Alginate; Dentsply) was used to make primary impressions. Impressions were poured immediately with Type 3 Dental Stone (Kalstone; Kalabhai Karson Pt Ltd.) to obtain primary cast for custom tray fabrication. A minimum window (1.5 cm2) was prepared over the area of the implant to allow clearance for manipulation of the impression coping in the custom tray. Implant-level open-tray impression was made with polyvinyl siloxane impression material (Photosil; DPI) [Figure 1]. A master cast with implant analogs was created. A vinyl polysiloxane (GI-MASK Automix; Coltene/Whaledent Private Ltd.) was used to simulate soft tissues. After try-in of implant verification jig [Figure 2], the master cast with embedded implant analogs was sent for scanning, designing, and milling of abutment and superstructure/coping.
Figure 1: Implant-level open-tray impression

Click here to view
Figure 2: Try-in of implant verification jig

Click here to view


Three consecutive phases are involved in computer-aided design and computer-aided manufacturing (CAD/CAM) production: scanning, designing, and milling. Scanning: the master cast with implant analogs was digitally scanned by an extraoral scanner (Identica T500; MEDIT). Designing [Figure 3]: 2° conical titanium abutments were designed using CAD software (DentalCAD; Exocad GmbH) and were made parallel to each other. The abutments were allowed a uniform 2° axial taper to allow for complete seating and yet provide sufficient resistance form. The custom abutments were designed to be parallel and had the desired subgingival emergence profiles and heights. Milling: the customized implant abutments were created by the CAM device (ME-300HP; TDS Biotechnology Co. Ltd.) in accordance with the virtual design.
Figure 3: Abutment design using exocad DentalCAD software abutment design. (a) Lateral view, (b) occlusal view

Click here to view


After milling, abutment try-in was done to ensure a complete fit of customized abutments over implants [Figure 4]. Thereafter, customized titanium abutments were completely seated on the master cast and digitally scanned with Extraoral Scanner (Identica T500; MEDIT) for designing the prosthesis [Figure 5]. Superstructure/prosthesis was designed directly over abutments [Figure 6] and [Figure 7]. It was ensured that to achieve friction fit, zero cement space was left after milling (the outer diameter of the abutment was the same as the internal diameter of the superstructure), and a 2° axial taper was given. Thereafter, the superstructure was milled (ME-300HP; TDS Biotechnology Co. Ltd.). The abutments were tightened with a torque ratchet and superstructure was placed over abutments. Activation of friction fit attachment was achieved by biting force in posteriors and by gentle tapping with the handle of mouth mirror in case of anteriors. Implant-protected occlusion was ensured for all prostheses. Lateral tipping using a wood stick or lateral rocking of the prosthesis using forceps with silicon coating could be used for retrieving the prosthesis.[15],[16]
Figure 4: Customized milled abutment in situ

Click here to view
Figure 5: Scanned image of milled abutment. (a) Lateral view, (b) occlusal view

Click here to view
Figure 6: Prosthesis design using exocad DentalCAD software

Click here to view
Figure 7: Milled superstructure with layered porcelain in situ

Click here to view


Examination

Clinical parameters

PPD was evaluated at the time of prosthesis placement (T2) and 12 months after prosthesis placement (T3) using plastic instruments to avoid scarring and/or damage to the implant surface. Peri-implant PPD was measured using a plastic periodontal probe from the gingival margin to the bottom of the pocket at mesial, distal, facial, and lingual/palatal side with a pressure calibration stop of 0.25 N (TPS probe; Ivoclar Vivadent AG).[17],[18]

Radiographic parameters

Radiographic analysis of the peri-implant bone was done by the cone-beam computed tomography (CBCT) (CS3D-9000; Carestream Dental LLC). CBCT radiographs were taken for measurements of the quality and quantity of bone in the peri-implant area, immediately following implant placement (T1), at prosthesis placement (T2), and 12 months after prosthesis placement (T3). The analysis was done using a measuring tool inbuilt in the CS3D-9000 CBCT machine software.

