diff --git a/src/main/java/org/gcube/informationsystem/resourceregistry/instances/base/ElementManagement.java b/src/main/java/org/gcube/informationsystem/resourceregistry/instances/base/ElementManagement.java
index fdb9b4b..46ede8b 100644
--- a/src/main/java/org/gcube/informationsystem/resourceregistry/instances/base/ElementManagement.java
+++ b/src/main/java/org/gcube/informationsystem/resourceregistry/instances/base/ElementManagement.java
@@ -31,7 +31,6 @@ import org.gcube.informationsystem.base.reference.IdentifiableElement;
 import org.gcube.informationsystem.model.reference.ERElement;
 import org.gcube.informationsystem.model.reference.ModelElement;
 import org.gcube.informationsystem.model.reference.properties.Metadata;
-import org.gcube.informationsystem.model.reference.properties.Property;
 import org.gcube.informationsystem.model.reference.relations.Relation;
 import org.gcube.informationsystem.resourceregistry.api.exceptions.AlreadyPresentException;
 import org.gcube.informationsystem.resourceregistry.api.exceptions.AvailableInAnotherContextException;
@@ -1255,7 +1254,7 @@ public abstract class ElementManagement<El extends OElement, T extends Type> {
 				// TODO check a solution for supertypes
 				TypesCache typesCache = TypesCache.getInstance();
 				@SuppressWarnings("unchecked")
-				CachedType<PropertyType<Property>> metadataType = (CachedType<PropertyType<Property>>) typesCache.getCachedType(Metadata.NAME);
+				CachedType<PropertyType> metadataType = (CachedType<PropertyType>) typesCache.getCachedType(Metadata.NAME);
 				ObjectMapper objectMapper = new ObjectMapper();
 				Collection<String> superClasses = metadataType.getSuperTypes();
 				ArrayNode arrayNode = objectMapper.valueToTree(superClasses);
diff --git a/src/main/java/org/gcube/informationsystem/resourceregistry/instances/base/properties/PropertyElementManagement.java b/src/main/java/org/gcube/informationsystem/resourceregistry/instances/base/properties/PropertyElementManagement.java
index fdb5e2d..9e1e733 100644
--- a/src/main/java/org/gcube/informationsystem/resourceregistry/instances/base/properties/PropertyElementManagement.java
+++ b/src/main/java/org/gcube/informationsystem/resourceregistry/instances/base/properties/PropertyElementManagement.java
@@ -12,7 +12,6 @@ import org.gcube.com.fasterxml.jackson.databind.node.ArrayNode;
 import org.gcube.com.fasterxml.jackson.databind.node.ObjectNode;
 import org.gcube.common.encryption.encrypter.StringEncrypter;
 import org.gcube.informationsystem.base.reference.AccessType;
-import org.gcube.informationsystem.base.reference.properties.PropertyElement;
 import org.gcube.informationsystem.model.reference.ModelElement;
 import org.gcube.informationsystem.model.reference.properties.Encrypted;
 import org.gcube.informationsystem.model.reference.properties.Metadata;
@@ -80,7 +79,7 @@ public class PropertyElementManagement {
 			try {
 				TypesCache typesCache = TypesCache.getInstance();
 				@SuppressWarnings("unchecked")
-				CachedType<PropertyType<PropertyElement>> cachedType = (CachedType<PropertyType<PropertyElement>>) typesCache.getCachedType(type);
+				CachedType<PropertyType> cachedType = (CachedType<PropertyType>) typesCache.getCachedType(type);
 				oClass = cachedType.getOClass();
 				AccessType gotAccessType = cachedType.getAccessType();
 				if(!AccessType.PROPERTY_ELEMENT.getClass().isAssignableFrom(gotAccessType.getClass())) {
@@ -157,7 +156,7 @@ public class PropertyElementManagement {
 			
 			TypesCache typesCache = TypesCache.getInstance();
 			@SuppressWarnings("unchecked")
-			CachedType<PropertyType<PropertyElement>> cachedType = (CachedType<PropertyType<PropertyElement>>) typesCache.getCachedType(type);
+			CachedType<PropertyType> cachedType = (CachedType<PropertyType>) typesCache.getCachedType(type);
 			OClass oClass = cachedType.getOClass();
 			AccessType gotAccessType = cachedType.getAccessType();
 			if(!AccessType.PROPERTY_ELEMENT.getClass().isAssignableFrom(gotAccessType.getClass())) {
diff --git a/src/main/java/org/gcube/informationsystem/resourceregistry/types/properties/PropertyTypeDefinitionManagement.java b/src/main/java/org/gcube/informationsystem/resourceregistry/types/properties/PropertyTypeDefinitionManagement.java
index 5f4f65f..50c1096 100644
--- a/src/main/java/org/gcube/informationsystem/resourceregistry/types/properties/PropertyTypeDefinitionManagement.java
+++ b/src/main/java/org/gcube/informationsystem/resourceregistry/types/properties/PropertyTypeDefinitionManagement.java
@@ -31,7 +31,7 @@ import com.orientechnologies.orient.core.sql.executor.OResultSet;
 /**
  * @author Luca Frosini (ISTI - CNR)
  */
-public class PropertyTypeDefinitionManagement extends ElementManagement<OElement, PropertyType<?>> {
+public class PropertyTypeDefinitionManagement extends ElementManagement<OElement, PropertyType> {
 	
