You will be shown an abstract from a biomedical research paper. Given this abstract, your task is to extract all unique entities of the following types: ["Outcome", "Participant", "Intervention"].

Please return the output as a JSON object of the format: {"Participant" : ["patients with COPD", ...], "Intervention" : ["Atenolol", ...], "Outcome" : ["blood pressure", ...]}. The keys should be entity types and values should be lists of extracted entities belonging to the corresponding type. If you cannot find entities belonging to a specific type, the value should be [].

Only output the JSON object and do not include any additional text.

Abstract:

Postoperative pain control for outpatient oral surgery . 16 healthy patients requiring removal of bilateral symmetrically-impacted mandibular third molars participated in a double-blind randomised crossover trial to test the effectiveness of postoperative pain control using a long-acting anti-inflammatory agent ( diflunisal ) in combination with a long-acting local anaesthetic agent ( bupivacaine ) . Results were compared to the more traditional method of using an oral analgesic with shorter duration of action ( paracetamol with codeine ) with lignocaine as the local anaesthetic . Using a visual analogue pain scale , patients reported that significantly reduced pain was experienced over the first 4 days postoperatively with the diflunisal/bupivacaine treatment and patient preference for this treatment was highly significant . This report represents the first such study of diflunisal used for an extended course in oral surgery with pain assessment over the same period . No significant side-effects or adverse reactions were encountered .
{"Intervention": ["diflunisal", "diflunisal/bupivacaine treatment", "lignocaine", "( paracetamol with codeine )", "( bupivacaine )"], "Outcome": ["pain", "Postoperative pain control", "effectiveness of postoperative pain control", "patient preference", "side-effects or adverse reactions", "visual analogue pain scale"], "Participant": ["oral surgery", "healthy", "requiring removal of bilateral symmetrically-impacted mandibular third molars", "16"]}