A meta-analysis indicating extra-short implants (≤ 6 mm) as an alternative to longer implants (≥ 8 mm) with bone augmentation

Abstract

Extra-short implants, of which clinical outcomes remain controversial, are becoming a potential option rather than long implants with bone augmentation in atrophic partially or totally edentulous jaws. The aim of this study was to compare the clinical outcomes and complications between extra-short implants (≤ 6 mm) and longer implants (≥ 8 mm), with and without bone augmentation procedures. Electronic (via PubMed, Web of Science, EMBASE, Cochrane Library) and manual searches were performed for articles published prior to November 2020. Only randomized controlled trials (RCTs) comparing extra-short implants and longer implants in the same study reporting survival rate with an observation period at least 1 year were selected. Data extraction and methodological quality (AMSTAR-2) was assessed by 2 authors independently. A quantitative meta-analysis was performed to compare the survival rate, marginal bone loss (MBL), biological and prosthesis complication rate. Risk of bias was assessed with the Cochrane risk of bias tool 2 and the quality of evidence was determined with the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. 21 RCTs were included, among which two were prior registered and 14 adhered to the CONSORT statement. No significant difference was found in the survival rate between extra-short and longer implant at 1- and 3-years follow-up (RR: 1.002, CI 0.981 to 1.024, P = 0.856 at 1 year; RR: 0.996, CI 0.968 to 1.025, P = 0.772 at 3 years, moderate quality), while longer implants had significantly higher survival rate than extra-short implants (RR: 0.970, CI 0.944 to 0.997, P < 0.05) at 5 years. Interestingly, no significant difference was observed when bone augmentations were performed at 5 years (RR: 0.977, CI 0.945 to 1.010, P = 0.171 for reconstructed bone; RR: 0.955, CI 0.912 to 0.999, P < 0.05 for native bone). Both the MBL (from implant placement) (WMD: − 0.22, CI − 0.277 to − 0.164, P < 0.01, low quality) and biological complications rate (RR: 0.321, CI 0.243 to 0.422, P < 0.01, moderate quality) preferred extra-short implants. However, there was no significant difference in terms of MBL (from prosthesis restoration) (WMD: 0.016, CI − 0.036 to 0.068, P = 0.555, moderate quality) or prosthesis complications rate (RR: 1.308, CI 0.893 to 1.915, P = 0.168, moderate quality). The placement of extra-short implants could be an acceptable alternative to longer implants in atrophic posterior arch. Further high-quality RCTs with a long follow-up period are required to corroborate the present outcomes.Registration number The review protocol was registered with PROSPERO (CRD42020155342).

Insertion Torque, Removal Torque, and Resonance Frequency Analysis Values of Ultrashort, Short, and Standard Dental Implants: An In Vitro Study on Polyurethane Foam Sheets

“…In the last few years, short and ultrashort-length implants have been proposed as effective alternatives to more complicated reconstructive bone surgery procedures. In fact, using implants of such lengths implies a less invasive approach and reduces cost, healing time, peri-operative morbidity, and patient discomfort [ 5 , 13 , 22 , 23 , 38 ].…”

“…The definition of short- and ultrashort- (or extra-short) length implants is still debated in the literature. Most of the authors agree in defining as “short” those implants with a length ranging from 5 to 8 mm [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 ]. Recently, Lombardo et al (2020) defined “ultrashort“as implants with a length less than or equal to 5 mm [ 13 ], reporting a survival rate of 96.6% for single-crown restorations supported by short- and ultrashort-length implants in a 3-year follow-up study.…”

“…Hence, there is need for a less invasive treatment option in areas of poor bone quantity and quality. As an alternative, short- and ultrashort-length implants have been introduced to reduce rehabilitative times and costs, avoid the possible use of grafting procedures [ 23 ] and other more invasive surgical treatments, and reduce patient discomfort and morbidity [ 5 , 19 , 20 ]. Due to the biological and economic advantages in using this type of fixture to prosthetically rehabilitate an atrophic jaw, several studies have reported the survival rates of fixed prostheses implants supported at various follow-up points, showing their efficacies [ 13 , 14 , 15 ].…”

Short versus standard implants at sinus augmented sites: a systematic review and meta-analysis

“…No consensus has been reached on the controversial issue that whether the length of implants is considered as short or standard implant. According with the last European Association of Dental Implantologists consensus in 2016, ultrashort implants are defined as < 6 mm and dental implants with length of 8 mm or more (≥ 8 mm) could be accepted as standard-length implants [ 1 , 21 ] . Pending more long-term studies, the success rates of short implants in the posterior maxillae are still controversial [ 22 ].…”

Comparative analysis between extra‐short implants (≤6 mm) and 6 mm‐longer implants: a meta‐analysis of randomized controlled trial

“…22 Thus, after verifying some contradictions in the literature, this systematic review and meta-analysis aimed to compare extra-short implants (≤6 mm) and 6-mm-longer implants. Here we included all implants greater than 6 mm in the longer length group, differently from the systematic study published by Yu et al, 23 who have chosen to exclude implants with 7-mm length. Moreover, these authors only include greater length implants when associated with bone augmentation procedures.…”