Abutment Screw Fracture Research Articles

Risk of Postoperative Sensitivity and Pulpal Complications in Respect of: Amount of Reduction, Temporization, Cement Type

Fixed partial dentures (FPDs) made of metal ceramic are a popular treatment option for missing teeth. Studies have shown that posterior abutments of FPDs had a higher pulp survival rate than anterior abutments. Postoperative sensitivity following the cementation of a fixed prosthesis is a frequent symptom, especially when the abutments include important pulp. Dentinal hypersensitivity affects between 4 and 74 percent of people. Females are found to have a somewhat greater DH incidence than males. While DH can affect individuals of any age, there have been several theories on what causes abutment sensitivity after tooth preparation and cementation. In this review we included some of it. Also, we discussed methods of management of postoperative sensitivity and Management of fractured abutment screw.

Hydrothermal aging affects the three-dimensional fit and fatigue lifetime of zirconia abutments

ObjectiveEvaluate the effect of aging using two different methods on the three-dimensional fit of zirconia abutments at the implant-abutment connection and estimate the probability of survival of anterior crowns supported by straight and 17-degree angled abutments. Materials and methodsTwo different zirconia abutment designs, straight and 17-degree angled abutments (n = 63/group), were evaluated in the current study. The abutments were randomly allocated into three experimental groups according to laboratory aging condition (134°C, 2.2 bar, 20 h): (i) control, (ii) autoclave aging, and (iii) hydrothermal reactor aging. Crystalline content was determined by X-Ray diffraction (XRD) and Raman spectroscopy, and microstructure was analyzed using field-emission gun scanning electron microscope (FEG-SEM). Implant-abutment volume misfit was determined in the straight abutments by micro-computed tomography using the silicone replica technique. For fatigue testing, abutments were torqued to the implants and connected to standardized maxillary incisor zirconia crowns. The assemblies were subjected to step-stress accelerated life testing (SSALT) in water until fracture or suspension. The use level probability Weibull curves and probability of survival for a mission of 50,000 cycles at 50, 100, 150 and 200 N were calculated and plotted. Fractured samples were analyzed using a stereomicroscope and scanning electron microscope. ResultsThe crystalline spectra depicted a zirconia system primarily composed of the tetragonal phase. Laboratory aging yielded a 20%- and 37%-increase in the monoclinic content for abutments aged in autoclave and hydrothermal reactor relative to control, respectively. A fully crystalline matrix with a regular grain size was observed in the FEG-SEM for control abutments, with a considerable presence of intergranular defects. While autoclave aging triggered no significant alteration to the microstructure, defect population was reduced after hydrothermal reactor aging. Control abutments presented a significantly higher volume misfit (2.128 ± 0.54 mm3) relative to aged abutments using autoclave (1.244 ± 0.48 mm3) or hydrothermal reactor (1.441 ± 0.41 mm3). The beta (β) values indicated that failures were predominantly controlled by material strength rather than fatigue damage accumulation for all groups, except for straight control abutments. Irrespective of aging, the probability of survival of straight and angled zirconia abutments was up to 95% (95–100%) at 50 and 100 N. A 50N-increase in the load resulted in wider range of survival estimate, with straight autoclave abutments percentage significantly lower probability of survival (77%) than angled hydrothermal reactor abutments (99%). At 200N, angled hydrothermal reactor (97%) or autoclave (82%) aged abutments demonstrated the highest probability of survival, angled control (71%) and straight hydrothermal reactor (69%) abutments intermediate values, and straight autoclave (23%) and control (7%) abutments the lowest estimate. The failure mode predominantly involved abutment and/or abutment screw fracture for both straight and angled abutments. ConclusionsHydrothermal aging significantly influenced volume misfit, as well as the probability of survival of zirconia abutments at higher loads for both angled and straight abutments.

Management of perishing implants with abutment screw fracture - A systematic review.