Change in the crestal bone level (linear measurements of bone loss around the implant) was measured in millimeters using CBCT. Navigation was done on the multiplanar screen to show the precise reformatted panoramic and sagittal view of the implant. The bone loss around the implant was assessed by a line drawn on the mesial, distal, buccal, and palatal image on the collar margin of the implant to the alveolar crest, using software tools [Figure 8], [Figure 9], [Figure 10], [Figure 11].[19] Mean marginal bone loss was obtained by dividing the sum of marginal bone loss of mesial, distal, buccal, and palatal sides by four.
Figure 8: CBCT MARGINAL bone-level determination. (A) Bone crest buccally, (B) bone crest lingually, (C) line passing through implant shoulder buccolingually, (D) vertical distance between A and C, (E) vertical distance between B and C

Click here to view
Figure 9: Marginal bone level at T1. (a) Faciolingual, (b) mesiodistal

Click here to view
Figure 10: Marginal bone level at T2. (a) Faciolingual, (b) mesiodistal

Click here to view
Figure 11: Marginal bone level at T3. (a) Faciolingual, (b) mesiodistal

Click here to view


Data obtained were compiled on a spreadsheet (MS Office Excel 2010; Microsoft Corp.). Data were subjected to statistical analysis using the statistical software program (IBM SPSS Statistics, v20.0; IBM Corp.). Descriptive statistics such as mean and standard deviation for numerical data have been depicted. Paired sample t-test was performed for quantitative variables. For all the statistical tests, P < 0.05 was considered to be statistically significant, keeping α error at 5% and β error at 20%, thus giving a power to the study as 80%.


  Results Top


Clinical evaluation

Pocket probing depth

The mean value of PPD was 1.66 mm with a standard deviation of 0.20 at T2 and 1.69 mm with a standard deviation of 0.23 at T3. Results showed no significant difference between T2 and T3. Furthermore, the surface-wise result showed a statistically nonsignificant difference between T2 and T3 with a higher value at T3 [Table 1].
Table 1: Statistical comparison of pocket probing depth (paired t-test)

Click here to view


Radiographic evaluation

Marginal bone loss

Mean marginal bone loss was assessed before and after functional loading. Mean marginal bone loss at T2 represents bone loss before loading (between T1 and T2), while the mean marginal bone loss at T3 represents bone loss after functional loading (between T2 and T3). The mean values of marginal bone loss were 0.26 mm with a standard deviation of 0.08 at T2 and 0.12 mm with a standard deviation of 0.05 at T3. Comparison of marginal bone loss using paired t-test showed a statistically highly significant difference at T2 and T3 with higher value at T2 (0.26 mm ± 0.08). The above comparison indicates the marginal bone loss that occurred before functional loading was significantly higher than after loading [Table 2] and [Table 3]. Comparison of mesiodistal and faciolingual bone loss using paired t-test showed a highly significant (P = 0.000) difference at T2 and T3 with higher value at the mesiodistal surface [Table 4].
Table 2: Marginal bone level at T1, T2, and T3

Click here to view
Table 3: Statistical comparison of marginal bone loss (paired t-test)

Click here to view
Table 4: Statistical comparison of marginal bone loss (paired t-test) (mesiodistal vs. faciolingual)

Click here to view


Prosthetic evaluation

No prostheses were dislodged during postprosthetic follow-up. Clinical parameters and complications were evaluated in terms of esthetic and functional properties according to FDI clinical criteria and scoring system modified by Monaco et al. [Table 5].[13],[20] No change in surface luster was observed in any cases at T3 (12 months after placement of friction fit prostheses). No prostheses and framework fractures were reported and all patients were satisfied with the prosthesis received.
Table 5: Clinical parameters and complications in terms of esthetic and functional properties (as modified by Monaco et al.)

