The present case series aims to investigate the use of polynucleotides mixed with hyaluronic acid (PN-HA) in a gel form to promote bone regeneration in horizontal alveolar defects. Overall, six adult patients underwent localized horizontal guided bone regeneration by means of xenogeneic bone substitute and a resorbable barrier with a staged approach. The graft was a mixture of deproteinized bovine bone mineral (DBBM) particles and PN-HA gel in a 3:1 ratio, respectively. The material was covered by a resorbable collagen membrane fixed with pins to the underlying bone. Implant placement was performed after 5 months. Healing proceeded uneventfully, and, upon reentry, the graft appeared well vascularized and firmly attached to the recipient bone. Histologically, the regenerated bone appeared highly mineralized and well-organized in lamellae, and the residual biomaterial granules were completely embedded. Histomorphometric evaluations revealed that newly formed bone
occupied an average of 41.2% ± 12.4% of the analyzed samples. Linear measurements performed on CBCT scans yielded an overall linear horizontal bone gain of 4.91 ± 0.88 mm. These data suggest that a mixture of DBBM and PN-HA can be safely used to promote bone regeneration in cases of horizontal alveolar defects.