Aim:To systematically review the reported techniques, for evaluating the risk and difficulty encountered in the management of fractured abutment screw in accordance with the location of fracture, and to develop a logical sequence in managing an implant abutment screw fracture.Settings and Design:Systematic review following PRISMA guidelines.Materials and Methods:A systematic search of the PubMed/MEDLINE database for articles published between January 2000 and March 2020 was performed by 2 independent reviewers. Case reports and case series that described the management of fractured implant abutment screw were included. Published articles were qualitatively analyzed employing CARE guidelines and were classified according to the location of screw fracture with respect to implant platform, risk of damage to the implant, and intervention for managing the fractured screw.Statistical Analysis Used:Qualitative analyisis.Results:A total of 28 articles were included in the review. Two of them explained the management of screw fracture at or above the implant platform and required only mild approach with low risk while the others explained the management of screw fracture below the level of implant platform. Among them, 6 were considered mild approach with low risk, 13 moderate approach with moderate risk, and 8 of them severe approach with high risk.Conclusion:Irrespective of the technique, any attempt to retrieve abutment screw fragment poses some risk to the implant which is varying from mild to severe. As the location of fracture is more gingival to the implant platform, difficulty of retrieval as well as risk to the implant increases. The proposed decisionmaking tree will be a useful tool in helping clinicians to manage abutment screw fracture.

Evaluation of the Success of Strategic Implantandreg; Placement for Immediate Loading Prosthesis in Edentulous Cases

Purpose: To compare and evaluate the efficacy of strategic implant® placement followed by immediate loading in regard to primary stability, quality of bone and survival and success of implants. Material and Methods: This prospective cohort study included total 26 patients were selected from both sex, 19 males/7 females in age group of 40 to 70 years, were restored with strategic implant® irrespective of the quality and quantity of cancellous/alveolar bone following immediate functional loading protocols. 8 to 10 strategic implant® were placed per jaw and restored with a prosthesis within 72 hours. 447 BECES® implants, 20 BECES EX® implants, 4 KOC MICRO® implants and 2 ZDI implants were placed in the study. Result: With the follow-up period of 22 months, results with strategic implant® were of great success with no delayed complications and failure with a success rate of ~99%. Secondary complications such as abutment screw loosening/fracture and peri-implantitis were not observed within the limitations of this study (p>0.05). Conclusion: Regardless the bone volume, quantitively and qualitatively, functional rehabilitation of missing stomatognathic system following graft-less protocol is possible with the least traumatic and in-expensive technology thereby providing desired results benefitting the needful; secondary complications like graft resorption resulting in implant failure, abutment screw loosening, abutment screw fracture, peri-implantitis can be avoided with the technology of strategic implant®.

Failure Modes and Survival of Anterior Crowns Supported by Narrow Implant Systems.

The reduced hardware design of narrow implants increases the risk of fracture not only of the implant itself but also of the prosthetic constituents. Hence, the current study is aimed at estimating the probability of survival of anterior crowns supported by different narrow implant systems. Three different narrow implant systems of internal conical connections were evaluated (Ø3.5 × 10 mm): (i) Active (Nobel Biocare), (ii) Epikut (S.I.N. Implant System), and (iii) BLX (Straumann). Abutments were torqued to the implants, and standardized maxillary incisor crowns were cemented. The assemblies were subjected to step-stress accelerated life testing (SSALT) in water through load application of 30 degrees off-axis lingually at the incisal edge of the crowns using a flat tungsten carbide indenter until fracture or suspension. The use level probability Weibull curves and reliability for completion of a mission of 100,000 cycles at 80 N and 120 N were calculated and plotted. Weibull modulus and characteristic strength were also calculated and plotted. Fractured samples were analyzed in a stereomicroscope. The beta (β) values were 1.6 (0.9-3.1) and 1.4 (0.9-2.2) for BLX and Active implants, respectively, and 0.5 (0.3-0.8) for the Epikut implant, indicating that failures were mainly associated with fatigue damage accumulation in the formers, but more likely associated with material strength in the latter. All narrow implant systems showed high probability of survival (≥95%, CI: 85-100%) at 80 and 120 N, without significant difference between them. Weibull modulus ranged from 6 to 14. The characteristic strength of Active, Epikut, and BLX was 271 (260-282) N, 216 (205-228) N, and 275 (264-285) N, respectively. The failure mode predominantly involved abutment and/or abutment screw fracture, whereas no narrow implant was fractured. Therefore, all narrow implant systems exhibited a high probability of survival for anterior physiologic masticatory forces, and failures were restricted to abutment and abutment screw.

Management of Implant Abutment screw Fracture Using A Non-Invasive Technique: 9 Months Follow Up Case Report

This article describes a case of a 65-year-old male patient who presented with a chief complaint of missing teeth avulsed for 2 years. He was asking for its replacement. The treatment plan included the implant-supported crown associated with the bone grafting technique. The abutment screw was fractured during its insertion in the final appointment. A conservative and non-invasive technique based on converting the healing abutment into prosthetic abutment was illustrated. A follow up after 9monthswasrecorded and satisfactory results were maintained. Thanks to a well-planned approach, the patient was satisfied.

