AbstractBackgroundWith the entire papilla preservation (EPP) technique, it is possible to perform regenerative therapy without incisions in the interdental papilla and to reduce the risk of papillary rupture. However, one limitation of the EPP is the sole access from the buccal side. Here, we present a case of periodontitis treated by the combination regenerative therapy employing the Double‐sided (buccal‐palatal) EPP (DEPP) technique, which adds a palatal vertical incision to the EPP.MethodsA patient with 1–2 wall intrabony defects received the regenerative therapy using recombinant human fibroblast growth factor (rhFGF)‐2 and carbonate apatite (CO3Ap). Using the DEPP technique, vertical incisions at buccal and palatal aspects were placed to gain adequate access to the 1–2 wall intrabony defects between #11 and #12 without incision in the interdental papilla. After debridement, rhFGF‐2 and CO3Ap were applied to the defect. Periodontal clinical parameters and radiographic images were evaluated at the first visit, following initial periodontal therapy (baseline), 6, 9, and 12 months postoperatively.ResultsWound healing was uneventful. Scarring of the incision lines was minimal. At 12 months postoperatively, probing depth reduction was 4 mm, clinical attachment gain was 4 mm, and gingival recession was not observed. An improvement in radiopacity in the previous bone defect was observed.ConclusionThe DEPP is an innovative technique that allows approaching from both the buccal and palatal sides while ensuring flap extensibility without compromising the interdental papilla. This report suggests that the combination of regenerative therapy with the DEPP may be promising in the treatment of intrabony defects.Key pointsWhy is this case new information?The DEPP allows a direct visual approach to a 1–2 wall intrabony defect extending from the buccal to palatal sides, and increases flap extensibility, without compromising the papilla.What are the keys to the successful management of this case?Assessment of three‐dimensional bone defect morphology is required. Computed tomography images are very useful. The flap elevation just under the interdental papilla should be carefully performed with a small excavator to avoid damage to the interdental papilla.What are the primary limitations to success in this case?Despite the addition of a palatal incision, it was not possible to obtain complete flexibility of the palatal gingiva. Caution must be taken in a case in which the distance between the interdental papilla is narrow. Even if the interdental papilla is ruptured during the operation, recovery is possible by continuing the operation and suturing the rupture at the end.