 	private static Logger logger = LoggerFactory.getLogger(PropertyTypeDefinitionManagement.class);
 	
diff --git a/src/main/java/org/gcube/informationsystem/resourceregistry/utils/EncryptedOrient.java b/src/main/java/org/gcube/informationsystem/resourceregistry/utils/EncryptedOrient.java
index cce06bc..2cabaa8 100644
--- a/src/main/java/org/gcube/informationsystem/resourceregistry/utils/EncryptedOrient.java
+++ b/src/main/java/org/gcube/informationsystem/resourceregistry/utils/EncryptedOrient.java
@@ -6,7 +6,6 @@ import java.util.List;
 import java.util.Map;
 
 import org.gcube.common.encryption.encrypter.StringEncrypter;
-import org.gcube.informationsystem.base.reference.properties.PropertyElement;
 import org.gcube.informationsystem.model.reference.properties.Encrypted;
 import org.gcube.informationsystem.model.reference.properties.Property;
 import org.gcube.informationsystem.resourceregistry.dbinitialization.DatabaseEnvironment;
@@ -46,7 +45,7 @@ public class EncryptedOrient extends ODocument implements Encrypted {
 	public List<String> getSupertypes() {
 		TypesCache typesCache = TypesCache.getInstance();
 		@SuppressWarnings("unchecked")
-		CachedType<PropertyType<PropertyElement>> cachedType = (CachedType<PropertyType<PropertyElement>>) typesCache.getCachedType(getTypeName());
+		CachedType<PropertyType> cachedType = (CachedType<PropertyType>) typesCache.getCachedType(getTypeName());
 		try {
 			return cachedType.getSuperTypes();
 		} catch (Exception e) {
diff --git a/src/main/java/org/gcube/informationsystem/resourceregistry/utils/MetadataOrient.java b/src/main/java/org/gcube/informationsystem/resourceregistry/utils/MetadataOrient.java
index ce6fc1f..931649e 100644
--- a/src/main/java/org/gcube/informationsystem/resourceregistry/utils/MetadataOrient.java
+++ b/src/main/java/org/gcube/informationsystem/resourceregistry/utils/MetadataOrient.java
@@ -5,7 +5,6 @@ import java.util.Date;
 import java.util.List;
 import java.util.Map;
 
-import org.gcube.informationsystem.base.reference.properties.PropertyElement;
 import org.gcube.informationsystem.model.reference.properties.Metadata;
 import org.gcube.informationsystem.model.reference.properties.Property;
 import org.gcube.informationsystem.resourceregistry.types.CachedType;
@@ -37,7 +36,7 @@ public class MetadataOrient extends ODocument implements Metadata {
 	public List<String> getSupertypes() {
 		TypesCache typesCache = TypesCache.getInstance();
 		@SuppressWarnings("unchecked")
-		CachedType<PropertyType<PropertyElement>> cachedType = (CachedType<PropertyType<PropertyElement>>) typesCache.getCachedType(getTypeName());
+		CachedType<PropertyType> cachedType = (CachedType<PropertyType>) typesCache.getCachedType(getTypeName());
 		try {
 			return cachedType.getSuperTypes();
 		} catch (Exception e) {
diff --git a/src/main/java/org/gcube/informationsystem/resourceregistry/utils/PropagationConstraintOrient.java b/src/main/java/org/gcube/informationsystem/resourceregistry/utils/PropagationConstraintOrient.java
index a8a1259..6e8ac12 100644
--- a/src/main/java/org/gcube/informationsystem/resourceregistry/utils/PropagationConstraintOrient.java
+++ b/src/main/java/org/gcube/informationsystem/resourceregistry/utils/PropagationConstraintOrient.java
@@ -4,7 +4,6 @@ import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
 
-import org.gcube.informationsystem.base.reference.properties.PropertyElement;
 import org.gcube.informationsystem.model.reference.properties.PropagationConstraint;
 import org.gcube.informationsystem.model.reference.properties.Property;
 import org.gcube.informationsystem.resourceregistry.types.CachedType;
@@ -36,7 +35,7 @@ public class PropagationConstraintOrient extends ODocument implements Propagatio
 	public List<String> getSupertypes() {
 		TypesCache typesCache = TypesCache.getInstance();
 		@SuppressWarnings("unchecked")
-		CachedType<PropertyType<PropertyElement>> cachedType = (CachedType<PropertyType<PropertyElement>>) typesCache.getCachedType(getTypeName());
+		CachedType<PropertyType> cachedType = (CachedType<PropertyType>) typesCache.getCachedType(getTypeName());
 		try {
 			return cachedType.getSuperTypes();
 		} catch (Exception e) {