Implant-abutment fit influences the mechanical performance of single-crown prostheses

ObjectivesTo evaluate the three-dimensional fit of abutments fabricated by the industry to those either milled or cast by a commercial laboratory and to correlate the implant-abutment connection fit with stress at fatigue failure of prostheses. Probability of survival (reliability) and fractography to characterize failure modes were also performed for cemented and screw-retained prostheses. MethodsOne-hundred and twenty-six maxillary central incisor crowns were milled to restore implants and divided in 3 cemented and 3 screwed-retained groups (n = 21/each), as follows: [Digital-Sc]: milled one-piece monolithic abutment/crown; [TiB-Sc]: milled crowns cemented onto Ti-base abutments; [UCLA]: screw-retained crown using UCLA abutments; [Digital-Ce]: milled two-piece assembly comprised by screwed monolithic abutment and a cemented crown; [TiB–Ce]: milled coping cemented onto Ti-base abutments to receive a cemented crown; [UCLA-Ce]: UCLA abutments that received an overcast coping and a cemented crown. Implant-abutment volume misfit was assessed by micro-computed tomography using the silicone replica technique. Implant/crown systems were subjected to step-stress accelerated life testing (SSALT) in water. The use-level probability Weibull curves and reliability for a mission of 50,000 cycles at calculated stress at failure of 2,300, 3300 and 4300 MPa were plotted. Fractographic analysis was performed with scanning electron microscopy. Internal misfit was analyzed through one-way ANOVA following post-hoc comparisons by Tukey test (p < 0.05). Correlation between misfit volume and the stress at fatigue failure was assessed by Pearson test. ResultsSimilar misfit volumes were observed for TiB-Sc (0.458 mm3), TiB–Ce (0.461 mm3), UCLA (0.471 mm3) and UCLA-Ce (0.480 mm3), which were significantly lower than Digital-Sc (0.676 mm3) and Digital-Ce (0.633 mm3). The mean β values were: 1.68, 1.39, 1.48, 2.41, 2.27 and 0.71 for Digital-Sc, TiB-Sc, UCLA, Digital-Ce, TiB–Ce and UCLA-Ce, respectively, indicating that fatigue was an accelerating factor for failure of all groups. Higher stress at failure decreased the reliability of all groups, more significantly for screw compared to cement-retained groups, especially for Digital-Sc that demonstrated the lowest reliability. The failure mode was restricted to abutment screw fracture. A negative correlation was observed between misfit values and stress at failure (r = -0.302, p = 0.01). ConclusionsAbutments milled by a commercial lab presented higher misfit compared to those provided by the industry and a moderate correlation was observed between higher misfit and lower stress at failure during fatigue. Probability of survival decreased at higher stress, especially for screw compared to cement-retained groups, and failures were confined to abutment screws.

Incidence of abutment screw failure of single or splinted implant prostheses: A review and update on current clinical status.

Osseointegrated implants have been widely used for decades with high survival and success rates. However, mechanical complications continue to be reported in the literature, and their clinical management can be often very challenging for the clinician while there is no consensus on the ideal management. The aim of this manuscript was to review the risk factors of abutment screw complications, to identify the most recent incidence of screw failure in the clinical setting and report on the methodology used and the outcome of intervention. Clinical studies and reports were reviewed that reported on abutment screw looseness and/or fracture. A search of the electronic database PUBMED was conducted in November 2018, including manuscripts published in English from 2004 to 2018. Study selection: animal studies, narrative reviews, expert opinions and communications/letters were excluded. Further exclusion criteria included reports on occlusal prosthetic screws and fracture of abutments, and reports that did not provide adequate data. A total of 12 manuscripts were finally included that reported on single implant crowns or 2-unit implant fixed dental prosthesis. To conclude, the most current abutment screw loosening incidence ranges between 7% and 11%, while the abutment screw fracture incidence was found to be 0.6%. The majority reported on fracture of the screw body. Screw loosening or fracture was often located at the first molar restored area, while the maxillary central incisor area was also reported as an area that presented screw fracture. No single abutment screw failure management can be identified as the ideal treatment approach.

Performance of a repair service set for the retrieval of fractured abutment screws: a pilot in vitro study.

