ABSTRACT
PURPOSE: This study aims to evaluate the digitally designed ball attachment housing in its initial retentive force and after 2 years of simulated clinical use and to compare it with the regular nylon ball attachment housing. MATERIALS AND METHODS: Twenty implants with their corresponding ball abutments (diameter 4.5 × 4.0 mm) were inserted in resin blocks. They were divided into two groups. In Group I, ten ball abutments each received their corresponding conventional attachment with nylon rings. In Group II, ten ball abutments received the novel CAD-CAM polyetheretherketone ball attachment housing. A universal testing machine was used to measure the retention force. The achieved maximum values of retention force were recorded at the beginning of the study (initial retention) and after 2 years of artificial ageing (2000 cycles of insertion and removal). Results were statistically analyzed using an independent sample T test. RESULTS: The PEEK attachment housing showed high retention forces (25.12 ± 0.99 N) compared to the conventional attachment with a nylon ring (15.76 ± 0.93 N) in the initial dislodgement test. There was a statistically significant difference in mean retention at the initial retention test and after 2 years of stimulated usage between the two studied groups, p = 0.000. CONCLUSIONS: Within the limitations of this study, the novel CAD-CAM-PEEK attachment showed high retention characteristics compared to the conventional attachment with nylon rings, initially and after simulated long-term use.
Subject(s)
Housing , Nylons , Humans , Denture Retention/methods , Denture, Overlay , Materials Testing , Polyethylene Glycols , Ketones , Computer-Aided DesignABSTRACT
PURPOSE: This retrospective study aims to evaluate the mandibular flexure on a long-span rigid fixed prosthesis supported by natural teeth. MATERIALS AND METHODS: Nine patients (five males and four females) were included in this study who had long-span rigid mandibular fixed prostheses for long-term (10-15 years) that have led to radiographic changes around the supporting teeth. The mandibular flexure was measured digitally after adhering reference markers to the prostheses. Intraoral scans were obtained at the minimum and maximum mouth openings before and after splitting the preexisting prostheses. The distances between the markers were measured, and mandibular flexure was calculated. RESULTS: This study showed a significant deviation (narrowing) of the mandible before and after splitting the rigid fixed prostheses (P value < 0.05). CONCLUSION: Digital analysis of the data collected from the patients in this retrospective study indicated that deviations occur during mandibular flexure. CLINICAL RELEVANCE: Splitting the full arch prosthesis could prevent the negative consequences of mandibular flexure on restorations. Trial registration The study was registered on clinicaltrials.gov with registration number NCT05617274 (15/11/2022).
Subject(s)
Mandible , Patients , Female , Male , Humans , Retrospective Studies , Mandible/diagnostic imagingABSTRACT
Slippage of an implant into the maxillary sinus is an exceptional complication that may occur during immediate implant placement. In this study, removal of a displaced implant into the maxillary sinus with the aid of endoscopy via buccal window approach is reported. Management of such a rare complication is also addressed.