Click here to view



  Discussion Top


The friction fit abutment system achieves retention by principles of transition fit. The transition fit is used where accuracy is important, but where a small amount of clearance or a small amount of interference is acceptable and it results in size to size fit.[21],[22],[23],[24],[25],[26],[27] A friction fit is dependent on the accuracy at the prosthesis abutment interface and increases as the area of contact increases. Friction is maximum when the coping is fully seated on the abutment.[10],[11],[12],[28]

This is, to the best of our knowledge, the first protocol that investigated the performance of friction fit conical abutment system in 3- or 4-unit fixed dental prosthesis supported by two implants. The present study was developed and carried out using methods that had been used in previous studies that examined the friction fit retention but with notable changes. Previous studies comprised three components (abutment-coping-superstructure) prosthetic assembly, where friction fit connection exists between abutment and coping and coping was then luted to the superstructure, while the present study design comprised two-component (abutment-superstructure) prosthetic assembly, where coping is an inherent part of the superstructure and friction fit connection exists between abutment and superstructure. In the present study, CAD-CAM-milled 3- or 4-unit metal-ceramic fixed dental prostheses were fabricated directly over the paralleled customized abutments instead of prefabricated abutment and coping, which were utilized in previous studies [Figure 12].[10],[29],[30],[31] This eliminates the need for the dentist to choose prefabricated stock abutments and make them parallel intraorally. CAD-CAM abutments, on the other hand, are already parallel to each other with optimized height and emergence profile.[16]
Figure 12: Two-component prosthetic assembly

Click here to view


In the present study, customized titanium abutments with 2° axial tapers were designed using CAD software (DentalCAD; Exocad GmbH) and were made parallel to each other. In one of our cases, abutment angle correction was >30 and it was compensated by using a multiunit abutment. This was done as retention of friction fit conical abutment system depends on the area covered. The more the area, the more will be retention.[28] Implant placement parallel to each other keeps the screw access hole occlusally and utilizes all axial surfaces for retention [Figure 13]. If the implants are not placed parallel to each other, it will result in shifting of screw access gingivally, thereby reducing the axial wall and thus the area covered by the superstructure [Figure 14].
Figure 13: Implant placement parallel to each other keeps the screw access hole occlusally and utilizes all axial surfaces for retention. (a) Implant placed nearly parallel to each other, (b) occlusal screw access hole

Click here to view
Figure 14: Implants placed nonparallel to each other will result in shifting of screw access gingivally, thereby reducing the axial wall and thus the area covered by the superstructure. (a) Implants placed nonparallel to each other, (b) shifting of screw access hole gingivally

Click here to view


Nardi et al. found the retention of friction fit prostheses to be directly proportional to the height and diameter of the abutment. The retentive strength of friction fit prostheses was found to be comparable with values reported for commonly used cement.[28] One advantage of the friction fit abutment system is the ease with which the clinician may retrieve the prosthesis to assess periodontal health and conveniently execute professional oral care.[16],[32] In the present study, the prostheses were found to be acceptable on clinical parameters with 100% patient satisfaction in terms of retention and soft-tissue response.

Radiographic evaluation of marginal bone loss was done using CBCT. The amount of marginal bone loss was measured buccally, lingually, mesially, and distally using the inbuilt software of CBCT machine (CS3D-9000; Carestream Dental LLC) as conventional radiographs (periapical and panoramic) are two-dimensional and give no information about the alveolar bone quality and quantity.[33],[34] Marginal bone loss assessment has been regarded as a critical criterion to assess implant success. The accepted implant success criteria are 1–1.5 mm of bone loss during the 1st year of loading and <0.2 mm annually thereafter.[35],[36],[37] Comparison of marginal bone loss using paired t-test showed a statistically highly significant difference at T2 (0.26 mm ± 0.08) and T3 (0.12 mm ± 0.05) with a higher value at T2. This can be attributed to surgical crestal bone trauma at the time of implant placement. These findings were in agreement with the study by Chou et al.[38] and Kline et al.[39] Marginal bone loss in the present study was 0.12 ± 0.05 mm during the 1st year of loading, which is less than the threshold specified in the success criteria.