To report the success of a repair service set for the retrieval of fractured screws and to compare three clinical assessments to an in vitro assessment to verify the completeness of removal of the fractured screws. Twelve clinicians were asked to remove fractured implant abutment screws from prepared specimens by means of a repair service set. The completeness of the removal of any abutment screw material was measured by the fit of an impression post, a dental surgery microscope, and the use of an elastomeric impression material. After the participants attempted to remove the fractured screw with the repair service set, 100%, 83.3%, 66.7%, and 75% of the fractured screws were considered successful in the impression post, dental surgery microscope, silicone replica, and stereomicroscope assessments, respectively. The retrieval of fractured screws succeeded in 75% of the cases. The silicone replica technique and the dental surgery microscope had similar diagnostic values to the stereoscopic microscope assessment.

Removal torque pattern of a combined cone and octalobule index implant-abutment connection at different cyclic loading: an in-vitro experimental study

BackgroundDespite the high survival rate of dental implants, screw loosening is frequently reported. Screw loosening can cause a misfit of the implant-abutment connection leading to peri-implantitis or abutment screw fracture. Therefore, studies about related factors and mechanism of screw loosening are needed. The aim of this study was to evaluate the decreasing pattern of removal torque values (RTVs) of a combined cone and octalobule index implant-abutment connection under different numbers of mechanical loading cycles.Materials and methodsThe study was performed in accordance with ISO 14801:2007. Eighty-four implants with the combined cone and octalobule index implant-abutment connection (PW Plus dental implant system, PW Plus Company) were used. All abutment screws were tightened 30 N cm twice with a 10-min interval. The control group was without cyclic loading and the experimental groups underwent different numbers of loading cycles until 2,000,000 cycles. Then, the abutment screws of all samples were untightened to measure the RTVs. The data were analyzed using ANOVA and Tukey’s HSD test.ResultsThe RTVs of the control group decreased 7.78% compared to the insertion torque. All experimental groups from 50,000 to 2,000,000 cycles showed significant decreases in RTVs compared to the control group (P < 0.05). RTVs in the group of 50,000 cycles to 1,800,000 cycles did not change significantly, but there was a significant reduction of RTVs in the group of 2,000,000 cycles when compared to the group of 50,000 cycles (P < 0.05).ConclusionsAccording to the setting condition for the fatigue test complied to ISO 14801:2007, the RTVs of the combined cone and octalobule index implant-abutment connection reduced significantly after 50,000 cycles and did not change significantly until 2,000,000 cycles.

Repairment of abutment and abutment screw fracture in implant prosthesis: A case report

Repairment of abutment and abutment screw fracture in implant prosthesis: A case report

Different Mechanical Complications of Implant Prosthodontics: Review Article

Nowadays implant therapy is an effective and reliable treatment with a high success rate, but various mechanical Complications can occur. Thus, the scope for prevention and management needs to be emphasized. The aim of this review article is to identify the different causes of dental implant failure due to fixture and or abutment screw fractures and to describe the management and the preventive options for these failures, so trying to assist the clinicians to plan accurately the implant-supported prosthesis treatment.

An accessory technique for the intraoral removal of a fractured implant abutment screw

As the use of dental implants becomes more prevalent, mechanical complications become more common. When an implant abutment screw fractures, it can be difficult to retrieve the retained fragment. The purpose of this article is to describe a technique to remove the abutment screw fragments without damaging the implant body or its screw threads.

Stability of Implant-Abutment Connection After Using the Rescue Kit: An In Vitro Study.

To evaluate whether removing a fractured abutment screw with a specific rescue device negatively affects the success of a new restoration in terms of early abutment loosening. Implants (n = 10) with a regular platform of 4.1 mm (tissue level [TL]) and implants (n = 10) with a reduced diameter of 3.3 mm (bone level [BL]) were used. The screws of eight respective abutments for both implant types were artificially weakened in order to fracture during torque application for abutment insertion. The fractured abutment screws were removed applying a specific rescue kit. The implant inner threads were cleaned and remodeled with a system-specific tapper. New abutments were inserted, and computer-aided design/computer-aided manufactured (CAD/CAM) full zirconia crowns were luted. Aging by thermal cycling and mechanical loading was performed with a customized masticator simulator, and the number of crown and/or abutment loosenings was determined. In cases in which no loosening was observed, sawing and grinding were performed to determine the contact zone between the inner implant thread and abutment screw. Data were compared with a control group, eg, unmodified implant-abutment connections. No abutment loosening was observed. All crowns were in function after mastication simulation. The inner thread contact zones of both test groups were generally smaller than in the control group, with a mean contact area of 448.6 μm and 459 μm for BL implants, and 608.8 μm and 620.5 μm for the TL implants in test and control groups, respectively. Removing a fractured abutment screw with a specific rescue device and modifying the inner thread seems not to negatively affect the functional connection between a new abutment and the implant.