In clinical parameter, PPD was recorded in the present study. The PPD results of the present study were in concordance with the results of the studies conducted by Degidi and Bressan, which also reported a nonsignificant difference in PPD at postprosthetic follow-up.[10],[30]

The survival rate was 100% for both the abutments and implants. The frictional fit was viable, and even after 12 months of loading, a 100% prosthesis survival rate was achieved without prosthetic complications. These results were in concordance with the study conducted by Degidi et al., which also reported similar results.[10] No change in surface luster was observed 12 months following prosthetic rehabilitation in any case. No prostheses or framework fracture was reported and all patients were satisfied with the prosthesis received. No prostheses were dislodged during postprosthetic follow-up. However, to validate these findings, further long-term studies with a larger sample size are required.


  Conclusions Top


Within the limitation of the present study, the friction fit abutment-prosthesis connection showed a 100% survival with encouraging data of PPD and marginal bone loss endorsing the reliability of friction-retained prosthesis without compromising the periodontal status. Thus, the friction fit conical abutment system can act as a novel approach for the retention of implant-supported fixed dental prostheses.

Acknowledgment

Dr. Sankalp Mittal, Associate Professor, Dept. of Oral and maxillofacial surgery, for performing implant surgeries.

Financial support and sponsorship.

Nil.

Conflicts of interest.

There are no conflicts of interest.



 
  References Top

1.
Singer A, Serfaty V. Cement retained implant-supported fixed partial dentures: A 6-month to 3 year follow-up. Int J Oral Maxillofac Implants 1996;11:645-49.  Back to cited text no. 1
    
2.
Shadid R, Sadaqa N. A comparison between screw and cement-retained implant prostheses: A literature review. J Oral Implantol 2012;38:298-307.  Back to cited text no. 2
    
3.
Chee W, Jivraj S. Screw versus cemented implant supported restorations. Br Dent J 2006;201:501-7.  Back to cited text no. 3
    
4.
Vigolo P, Mutinelli S, Givani A, Stellini E. Cemented versus screw-retained implant-supported single-tooth crowns: A 10-year randomised controlled trial. Eur J Oral Implantol 2012;5:355-64.  Back to cited text no. 4
    
5.
Lindhe J, Lang N, Karring T. Clinical Periodontology and Implant Dentistry. 5th ed. Oxford: Blackwell Munksgaard; 2008. p. 1222-38.  Back to cited text no. 5
    
6.
Kourtis S, Damanaki M, Kaitatzidou S, Kaitatzidou A, Roussou V. Loosening of the fixing screw in single implant crowns: Predisposing factors, prevention and treatment options. J Esthet Restor Dent 2017;29:233-46.  Back to cited text no. 6
    
7.
Wilson TG. The positive relationship between excess cement and peri-implant disease: A prospective clinical endoscopic study. J Periodontol 2009;80:1388-92.  Back to cited text no. 7
    
8.
Linkevicius T, Vindasiute E, Puisys A, Peciuliene V. The influence of margin location on the amount of undetected cement excess after delivery of cement-retained implant restorations. Clin Oral Implants Res 2011;22:1379-84.  Back to cited text no. 8
    
9.
McGlumphy EA, Papazoglou E, Riley RL. The combination implant crown: A cement- and screw-retained restoration. Compendium 1992;13:34, 36, 38 passim.  Back to cited text no. 9
    
10.
Degidi M, Nardi D, Sighinolfi G, Piattelli A. The Conometric concept: Definitive fixed lithium disilicate restorations supported by conical abutments. J Prosthodont 2018;27:605-10.  Back to cited text no. 10
    
11.
Eccellente T, Piombino M, Piattelli A, Perrotti V, Iezzi G. A new treatment concept for immediate loading of implants inserted in the edentulous mandible. Quintessence Int 2010;41:489-95.  Back to cited text no. 11
    