Fatigue Failure of External Hexagon Connections on Cemented Implant-Supported Crowns

To evaluate the probability of survival and failure modes of different external hexagon connection systems restored with anterior cement-retained single-unit crowns. The postulated null hypothesis was that there would be no differences under accelerated life testing. Fifty-four external hexagon dental implants (∼4 mm diameter) were used for single cement-retained crown replacement and divided into 3 groups: (3i) Full OSSEOTITE, Biomet 3i (n = 18); (OL) OEX P4, Osseolife Implants (n = 18); and (IL) Unihex, Intra-Lock International (n = 18). Abutments were torqued to the implants, and maxillary central incisor crowns were cemented and subjected to step-stress-accelerated life testing in water. Use-level probability Weibull curves and probability of survival for a mission of 100,000 cycles at 200 N (95% 2-sided confidence intervals) were calculated. Stereo and scanning electron microscopes were used for failure inspection. The beta values for 3i, OL, and IL (1.60, 1.69, and 1.23, respectively) indicated that fatigue accelerated the failure of the 3 groups. Reliability for the 3i and OL (41% and 68%, respectively) was not different between each other, but both were significantly lower than IL group (98%). Abutment screw fracture was the failure mode consistently observed in all groups. Because the reliability was significantly different between the 3 groups, our postulated null hypothesis was rejected.

Heat generation during removal of an abutment screw fragment from dental implants

Statement of problemLittle information is available on the effect of drilling speed on surrounding bone during the removal of an abutment screw fragment. PurposeThe purpose of this in vitro study was to compare, in vitro, the peak temperature increase during the removal of fractured abutment screws from implants placed in a porcine mandible, using drilling speeds of 600 or 2000 rpm. Material and methodsTwenty 4.3×13-mm dental implants were placed in 10 dissected porcine mandibles: 2 implants per mandible, 1 on each side. Localized defects were created in 20 surface-treated abutment screws, which were then tightened into each implant until a reproducible fracture occurred in each screw. The fractured screws were removed with a handpiece removal kit and irrigated with room-temperature water at either 600 or 2000 rpm. The temperature rise at the implant surface was measured at 3 levels with 3 type-K thermocouples. Repeated measure ANOVA was performed with the Tukey-Kramer post hoc test for mean pair-wise comparisons (α=.05 for all tests). ResultsMean peak temperatures were significantly higher at 2000 rpm than at 600 rpm in the mid-body (P<.001) and crestal (P=.003) regions but not in the apical (P=.225) implant locations. No significant differences in mean peak temperatures were found among the 3 locations using 600 rpm (P=.179). In the 2000-rpm group, mean peak temperature in the mid-body area was consistently higher than that in the apical (P<.001) area, and more instances of temperature rise above 56°C and 60°C were observed. In 1 implant from this group, the estimated peak temperature exceeded the bone damage threshold value (50°C for 30 seconds). ConclusionsA drilling speed of 2000 rpm during the removal of abutment screw fragments caused overheating of the outer surface of the implant which may damage the surrounding bone; a speed of 600 rpm appears to be safe.

Reconstruction of failed fixed implant prosthesis accompanied by abutment screw loosening and fracture : A case report

In the case of failed fixed implant prosthesis accompanied by abutment screw fracture, fractured screw fragment must be removed to use the existing implant fixtures. A 61-year-old male patient, who had a failed maxillary fixed implant prosthesis accompanied by three abutment screw fracture, hoped to reconstruct the maxillary implant prosthesis, while maintaining the existing implant fixtures. To use the existing implant fixtures, fractured screw fragments were removed. A maxillary implant overdenture using available existing implants was planned. Bar-attachment with Locator was used for implant splinting, denture stability, and retention. Final impression was taken after treatment of peri-implantitis. Jaw relation registration was taken to evaluate available interarch space for bar-attachment. After fabricating bar-attachment, centric relation was taken. Implant overdenture using bar-attachment with Locator was delivered after wax-denture evaluation. This case report showed that a satisfactory clinical result was achieved by implant overdenture using existing implant fixtures in a maxillary edentulous patient.

Prediction of biomechanical complications in patients with implant supported fixed dental prostheses in different terms of functional loading

Objective – to study features of biomechanical complications (structural fractures, loss of retention, screw loosening/fracture) of implant restorations in different terms of functional loading and work out preventive measures. Materials and Methods. The results of prosthetic treatment with implant supported fixed dental prostheses were analyzed among 65 patients, who were treated between 2011 and 2016. There were 28 (47.1 %) men, 37 women (56.9 %), the average age of patients was 35.6 ± 12.7 years. All patients had small defects of dentition in posterior region without severe periodontal or general pathology. Prosthetic treatment was performed on two-staged osteointegrated “root form” implants with a screw design. According to the objective of the study all patients were divided into three groups depending on the period within implant placement and tooth extraction (6–8 month or more than 2 years), the terms of functional loading and usage of protective occlusal splits. The incidence of biomechanical complications and functional activity of masticatory muscles were detected. Results. The incidence of mechanical complications during 5-year period was 3.85 times higher in patients with long-term existing defects of dentition after tooth extraction and conventional prosthetic treatment with deferred occlusal loading (3 cases (15 %) of loss of retention, 5 cases (25 %) of veneering material fracture, 1 case (5 %) of abutment screw loosening and 1 case (5 %) of abutment screw fracture) in comparison to patients with early functional loading and shorter period after tooth extraction (1 case (4.3 %) of loss of retention and 2 cases (8.7 %) of veneering material fracture). Protective occlusal splints’ application and early functional loading in prosthetic treatment of patients with long-term existing defects of dentition after tooth extraction allowed to decrease the incidence of mechanical complications in 1.57 times in comparison to conventional treatment with deferred loading. Conclusions. The incidence of biomechanical complications of implant restorations is higher in patients with long-term existing defects of dentition after tooth extraction and deferred occlusal loading in comparison to cases of well-timed prosthetics and early functional loading. Protective occlusal splints are proved as effective preventive measures to decrease the incidence of mechanical complications of implant supported fixed dental prostheses and to induce faster normalization of masticatory activity.

Custom Cast Ball Attachments Used on Outdated Implants to Restore a Maxillary Implant-Supported Overdenture.

The lack of compatible prosthetic components can be a complication during oral rehabilitation using outdated implants. The aim of the present clinical report was to describe an alternative technique for the fabrication of a maxillary implant-supported overdenture in a patient with 20-year-old dental implants using castable spherical patterns and ball attachments. The patient had been wearing a relined bar/clip overdenture in the mandible on 4 external-hexagon dental implants and a relined complete denture in the maxilla on 4 internal-hexagon implants due to abutment screw fracture inside of the implants, losing the attachment system. The remaining maxillary dental implants did not possess attachments compatible with current systems due to configuration changes by the manufacturer in the dental implant's platform and the components over time. Therefore, castable spherical patterns and cast ball attachments were used to fabricate a maxillary implant-supported overdenture. The mandible rehabilitation was performed using 4 osseointegrated dental implants with a fixed implant-supported prosthesis. The use of cast ball attachments on the maxillary dental implants avoided invasive procedures on the remaining implants. Considering the lack of available compatible prosthetic components for the osseointegrated implants, this technique was considered a viable and satisfactory treatment option.

Hollow Abutment Screw Design for Easy Retrieval in Case of Screw Fracture in Dental Implant System.

The prosthetic component of dental implant is attached on the abutment which is connected to the fixture with an abutment screw. The abutment screw fracture is not frequent; however, the retrieval of the fractured screw is not easy, and it poses complications. A retrieval kit was developed which utilizes screw removal drills to make a hole on the fractured screw that provides an engaging drill to unscrew it. To minimize this process, the abutment screw is modified with a prefabricated access hole for easy retrieval. This study aimed to introduce this modified design of the abutment screw, the concept of easy retrieval, and to compare the mechanical strengths of the conventional and hollow abutment screws by finite element analysis (FEA) and mechanical test. In the FEA results, both types of abutment screws showed similar stress distribution in the single artificial tooth system. A maximum load difference of about 2% occurred in the vertical load by a mechanical test. This study showed that the hollow abutment screw may be an alternative to the conventional abutment screws because this is designed for easy retrieval and that both abutment screws showed no significant difference in the mechanical tests and in the FEA.