12.
Eccellente T, Piombino M, Piattelli A, D'Alimonte E, Perrotti V, Iezzi G. Immediate loading of dental implants in the edentulous maxilla. Quintessence Int 2011;42:281-9.  Back to cited text no. 12
    
13.
Monaco C, Caldari M, Scotti R. Clinical evaluation of zirconia-based restorations on implants: A retrospective cohort study from the AIOP clinical research group. Int J Prosthodont 2015;28:239-42.  Back to cited text no. 13
    
14.
Albrektsson T, Brånemark P I, Hansson H A, Lindström J. Osseointegrated titanium implants. Requirements for ensuring a long-lasting, direct bone-to-implant anchorage in man. Acta Orthop Scand 1981;52:155-70.  Back to cited text no. 14
    
15.
Block MS, Goldenberg BS. Preliminary results using a friction-fit crown to abutment connection. Int J Periodontics Restorative Dent 2021;41:217-24.  Back to cited text no. 15
    
16.
Bressan E, Venezze AC, Magaz VR, Lops D, Ghensi P. Fixed conometric retention with CAD/CAM conic coupling abutments and prefabricated syncone caps: A case series. Int J Periodontics Restorative Dent 2018;38:277-80.  Back to cited text no. 16
    
17.
Salvi GE, Lang NP. Diagnostic parameters for monitoring peri-implant conditions. Int J Oral Maxillofac Implants 2004;19 Suppl: 116-27.  Back to cited text no. 17
    
18.
Mombelli A, Muhle T, Bragger U, Lang NP, Burgin WB. Comparision of periodontal and peri implant probing by depth force pattern analysis. Clin Oral Impl Res 1997;8:448-54.  Back to cited text no. 18
    
19.
Hazzaa HH, Shawki NA, Abdelaziz LM, Shoshan HS. Early loading of dental implant grafted with autogenous bone alone or combined with melatonin gel: A randomized clinical trial. Austin J Dent 2020;7:1137.  Back to cited text no. 19
    
20.
Hickel R, Peschke A, Tyas M, Bayne S, Peters M, Hiller KA. FDI World Dental Federation: Clinical criteria for the evaluation of direct and indirect restorations update and clinical examples. Clin Oral Investig 2010;14:349-66.  Back to cited text no. 20
    
21.
Budynas R, Nisbett J, Shigley J. Shigley's Mechanical Engineering Design. 9th ed. New York: The McGraw-Hill Companies; 2011. p. 395-408.  Back to cited text no. 21
    
22.
Mott RL, Vavrek EM, Wang J. Machine Elements in Mechanical Design. 6th ed. New York: Pearson Education; 2018. p. 546-87.  Back to cited text no. 22
    
23.
ANSI/ASME. Standard B4.1-1967 (R2009). Preferred Limits and Fits for Cylindrical Parts. New York: American Society of Mechanical Engineers; 2009. Available from: https://webstore.ansi.org/Standards/ASME/ANSIASMEB41967R2009. [Last accessed on 2021 Mar 21].  Back to cited text no. 23
    
24.
ANSI/ASME. Standard B4.2-1978 (R2009). Preferred Metric Limits and Fits. New York: American Society of Mechanical Engineers; 2009. Available from: https://webstore.ansi.org/Standards/ASME/ASMEB41978R2009. [Last accessed on 2021 Mar 21].  Back to cited text no. 24
    
25.
Bertoline GR, Wiebe EN, Hartman NW, Ross WA. Fundamentals of Graphics Communication. 6th ed. New York: McGraw-Hill; 2011. p. 506-31.  Back to cited text no. 25
    
26.
Giesecke FE, Lockhart S, Goodman M, Johnson CM. Technical Drawing with Engineering Graphics. 15th ed. Upper Saddle River, NJ: Pearson/Prentice-Hall; 2016. p. 546-88.  Back to cited text no. 26
    
27.
Oberg E, Jones FD, Horton HL, Ryffel HH. Machinery's Handbook. 30th ed. New York: Industrial Press, 2016. p. 596-802.  Back to cited text no. 27
    
28.
Nardi D, Degidi M, Sighinolfi G, Tebbel F, Marchetti C. Retention strength of conical welding caps for fixed implant-supported prostheses. Int J Prosthodont 2017;30:553-5.  Back to cited text no. 28
    
29.
Bressan E, Lops D, Tomasi C, Ricci S, Stocchero, Carniel EL. Experimental and computational investigation of Morse taper conometric system reliability for the definition of fixed connections between dental implants and prostheses. J Eng Med 2014;228:674-81.  Back to cited text no. 29
    
30.
Bressan E, Lops D. Conometric retention for complete fixed prosthesis supported by four implants: 2-years prospective study. Clin Oral Impl Res 2014;25:546-52.  Back to cited text no. 30
    
31.
Degidi M, Nardi D, Piattelli A. The conometric concept: Coupling connection for immediately loaded titanium-reinforced provisional fixed partial dentures a case series. Int J Periodontics Restorative Dent 2016;36:347-54.  Back to cited text no. 31
    
32.
Degidi M, Nardi D, Sighinolfi G, Degidi D. The conometric concept for the definitive rehabilitation of a single posterior implant by using a conical indexed abutment: A technique. J Prosthet Dent 2020;123:576-9.  Back to cited text no. 32
    
33.
Schmidt JC, Gutekunst CJ, Walter C. Comparison of two-dimensional and three-dimensional radiographs using clinically relevant parameters. Dent J (Basel) 2019;7:50.  Back to cited text no. 33
    
34.
Venkatesh E, Elluru SV. Cone beam computed tomography: Basics and applications in dentistry. J Istanb Univ Fac Dent 2017;51 3 Suppl 1: S102-21.  Back to cited text no. 34
    
35.
Albrektsson T, Zarb G, Worthington P, Eriksson AR. The long-term efficacy of currently used dental implants: A review and proposed criteria of success. Int J Oral Maxillofac Implants 1986;1:11-25.  Back to cited text no. 35
    
36.
Smith DE, Zarb GA. Criteria for success of osseointegrated endosseous implants. J Prosthet Dent 1989;62:567-72.  Back to cited text no. 36
    
37.
Misch CE, Perel ML, Wang HL, Sammartino G, Galindo-Moreno P, Trisi P, et al. Implant success, survival, and failure: The international congress of oral implantologists (ICOI) pisa consensus conference. Implant Dent 2008;17:5-15.  Back to cited text no. 37
    
38.
Chou CT, Morris HF, Ochi S, Walker L, DesRosiers D. AICRG, Part II: Crestal bone loss associated with the Ankylos implant: Loading to 36 months. J Oral Implantol 2004;30:134-43.  Back to cited text no. 38
    
39.
Kline R, Hoar JE, Beck GH, Hazen R, Resnik RR, Crawford EA. A prospective multicenter clinical investigation of a bone quality-based dental implant system. Implant Dent 2002;11:224-34.  Back to cited text no. 39
    


    Figures

  [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7], [Figure 8], [Figure 9], [Figure 10], [Figure 11], [Figure 12], [Figure 13], [Figure 14]
 
 
    Tables

  [Table 1], [Table 2], [Table 3], [Table 4], [Table 5]



 

Top
 
 
  Search
 
Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
Access Statistics
Email Alert *
Add to My List *
* Registration required (free)

 
  In this article
Abstract
Introduction
Materials and Me...
Results
Discussion
Conclusions
References
Article Figures
Article Tables

 Article Access Statistics
    Viewed1539    
    Printed54    
    Emailed0    
    PDF Downloaded301    
    Comments [Add]    

Recommend this journal


[TAG2]
[TAG3]
[TAG4]